Journal articles: 'Radiotherpy Dose Evaluation'

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Липенгольц, А. А., Е. С. Воробьева, А. А. Черепанов, М. А. Абакумов, Т. О. Абакумова, А. В. Смирнова, Ю. А. Финогенова, Е. Ю. Григорьева, И. Н. Шейно, and В. Н. Кулаков. "Исследование распределения поглощенной дозы при фотон-захватной терапии с интратуморальным введением дозоповышающего агента в меланоме B16F10." ПРОФИЛАКТИЧЕСКАЯ МЕДИЦИНА, no. 5 (November 30, 2018): 70–75. http://dx.doi.org/10.24075/vrgmu.2018.062.

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В фотон-захватной терапии (ФЗТ) величина поглощенной дозы определяется не только параметрами облучения, но и концентрацией дозоповышающего агента (ДПА) в облучаемом объекте. В данной работе было проведено расчетно- экспериментальное исследование распределения поглощенной дозы на опухолевой модели мышиной меланомы B16F10, после однократной интратуморальной инъекции висмута в качестве ДПА в форме водного раствора комплекса Bi-ДТПА. Оценку поглощенной дозы проводили для однофракционного рентгеновского облучения длительностью 28,5 мин. Количественное определение ДПА in vivo осуществляли при помощи микро-КТ, используя значения рентгеноплотности опухолевых тканей на полученных КТ-томограммах. В результате исследования установлено, что за счет присутствия ДПА в 6% объема опухоли поглощенная доза увеличивалась более чем в 2 раза и в 29% объема опухоли наблюдалось увеличение поглощенной дозы отличное от 1. Время задержки роста опухоли, рассчитанное для полученного дозо-объемного распределения с учетом только непосредственного радиационного поражения опухолевых клеток, составило 0,76 суток, тогда как в ранее проведенных экспериментальных исследованиях данная величина равнялась 10 суткам. Полученное несоответствие может указывать на то, что торможение роста опухоли при ФЗТ с интратуморальным введением ДПА достигается за счет не только непосредственного радиационного поражения опухоли, но и иных противоопухолевых механизмов.

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Dieng, A., and A. Veres. "Radiotherapy dose measurement uncertainty evaluation." Physica Medica 29 (June 2013): e45. http://dx.doi.org/10.1016/j.ejmp.2013.08.137.

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Yu, Hui, Xi Tang, Xinglong Yang, Danxia Wen, Zhouyu Li, Xiaomin Wen, Jinquan Liu, and Mingyi Li. "Dose fusion and efficacy evaluation of different radical radiotherapy doses for cervical cancer." Brachytherapy 20, no. 3 (May 2021): 519–26. http://dx.doi.org/10.1016/j.brachy.2020.12.001.

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Aisyah, Siti, Aditya Prayugo Hariyanto, Endarko Endarko, Agus Rubiyanto, Nasori Nasori, Mohammad Haekal, and Andreas Nainggolan. "Evaluation Treatment Planning for Breast Cancer Based on Dose-Response Model." Jurnal ILMU DASAR 22, no. 1 (January 29, 2021): 75. http://dx.doi.org/10.19184/jid.v22i1.19732.

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The delivery of radiation therapy to patients requires prior planning made by medical physicists to achieve radiotherapy goals. Radiotherapy has a plan to eradicate the growth of cancer cells by giving high doses and minimizing the radiation dose to normal tissue. Evaluation of planning is generally done based on dosimetric parameters, such as minimum dose, maximum dose, and means dose obtained from the DVHs data. Based on the same DVHs, data were evaluate dinterms of biological effects to determine the highest possible toxicity in normal tissue after the tumor had been treated with radiation using the NTCP model. The evaluation was conducted by selecting three DICOM-RT data of post-mastectomy right breast cancer patients who had been prescribed a dose of 50 Gy obtained from the Hospital MRCCC Siloam Semanggi database. All data were processed using open-source software DICOManTX to get the DVH and isodose information. Matlab-based CERR software was used to calculate the NTCP model. The results show that the three patients' DVH and isodose treatment planning result in a homogeneous dose distribution result because the PTV area obtains adose limit of ≥ 95%. Moreover, normalt issue still gets adose below the tolerance limit based on the standard from RTOG 1005 and ICRU 83. Analysis of NTCP shows a complication probability below 1% for each organ, suggesting that any organ which has been irradiated has a low likelihood of complications. Therefore, it can be concluded that the treatment planning which has been made in the three patients using the IMRT technique has achieved the objectives of radiotherapy, which is to minimize toxicity to healthy organs. |Keywords: DVH, isodose, NTCP, radiotherapy.

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Petera, Jiri, Renata Neumanová, Karel Odrazka, Martin Ondrak, and Egon Prochazka. "Perioperative Hyperfractionated High-Dose Rate Brachytherapy Combined with External Beam Radiotherapy in the Treatment of Soft Tissue Sarcomas." Tumori Journal 91, no. 4 (July 2005): 331–34. http://dx.doi.org/10.1177/030089160509100409.

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Aims and background Low-dose rate brachytherapy alone or in combination with external beam radiotherapy represents a well-established adjuvant treatment in soft tissue sarcomas following surgical resection. The experience with high-dose radiotherapy in this indication is limited. The purpose of our study was an evaluation of the viability of perioperative hyperfractionated high-dose rate brachytherapy in combination with external beam radiotherapy for primary and recurrent soft tissue sarcomas. Patients and methods From February 1998 through June 2002, 10 adult patients with soft tissue sarcomas were treated by interstitial perioperative high-dose rate brachytherapy and external beam radiotherapy. TNM classification was pT2bpN0pM0 in 9 patients and pT1bpN0pM0 in 1 patient. Grade of differentiation was G1 (2 patients), G2 (n = 1), G3 (n = 5), G4 (n = 2). Surgical margins were negative in 7 cases, close in 2 cases and positive in 1 case. The tumor was localized in an extremity in all cases. Hyperfractionation 3 Gy twice daily at 10 mm from the plane of sources was used for brachytherapy, with total doses 18–30 Gy. The patients received external beam radiotheapy with doses 40–50 Gy after brachytherhapy. Follow-up periods were between 24–71 months (median, 46). Results Local control of the disease was achieved in all 10 patients. Distant metastases occurred in 2 cases. One patient was disease free after salvage surgery and chemotherapy, and one patient died of lung disease progression 14 months after brachytherapy. In one case, subcutaneous fistula occurred after radiotherapy and was cured by an excision. Six patients experienced grade 1 or 2 fibrosis and 1 case a mild peripheral neuropathy was recorded. Conclusions Our study on a small number of patients suggests that perioperative hyperfractionated high-dose rate brachytherapy with doses 8 × 3 Gy in combination with external beam radiotherapy 40–50 Gy is a promising method to achieve high biological doses in the postoperative radiotherapy of soft tissue sarcomas without severe late morbidity and warrants further research.

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Antypas, Christos, Panagiotis Sandilos, John Kouvaris, Ersi Balafouta, Eleftheria Karinou, Nikos Kollaros, and Lambros Vlahos. "Fetal Dose Evaluation During Breast Cancer Radiotherapy." International Journal of Radiation Oncology*Biology*Physics 40, no. 4 (March 1998): 995–99. http://dx.doi.org/10.1016/s0360-3016(97)00909-7.

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Romero-Expósito, M., C. Domingo, F. Sánchez-Doblado, O. Ortega-Gelabert, and S. Gallego. "Experimental evaluation of neutron dose in radiotherapy patients: Which dose?" Medical Physics 43, no. 1 (December 29, 2015): 360–67. http://dx.doi.org/10.1118/1.4938578.

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Demaria, Sandra, Chandan Guha, Jonathan Schoenfeld, Zachary Morris, Arta Monjazeb, Andrew Sikora, Marka Crittenden, et al. "Radiation dose and fraction in immunotherapy: one-size regimen does not fit all settings, so how does one choose?" Journal for ImmunoTherapy of Cancer 9, no. 4 (April 2021): e002038. http://dx.doi.org/10.1136/jitc-2020-002038.

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Recent evidence indicates that ionizing radiation can enhance immune responses to tumors. Advances in radiation delivery techniques allow hypofractionated delivery of conformal radiotherapy. Hypofractionation or other modifications of standard fractionation may improve radiation’s ability to promote immune responses to tumors. Other novel delivery options may also affect immune responses, including T-cell activation and tumor-antigen presentation changes. However, there is limited understanding of the immunological impact of hypofractionated and unique multifractionated radiotherapy regimens, as these observations are relatively recent. Hence, these differences in radiotherapy fractionation result in distinct immune-modulatory effects. Radiation oncologists and immunologists convened a virtual consensus discussion to identify current deficiencies, challenges, pitfalls and critical gaps when combining radiotherapy with immunotherapy and making recommendations to the field and advise National Cancer Institute on new directions and initiatives that will help further development of these two fields.This commentary aims to raise the awareness of this complexity so that the need to study radiation dose, fractionation, type and volume is understood and valued by the immuno-oncology research community. Divergence of approaches and findings between preclinical studies and clinical trials highlights the need for evaluating the design of future clinical studies with particular emphasis on radiation dose and fractionation, immune biomarkers and selecting appropriate end points for combination radiation/immune modulator trials, recognizing that direct effect on the tumor and potential abscopal effect may well be different. Similarly, preclinical studies should be designed as much as possible to model the intended clinical setting. This article describes a conceptual framework for testing different radiation therapy regimens as separate models of how radiation itself functions as an immunomodulatory ‘drug’ to provide alternatives to the widely adopted ‘one-size-fits-all’ strategy of frequently used 8 Gy×3 regimens immunomodulation.

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Nayan, Navin, M. Bhattacharyya, Vikas K. Jagtap, A. K. Kalita, R. Sunku, and P. S. Roy. "Standard-dose versus high-dose radiotherapy with concurrent chemotherapy in esophageal cancer: A prospective randomized study." South Asian Journal of Cancer 07, no. 01 (January 2018): 27–30. http://dx.doi.org/10.4103/sajc.sajc_178_17.

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Abstract Objective: The objective of this study is comparision of local and distant control rates with high-dose versus standard-dose radiotherapy along with concurrent chemotherapy in esophageal cancer – a prospective randomized study. Materials and Methods: Histologically proven Stage I–III patients with carcinoma esophagus were randomized into two groups. One group has been treated with standard-dose radiotherapy, i.e., a total dose of 50.4 Gy (1.8 Gy/day, 28#, 5 days/week). The other group (study arm) has received high-dose radiotherapy, i.e. a total dose of 64.8 Gy (1.8 Gy/day, 36#, 5 days/week). Both groups have received 2 cycles of 3 weekly concurrent chemotherapy (cisplatin 75 mg/m[2] on day 1 and 5-fluorouracil 750 mg/m[2] continuous intravenous infusion over 24 h on day 1–4). Follow-up response evaluation was done by both endoscopy and computed tomography scan after 6–8 weeks and after 2 months thereafter. Results: Out of a total of 28 patients, 68% showed a complete response, 14% showed partial response, and 18% patients developed progressive disease at first and subsequent follow up (median follow-up of 21 months). Among the complete response patients, rates were higher in high-dose group compared to standard-dose radiotherapy group (71% vs. 64%, P = 0.38). Treatment-related toxicities were acceptable in both groups. Conclusion: High-dose radiotherapy with concurrent chemotherapy seems to be more effective with acceptable toxicity in our study. However, further follow-up and large sample size may be required to validate the current study conclusion.

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Grimm, J., T. LaCouture, Y. Zhu, J. Xue, I. Yeo, R. Croce, and S. L. Hughes. "Dose Tolerance Limit Evaluation for Stereotactic Body Radiotherapy." International Journal of Radiation Oncology*Biology*Physics 75, no. 3 (November 2009): S689. http://dx.doi.org/10.1016/j.ijrobp.2009.07.1571.

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Salmo, E. N., and N. Y. Haboubi. "Radiation bowel disease and its clinical implication." Acta chirurgica Iugoslavica 57, no. 3 (2010): 51–54. http://dx.doi.org/10.2298/aci1003051s.

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Pre-operative radiotherapy may induce radiation colitis and tumour regression. Histological evaluation of radiation colitis needs to be reproducible to assess disease progression. The severity of radiation colitis can be assessed and graded according to its histological features. Increased severity of disease appears to be associated with a higher degree of cellular atypia and a lesser eosinophilic infiltrate. The severity of histological changes does not appear to be associated with post-operative complications. Tumour regression is an interesting phenomenon, the histological grading of which is of prognostic importance. Patients treated with long course radiotherapoy appear to have more incidences of postoperative complications. However, these are though to be related to the degree of tumour regression rather than to the type of radiotherapy.

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Samant, Pratik, Ben George, Tom Whyntie, and Maxwell Robinson. "Automated scripting of the dosimetric evaluation of adaptive versus non-adaptive radiotherapy." Biomedical Physics & Engineering Express 8, no. 3 (March 15, 2022): 037001. http://dx.doi.org/10.1088/2057-1976/ac5ad2.

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Abstract Objective. To quantify the benefit of adaptive radiotherapy over non-adaptive radiotherapy it is useful to extract and compare dosimetric features of patient treatments in both scenarios. This requires Image-Guided Radiotherapy (IGRT) matching of baseline planning to adaptive fraction imaging, followed by extraction of relevant dose metrics. This can be impractical to retrospectively perform manually for multiple patients. Approach. Here we present an algorithm for automatic IGRT matching of baseline planning with fraction imaging and performing automated dosimetric feature extraction from adaptive and non-adaptive treatment plans, thereby allowing comparison of the two scenarios. This workflow can be done in an entirely automated way via scripting solutions given structure and dose Digital Imaging and Communications in Medicine (DICOM) files from baseline and adaptive fractions. We validate this algorithm against the results of manual IGRT matching. We also demonstrate automated dosimetric feature extraction. Lastly, we combine these two scripting solutions to extract daily adaptive and non-adaptive radiotherapy dosimetric features from an initial cohort of patients treated on an MRI guided linear accelerator (MR-LINAC). Results. Our results demonstrate that automated feature extraction and IGRT matching was successful and comparable to results performed by a manual operator. We have therefore demonstrated a method for easy analysis of patients treated on an adaptive radiotherapy platform. Significance. We believe that this scripting solution can be used for quantifying the benefits of adaptive therapy and for comparing adaptive therapy against various non-adaptive IGRT scenarios (e.g. 6 degree of freedom couch rotation).

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Dolera, Mario, Luca Malfassi, Simone Pavesi, Silvia Marcarini, Massimo Sala, Giovanni Mazza, Nancy Carrara, Sara Finesso, and Gaetano Urso. "Stereotactic Volume Modulated Arc Radiotherapy in Canine Meningiomas: Imaging-Based and Clinical Neurological Posttreatment Evaluation." Journal of the American Animal Hospital Association 54, no. 2 (March 1, 2018): 77–84. http://dx.doi.org/10.5326/jaaha-ms-6488.

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ABSTRACT A prospective study to assess high-dose hypofractionated volume modulated arc radiotherapy feasibility and efficacy in canine meningiomas was conducted. Thirty-nine patients with encephalic and spinal meningiomas assumed from MRI findings were recruited and received high-dose hypofractionated volumetric modulated arc radiotherapy by a linear accelerator equipped with an external beam modulator micro-multileaf collimator and an XVI cone beam computed tomography system. The prescribed mean dose was 33 Gy in five fractions. The treatment feasibility was tested through planned and delivered dose agreement checks. Regular clinical examinations were performed during and after irradiation time, with regard to mentation, deambulation, cranial nerve dysfunction, and seizures. Serial MRI exams were done 60 days after irradiation and after 4, 6, 12, 18, and 24 mo. Volumetric disease reduction criteria implemented with clinical neurological systematic evaluation were adopted to assess the course and to categorize patients’ responses. Complete and partial responses were observed on the whole in 65.5% of alive patients 24 mo after irradiation. Two-yr overall and disease-specific survival rates were 74.3% and 97.4%, respectively, and the putative radiotoxic effects were found to be few and slight.

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Zhou, Han, Jing Li, AoMei Li, XiangNan Qiu, ZeTian Shen, and Yun Ge. "Diagnostic Application and Systematic Evaluation of Image Registration Software in External Radiotherapy." Journal of Medical Imaging and Health Informatics 12, no. 1 (January 1, 2022): 68–76. http://dx.doi.org/10.1166/jmihi.2022.3928.

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Purpose: Analyze the clinical application of MIM maestro in cancer radiotherapy and evaluate the advantage of the software compare to the clinical applied tools. Materials and Methods: Potentially relevant studies published were identified through a pubmed and web of science search using words “MIM Maestro,” “Atlas,” “image registration,” “dose accumulation,” “irradiation.” Combinations of words were also searched as were bibliographies of downloaded papers in order to avoid missing relevant publications. Results: In many patients with cancer radiotherapy, multiple types of images are demanded, MIM Maestro is a multi-modality image information processing system for radiotherapy. Contour atlas and image registration among dose accumulation and individual fractions is beneficial for radiotherapy. Overall 34 papers were enrolled for analysis. The MIM appears to provide excellent clinical applications such as the function of contour altas, image fusion and registration, dose accumulation in radiotherapy compared to the other software. Conclusions: The regular optimization of radiotherapy technology and the development of image technology, improve the clinical efficiency. The current paper give a systematic review of MIM Maestro multi-modality image processing software.

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Grimm, Jimm, Tamara LaCouture, Raymond Croce, Inhwan Yeo, Yunping Zhu, and Jinyu Xue. "Dose tolerance limits and dose volume histogram evaluation for stereotactic body radiotherapy." Journal of Applied Clinical Medical Physics 12, no. 2 (February 8, 2011): 267–92. http://dx.doi.org/10.1120/jacmp.v12i2.3368.

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Bahl, Amit, Arun Singh Oinam, Arun Elangovan, Satinder Kaur, Gaurav Trivedi, Roshan Verma, Sudhir Bhandari, Sushmita Ghoshal, and Naresh Kumar Panda. "Evaluation of Reirradiation in Locally Advanced Head and Neck Cancers: Toxicity and Early Clinical Outcomes." Journal of Oncology 2018 (2018): 1–5. http://dx.doi.org/10.1155/2018/8183694.

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Objectives. Locoregional recurrence is the predominant pattern of treatment failure in advanced head and neck cancers. Reirradiation is a useful modality to treat inoperable head and neck cancer patients with recurrent disease. The aim of the present study was to analyze the treatment toxicity and early clinical outcomes in patients undergoing reirradiation. Methods. Twenty patients of head and neck cancers with recurrences or second cancers were evaluated. Reirradiation was done using simultaneous integrated boost volumetric modulated arc therapy (SIB VMAT), intensity modulated radiotherapy (IMRT), or conventional radiotherapy using 6MV photons. Dose prescription ranged from 30 to 60 Gy in conventional fractionation. Results. Seventeen males and three females were evaluated in this analysis. The median age of patients under study was 56.5 years. At time of analysis 8 patients (40%) had a complete response, 7 patients (35%) had progressive disease, and 25% had partial response or stable disease. Grade III-IV mucositis, dermatitis, xerostomia, dysphagia, and trismus were seen in 20%, 20%, 50%, 35%, and 45% patients, respectively, during retreatment. Patients receiving a radiotherapy dose less than 45 Gy showed a higher incidence of progressive disease (p=0.01). The median disease-free survival for patients receiving reirradiation dose of ≥46 Gy was 19±3.3 months (median ± S Error) compared to 8±2.61 months for those with a dose prescription less than 45 Gy (p=0.03). At 18-month follow-up 26% of patients undergoing reirradiation were disease-free. Conclusions. Our results show improved tumor control using a prescription of doses ≥46 Gy in retreatment setting.

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Peters, Christopher A., Andrew Kaleda, Anthony Manfredo, Elizabeth Tapen, and Lawrence Koutcher. "Cardiac dose evaluation in patients undergoing breast radiotherapy in the modern era." Journal of Clinical Oncology 32, no. 26_suppl (September 10, 2014): 78. http://dx.doi.org/10.1200/jco.2014.32.26_suppl.78.

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78 Background: Breast radiotherapy (RT) after conservative surgery improves overall survival and minimizes locoregional recurrence. The therapeutic ratio of adjuvant RT continues to improve with time. Cardiac toxicity from breast cancer treatment remains a concern, and can result from chemotherapy, biologic therapy, or RT in a dose-dependent fashion. Dose to avoidance structures can be minimized as technological improvements in radiotherapy evolve. We sought to investigate heart and coronary artery dose using modern RT techniques. Methods: We reviewed 164 consecutive non-metastatic breast cancer patients treated with adjuvant breast RT, from 3/2011 to 12/2013. 8 patients were excluded because they did not complete the prescribed dose. Patients were treated on 3 different machines, at 2 centers. Data was extracted using both the treatment planning system and electronic medical records. Univariate analysis was done using t-test and one way ANOVA for variables predicting higher mean heart dose (MHD). Multivariate analysis was performed using multiple linear regression. p values ≤0.05 were considered significant. Results: The median age of our cohort was 63 (range 33-85), and 90% had ≤ stage 2 disease. 53% had left sided RT, 45% right, and 2% had bilateral RT. 18% had breast/chest wall and nodal RT, with 2% dedicated IMN targeting. 22% of patients were treated prone. The median dose, including boost, was 60.4 Gy (range 42.4-66.4). 35% received cytotoxic chemotherapy and 10% received trastuzumab. Mean heart dose was 1.4Gy (SD 2.2), and mean LAD dose was 4.9Gy (SD 4.4). MHD were lower in the prone position compared to supine, but did not reach statistical significance p=0.3. Advanced AJCC stage grouping, left sided or bilateral treatment, breast/nodal target volume, and helical treatment were associated with significantly higher MHD on univariate analysis. On multivariate analysis, only breast/nodal volume and helical technique remained significant, both p<0.001. Conclusions: Modern techniques result in low heart and LAD doses in our series. Because adjuvant breast RT plays a critical role in the definitive management of breast cancer, these data are reassuring to patients, physicians, and payers.

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Mizukami, Shinya, Yusuke Watanabe, Takahiro Mizoguchi, Tsutomu Gomi, Hidetake Hara, Hideyuki Takei, Nobuhisa Fukunishi, Kenichi L. Ishikawa, Shigekazu Fukuda, and Takuya Maeyama. "Whole Three-Dimensional Dosimetry of Carbon Ion Beams with an MRI-Based Nanocomposite Fricke Gel Dosimeter Using Rapid T1 Mapping Method." Gels 7, no. 4 (November 25, 2021): 233. http://dx.doi.org/10.3390/gels7040233.

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MRI-based gel dosimeters are attractive systems for the evaluation of complex dose distributions in radiotherapy. In particular, the nanocomposite Fricke gel dosimeter is one among a few dosimeters capable of accurately evaluating the dose distribution of heavy ion beams. In contrast, reduction of the scanning time is a challenging issue for the acquisition of three-dimensional volume data. In this study, we investigated a three-dimensional dose distribution measurement method for heavy ion beams using variable flip angle (VFA), which is expected to significantly reduce the MRI scanning time. Our findings clarified that the whole three-dimensional dose distribution could be evaluated within the conventional imaging time (20 min) and quality of one cross-section.

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Lipengolts, AA, ES Vorobyeva, AA Cherepanov, MA Abakumov, TO Abakumova, AV Smirnova, YuA Finogenova, EYu Grigorieva, IN Sheino, and VN Kulakov. "Evaluation of absorbed dose distribution in melanoma B16F10 during contrast enhanced radiotherapy with intratumoral administration of dose-enhancing agent." Bulletin of Russian State Medical University, no. (5)2018 (November 30, 2018): 60–64. http://dx.doi.org/10.24075/brsmu.2018.062.

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Contrast-enhanced radiotherapy (CERT) is a binary treatment modality in which the absorbed radiation dose is not only determined by the parameters of the external radiation source but also affected by the concentration of a dose-enhancing agent (DEA) in the studied object. In this work we assessed the distribution of the absorbed dose in a murine B16F10 melanoma injected with a single dose of an aqueous Bi-DTPA solution. The mice were exposed to a single fraction of X-ray irradiation for 28.5 min. In vivo measurements of DEA concentrations were done on a micro-CT scanner using the radiopacity values of malignant tissues from the obtained CT images. We found that the presence of DEA enhanced the absorbed dose more than twofold in 6% of the tumor volume; in 29% of the tumor volume the absorbed dose increased more than onefold. The tumor growth delay time calculated for our model was 0.76 days (we only accounted for the damage caused directly by radiation), whereas in our previous research study tumor growth delay was 10 days. This discrepancy may indicate that in the tumors exposed to contrast-enhanced radiotherapy growth delay results from both the damage directly caused by radiation and other antitumor mechanisms.

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Suesada, Milena Mako, Heloisa de Andrade Carvalho, André Luis Pereira de Albuquerque, João Marcos Salge, Silvia Radwanski Stuart, and Teresa Yae Takagaki. "Impact of thoracic radiotherapy on respiratory function and exercise capacity in patients with breast cancer." Jornal Brasileiro de Pneumologia 44, no. 6 (December 2018): 469–76. http://dx.doi.org/10.1590/s1806-37562017000000120.

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ABSTRACT Objective: To evaluate the impact of thoracic radiotherapy on respiratory function and exercise capacity in patients with breast cancer. Methods: Breast cancer patients in whom thoracic radiotherapy was indicated after surgical treatment and chemotherapy were submitted to HRCT, respiratory evaluation, and exercise capacity evaluation before radiotherapy and at three months after treatment completion. Respiratory muscle strength testing, measurement of chest wall mobility, and complete pulmonary function testing were performed for respiratory evaluation; cardiopulmonary exercise testing was performed to evaluate exercise capacity. The total radiotherapy dose was 50.4 Gy (1.8 Gy/fraction) to the breast or chest wall, including supraclavicular lymph nodes (SCLN) or not. Dose-volume histograms were calculated for each patient with special attention to the ipsilateral lung volume receiving 25 Gy (V25), in absolute and relative values, and mean lung dose. Results: The study comprised 37 patients. After radiotherapy, significant decreases were observed in respiratory muscle strength, chest wall mobility, exercise capacity, and pulmonary function test results (p < 0.05). DLCO was unchanged. HRCT showed changes related to radiotherapy in 87% of the patients, which was more evident in the patients submitted to SCLN irradiation. V25% significantly correlated with radiation pneumonitis. Conclusions: In our sample of patients with breast cancer, thoracic radiotherapy seemed to have caused significant losses in respiratory and exercise capacity, probably due to chest wall restriction; SCLN irradiation represented an additional risk factor for the development of radiation pneumonitis.

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Park, Eun-Tae. "Evaluation of Photoneutron Dose in Radiotherapy Room Using MCNPX." Journal of the Korea Contents Association 15, no. 6 (June 28, 2015): 283–89. http://dx.doi.org/10.5392/jkca.2015.15.06.283.

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Hong, J., E. D. Yorke, L. Kuo, Y. C. Hu, X. Li, A. J. Wu, Y. Liu, J. G. Mechalakos, P. Zhang, and L. I. Cervino. "Evaluation of Repeated Lung Stereotactic Body Radiotherapy Using a Radiotherapy Dose Accumulation Routine." International Journal of Radiation Oncology*Biology*Physics 114, no. 3 (November 2022): e573. http://dx.doi.org/10.1016/j.ijrobp.2022.07.2232.

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Kraus, Kim Melanie, Johanna Winter, Yating Zhang, Mabroor Ahmed, Stephanie Elisabeth Combs, Jan Jakob Wilkens, and Stefan Bartzsch. "Treatment Planning Study for Microbeam Radiotherapy Using Clinical Patient Data." Cancers 14, no. 3 (January 28, 2022): 685. http://dx.doi.org/10.3390/cancers14030685.

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Microbeam radiotherapy (MRT) is a novel, still preclinical dose delivery technique. MRT has shown reduced normal tissue effects at equal tumor control rates compared to conventional radiotherapy. Treatment planning studies are required to permit clinical application. The aim of this study was to establish a dose comparison between MRT and conventional radiotherapy and to identify suitable clinical scenarios for future applications of MRT. We simulated MRT treatment scenarios for clinical patient data using an inhouse developed planning algorithm based on a hybrid Monte Carlo dose calculation and implemented the concept of equivalent uniform dose (EUD) for MRT dose evaluation. The investigated clinical scenarios comprised fractionated radiotherapy of a glioblastoma resection cavity, a lung stereotactic body radiotherapy (SBRT), palliative bone metastasis irradiation, brain metastasis radiosurgery and hypofractionated breast cancer radiotherapy. Clinically acceptable treatment plans were achieved for most analyzed parameters. Lung SBRT seemed the most challenging treatment scenario. Major limitations comprised treatment plan optimization and dose calculation considering the tissue microstructure. This study presents an important step of the development towards clinical MRT. For clinical treatment scenarios using a sophisticated dose comparison concept based on EUD and EQD2, we demonstrated the capability of MRT to achieve clinically acceptable dose distributions.

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Koukourakis, Michael I. "Low-Dose Radiotherapy for Late-Stage COVID-19 Pneumonia?" Dose-Response 18, no. 3 (July 1, 2020): 155932582095135. http://dx.doi.org/10.1177/1559325820951357.

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Low dose radiotherapy has been used in the pre-antibiotic era for the treatment of all kind of pneumonia, with relative success. The unimaginable daily death toll of thousands of victims dying from COVID-19 pneumonia and the marginal therapeutic value of agents tested, brings forward the re-evaluation of the position of radiotherapy in the treatment of late stage lethal COVID-induced respiratory failure. A sound biological rationale supports this idea. Immunopathology studies show that excessive inflammation and infiltration of the lung parenchyma by immune cells is the cause of death. Mice lacking IFNαβ receptors remain unaffected by the virus. Radiotherapy at doses of 50-200cG may exert an intense anti-inflammatory effect and reduce the burden of inflammatory cells infiltrating the lungs. Whether radiotherapy, in conjunction with remdesivir and/or macrolides can reduce the dramatic death rates related to COVID-19 is an open challenge, under the absence of an alternative solution.

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Ghazi, Ismail, Mustapha Krim, Zineb Sobhy, Meriem Tantaoui, Abdelkrim Kartouni, Hamid Chakir, and Jamal Inchaouh. "Measurement and Evaluation of the Deposed Dose by a Beam of Photons in Radiotherapy into the Prostate Using the Monte Carlo Simulation Platform GEANT4." Journal of Advanced Research in Dynamical and Control Systems 11, no. 11-SPECIAL ISSUE (November 20, 2019): 1054–59. http://dx.doi.org/10.5373/jardcs/v11sp11/20193136.

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Spasic-Jokic, Vesna, Aleksandar Dobrosavljevic, and Petar Belicev. "Absorbed dose uncertainty estimation for proton therapy." Nuclear Technology and Radiation Protection 27, no. 3 (2012): 297–304. http://dx.doi.org/10.2298/ntrp1203297s.

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Successful radiotherapy treatment depends on the absorbed dose evaluation and the possibility to define metrological characteristics of the therapy beam. Radiotherapy requires tumor dose delivery with expanded uncertainty less than ?5 %. It is particularly important to reduce uncertainty during therapy beam calibration as well as to apply all necessary ionization chamber correction factors. Absorbed dose to water was determined using ionometric method. Calibration was performed in reference cobalt beam. Combined standard uncertainty of the calculated absorbed dose to water in 65 MeV proton beam was ?1.97% while the obtained expanded uncertainty of absorbed dose for the same beam quality was ?5.02%. The uncertainty estimation method has been developed within the project TESLA.

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Rubira, Cássia Maria Fischer, Nádia Juliana Devides, Liliane Torsani Úbeda, Antônio Geraldo Bortolucci Jr, José Roberto Lauris, Izabel Regina Fischer Rubira-Bullen, and José Humberto Damante. "Evaluation of some oral postradiotherapy sequelae in patients treated for head and neck tumors." Brazilian Oral Research 21, no. 3 (September 2007): 272–77. http://dx.doi.org/10.1590/s1806-83242007000300014.

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The aim of this study was to evaluate the oral sequelae of radiotherapy in patients treated between 1999 and 2003 for head and neck tumors. One-hundred patients (24 women, 76 men) ranging in age from 30 to 83 years (mean 59.2 years) were examined. Time since radiotherapy ranged from 1 to 72 months (mean 28 months). The total mean radiation dose received by the patients was 5,955 cGy. The evaluation protocol included anamnesis, intraoral and extraoral examination, measurement of stimulated salivary flow and salivary pH. Symptoms reported by the patients included dry mouth (68%), dysphagia (38%), and dysgeusia (30%). In 64% of the patients, the mean stimulated salivary flow rate was less than 0.7 ml/min. The mean salivary pH was 6.97 (± 0.714). Stimulated salivary flow increased with increasing postradiotherapy time (p < 0.05). The prevalence of mucositis was associated with higher radiation doses (p < 0.05), and the prevalence of atrophic candidiasis was related to a longer post-treatment period (p < 0.05). Two cases of recurrence of the primary tumor were detected during the study. The main effect of radiotheraphy in the head and neck region was a reduction of the salivary flow rate, even though our study demonstrated that there was a modest late improvement of the salivary flow.

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Asha, Wafa, Sami Koro, Wafa Asha, Wei Wei, Yanwen Chen, Eric Murray, Erin Murphy, et al. "NCOG-36. DOSIMETRY AND COGNITIVE FUNCTION AFTER RADIATION THERAPY IN LOW GRADE GLIOMAS." Neuro-Oncology 24, Supplement_7 (November 1, 2022): vii205. http://dx.doi.org/10.1093/neuonc/noac209.787.

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Abstract PURPOSE We found that cognitive function remained stable following radiotherapy with concurrent and adjuvant temozolomide (RT+TMZ) in low-grade glioma (LGG) patients evaluated prospectively up to 2 years. This study evaluates the effects of radiotherapy dosimetry on neurocognitive function in a larger group of molecularly defined LGG patients treated with radiotherapy (RT). METHODS A total of 39 LGG patients were evaluated with comprehensive psychometric tests at baseline (prior to RT) and at various time intervals following RT. Patients served as their own controls by evaluating change in scores over time. Dosimetric parameters included mean and maximum dose to the pituitary, mean and maximum dose to the hypothalamus, mean dose to contralateral hippocampus, brain, cochlea, and PTV volume. Correlation between dosimetry and neurocognitive tests were assessed by Spearman correlation for the baseline correlation and Cox proportional hazard regression analysis for the survival analysis. RESULTS Patients were followed for a median of 60 months. Overall, patients showed group mean test scores similar to their initial performances following radiotherapy on all psychometric measures. There was a significant correlation between mean dose to cochlea (p=0.006), pituitary (p=0.035), mean PTV volume (0.019) and neurocognitive outcome.. CONCLUSION Cognitive function remained stable following radiotherapy in LGG patients evaluated prospectivelys. There was a significant correlation between specific dosimetric endpoints and neurocognitive outcomes over time. Further study needs to be done in a larger population to validate these findings.

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Gupta, Subhash, M. A. Laviraj, Haresh Kunhiparambath, Dayanand Sharma, Rajendran M, Pramod Kumar Julka, and Goura Kishor Rath. "Comparative dosimetric study of three-dimensional conformal (3DCRT), intensity modulated radiotherapy (IMRT), and volumetric modulated arc therapy (VMAT) for treatment in pituitary adenomas." Journal of Clinical Oncology 31, no. 15_suppl (May 20, 2013): e13043-e13043. http://dx.doi.org/10.1200/jco.2013.31.15_suppl.e13043.

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e13043 Background: Radiotherapy is usually delivered after surgery in pituitary adenomas. Usually stereotactic radiotherapy is used in their treatment. The studies evaluating the recent advances like IMRT, VMAT for pituitary adenomas are rare. Present study evaluates 3DCRT, IMRT, and VMAT for the treatment of pituitary adenomas. Methods: Ten patients of pituitary adenomas who were planned for post operative adjuvant radiotherapy were included. Planning CT was done with the patient supine with a customized thermoplastic cast of head on Philips wide bore CT (for 3 mm). The CT images were transferred online to the Pinnacle TPS V.8.0M. Tumor and the critical structures like brain stem and optic nerves were contoured on pinnacle. 3DCRT was planned on pinnacle. The CT images with the contoured structures were sent to Monaco TPS V.3.10.02. IMRT and VMAT were planned on Monaco. Dose: 50 Gy in 25 fractions. PTV indices analyzed: D mean, D2 (dose received by the hottest 2 percent volume), D98 (dose received by 98 percent), homogeneity index HI [(D2-D98)/D50)], and conformity index CI (PTV volume/volume of PTV covered by 95 percent isodose). Dmax and D2 (dose received by hottest 2cc) for the brain stem, right and left optic nerve PRV were evaluated. The average were calculated and compared. Statistical analysis was done by SPSS Version 14. Results: The Table shows that VMAT is better in terms of PTV indices. For the normal structures also VMAT provides the least dose. Conclusions: VMAT is superior to IMRT and both are better than 3DCRT for the radiotherapeutic treatment of pituitary adenoma. [Table: see text]

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Xu, Yong, Lina Abdelghany, Reiko Sekiya, Da Zhai, Keiichi Jingu, and Tao-Sheng Li. "Optimization on the dose and time of nicaraven administration for mitigating the side effects of radiotherapy in a preclinical tumor-bearing mouse model." Therapeutic Advances in Respiratory Disease 16 (January 2022): 175346662211372. http://dx.doi.org/10.1177/17534666221137277.

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Objective: Radiation-induced lung injury (RILI) is one of the serious complications of radiotherapy. We have recently demonstrated that nicaraven can effectively mitigate RILI in healthy mice. Here, we further tried to optimize the dose and time of nicaraven administration for alleviating the side effects of radiotherapy in tumor-bearing mice. Methods and results: A subcutaneous tumor model was established in the back of the chest in C57BL/6N mice by injecting Lewis lung cancer cells. Therapeutic thoracic irradiations were done, and placebo or different doses of nicaraven (20, 50, 100 mg/kg) were administrated intraperitoneally pre-irradiation (at almost 5–10 min before irradiation) or post-irradiation (within 5 min after irradiation). Mice that received radiotherapy and nicaraven were sacrificed on the 30th day, but control mice were sacrificed on the 15th day. Serum and lung tissues were collected for evaluation. Nicaraven significantly decreased the level of CCL8, but did not clearly change the levels of 8-OHdG, TGF-β, IL-1β, and IL-6 in serum. Besides these, nicaraven effectively decreased the levels of TGF-β, IL-1β, and SOD2 in the lungs, especially by post-irradiation administration with the dose of 20 mg/kg. Although there was no significant difference, the expression of SOD1, 53BP1, and caspase 3 was detected lower in the lungs of mice received nicaraven post-irradiation than that of pre-irradiation. Conclusion: According to our data, the administration of nicaraven at a relatively low dose soon after radiotherapy will be recommended for attenuating the side effects of radiotherapy.

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Korfel, Agnieszka, Uwe Schlegel, Derek R. Johnson, Timothy J. Kaufmann, Caterina Giannini, and Takanori Hirose. "Case-based review: primary central nervous system lymphoma." Neuro-Oncology Practice 4, no. 1 (February 9, 2017): 46–59. http://dx.doi.org/10.1093/nop/npw033.

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Abstract Primary CNS lymphoma (PCNSL) is a rare diffuse large B-cell lymphoma originating within the central nervous system. The overall incidence of PCNSL is rising, particularly in the elderly population. Immunosuppression is a strong risk factor, but most patients with this tumor are apparently immunocompetent. Diagnosis of PCNSL can be challenging. Non-invasive or minimally invasive tests such as ophthalmological evaluation and spinal fluid analysis may be useful, but the majority of patients require tumor biopsy for definitive diagnosis. Our knowledge concerning optimum treatment of PCNSL is fragmentary due to paucity of adequately sized trials. Most patients are now initially treated with high-dose-methotrexate-based chemotherapy alone, as the addition of whole-brain radiotherapy at standard doses has not been shown to increase survival and does increase the risk of neurological toxicity. Ongoing trials are addressing issues such as the roles of reduced-dose radiotherapy, the addition of the CD20 antibody rituximab to chemotherapy, high-dose chemotherapy followed by autologous stem cell transplantation, and maintenance therapy in the primary management of PCNSL.

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A. Hassan, Hunar, Kharman A. Faraj, and Zarean Y. Saeed. "Evaluation of Radiation Doses Received by Organs at Risk in 3D Conformal and Intensity Modulated Radiotherapy for Head and Neck Cancer." Journal of Zankoy Sulaimani - Part A 21, no. 1 (June 20, 2019): 91–98. http://dx.doi.org/10.17656/jzs.10747.

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Majdoul, Soufya, Laurianne Colson-Durand, Nu Hanh To, and Yazid Belkacemi. "Adaptive Radiotherapy for an Uncommon Chloroma." Case Reports in Oncology 9, no. 3 (October 12, 2016): 593–98. http://dx.doi.org/10.1159/000450599.

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Granulocytic sarcomas, also referred to as chloromas or myeloid sarcomas, are extramedullary neoplasms that are composed of immature myeloid cells. This uncommon disease is known to be radiosensitive. However, the total dose and dose per fraction are not standardized. In addition, during the course of radiation therapy, significant reduction of the tumor is usually obtained. Thus, target volume reduction may require an intermediate radiotherapy plan evaluation for an adaptive treatment. A second plan at mid-dose is highly recommended.

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Loginova, A. A., D. A. Tovmasian, A. P. Chernyaev, D. A. Kobyseva, A. O. Lisovskaya, and A. V. Nechesnyuk. "EVALUATION OF DOSE DELIVERY FOR TOTAL MARROW IRRADIATION USING IMAGING DATA OBTAINED WITH TOMOTHERAPY DEVICE." Russian Electronic Journal of Radiology 11, no. 1 (2021): 230–37. http://dx.doi.org/10.21569/2222-7415-2021-11-1-230-237.

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Fractionated total marrow irradiation and lymphoid irradiation (TMLI) is a highly conformal method of radiotherapy, requiring a high degree of dose delivery accuracy. This study presents a quantitative assessment of the delivered dose while taking into account the influence of daily positioning using one patient receiving TMLI as an example. Material and methods. Before each treatment session on TomoTherapy preliminary visualization is performed by megavoltage computer tomography (MVCT). The resulting images are used to correct the position of the patient and thereby to minimize the error of dose adjustment. In this study dose was recalculated for each treatment fraction, taking into account the current radiation geometry based on the MVCT images of the patient. The planned and delivered total dose distributions were compared. Results. The difference between the delivered and planned average dose in target comprising bone marrow and lymphoid tissue was less than 0.5%. The volume of the lungs, receiving a dose of 8 Gy did not exceed 39.3% of the total delivered dose, at the same time the coverage of the targets met prescribed requirements. Discussion. Appropriate immobilization, visualization with subsequent correction of the patient's position prior to each fraction allowed for reliable and accurate dose delivery. The evaluation of the delivered dose provides opportunity for an objective analysis of the therapy. Conclusion. The analysis of the delivered dose distribution based on MVCT visualization of the patient's body demonstrated the safety of TMLI method in terms of dose to the organs at risk, as well as the acceptable quality of the target coverage

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Bai, Shuheng, YinYing Wu, Yanli Yan, Rong Li, Haojing Kang, Jiangzhou Zhang, Wen Ma, et al. "Evaluation of the Efficacy and Toxicity of Radiotherapy for Type III-IV Portal Vein Tumor Thrombi." Technology in Cancer Research & Treatment 20 (January 1, 2021): 153303382199528. http://dx.doi.org/10.1177/1533033821995286.

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Background: Type Ⅲ and Ⅳ portal vein tumor thrombi (PVTT) cannot be removed through surgery, and no effective therapeutic procedure is available. Type Ⅲ/Ⅳ PVTT can be downstage to type I/II PVTT by using Radiotherapy, and can further be can be removed surgically. Thus, radiotherapy may be an effective treatment for type Ⅲ/Ⅳ PVTT. This study aims to evaluate the efficacy and toxicity of radiotherapy for type III-IV PVTT. Methods: This prospective study was conducted from August 1, 2017, to September 30, 2019, for patients with type Ⅲ and Ⅳ PVTT. Patients received radiotherapy with a target dose of 50Gy/25f or 59.5Gy/17 f. Advanced radiological technique such as image fusion technique for CT image and MRI image were utilized to produce more precise lesion localization, and limit the dose to organs at risk in order to get a better downstage rate and less adverse complications. Results: Nine (9) patients with type Ⅲ PVTT and 5 patients with type Ⅳ PVTT were included in this study. 12 patients received a radiotherapy dose of 50Gy/25f, 2 patients received 59.50Gy/17 f. After radiotherapy, 92.9% of patients with PVTT were successfully downstage to type II/I. In patients with primary hepatocellular carcinoma, 8 patients (accounting 88.9%) achieved down-stage. 5 patients with other types of tumors achieved downstage which accounts 100%. In addition, none of the 14 patients observed radiation hepatitis and radiation liver failure. And none of the patients developed gastrointestinal ulcers and thrombocytopenia. Conclusion: Radiotherapy is a suitable treatment measure for type Ⅲ and Ⅳ PVTT to get downstage and make the opportunity for surgery. Image fusion technology for precise lesion location such as CT-MRI image fusion, and strict dose limitation of organ at risk, contributed to the improvement of radiotherapy efficiency and the significant decrease in adverse complications.

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Seppälä, Jan, Sami Suilamo, Mikko Tenhunen, Liisa Sailas, Heli Virsunen, Erna Kaleva, and Jani Keyriläinen. "Dosimetric Comparison and Evaluation of 4 Stereotactic Body Radiotherapy Techniques for the Treatment of Prostate Cancer." Technology in Cancer Research & Treatment 16, no. 2 (December 8, 2016): 238–45. http://dx.doi.org/10.1177/1533034616682156.

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Purpose: The aim of this study was to compare dosimetric characteristics, monitor unit, and delivery efficiency of 4 different stereotactic body radiotherapy techniques for the treatment of prostate cancer. Methods: This study included 8 patients with localized prostate cancer. Dosimetric assets of 4 delivery techniques for stereotactic body radiotherapy were evaluated: robotic CyberKnife, noncoplanar intensity-modulated radiotherapy, and 2 intensity-modulated arc therapy techniques (RapidArc and Elekta volumetric-modulated arc therapy). All the plans had equal treatment margins and a prescription dose of 35 Gy in 5 fractions. Results: Statistically significant differences were observed in homogeneity index and mean doses of bladder wall and penile bulb, all of which were highest with CyberKnife. No significant differences were observed in the mean doses of rectum, with values of 15.2 ± 2.6, 13.3 ± 2.6, 13.1 ± 2.8, and 13.8 ± 1.6 Gy with CyberKnife, RapidArc, volumetric-modulated arc therapy, and noncoplanar intensity-modulated radiotherapy, respectively. The highest dose conformity was realized with RapidArc. The dose coverage of the planning target volume was lowest with noncoplanar intensity-modulated radiotherapy. Treatment times and number of monitor units were largest with CyberKnife (on average 34.0 ± 5.0 minutes and 8704 ± 1449 monitor units) and least with intensity-modulated arc therapy techniques (on average 5.1 ± 1.1 minutes and 2270 ± 497 monitor units). Conclusion: Compared to CyberKnife, the RapidArc, volumetric-modulated arc therapy, and noncoplanar intensity-modulated radiotherapy produced treatment plans with similar dosimetric quality, with RapidArc achieving the highest dose conformity. Overall, the dosimetric differences between the studied techniques were marginal, and thus, the choice of the technique should rather focus on the delivery accuracies and dose delivery times.

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Bajracharya, Barsha, Subrata Bhattacharyya, and Pratibha Poudel. "Evaluation of oral mucositis in oral cancer patients undergoing radiotherapy." Journal of Chitwan Medical College 8, no. 2 (June 30, 2018): 6–9. http://dx.doi.org/10.3126/jcmc.v8i2.23730.

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Introduction: The present study was conducted to evaluate oral mucositis in oral cancer patients receiving head and neck radiotherapy. Methods: Sixty oral cancer patients who had received at least 40 grays of radiation were included in the study. Mucositis was scored by oroscopy using WHO scale. Grades of mucositis were then compared with total dose of radiation received by the patients. Results: The cases were receiving the mean cumulative dose of standard radiation therapy of 2Gy per fraction, 5 fractions per week. All the patients developed oral mucositis. The majority had grade I mucositis, followed by grade III, II and IV. The grade of mucositis was directly proportional to the dose of radiation exposure. Conclusion: Oral mucositis occurs among all the patients undergoing head and neck radiotherapy and grade of mucositis is proportional to the dose of radiation exposure.

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Sukhikh, E. S., I. N. Sheyno, L. G. Sukhikh, A. V. Taletskiy, A. V. Vertinskiy, and P. V. Izhevskiy. "Radiobiological Evaluation of Dosimetric Plans for Stereotactic Radiotherapy for Prostate Cancer According to Fractionation Regimen." Journal of radiology and nuclear medicine 100, no. 5 (November 4, 2019): 263–69. http://dx.doi.org/10.20862/0042-4676-2019-100-5-263-269.

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Objective. To determine the most effective irradiation regimen (total dose and dose per fraction) for hypofractionated treatment for prostate carcinomas according the TCP/NTCP radiobiological criteria.Material and methods. Using the tomographic information of five patients with low-risk prostate adenocarcinoma as an example, the authors devised dosimetric radiation therapy plans using the volumetric modulated arc therapy (VMAT) procedure. They considered the range of total doses of 33.5 to 38 Gy administered in 4 and 5 fractions. Based on the equivalent uniform dose concept proposed by A. Niemierko and on the computed differential dose volume histograms, the investigators modeled local tumor control probability (TCP) values, by taking into account the uncertainties of main radiobiological parameters, and estimated normal tissue complication probabilities (NTCP) for the anterior rectal wall as the organ most at risk of irradiation. An effective dosimetric plan was selected according to the UTCP criterion and the probability of complication-free tumor control, i.e. TCP (1 – NTCP).Results. The results of modeling the UTCP criterion show that with a higher total dose, the TCP value increases and so does the NTCP value, therefore the optimal radiation therapy plans are to irradiate with a total dose of 34 Gy over 4 fractions or with a dose of 36–37 Gy over 5 fractions. The difference between the fractionation regimens is that the UTCP value is achieved with a higher TCP value over 4 fractions and with a lower load on the rectal wall over 5 fractions.Conclusion. The choice of a specific fractionation regimen should be determined from the calculated values of differential dose volume histograms for each patient, as well as from radiobiological criteria, such as TCP, NTCP and UTCP.

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Amit, Bahl, R. Kapoor, T. Parsee, Singh Arun, R. Gupta, S. Sharma, and T. Bhattacharya. "Evaluation of Bowel Doses in Patients Undergoing Dose Escalated Post Operative Intensity Modulated Radiotherapy in Perimapullary Cancers." Annals of Oncology 25 (June 2014): ii48. http://dx.doi.org/10.1093/annonc/mdu165.108.

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ŚLOSAREK, Krzysztof, Aleksandra GRZĄDZIEL, Marta SZLAG, and Joanna BYSTRZYCKA. "Radiation Planning Index for dose distribution evaluation in stereotactic radiotherapy." Reports of Practical Oncology & Radiotherapy 13, no. 4 (July 2008): 182–86. http://dx.doi.org/10.1016/s1507-1367(10)60007-7.

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Lee, Jonny, Christopher Dean, Rushil Patel, Gareth Webster, and David J. Eaton. "Multi-center evaluation of dose conformity in stereotactic body radiotherapy." Physics and Imaging in Radiation Oncology 11 (July 2019): 41–46. http://dx.doi.org/10.1016/j.phro.2019.08.002.

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Plieskienė, Aista, and Dainius Burdulis. "Assessment Of The Dose To The Heart And The Left Anterior Descending Coronary Artery For The Left Breast Radiotherapy." Sveikatos mokslai 26, no. 5 (December 22, 2016): 79–83. http://dx.doi.org/10.5200/sm-hs.2016.076.

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Radiotherapy for left breast cancer may increase risk of cardiovascular diseases. Exposing the anterior portion of the heart and left anterior descending coronary artery (LAD) to the highest radiation dose depends on individual anatomical location of these structures. The purpose of this work was to assess the radiation doses delivered to the heart and the LAD for the left sided breast cancer patients treated with 3D conformal radiotherapy. Thirty two randomly selected patients referred for adjuvant radiotherapy after conservation surgery for left sided breast cancer were evaluated. The whole heart, the arch of the LAD (LADarch) and the whole LAD were contoured. The radiation doses (Dmax, Dmean) to these three anatomical cardiac structures were evaluated. For all 32 patients, the assessed radiotherapy plans were acceptable based on the dose constraints to critical structures: heart, LADarch. The average mean doses (Dmean) to the heart are well below 5 Gy and 7,3 (range, 3,82 – 17,15 Gy) for the LADarch respectively. For 21,9% of patients, the Dmean to the heart and dose to the LADarch was relatively low while the Dmean to the whole LAD was considerably higher. Conclusion. Evaluation of the mean dose to the heart only could lead to excessive heart irradiation. The results of the study indicate that it is necessary to assess the dose delivered to the whole heart as well as to the whole LAD for evaluation of the left breast irradiation treatment plan. This is very important to minimise the risk of clinically significant cardiac events after left breast radiotherapy.

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Gold, Deborah R., Roger J. Packer, and Bruce H. Cohen. "Treatment strategies for medulloblastoma and primitive neuroectodermal tumors." Neurosurgical Focus 7, no. 2 (August 1999): E3. http://dx.doi.org/10.3171/foc.1999.7.2.3.

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Medulloblastoma and primitive neuroectodermal tumors (PNETs) are the most common malignant brain tumors in children. The concern for late sequelae of neuraxis irradiation and the obligation to improve disease-free survival in children who harbor malignant brain tumors has led to the additional provision of systemic chemotherapy to standard- and reduced-dose radiotherapy, as well as to the evaluation of alternate modes of radiotherapy delivery. Analysis of evidence has suggested that chemotherapy has an impact on length of survival in children with medulloblastoma and PNETs. The question remains as to whether chemotherapy combined with reduced-dose radiotherapy provides greater benefit than standard-dose radiotherapy alone, and which subset of children the treatment most benefits. Also unanswered is the question of whether chemotherapy can serve as the primary treatment in infants with these lesions. In an attempt to help answer these questions, the authors review the major chemotherapy and radiotherapy trials for newly diagnosed patients and those with recurrent medulloblastoma and PNETs.

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Singh, Gaganpreet, Rose Kamal, Deepak Thaper, Arun Singh Oinam, Bhumika Handa, Vivek Kumar, and Narendra Kumar. "Voxel based evaluation of sequential radiotherapy treatment plans with different dose fractionation schemes." British Journal of Radiology 93, no. 1112 (August 2020): 20200197. http://dx.doi.org/10.1259/bjr.20200197.

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Objective: This study presents a methodology for voxel-based evaluation of two phase sequential radiotherapy treatment plans having conventional dose scheme in the first phase and subsequent hypofractionation dose scheme in the second phase based upon different priority [planning target volume (PTV), clinical target volume (CTV) and organs at risk (OAR)] of display modes. Methods: A case of carcinoma prostate was selected for demonstration. Varian Eclipse treatment planning system (TPS) was used for contouring and planning. In the first phase, a dose of 52 Gy in 26 fractions to the PTV and in the second phase, a dose of 19.5 Gy in 3 fractions to the PTV Boost was planned on the same CT data set. Both the plans (Phase 1 and Phase 2) were exported and processed using “Voxel-based radiobiology display (VRb) tool”. Plan Sum for Biologically effective dose (BED)-Cube and equivalent dose of 2Gy (EQD2)-Cube was reconstructed using a combination of linear quadratic (LQ) and linear quadratic-linear (LQ-L) radiobiological models. Tumor control probability (TCP) and normal tissue complication probability (NTCP) for different target volumes and organs were also calculated using EQD2-volume histograms of the Plan Sum. Results: An in-house graphical user interface (GUI) is developed to present the qualitative and quantitative evaluation of the multiphase treatment plans with different display modes and dose regimens. The voxel based TCP obtained for the combined target volume was 90.56%. NTCP for the bladder and rectum was calculated from the Plan Sum histograms and found to be 0.33% and ~0.0% respectively. Conclusion: The proposed methodology using the VRb tool offers superior plan evaluation for multiphase sequential radiotherapy treatment plans over the existing methods. Advances in knowledge: PTV, CTV and OAR priority based display modes in VRb tool offers better understanding of radiobiological evaluation of sequential radiotherapy treatment plans.

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Nikolakopoulou, Aggeliki, Vasiliki Peppa, Antigoni Alexiou, George Pissakas, Georgia Terzoudi, and Pantelis Karaiskos. "Comparison and Evaluation of Different Radiotherapy Techniques Using Biodosimetry Based on Cytogenetics." Cancers 14, no. 1 (December 29, 2021): 146. http://dx.doi.org/10.3390/cancers14010146.

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While rapid technological advances in radiotherapy techniques have led to a more precise delivery of radiation dose and to a decreased risk of side effects, there is still a need to evaluate the efficacy of the new techniques estimating the biological dose and to investigate the radiobiological impact of the protracted radiotherapy treatment duration. The aim of this study is to compare, at a cytogenetic level, advanced radiotherapy techniques VMAT and IMRT with the conventional 3D-CRT, using biological dosimetry. A dicentric biodosimetry assay based on the frequency of dicentrics chromosomes scored in peripheral blood lymphocytes from prostate cancer patients and PC3 human prostate cancer cell line was used. For each patient blood sample and each subpopulation of the cultured cell line, three different irradiations were performed using the 3D-CRT, IMRT, and VMAT technique. The absorbed dose was estimated with the biodosimetry method based on the induced dicentric chromosomes. The results showed a statistically significant underestimation of the biological absorbed dose of ~6% for the IMRT and VMAT compared to 3D-CRT irradiations for peripheral blood lymphocytes, whereas IMRT and VMAT results were comparable without a statistically significant difference, although slightly lower values were observed for VMAT compared to IMRT irradiation. Similar results were obtained using the PC3 cell line. The observed biological dose underestimation could be associated with the relative decreased dose rate and increase irradiation time met in modulated techniques compared to the conventional 3D-CRT irradiations.

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Сухих, Е., E. Sukhikh, Л. Сухих, L. Sukhikh, О. Аникеева, O. Anikeeva, П. Ижевский, P. Izhevsky, И. Шейно, and I. Sheino. "Dosimetric Evaluation for Various Methods of Combined Radiotherapy of Cervical Cancer." Medical Radiology and radiation safety 64, no. 1 (January 20, 2019): 45–52. http://dx.doi.org/10.12737/article_5c55fb4a074ee1.27347494.

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Purpose: Carrying out dosimetric investigation of possibility to replace a traditional combined radiation therapy of cervical cancer by combinations only external irradiation, without change of total course dose and number of fractions. Material and Methods: Eleven patients with a diagnosis of cervical cancer (stages T2bNxM0 and T3NxM0) who received a course of combined radiotherapy (CRT) have been considered in this study. The combination of dose delivery techniques 3D-CRT + high dose rate brachytherapy (HDR) was used as a basic one. The following fractionation regimes for CRT were simulated: external beam RT (EBRT) of the first stage – total dose 50 Gy and fraction dose 2 Gy (25 fractions), the second stage – total dose 28 Gy and fraction dose 7 Gy (4 fractions). Total CRT course dose was 89.7 Gy EQD2. Dosimetric planning of EBRT using conventional radiography and 3D-CRT has been carried out using XIO dosimetry planning system. Dosimetric planning of first-stage EBRT and second-stage EBRT using the VMAT technique has been performed in the Monaco dosimetry planning system. HDR of the second stage has been planned using the HDRplus dosimetric planning system for the Multisource HDR unit with a 60Co source. Results: Coverage of the clinical volume of the tumor using HDR, on average, was equal to 95 % of the prescribed dose at 91.8 % of the volume, 110 % of the dose – 75.7 % of the volume. 60Co + VMAT results in the coverage level 95 % of the dose at 97.1 % of the volume and 110 % of the dose at 2.1 % of the volume. 3D-CRT + VMAT provide the coverage level of 95 % of the dose at 98 % of the volume and 110 % of the dose at 2.6 % of the volume. Using the combination VMAT + VMAT allows achieving the average coverage of the target at the level of 98 % of the dose at 97 % of the volume, 110 % of the dose at 8.8 % of the volume. The maximum dose per volume of the organs at risk equal to 2 cm3 did not exceed their tolerant levels both for the bladder and for the rectum. Conclusion: At present, there is a technical possibility to replace the second stage of CRT cervical cancer by EBRT using the VMAT technique. Implementation of the VMAT technique allows to increase the uniformity of irradiated volume coverage comparing with traditional HDR. While using VMAT technique the tolerant levels of organs at risk are not exceeded.

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Mishra, S. P., B. Paul, R. R. Ghosh, V. Gupta, and A. Kr Srivastava. "288 Correlation between Computed Dose And Clinical Doses using TL Measurement and Evaluation of Doses to Local Anatomy in Gynecological Radiotherapy." Radiotherapy and Oncology 76 (September 2005): S135. http://dx.doi.org/10.1016/s0167-8140(05)81264-2.

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Sahu, Kamal Kant, Deepali Pandey, Ajay Kumar Mishra, James O’Shea, Yayan Chen, and Bradley McGregor. "Mystery of neck lump: an uncommon presentation of urachal cancer." BMJ Case Reports 12, no. 8 (August 2019): e230215. http://dx.doi.org/10.1136/bcr-2019-230215.

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We present the case of a 55-year-old male patient who presented with palpable cervical lymphadenopathy. Excisional biopsy showed metastatic adenocarcinoma of unknown origin. Imaging showed a bladder mass following which he underwent transurethral resection of bladder tumour. Histopathological evaluation of mass confirmed a poorly differentiated adenocarcinoma with signet-ring cell features. Immunohistochemistry was suggestive of metastatic urachal cancer. He agreed for enrollment in a clinical trial, however soon after 1st cycle, he developed immune pneumonitis requiring high dose steroids. On follow-up, MRI brain was done for evaluation of headache which showed metastatic intracranial disease. He completed radiotherapy following which he was started on FOLFOX chemo regimen (folinic acid, 5-fluorouracil and oxaliplatin).

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Rozati, Hamoun, Felicity J. Ferguson, Ellie Rashidghamat, and Girija Anand. "Delivery of high-dose radiation for recurrence of breast cancer in a patient with hidradenitis suppurativa." BMJ Case Reports 13, no. 11 (November 2020): e238848. http://dx.doi.org/10.1136/bcr-2020-238848.

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Hidradenitis suppurativa (HS) is a chronic inflammatory skin condition characterised by inflammatory nodules, abscesses, sinus tract formation and scarring. There is a lack of evidence for the use of radical radiotherapy for patients with a diagnosis of HS. A 56-year-old woman with a long-standing diagnosis of HS presented with a cutaneous local recurrence of breast cancer. Radical radiotherapy was offered despite issues with previous prolonged postoperative wound healing associated with the underlying HS. A multidisciplinary evaluation was conducted with breast surgeons, dermatologists and radiation oncologists to assess the safety of delivery of radical radiotherapy. Five weeks post radiotherapy, the patient had no significant residual symptoms from her breast cancer treatment for her HS and no escalation of treatment was required for her HS. Factors contributing to safe delivery of radical radiotherapy include medical optimisation prior to and during treatment, radiation dose, radiation technique and vigilant post-treatment surveillance.

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Dufek, V., H. Zackova, L. Kotik, and I. Horakova. "RESULTS OF CZECH NATIONAL STUDY OF RADIATION EXPOSURE FROM RADIOTHERAPY OF NON-MALIGNANT DISEASES, IN PARTICULAR OF HEEL SPURS." Radiation Protection Dosimetry 186, no. 2-3 (November 11, 2019): 386–90. http://dx.doi.org/10.1093/rpd/ncz237.

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Abstract About 26 000 patients are treated per year with radiotherapy for non-malignant diseases in the Czech Republic. Approximately 75% of them are treated on X-ray therapy units and most of these patients undergo radiotherapy of heel spurs. The evaluation of radiation exposure of these patients was based on measured organ doses and on data from clinical practice. Collective effective doses for particular diagnoses were calculated in order to compare doses resulting from different diagnoses treated on X-ray therapy units. The collective effective dose from radiotherapy of heel spurs in the Czech Republic in 2013 was evaluated to 77 manSv. It represents 25.6% of the total collective effective dose for all diagnoses of radiotherapy for non-malignant diseases treated on X-ray therapy units.

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Journal articles on the topic 'Radiotherpy Dose Evaluation'

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