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Byline: Ankur. Mourya, Lalit. Aggarwal, Sunil. Choudhary Brachytherapy applicators have come a long way since Danlos developed early intracavitary applicators to treat cervical cancer patients. Therefore, this review will help [...]

Purpose: Development and validation of a simple and convenient computational program in MATLAB environment for estimating the tumor control probability (TCP) and the normal tissue complication probability (NTCP), as a decision support system for routine plan evaluation.Materials and Methods: We developed an in-house software using MATLAB 2016b (Mathworks) for estimating TCP and NTCP named as RBMODELV1. The program contains Niemierko free equivalent uniform dose (EUD) program code provided in authors research article. For rest of radiobiological (RB) models in the software separate coding is performed. The program accepts cumulative dose-volume histogram file in (.txt) format containing two columns dose and volume. A set of two RB parameters were prepared, default and user-dependent in excel sheet named as RBDATA. We cross-validated results of RBMODELV1 software with BioSuite software for Poisson's TCP model and Lyman-Kutcher-Burman (LKB) model. A set of total 20 patient's data of head and neck site took under study and respective TCP and NTCP calculated by all the RB models and compared.Results: This is the first study in which we tried to establish correlation between the mean doses (EUD) received by parallel structure (parotid gland and oral cavity) and predicted percentage of NTCP values. It is found that mean dose in the range of 35-40 Gy for parotid gland can result in more than 50% NTCP predicted by all four RB models. Similarly oral cavity receiving mean dose in the range of 53-58 Gy can results in more than 35% NTCP predicted by all the four models. There is <3% variation observed between TCP calculated by BioSuite and RBMODELV1 software and <4% variation observed between predicted NTCP for parotid gland and oral cavity OAR from LKB model by both the software.Conclusion: We created simple software RBMODELV1 which can be used as a research tool as well as decision support system. [ABSTRACT FROM AUTHOR]

Introduction: The role of hypofractionated radiotherapy (HFRT) in postmastectomy breast cancer patients is not well established. This study was done to establish the role of two different HFRT schedules in the treatment of chest wall and regional lymph nodes after mastectomy. Materials and Methods: Between 2012 and 2016, consecutively registered patients of locally advanced breast cancer patients having undergone mastectomy and adjuvant radiotherapy (RT) at a tertiary cancer center were analyzed. Locoregional recurrence (LRR) was the primary endpoint, whereas overall survival (OS), disease-free survival (DFS), and both acute and late adverse events were secondary endpoints. Results: A total of 34 patients who were treated with 39 Gy in 13 fractions over 2½ weeks and 35 patients who were treated with 40 Gy in 15 fractions over 3 weeks were identified. The median follow-up period was 47 months and 63.5 months in the 39 Gy and 40 Gy arms, respectively. LRR was seen in 11.8% and 8.6% of patients in the 39 Gy and 40 Gy arms, respectively. OS at 4 years was 66% and 71.5% in the 39 Gy and 40 Gy arms, respectively. The mean DFS for 39 Gy and 40 Gy arms was 43.6 months and 66.4 months, respectively (P = 0.822). Acute skin toxicity was similar in the two groups. Arm edema was significantly more in the 40 Gy arm. Conclusion: The two HFRT schedules are equivalent to each other in terms of survival outcomes. Arm edema is higher with 40 Gy arm as compared to 39 Gy arm. [ABSTRACT FROM AUTHOR]

Patient specific QA tests for IMRT and VMAT using different dosimetric tools: A comparative study Radhika V Kartha, Abhijit Mandal, Sajini S Kurup, Ankur Mourya, Chhape Ram, Satyajit Pradhan, Sunil Chaudhary, Uday P Shahi, and Lalit M Aggarwal Department of Radiotherapy and Radiation Medicine, Institute of Medical Sciences, Banaras Hindu University, Varanasi (UP) - 221005 Aims and Objectives: Purpose of this study is • To compare the pre-treatment patient specific quality assurance (QA) results obtained with two dosimetric tools - Electronic Portal Imaging Device (EPID) and MatriXX Evolution (2-D ion chamber array) by evaluating gamma index (gamma), dose difference (DD) and distance-toagreement (DTA) for different head and neck cancer patients treated by IMRT/VMAT. • To find the accurate dosimetric tool among these for the patient specific QA by seeing their passing rates. Material and Methods: In this study, ten Carcinoma head and neck patients were taken who were treated by IMRT/VMAT during April 2015 to June 2017 by a 6MV LINAC - Photon beam (UNIQUE performance, VARIAN). The plans were created on Eclipse treatment planning system (version 11.0.31) using Anisotropic Analytical Algorithm (AAA). Patient-specific QA was carried out by generating verification plans for each patient followed by the irradiation onto an ion chamber array (MatriXXEvolution) and an electronic portal imaging device (EPID). Analysis of MatriXX Evolution was carried out by myQA®software (version 2.5.10.0) provided by IBA Pvt. Ltd. and that of EPID was done with the in-built calculation model (Portal Dose Image Prediction [PDIP]) provided by Varian available in the TPS. Gamma analysis of measured dose distribution with the TPS generated dose distribution for all the plans was carried out using a passing criterion of gamma ? 1, dose difference (DD) ? 3%, distance-to-agreement (DTA) ? 3 mm . The passing rates of the two dosimetric tools were compared. Result: Passing rates ( ? 95% ± standard deviation), average gamma value and the average dose difference between the TPS generated dose distribution and the measured dose distribution by both the dosimetric tools (MatriXXEvolution and EPID) were obtained and given in Table.1. For all the plans, an average difference of 0.1 for the ? index and 0.77 % for DD were observed between the two dosimetric tools. All the results obtained were under tolerances (DD ? 3 %, DTA ? 3 mm, ? ? 1). Table.1 Comparison between MatriXX Evolution and EPID Dosimetric parameter MatriXX Evolution EPID Passing rate 97.88% 95.23% SD 0.35% 2.70% Gamma 0.46 0.36 DD 1.28% 2.05% DTA 0.79 mm NA* *SD: Standard deviation *EPID does not provide the value of DTA. Conclusion: MatriXXEvolution results are in good agreement with the TPS generated values than the values measured by EPID for all plans. However, Gamma value with both the systems is more or less same. Therefore, our study suggests that QA results and its consistencies depend on the choice of dosimetric tool. EPID can be used as a routine QA tool since it is a time saving method whereas MatriXXEvolution can be used for absolute dosimetry. [ABSTRACT FROM AUTHOR]