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Purpose: To explore the feasibility and efficacy of interstitial brachytherapy application for nonresectable and chemo-resistant malignant liver and lung lesions. Materials and Methods: Percutaneous high-dose-rate interstitial brachytherapy (HDR ISBT) was applied in nine lesions of seven middle-aged patients with advanced carcinoma (five patients with liver lesion and two patients with lung lesion). All patients were surgically ineligible. All patients had already received systemic chemotherapy. Under computed tomography (CT) guidance (for lung lesion) or ultrasonography (USG) guidance (for liver lesion), a single stainless steel brachytherapy needle was inserted percutaneously in patients with lesion size ≤4 centimeter (cm) and multiple needles were inserted in patients of lesion size >4cm. A single dose of 15 Gy to 20 Gy with HDR ISBT was prescribed at the periphery of the lesion. The needles were removed just after treatment. Patients were kept under observation for 24 h after treatment. Results: The median size of the lesion was 6.5 cm. In all the cases of liver lesion, more than 75% shrinkage of tumor volume in follow-up at 6 mo was observed. It was more than 50% for lung lesion. None of the patients had developed significant complications as on the median follow up period of 15 mo (ranges 3–27 mo). Conclusions: Percutaneous CT-guided high-dose-rate interstitial brachytherapy is a minimally invasive, safe, and feasible treatment option with minimal complication for inoperable, chemo resistant, advanced cancers with encouraging treatment outcomes. [ABSTRACT FROM AUTHOR]

Purpose: To explore the feasibility and efficacy of interstitial brachytherapy application for nonresectable and chemo-resistant malignant liver and lung lesions. Materials and Methods: Percutaneous high-dose-rate interstitial brachytherapy (HDR ISBT) was applied in nine lesions of seven middle-aged patients with advanced carcinoma (five patients with liver lesion and two patients with lung lesion). All patients were surgically ineligible. All patients had already received systemic chemotherapy. Under computed tomography (CT) guidance (for lung lesion) or ultrasonography (USG) guidance (for liver lesion), a single stainless steel brachytherapy needle was inserted percutaneously in patients with lesion size =4 centimeter (cm) and multiple needles were inserted in patients of lesion size >4cm. A single dose of 15 Gy to 20 Gy with HDR ISBT was prescribed at the periphery of the lesion. The needles were removed just after treatment. Patients were kept under observation for 24 h after treatment. Results: The median size of the lesion was 6.5 cm. In all the cases of liver lesion, more than 75% shrinkage of tumor volume in follow-up at 6 mo was observed. It was more than 50% for lung lesion. None of the patients had developed significant complications as on the median follow up period of 15 mo (ranges 3-27 mo). Conclusions: Percutaneous CT-guided high-dose-rate interstitial brachytherapy is a minimally invasive, safe, and feasible treatment option with minimal complication for inoperable, chemo resistant, advanced cancers with encouraging treatment outcomes. [ABSTRACT FROM AUTHOR]

Purpose: A comparison of simultaneous integrated boost (SIB) with sequential boost (SEQ) using intensity-modulated radiotherapy along with concurrent cisplatin in locally advanced head and neck cancer (HNC) was made with regard to their survival outcomes and toxicity profile. Materials and Methods: A total of 34 patients were enrolled between October 2016 and March 2019. They were randomized into two arms, SIB and SEQB. All patients were treated with 6 MV photon beam on Linear Accelerator with weekly concurrent cisplatin at 35 mg/m2. Overall survival (OS) and disease-free survival (DFS) were the primary end points and acute and late toxicities were the secondary end points. Results: The median follow-up period was 40.6 and 37.3 months for SIB and SEQB, respectively. At the end of 5 years, the median OS was 40.6 and 37.3 months (P = 0.947) and the median DFS was 35.1 and 37.3 months in the SIB and SEQB arms, respectively (P = 0.991). Complete response at 3 months was 64.7% and 76.5% and partial response was 23.5% and 17.6%, whereas progressive disease was 11.8% and 5.9% in SIB and SEQB arms, respectively. Acute dermatitis, mucositis, dysphagia, and salivary gland toxicities were higher in the SIB arm compared to the SEQB arm. Conclusion: SIB and SEQ arms were comparable in terms of OS and DFS. However, the acute toxicities were higher in the SIB arm, although the difference was not significant, compared to the SEQB arm. [ABSTRACT FROM AUTHOR]

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]

Purpose: To find out the simple relationship between Total Reference Air Kerma (TRAK) and various isodose volumes. Calculated isodose volumes were compared with experimental data for revised Manchester and International Commission on Radiation Units and measurements (ICRU)-89 Point A-based treatment plans. The accuracy of the formula was compared with the results of other relationships available in the literature.Materials and Methods: Dosimetric data from 62 intracavitary brachytherapy (ICBT) treatment plans of 31 patients with cervical cancer were studied. Each patient had treatment plans normalized to revised Manchester and ICRU-89 Points A (Aflange and Aicru89). For each treatment plan, TRAK values, V350, V700, V1050, and V1400 were obtained. The modeling curve was plotted between Isodose volume (Vd) and the ratio of d/TRAK obtained from Aflange plans to get a mathematical relation. The results of this formula were compared with the experimental data and outcomes of other formulas available in the literature. A paired-sample t-test was performed to assess the statistical significance.Results: In the case of revised Manchester-based Aflange normalization plans, the mean isodose volume of V350, V700, V1050, and V1400 were 285.98 ± 32.3 cm3, 101.96 ± 10.63 cm3, 52.71 ± 4.72 cm3, and 31.44 ± 2.33 cm3 respectively. Likewise, for ICRU-89 based Aicru89 normalization plans, the mean isodose volumes of V350, V700, V1050, and V1400 were 304.11 ± 26.17 cm3, 108.88 ± 8.29 cm3, 56.62 ± 3.69 cm3 and 34 ± 2.23 cm3 respectively. The mean difference was significant. The Mathematical relationship developed was [INLINE:1]. No correlation was found between TRAK and D0.1cm3,D2cm3 for organs at risk.Conclusions: The developed formula calculated isodose volumes within the accuracy of ± 3% in ICBT plans. [ABSTRACT FROM AUTHOR]

Brachytherapy applicators have come a long way since Danlos developed early intracavitary applicators to treat cervical cancer patients. Therefore, this review will help in the neoteric designs of intracavitary applicators. A detailed literature survey of the gynecological brachytherapy applicators from the era of preloading to conceptual intensity-modulated brachytherapy applicators has been carried out. Depending on the extent of the disease and patient anatomy, the selection of brachytherapy applicators plays a pivotal role in the treatment of cervical cancer. Furthermore, the selection of the applicators is also based on the imaging modalities to be used for applicator reconstruction and treatment planning. Dose acceleration in the target and reduction in nearby organs at risk can be optimized using an applicator having the capabilities of intensity-modulated brachytherapy. Now, three-dimensional printed applicators are used for patient-specific tailor-made treatment and they are fast replacing the old conventional applicators. Newer advancements in technology have greatly influenced the neoteric designs of intracavitary brachytherapy applicators. [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]

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]

The relative output factor for small field photon beams with EBT3 (External beam therapy, Gafchromic ™) Radiochromic film were obtained using indigenously developed a program in MATLAB. MLC and JAWS created square small field sizes for dosimetry. To calibrate Radiochromic film, we have cut the film into several small segments of 6 × 6 cm2. These small pieces of film were irradiated to known doses ranging from 25 to 300 cGy by SAD technique using 6 MV photon beam from Linear accelerator. A Program in MATLAB was written to analyze the scanned film data and all the images of the films were imported into this Program. To validate the accuracy of calibration curve, radiochromic films were irradiated with different field sizes of 10 × 10 cm2, 15 × 1 5 cm2, 20 × 20 cm2 to known dose of 200 cGy each by SAD technique. Field sizes were defined using two methods, in the first method fields were defined using X-Y collimator Jaws with the MLC retracted to their maximum position. In the Second method, MLCs were used to define square field sizes of 1 × 1 cm2 to 5 × 5 cm2, 10 × 10 cm2 and 15 × 15 cm2. Calibration curve created using gafchromic film show percentage variation between measured and delivered dose within 3% of standard field size. Output factors measured by Gafchromic EBT3 film showed close agreement with those measured using the other detector for field sizes of 2.0 × 2.0 cm2 and above. EBT3 film has properties such as linear response, energy, and dose-rate independence. It makes it suitable detector for small field dosimetry. Our Indigenous developed MATLAB Program for film dosimetry gave the desired results. From this study, we can conclude that EBT3 film can be used for relative output factors ranging from small field to large fields. [ABSTRACT FROM AUTHOR]

Aim Of Study: To establish trends of estimation error of dose calculation by anisotropic analytical algorithm (AAA) with respect to dose measured by thermoluminescent dosimeters (TLDs) in air-water heterogeneity for small field size photon.Materials and Methods: TLDs were irradiated along the central axis of the photon beam in four different solid water phantom geometries using three small field size single beams. The depth dose profiles were estimated using AAA calculation model for each field sizes. The estimated and measured depth dose profiles were compared.Results: The over estimation (OE) within air cavity were dependent on field size (f) and distance (x) from solid water-air interface and formulated as OE = - (0.63 f + 9.40) x2+ (-2.73 f + 58.11) x + (0.06 f2 - 1.42 f + 15.67). In postcavity adjacent point and distal points from the interface have dependence on field size (f) and equations are OE = 0.42 f2 - 8.17 f + 71.63, OE = 0.84 f2 - 1.56 f + 17.57, respectively.Conclusion: The trend of estimation error of AAA dose calculation algorithm with respect to measured value have been formulated throughout the radiation path length along the central axis of 6 MV photon beam in air-water heterogeneity combination for small field size photon beam generated from a 6 MV linear accelerator. [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]