A comparative study between two different dose fractionation schedules of cobalt-60-based HDR intracavitary brachytherapy in carcinoma cervix stages IIB-IIIC1.

INTRODUCTION: High dose rate (HDR) intracavitary brachytherapy (ICBT) is an integral element in the treatment of carcinoma uterine cervix. The main objective of brachytherapy in carcinoma cervix is to deliver a lethal dose to tumor cells without inducing unacceptable damage to the surrounding normal tissue. Because the absorbed dose falls off rapidly, higher doses can be safely delivered to the targeted tissue over a short time. The quest for optimum dose and fractionation schedule in HDR ICBT is still ongoing, and there is no uniform consensus. This study aimed to assess the acute dose-related toxicities of HDR brachytherapy schedule of 7 Gy x 3 fractions over 6 Gy x 4 fractions in the treatment of cervical cancer. OBJECTIVE: The aim of this study was to study the acute treatment-related gastrointestinal (GI) and genitourinary (GU) toxicities between two HDR brachytherapy regimens. MATERIAL AND METHODS: This is a prospective institutional study carried out from May 2018 to September 2018. In this time period, 66 patients of cervical cancers fulfilling our inclusion criteria were treated with concurrent chemoradiation (CCRT) following brachytherapy. During treatment, patients were randomized to arm A-7 Gy per fraction for three fractions and arm B-6 Gy per fraction for four fractions. Acute GI and GU toxicities were assessed using Common Terminology Criteria for Adverse Events (CTCAE) Version 4.03. All patients were kept for follow-up for 3 months in this study. RESULTS: There is no statistically significant difference between the two arms for acute GI and GU toxicities, and the results were comparable. CONCLUSIONS: Considering the increased hospital burden of locally advanced cervical cancer patients in the Indian context, the HDR brachytherapy schedule of 7 Gy per fraction is preferable to 6 Gy per fraction for a lesser fractionation schedule.

Comparison of sequential versus simultaneous integrated boost of volumetric modulated arc therapy in treatment of oropharyngeal carcinoma.

OBJECTIVE: Volumetric modulated arc therapy (VMAT) is a useful treatment technique that can reduce treatment time while producing improved dose distribution to target structures. The main aim of the study is to evaluate the outcome of oropharyngeal cancer patients treated with VMAT, sequential (SEQ) versus simultaneous integrated boost (SIB) technique in terms of survival and failures and to assess late radiation toxicities with their dosimetric parameters. MATERIAL AND METHODS: Total 54 patients of histologically proved oropharyngeal cancer patients treated by definitive radiotherapy using VMAT technique in January 2019 to December 2020 were followed up and evaluated in terms of survival, patterns of failure and late radiation toxicities by RTOG toxicity criteria. RESULTS: After a median follow up of 12 months, overall survival (OS) and disease free survival (DFS) were 64.8% and 48.1% respectively. In terms of patterns of failure, 44.4% showed local recurrence, 7.4% as regional relapse and 3.7% showed distant metastasis. While comparing sequential versus SIB, no significant difference was found in OS (64.9% vs. 59.8%, p = 0.689), DFS (52.8% vs. 35.3%, p = 0.266), local control (LC) (58.3% vs. 47.1%, p = 0.437) and regional control (RC) (94.3% vs. 88.2%, p = 0.151) respectively. Among late radiation toxicities, the most common were xerostomia (42.2% for SEQ and 24.2% for SIB group), dysphagia (33.3% for SEQ and 15.1% for SIB group) and hoarseness of voice (15.1% for SEQ and 12.1% for SIB group). CONCLUSION: SIB technique proved better than SEQ technique in terms of pattern of failure or late toxicity, but no significant difference can be reported.

A dosemetric and radiobiological impact of VMAT and 3DCRT on lumbosacral plexuses, an underestimated organ at risk in cervical cancer patients.

Background: The purpose of this study was to evaluate dosimetric and radiobiological difference between volumetric modulated arc therapy (VMAT) and 3-dimensional conformal radiotherapy (3DCRT) in organ at risk (OAR) lumbosacral plexus (LSP) in cervical cancer patients. Materials and methods: 30 patients of cervical cancer who were treated using 3DCRT or VMAT along with chemotherapy followed by brachytherapy were enrolled. LSP was delineated retrospectively. Dosimetric and radiobiological difference was evaluated. Patients were followed for radiation induced lumbosacral plexopathy (RILSP). Results: Median follow-up was 12 months (3-16 months). 53.3% of patients were treated by 3DCRT and 46.7% by VMAT. The mean (±SD) LSP volume: 119.03 ± 15 cm3. The mean volume percentages (%) of the LSP: V5, V10, V20, V30, V40, V50, V55, and V60 were 100%, 99.8%, 99.2%, 94.3%, 84.03%, 59.7%, 0%, 0%, respectively. All patients received doses to the LSP in excess of 50 Gy, one patient received 55 Gy. A statistically significant difference was observed in the median value of V20, V30, V40, V50, D50, P2, P4, P7, P8, P9, and P10 across two different techniques of radiotherapy - VMAT and 3DCRT. None of the patients presented with RILSP. NTCP value was less in VMAT plans compared to 3DCRT, which is also statistically significant. Conclusion: RILSP is a rare and often refractory complication of pelvic radiotherapy. Advance radiotherapy technique with proper OAR delineation and constraint can prevent the occurrence of RILSP. VMAT has potential benefits for the probability of dose reduction in LSP. Further studies are required focusing on dose distribution in LSP-OAR and radiotherapy modality.

Assessment of knowledge, attitude, practices and distress level of cancer patients in COVID-19 pandemic: A cross-sectional study.

The diagnosis and treatment of cancer can be an extremely stressful experience for the patient. COVID-19 pandemic has further created an environment of stress and anxiety amongst cancer patients. A cross-sectional study was conducted from March 2020 to May 2020 using google forms to assess the knowledge, distress level, practices, and attitude toward the COVID-19 pandemic in cancer patients. It was observed that the females and elderly patients (> 55 years) were more knowledgeable about the COVID-19 pandemic. Also, females were more prone to emotional stress compared to males. While the younger age group (18-35 years) had a more hard time in dealing with family-related issues compared to other age groups. Therefore, the younger age group (18-35 years) and female gender being more prone to distress, warrant more attention from health care staff and caretakers. Moreover, the study highlights the need for mental and general health screening and intervention to balance the oncological care and COVID-19 situation.

Dosimetric comparison of coplanar and non-coplanar volumetric-modulated arc therapy in head and neck cancer treated with radiotherapy.

PURPOSE: To evaluate the dosimetric variations in patients of head and neck cancer treated with definitive or adjuvant radiotherapy using optimized non-coplanar (ncVMAT) beams with coplanar (cVMAT) beams using volumetric arc therapy. MATERIALS AND METHODS: Twenty-two patients of head and neck cancer that had received radiotherapy using VMAT in our department were retrospectively analyzed. Each of the patients was planned using coplanar and non-coplanar orientations using an optimized couch angle and fluences. We analyzed the Conformity Index (CIRTOG), Dose Homogeneity Index (DHI), Heterogeneity Index (HIRTOG), low dose volume, target and organs-at-risk coverage in both the plans without changing planning optimization parameters. RESULTS: The prescription dose ranged from 60 Gy to 70 Gy. Using ncVMAT, CIRTOG, DHI and HIRTOG, and tumor coverage (ID95%) had improved, low dose spillage volume in the body V5Gy was increased and V10Gy was reduced. Integral dose and intensity-modulated radiation therapy factor had increased in ncVMAT. In the case of non-coplanar beam arrangements, maximum dose (Dmax) of right and left humeral head were reduced significantly whereas apex of the right and left lung mean dose were increased. CONCLUSION: The use of ncVMAT produced better target coverage and sparing of the shoulder and soft tissue of the neck as well as the critical organ compared with the cVMAT in patients of head and neck malignancy.

Adjuvant Irradiation in Carcinoma Breast Patients: Comparison of 3DCRT and Semi-automated Complex VMAT Hypofractionated Plans.

OBJECTIVE: Adjuvant radiotherapy is required for most post MRM breast cancer patients. Aim of treatment is to target radiation to region of interest while sparing Organs at Risk (OARs). Attempts are being made to decrease dose to OARs without compromising target coverage by evolving radiation techniques. In this study, a comparison of traditional 3DCRT plans is done with semi-automated complex VMAT plans for dose received by OARs namely Contralateral Breast (CLB), Ipsilateral lung (I/LL), and Contralateral Lung (C/LL). MATERIALS AND METHODS: It was planned for 30 post MRM breast cancer patients for chest wall, ipsilateral axilla and supraclavicular lymph node. The PTV dose was 42.5 Gy in 16 fractions, 2.66 Gy/fraction, 5 days a week. For each patient traditional 3DCRT and semi-automated complex VMAT plans (conventional + tangential VMAT plans) were prepared and evaluated by radiation oncologists. RESULTS: Dose evaluation of CLB shows higher Dmax for 3DCRT plans, while, Dmean was lower for the 3DCRT plan. Difference between D2 was not significant. V2.5 was significantly less in 3DCRT, while, difference between V5 and V10 were not significant. For C/LL Dmean, V2.5, V5, and V10 were higher for the VMAT plan. For I/LL Dmean, V5 and V10 were higher, while V20 and V30 were lower for VMAT plans. DISCUSSION AND CONCLUSION: The VMAT technique described here is a useful treatment option available for difficult planning situations. OARs stated above had a mixed result showing VMAT plans to be inferior at lower dose metrics, while, superior at higher dose metrics.