ABSTRACT
Introduction: The aim of the present study was to compare two immobilization systems for comparison of setup errors in targeted radiotherapy. Methods: Retrospective analysis was done for the patients undergoing radiotherapy from May 2012 to December 2018 at our institution. Immobilization was performed on 30 patients sessions (Vacuum cushion i.e., Vac-Lok™ = 15; Thermoplastic mould i.e., Pelvicast pelvic masks = 15). A total of 763 cone-beams were analysed. The target lesion location was verified by cone-beam computed tomography (CBCT) prior to each session, with displacements assessed by CBCT simulation prior to each treatment session. Systematic setup errors, random setup errors, isocenter deviations in the Medio-lateral (ML), Supero-inferior (SI), Antero-posterior (AP), Rotation (yaw) directions of the patient position was calculated. Results: On comparing the Vac-Lok™ and Pelvicast pelvic masks group with respect to Systematic and random error in the lateral, longitudinal, vertical and YAW direction, no statistically significant difference was seen except the random error in YAW direction (P=0.037, Unpaired t-test). There was no difference observed in comparing the isocentric deviation. Conclusion: It was inferred and concluded that using a vacuum cushion for pelvic radiotherapy provides no added benefit compared to using a thermoplastic mould. Thermoplastic mould is recommended for patients receiving pelvic radiotherapy to improve overall reproducibility
ABSTRACT
CONTEXT: The most commonly prescribed conventional fractionation radiotherapy uses 1.8–2.2 Gy per fraction for five fractions in a week. Many times, unwanted interruptions are encountered, which ultimately affect the local control and overall survival. AIMS: The present retrospective study was carried out to study the compliance to radiotherapy at our institute and to determine various factors related to it. PATIENTS AND METHODS: The present retrospective study was carried out at the department of Radiotherapy, SMS Medical College and attached group of hospitals, Jaipur; in patients who were treated with curative intent with conventional fractionation radiotherapy over telecobalt machine from January 2017 to April 2017. Noncompliance was studied for association with various factors such as age, sex, site of primary disease, stage of tumor, distance patients had to travel to receive treatment, administration of concurrent chemotherapy, and financial burden of the treatment. RESULTS: Of 203 patients, 138 were of head-and-neck cancer, 42 of cervical cancer, and 23 of breast cancer. The cumulative incidence of noncompliance was 12.8% (15.9% for head-and-neck cancer, 7.2% for cervical cancer, and 4.4% for breast cancer). Statistically significant association was found between noncompliance and higher age of the patients (P = 0.07), male gender (P = 0.002), advanced stage (P = 0.004), administration of concurrent chemoradiotherapy (CCRT) (P < 0.001), and greater distance patients had to travel for radiotherapy (P = 0.03). CONCLUSIONS: The factors with which noncompliance is significantly associated in the present study are higher age, male gender, advanced stage of tumor, administration of CCRT, and greater distance patients had to travel to avail radiotherapy.