Feasibility and Clinical Evaluation of a Custom-Fabricated Radiotherapy Headrest:A Comparative Study with Commercial Devices

Background: Headrest immobilization devices are specialized tools that support and stabilize the patient’s head during radiotherapy. For Brain and Head & Neck cancer patients, QFix® Silverman Head Support has been used, and as per requirement, Size-C is used for almost 60% of patients. Due to intensive use, the Size-C head support has become almost unusable which necessitated arranging a new set. This study has made a pair of Size-C head supports with ThermoLyn PE 200 material. The aim of this study is to investigate the feasibility of using the custom-made headrest and also to compare it with two other commercial head supports. Material and Methods: The ThermoLyn Support-C has been hand-made by 2 mm-thick polyethylene material (ThermoLyn sheet), plaster of Paris, heating and other cutting and tuning machineries. For further feasibility study of the ThermoLyn Support-C, a human brain shape has been formed with a brain thermoplastic mask and QFix® Moldcare Head Cushions. Three separate CT simulations have been taken with CT Simulator, with each three-head support and image artifact is keenly observed. 3DCRT and VMAT plan has been done for each Head Support-C for analysis. For beam transmission, check SNC plastic slab phantom, iba® 0.6cc FC65-P ionization chamber, and Dose-X electrometer have been used. Results & Discussion: The positional setup variation of dummy treatment plans has been found within a 2 mm shift. The beam transmission factor was 94.8%, 95.3% and 96.7% for ThermoLyn, QFix® and CIVCO® headrests, respectively. Gamma Index pass rate for test VMAT plan has been found to be 98.8%, 99.9% and 97.0%, respectively. The CI, HI and UI values are also found in an acceptable range. Randomly, 10 persons volunteered to check the suitability of the ThermoLyn Support-C and reported no significant change with other devices. After evaluating the image artifacts, volunteer feedback, dosimetric & geometrical analysis, five patients with whole brain metastasis have been treated by 3DCRT plans with two lateral parallel opposed beams with ThermoLyn Support-C. No discomfort has been reported by any of the patients compared to the other two devices. Conclusions: The in-house developed ThermoLyn Support-C showed as a viable alternative for commercial headrests, introducing no significant image artifacts and geometrical or dosimetric inaccuracies. Based on the facilities’ availability adoption of such custom supports can particularly benefit radiotherapy centers in resource-constrained settings while maintaining high standards of patient care and immobilization accuracy.