Baş-Boyun ve Beyin Tümörü IMRT Uygulamasında Vakumlu Boyun Yastığı (VBY)’ nın Set Up Doğruluğuna Katkısı

Abstract

Aim: An effective immobilization is warranted to minimize set up deviations while treating head & neck (HN) and brain tumors with intensity modulated radiotherapy (IMRT). In this study we evaluated the effectiveness of thermoformable vacuum head cushion (TVHC) on immobilization of these patients via weekly electronic digital port films (EDPF). Material and Method: Twenty patients treated with IMRT for HN and Brain tumors were enrolled in the study. Thermoplastic mask with additional standard plastic head rest (n:10) in Group A or TVHC supporting the head and neck region (n:10) in Group B were used for immobilization. Weekly EDPF images were obtained on the linear accelerator. Set-up displacements in latero-medial, anteroposterior and cranio-caudal directions in these images were compared with variation data of first treatment. Results: When each group was analyzed in terms of deviations in all 3 directions, deviations calculated in anteroposterior and craniocaudal directions were significantly higher for TVHC group (p:0.039 and p:0.002 respectively). Deviations >4mm in all three directions were also analyzed and similarly, higher rates of >4mm deviations were recorded for TVHC group in anteroposterior and craniocaudal directions (p:0.023 and p:<0.001 respectively) which of both were also statistically significant. Conclusion: We found that TVHC utilization in HN and brain IMRT for immobilization leads to significantly higher set-up deviations so future investigations with larger patient populations and evaluating set up accuracy via more sensitive alignments are needed to suggest TVHC for utilization in daily clinical practice.