Total Rectal Dose Estimated From Radical External Beam and Intracavitary Radiation Therapy for Uterine Cervical Cancer Using Deformable Image Registration Method

Abstract

Patients with uterine cervical cancer are generally treated with both intracavitary brachytherapy (ICBT) and external beam radiotherapy (EBRT) using a midline block in Japan. However the actual total dose delivered to the rectum is hard to calculate, because the location of the high dose region may not be identical for each fraction. To calculate the cumulative dose more accurately, we have adapted the deformable image registration (DIR) method and analyzed the difference between the cumulative rectal dose by adding rectal D2cc (simple rectal D2cc) and the cumulative rectal D2cc estimated on the basis of DIR (DIR-based rectal D2cc).