Image-guided radiotherapy for prostate cancer. Implementation of ultrasound-based prostate localization for the analysis of inter- and intrafraction organ motion.

Purpose: To evaluate inter- and intrafraction organ motion with an ultrasound-based prostate localization system (BAT) for patients treated with intensity-modulated radiotherapy for prostate cancer.

Patients And Methods: After set-up to external skin marks, 260/219 ultrasound-based alignments were performed before/after irradiation in 32 consecutive patients. Image quality was classified as good, satisfactory or poor.