Implementation of transabdominal ultrasound image guided conformal intensity modulated radiotherapy

摘要

PURPOSE: Optically guided ultrasound imaging has been used in our department since 2003 in order to implement an on line correction scheme in intensity modulated radiation therapy of prostate carcinoma. PATIENTS AND METHODS: The corrections observed during the initial time period of the system (17 patients) are compared to those observed more recently (10 patients). Treatment margins are calculated. RESULTS: Overall systematic errors decreased between 2003 and 2006, and are presently statistically not different from zero. Random errors remain the same (max 4.3 mm). Proposed margins are 7 mm both in lateral and longitudinal direction and 8.4 mm in anteroposterior. CONCLUSION: Ultrasound can be used for on line correction of both positioning and internal organs motion errors and allows reduction of the margins between clinical and planning volume.