Intra-fractional uncertainties in image-guided intensity-modulated radiotherapy (IMRT) of prostate cancer.

Purpose: To evaluate intra-fractional uncertainties during intensity-modulated radiotherapy (IMRT) of prostate cancer.

Patients And Methods: During IMRT of 21 consecutive patients, kilovolt (kV) cone-beam computed tomography (CBCT) images were acquired prior to and immediately after treatment: a total of 252 treatment fractions with 504 CBCT studies were basis of this analysis. The prostate position in anterior-posterior (AP) direction was determined using contour matching; patient set-up based on the pelvic bony anatomy was evaluated using automatic image registration.

Reliability of the bony anatomy in image-guided stereotactic radiotherapy of brain metastases.

Purpose: To evaluate whether the position of brain metastases remains stable between planning and treatment in cranial stereotactic radiotherapy (SRT).

Methods And Materials: Eighteen patients with 20 brain metastases were treated with single-fraction (17 lesions) or hypofractionated (3 lesions) image-guided SRT. Median time interval between planning and treatment was 8 days.