Cone Beam CT for Daily Image Guidance - Prostate Cancer

A Phase II Feasibility Study of Cone Beam Computed Tomography for Daily Image Guidance in Patients Receiving Dose Escalated Conformal Radiation Therapy for Prostate Cancer

Conformal dose escalated radiation therapy (CRT) is standard treatment for patients with low and intermediate risk prostate cancer. CRT requires accurate daily localization of the prostate prior to treatment to correct for prostate motion and set-up errors. Cone beam computed tomography (CT) can accurately localize fiducial markers within the prostate. Cone Beam CT also provides important information on daily position of organs within the pelvis. This study aims to assess the feasibility of cone beam CT for daily localization of the prostate as well as document changes in size and location of pelvic organs during an entire course of CRT.

To evaluate the feasibility of cone beam CT for daily on-line image guidance in patients receiving conformal radiation therapy for prostate cancer.

To measure the amount of interfraction movement of the prostate and seminal vesicles with current bowel regimen of daily milk of magnesia.

To measure the amount of interfraction movement and deformity of the rectum and bladder with current bowel regimen of daily milk of magnesia.

To develop a technique for delivery of radiation therapy that reduces normal tissue toxicity, based on rectal and bladder avoidance models.

Inclusion Criteria: Diagnosis of adenocarcinoma of the prostate Patient undergoing dose escalated conformal external beam radiation therapy Low or intermediate risk prognostic factors (PSA 20 or less, Gleason score <8, Clinical T category <T3, Clinical N category 0 or X, M category 0 or X Age 18 years or older ECOG performance status 0 or 1 Informed consent Exclusion Criteria: Inflammatory bowel disease or collagen vascular disease