Trial Information

The Use Of Multiple CT Scans To Reduce Target Positioning Errors In Patients Undergoing External Beam Radiotherapy Treatment For Prostate Cancer

OBJECTIVES:

- Compare the accuracy of radiotherapy delivery using multiple CT scans to guide patient
positioning vs the standard portal image guided procedure in patients with prostate
cancer undergoing external beam radiotherapy.

- Determine the reduction in the proportion of patients with large target positioning
errors using the CT-guided procedure.

- Determine organ motion and setup errors over the course of radiotherapy in order to
develop efficient clinical intervention strategies in these patients.

OUTLINE: Patients undergo radiotherapy over 9 weeks. Patients undergo a CT scan immediately
prior to receiving radiotherapy on treatment days 3-8 and then weekly thereafter. On 3
different days, patients also undergo CT scan immediately after radiotherapy. If the CT
scans indicate a correction that exceeds the action level currently in effect, then
beginning with the next treatment, the patient's position with respect to the radiation
field is adjusted.

PROJECTED ACCRUAL: A total of 25 patients will be accrued for this study within 2 years.