Computed Tomography-Guided Stereotactic Body Radiation Therapy With Intrafraction Motion Monitoring for the Treatment of Localized Prostate Cancer, ILLUSION Trial

PRIMARY OBJECTIVE: I. To determine the acute physician-scored GU toxicity associated with CT-guided SBRT utilizing a 2mm prostate ± seminal vesicles planning target volume (PTV) margin for localized prostate cancer. SECONDARY OBJECTIVES: I. To determine the acute physician-scored GI toxicity associated with the intervention. II. To determine the late physician-scored toxicity associated with the intervention. III. To determine the patient-reported quality of life outcomes associated with the intervention. IV. To determine the 5-year biochemical recurrence-free survival (BCRFS) associated with the intervention. V. To evaluate intrafraction prostate motion using on-board imaging data acquired during this trial in conjunction with prior data, described above. OUTLINE: Patients undergo CT-guided SBRT with intrafraction motion monitoring over 5 fractions every other day, or on consecutive days, if necessary, in the absence of disease progression or unacceptable toxicity. Patients also undergo CT and MRI on study and blood sample collection throughout the study. After completion of study treatment, patients are followed up at 1 and 3 months, every 3 months for the first year, every 6 months for a minimum of 5 years, and then annually thereafter.