Dose Escalation Study Using Ultra-Hypofractionated, Image-Guided, Intensity-Modulated Radiotherapy in Prostate Cancer

A standard dose escalation design is utilized, with the initial treatment assigned as 6.5 Gy/fraction for five fractions to a total dose of 32.5 Gy. For any given dose tier, an initial cohort of 30 patients will be treated. However to adjust for potentially inevaluable patients who dropout prior to a full toxicity collection to assess potential DLTs enrollment of up to five additional patients per cohort can occur, per PI's discretion. Dose escalation will proceed if \< 10% of the 30 patients treated per tier exhibit any dose limiting toxicity (DLT) once the entire tier cohort has a minimum follow-up of 3 months and half the tier cohort has a minimum follow-up of 6 months. Dose escalation to the next tier will occur by increasing the dose per fraction by 0.5 Gy while keeping the fraction number constant at 5, leading to a total dose increase of 2.5 Gy per dose tier.