Randomized Trial of Prostate Only or Pelvic RT in High Risk Prostate Cancer (POP-RT)

Prospective Phase III Randomized Trial of Prostate Only or Whole Pelvic RadioTherapy in High Risk Prostate Cancer (POP-RT) Trial

Evidence to justify the use of the pelvic field is lacking for men with high risk localized prostate cancer. An additional randomized study is needed in men with a potential risk of nodal involvement to test the hypothesis that the use of the pelvic field contributed to the benefit observed in those studies. This trial aims to compare the outcomes with whole pelvis RT and Prostate alone RT in patients with High risk, non metastatic Prostate cancer with a Lymph nodal >20% with Primary 5 year Biochemical failure free survival and Secondary Disease free survival, overall survival, Acute toxicity, Late toxicity and QOL Patients will be randomized to one of two arms Arm 1 Whole pelvis radiotherapy and Arm 2 Prostate only radiotherapy. The Dose prescription will be 66 Gy in 25 fractions will be prescribed for the prostate PTV in Arm 2 an additional 50 Gy in 25 fractions for nodal PTV in patients in Arm 1. An overlap volume at rectal-prostate interface will receive 64 Gy/25#. All patients will receive hormone therapy starting at least 8 weeks prior to the beginning of radiotherapy. They will continue the hormone therapy and later for a total duration of 2-3 years.

66-68 Gray (Gy) in 25 fractions will be prescribed for the prostate PTV and 50 Gy in 25 fractions to nodal region .

Biochemical failure is defined using the standard Phoenix consensus definition i.e. PSA>2ng/ml over the nadir PSA

Inclusion Any age according to the fitness estimated by the Physician Physician estimated life expectancy > 5 years Biopsy proven Adenocarcinoma of prostate High risk prostate cancer based on Staging and Risk of Pelvic Nodal Metastases ≥ 20% as per the Roach formula (2/3 PSA) + [(GS - 6) x 10] If Gleason Score 8-10 - Any PSA, T1- T3a N0 M0 If Gleason Score 7 - PSA > 15, T1-T3a N0 M0 If Gleason Score 6 - PSA > 30, T1-T3a N0 M0 T3b-T4a N0 M0, Any Gleason Score, Any PSA Ability to receive long term hormone therapy/ Orchidectomy KPS ≥ 70 (see appendix) Estimated life expectancy > 5 years No previous history of malignancy ≤5 years No prior history of therapeutic irradiation to pelvis Patient willing and reliable for follow-up and QOL No major co morbidities preventing radical treatment Signed study specific consent form Exclusion Any histopathology other than Adenocarcinoma Contraindication to Pelvic Radiotherapy like Inflammatory Bowel Disorders No prior history of pelvic surgery Uncontrolled diabetes Uncontrolled cardiac co morbidity Presence of nodal or distant metastatic disease

Murthy V, Maitre P, Bhatia J, Kannan S, Krishnatry R, Prakash G, Bakshi G, Pal M, Menon S, Mahantshetty U. Late toxicity and quality of life with prostate only or whole pelvic radiation therapy in high risk prostate cancer (POP-RT): A randomised trial. Radiother Oncol. 2020 Apr;145:71-80. doi: 10.1016/j.radonc.2019.12.006. Epub 2020 Jan 7.