PSMA-PET Guided Hypofractionated Salvage Prostate Bed Radiotherapy (PERYTON)

PSMA-PET Guided Hypofractionated Salvage Prostate Bed Radiotherapy of Biochemical Failure After Radical Prostatectomy for Prostate Cancer

After radical prostatectomy approximately 15-40% of men develop a biochemical recurrence (BR) within 5 years. The standard treatment of post-prostatectomy BR is salvage external beam radiation therapy (sEBRT). sEBRT can provide long-term disease control; with 5 year biochemical progression-free survival (bPFS) up to 60% and with most treatment failures in the first 2 years after sEBRT. The main goal of this project is to investigate whether the oncologic outcome in patients with post-prostatectomy recurrent PCa can be improved, by increasing the biological effective radiation dose using a hypofractionated schedule of 20 x 3 = 60 Gy. The study is designed as a prospective open phase III randomized multicenter trial. All patients with biochemical recurrence with a PSA < 1.0 ng/ml after radical prostatectomy for prostate cancer without evidence of lymph nodes or distance metastases will be included. PSA progression after prostatectomy defined as two consecutive rises with the final PSA > 0.1 ng/mL or three consecutive rises will be included. All eligible patients will be randomized to one of the following two treatment arms: Arm 1 = Conventional sEBRT to apply a total dose of 70 Gy in 35 daily fractions of 2 Gy during 7 weeks. Arm 2 = Hypofractionated sEBRT to apply a total dose of 60 Gy in 20 fractions of 3 Gy during 4 weeks. The primary endpoint will be the 5-year progression-free survival (PFS) after treatment.

Defined as biochemical progression, clinical progression, loco-regional or distant progression or start with hormonal therapy, whichever occurs first

As assessed using physician-reported score: Common Terminology Criteria for adverse events version 5.0 (CTCAE-5) toxicity score with a scale of 1 - 4.

As assessed using patient-reported questionnaires: measurend with European platform of cancer research-QLQ C30

Time from randomisation to the date of metastases reported by CT scan, MRI scan or PSMA-PET/CT during the follow up (date scan).

Using patient-reported questionnaires (Radiation Therapy Oncology Group (RTOG) / European platform of cancer research (EORTC) toxicity questionnaires with grade 1 to 4).

Using patient-reported questionnaires (Radiation Therapy Oncology Group (RTOG) / European platform of cancer research (EORTC) toxicity questionnaires with grade 1 to 4).

Using patient-reported questionnaires (Radiation Therapy Oncology Group (RTOG) / European platform of cancer research (EORTC) toxicity questionnaires with grade 1 to 4).

As assessed using patient reported quatinnaires: European platform of cancer research-Quality of Life Questionnaire - Prostate Cancer Module (PR 25).

Inclusion Criteria: Patients with prostate adenocarcinoma treated with radical prostatectomy; Tumour stage pT2-4, R0-1, pN0, or cN0, cNx according to the UICC TNM 2009, only with Gleason score available; No lymph node or distant metastases. A recent PSMA-PET scan (< 60 days) without evidence of lymph node or distant metastases; PSA progression after prostatectomy defined as two consecutive rises with the final PSA > 0.1 ng/mL or 3 consecutive rises. The first value must be measured at least 6 weeks after radical prostatectomy; PSA at inclusion < 1.0 ng/mL; WHO performance status 0-2 at inclusion; Age at inclusion between 18 and 80 years; Written (signed and dated) informed consent prior to registration. Exclusion Criteria: Prior pelvic irradiation, (chemo)hormonal therapy or orchiectomy; Previous or concurrent active invasive cancers other than superficial non-melanoma skin cancers; Patients with positive nodes or with distant metastases based on the surgical specimen of lymphadenectomy or the following minimum diagnostic workup: PSMA-PET/CT scan, 60 days prior to registration; Double-sided metallic hip prosthesis; Inability or unwillingness to understand the information on trial-related topics, to give informed consent or to fill out QoL questionnaires.

Staal FHE, Janssen J, Brouwer CL, Langendijk JA, Ng Wei Siang K, Schuit E, de Jong IJ, Verzijlbergen JF, Smeenk RJ, Aluwini S. Phase III randomised controlled trial on PSMA PET/CT guided hypofractionated salvage prostate bed radiotherapy of biochemical failure after radical prostatectomy for prostate cancer (PERYTON-trial): study protocol. BMC Cancer. 2022 Apr 15;22(1):416. doi: 10.1186/s12885-022-09493-5.