Salvage Ultrahypofractionated Postoperative External Radiotherapy For Biochemical Recurrence

Recently, the Radiation Oncology Department at Fondazione IRCCS San Gerardo dei Tintori has been renovated and has been equipped with cutting edge technologies to treat prostate cancer. Specifically, the now available technology can track organ motion in real time, thus allowing improved precision in radiation delivery, with increased protection of the surrounding organs at risk. These facilities have already enabled the kickoff of two prospective observational trials, the ABRUPT and the POPART, which are currently ongoing in the treatment of intact prostate and the biochemical recurrence, respectively. Taken together, these observations provide the basis for the prospective clinical study herein proposed. Patients enrolled in the study will undergo salvage single stereotactic RT to the prostate bed by means of image guided volumetric intensity-modulated arc technique (IGRT-VMAT) and state-of-the-art treatment-planning and quality assurance procedures, with emphasis on normal tissue sparing and and pinpoint delivery accuracy via the use of devices that ensure stability and beam location reproducibility

Patients enrolled in this observational prospective trial undergo image-guided, intensity-modulated radiotherapy using the same equipment, techniques, and treatment-planning procedures as per clinical practice. Eligible patients are those with (1) persistently detectable PSA post-operatively or (2) developing biochemical recurrence after prostatectomy with initially undetectable PSA, without evidence of macroscopic local relapse and/or regional and distant metastases at restaging, proposed for receiving up to 15 Gy in a single session to the prostate bed.

As per current practice, in case of PSMA positivity at the level of prostate bed, the treatment will be intended to cover this area up to 110% of the prescribed dose yet respecting the OARs constraints.

Patients will be followed at approximately one month, then approximately every 3 months for the first 12 months and every 6 months thereafter. At follow-up visit patients will be evaluated for urinary, rectal, and sexual toxicity. Baseline measures of these domains will be obtained prior to treatment. Serum PSA values will be drawn on the same schedule as clinical follow-up.

Eligibility Criteria:
Inclusion Criteria:

* Subjects of male sex ≥ 18 years of age.
* Subjects have freely signed the pertinent informed consent before the beginning of the study

  * Adenocarcinoma of the prostate treated with radical prostatectomy (any type of radical prostatectomy is permitted including retropubic, perineal, laparoscopic or robotically assisted; there is no time limit for the date of radical prostatectomy)
  * Detectable post-prostatectomy PSA of ≥ 0.1 - \< 2.0 ng/mL either (1) persistently detectable post-operatively or (2) developing biochemical recurrence after prostatectomy (initially undetectable)
  * No evidence of N1 and/or M1 disease assessed by PSMA PET-CT within 90 days prior to registration
  * Negative Magnetic Resonance Imaging (MRI) of the pelvis in case of equivocal evidence of local relapse on PSMA PET-CT
  * Androgen deprivation therapy (ADT) allowed as per physician's discretion
  * ECOG performance status of 0-1
  * Ability to complete the questionnaires

Exclusion Criteria:

* N1 and or M1 patients
* Macroscopic local relapse at pelvic MRI.
* Prior radiation of any kind to the prostate gland or pelvis
* Prior brachytherapy
* History of inflammatory colitis or other active severe comorbidities
* Patients who are on immunosuppressant medication