Efficacy of Repeat Stereotactic Radiation in Patients With Intraprostatic Tumor Recurrence

Prior treatment

• Late post-radiotherapy urinary or gastrointestinal toxicity of grade ≥2 (following primary radiotherapy)
• Transurethral resection of the prostate (TURP) in the 6 months before registrations
• Previous rectal surgery

Other illness

• Other cancers in the last 5 years except for non-melanoma-type skin cancer
• History of inflammatory bowel disease

Other

• Lymph node or metastatic spread
• Anticoagulant treatment
• Contraindications to undergoing MRI
• Prostate volume \>80 cc
• Presence of rectal telangiectasia grade 3 classified by the Vienna Rectoscopy Score (obligatory rectoscopy)
• Patients unable to undergo medical follow-up in the study for geographical, social or psychological
• Person deprived of their liberty or under protective custody or guardianship
• Patients enrolled in another therapeutic study
  • All patients during the SBRT planning with a ratio of clinical target volume (CTV) / prostate volume \>0.5 will be withdrawn from the study. These patients will be considered as not evaluable and will not be treated within the context of the study.

• Biochemical recurrence occurring at least 2 years after external radiotherapy for prostatic adenocarcinoma by the Phoenix definition (PSA nadir + 2 ng/mL)
• T1-T2c and PSA ≤20 ng/mL and Gleason score ≤7 at initial diagnosis of prostate cancer before the initial/first treatment.
• Recurrence of prostatic adenocarcinoma proven by histology following radiotherapy by transrectal or transperineal sextant biopsies of the two lobes of the prostate, with a minimum of 12 biopsies, irrespective of Gleason score. Biopsies of the seminal vesicles are optional.
• Clinical stage T1-T2 on relapse; unilateral extracapsular extension (T3a) on MRI permitted except posteriorly relative to the rectum
• Estimated clinical target volume (CTV) / prostate volume \< 0.5 based on imaging and biopsies
• Pelvic and prostatic assessment by multiparametric MRI- Absence of pelvic or metastatic recurrence proven by choline PET scan
• Performance status World Health Organization (WHO) 0-1
• PSA level ≤10 ng/mL at baseline (before salvage-SBRT)
• PSA doubling time \>10 months
• International Prostate Cancer Score (IPSS) ≤12
• Uroflowmetry with a maximum flow rate \>10 mL/s, a postvoid residual urine volume \<150 mL, and a urine volume \>150 mL.
• No other anti-cancer treatment since the external radiotherapy administered as first-line treatment
• No other anti-cancer treatment planned for the current recurrence
• No contraindication to fiducial marker implants; haemostatic disorders must be corrected before implantation
• Age \>18 years
• Life-expectancy greater than or equal to 5 years (Lee scale)
• Patient registered with a health insurance system
• Patient who has signed the informed consent form
• Patients willing and able to comply with the scheduled visits, treatment plan, laboratory tests, and other study procedures indicated in the protocol.