Trial Evaluating the Safety and Efficacy Of MR-Linac-Guided Radiotherapy as Salvage Treatment After External Beam Radiotherapy Recurrence (TUMORNATOR II)

Eligibility Criteria

• 1. 18 years of age or older male participants
• 2. Biopsy proven intraprostatic prostate cancer after prior definitive external beam radiotherapy (moderate hypofractionation or Stereotactic Body Radiation Therapy (SBRT) acceptable).
• 3. Pathology confirming recurrent disease must have evidence of viable cancer as indicated with pathology interpretation where a Gleason score can be assigned
• 4. Serum testosterone ≥ 50 ng/dL determined within 2 months prior to enrollment
• 5. At least 4 weeks must have elapsed from major surgery
• 6. Karnofsky Performance Scale (KPS) ≥ 80% or Eastern Cooperative Oncology Group (ECOG) 0-1
• 7. Prostate size as determined on MRI to be \< 90 cc.
• 8. International Prostatism Symptom Score (IPSS) ≤ 20
• 9. Patient must be available for follow-up. After 2 years of follow-up, upon completion of post-treatment biopsy, telephone, and chart review-based follow-up will be acceptable for up to 5 years
• 10. Presence of a T2 and/or DWI-visible prostatic lesion on mpMRI
• 11. Satisfy all MRI screening criteria and be willing to fill out the standard MRI screening form
• 1. History of prostate brachytherapy (low dose rate or high dose rate)
• 2. Actively undergoing androgen deprivation therapy and/or anti-androgens at time of enrollment
• 3. CT or MRI or PET scan evidence of extraprostatic disease
• 4. Patients with one or more positive lymph nodes considered suspicious as determined by clinical assessment on MRI or CT or PET scan
• 5. History of another malignancy within the previous 2 years except for the following: adequately treated basal cell or squamous cell skin cancer, superficial bladder cancer, currently in complete remission, or any other cancer that has been in complete remission for at least 3 years
• 6. Patients with Crohn's disease or ulcerative colitis
• 7. MRI ineligibility due to: the presence of a cardiac pacemaker, defibrillator, or other implanted metallic or electronic device which is considered MR unsafe; severe claustrophobia; inability to lie flat for the duration of the study; etc.
• 8. Metallic implant or device in the pelvis that might distort the local magnetic field and compromise quality of mp-MRI
• 9. Lateral pelvic separation greater than 50 cm and/or anterior-posterior separation greater than 35 cm which are incompatible with MRCAT reconstruction
• 10. Contra-indications to receiving gadolinium contrast or PSMA radioligand
• 11. Karnofsky Performance Scale (KPS) \< 80 or ECOG 2+
• 12. Grade 3 or higher toxicity experienced after the initial course of External Beam Radiation Therapy (EBRT)
• 13. Disease free interval \< 2 years
• 14. Hx of Transurethral Resection Of Prostate (TURP) within the year
• 15. Prior high-intensity focused ultrasound (HIFU) or Cryotherapy
• 16. Prior history of urethral stricture
• 17. Unable to give informed consent
• 18. Unable to complete quality of life questionnaires