Partial Prostate Salvage High Dose Rate Brachytherapy

Inclusion Criteria20

• Age \>45 and Life expectancy \>10 years
• Previous External Beam Radiotherapy (EBRT) dose up to 78Gray/39 fractions, 81 Gray/45 fractions or 70 Gray/28 fractions or LDR brachytherapy with site of recurrence in an under-dosed or untreated site
• \> 3 year interval since EBRT or LDR Brachytherapy
• No late toxicity from prior EBRT ≥ grade 2
• Rising PSA post EBRT \> nadir + 2 ng/ml but \< 10 ng/ml
• PSA Doubling time \> 6 months
• Negative staging with CT scan of the abdomen/pelvis and bone scan (PSMA PET scan can replace CT and bone scan)
• Able to undergo multiparametric MRI with endorectal coil
• Radiographic evidence of dominant intraprostatic lesion (DIL) as only area of recurrence (i.e unifocal recurrence) and corresponding to site of original disease
• Biopsy confirmation of DIL with pathology review by British Columbia Cancer Agency GenitoUrinary pathologist (TB)
• Willing to provide informed consent
• History and physical examination within 90 days of registration
• ECOG performance status 0-1 prior to registration
• IPSS \< 16, or adequate voiding study (post void residual \< 100cc and peak flow rate \> 10 cc/second).
• No prior trans urethral prostatic resection
• Recurrence suitable for implant with HDR brachytherapy as assessed on ultrasound simulation (maximum PTV ideally \< 65% of prostate volume)
• No history of inflammatory bowel disease or previous rectal surgery
• Suitable for procedure under anesthesia, spinal or general
• INR \<2.5 and platelet count \>75 x 109/L
• Androgen Deprivation Therapy may be initiated at the discretion of the treating oncologist