5500/20 vs. SABR or Brachytherapy for PRimary OligoMetastatic Prostate Cancer Treatment (PROMPT)
5500/20 vs. SABR or Brachytherapy for PRimary OligoMetastatic Prostate Cancer Treatment (PROMPT)
We will investigate whether ultrahypofractionation using stereotactic ablative radiotherapy
 (SABR) or brachytherapy is as well-tolerated as moderately hypofractionated external beam
 radiotherapy (EBRT) for treating the prostate in patients with oligometastatic prostate
 cancer. Secondary aims include assessment of progression-free survival (PFS) and overall
 survival (OS) as well as cost-effectiveness. We hypothesize that ultrahypofractionation will
 maintain favorable toxicity profiles and quality of life while achieving comparable or better
 efficacy, thereby providing a convenient and cost-effective alternative to moderately
 hypofractionated EBRT.
Men newly diagnosed with low volume oligometastatic prostate cancer defined as fewer than 5
 bone metastases and/or non regional lymph node involvement who agree to treatment of the
 primary cancer with radiation will be randomized between standard moderately hypofractionated
 external radiotherapy (5500 centiGray/20 fractions as per Stampede trial) and one of 3
 alternatives: stereotactic body radiotherapy (SABR) to deliver 36 Gy/5 fractions, or low dose
 rate Iodine 125 permanent seed implant or a single high dose rate temporary implant. The
 trial will take place in 4 regional cancer centers of British Columbia Cancer Agency, with
 each center choosing their preferred alternative to 5500/20. To achieve 4 equally sized
 treatment arms, each randomization is weighted 3:1 for 42 patients in each arm and 168 total
 accrual. The primary endpoint is urinary quality of life as assessed by the International
 Prostate Symptom Score (IPSS) . As the typical acute symptoms from each of these radiation
 modalities has a unique time course, assessments are done at 6 different points during the
 first 2 years. Secondary endpoints are global quality of life as assessed by Expanded
 Prostate Cancer Index (EPIC) urinary, bowel and sexual scores, progression free survival,
 overall survival and cost effectiveness.
Inclusion Criteria:

 -  Able to provide informed consent

 -  European Cooperative Oncology Group performance status 0 to 2

 -  Medically fit for all protocol treatment and follow-up

 -  Histologically confirmed adenocarcinoma of the prostate

 -  Newly diagnosed any Tumor stage, any Nodal stage but with oligo metastases

 -  No prior therapy for prostate cancer apart from androgen deprivation

 -  Luteinizing Hormone Releasing Hormone (LHRH) agonists or antagonists must have started
 within 24 weeks of randomization

 -  If used, anti-androgens must have started within 26 weeks of randomization

 -  Able to complete the necessary investigations prior to and within 12 weeks of starting
 Androgen Deprivation Therapy (ADT) or of randomization (History and physical
 examination, PSA, Transrectal ultrasound-guided biopsy, CT or MRI abdomen and pelvis,
 Bone scan)

 -  Planned for long-term androgen deprivation therapy

 Exclusion Criteria:

 -  High metastatic burden defined as 5 or more bone metastases or visceral metastases

 -  Abnormal liver function

 -  Contraindications to EBRT such as active inflammatory bowel disease or previous pelvic
 radiation

 -  Medically unfit for anesthesia

 -  International Prostate Symptom Score (IPSS) greater than 20

 -  Restrictive flow pattern with peak flow rate less than10 mL per second or post-void
 residual greater than 25 per cent of voided volume (when uroflowmetry available)

 -  Prostate volume greater than 60cc after maximal cytoreduction

 -  Pubic arch interference

 -  Transurethral resection of prostate (TURP) within 12 weeks of brachytherapy