5500/20 Vs. SABR or Brachytherapy for PRimary OligoMetastatic Prostate Cancer Treatment (PROMPT)

Not Applicable

Recruiting

• Conditions: Oligometastatic Prostate Cancer
• Interventions: Radiation: Permanent seed implant; Radiation: Hypofractionated external beam radiotherapy; Radiation: High dose rate brachytherapy; Radiation: Stereotactic body radiotherapy

• Registration Number: NCT04610372
• Lead Sponsor: British Columbia Cancer Agency

Brief Summary

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.

Detailed Description

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.

Study Timeline

• Study First Submitted: 2020-10-14
• Study First Submitted QC: 2020-10-26
• Study First Posted: 2020-10-30
• Study Start: 2021-07-12
• Status Verified: 2025-03
• Last Update Submitted: 2025-03-11
• Last Update Posted: 2025-03-13
• Primary Completion: 2030-06-30
• Study Completion: 2033-06-30

Recruitment & Eligibility

• Status: RECRUITING
• Sex: Male
• Target Recruitment: 168

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
• Able to complete the necessary investigations prior to randomization (History and physical examination, PSA)
• Able to complete the necessary investigations prior to start of Radiotherapy (Transrectal ultrasound-guided biopsy or equivalent, CT chest, abdomen & pelvis or MRI abdomen and pelvis, and Bone scan)
• Planned for long-term androgen deprivation therapy (greater than 9 months in duration)

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

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Permanent seed implant brachytherapy	Permanent seed implant	A single permanent implant of radioactive Iodine-125 seeds is performed under anesthesia as an out patient to deliver 125 Gy to the prostate
standard	Hypofractionated external beam radiotherapy	External beam radiotherapy to deliver 5500 centiGray (cGy) in 20 fractions to the prostate over 4 weeks
High dose rate brachytherapy	High dose rate brachytherapy	A single fraction of 19 Gray (Gy) is delivered to the prostate under anesthesia as an out patient.
Stereotactic body radiotherapy	Stereotactic body radiotherapy	36.25 Gy is delivered to the prostate in 5 fractions given either weekly or every second day, using a SABR technique.

Primary Outcome Measures

Name	Time	Method
Urinary symptoms	Baseline to 2 years	International Prostate Symptom score (0/35), higher worse

Secondary Outcome Measures

Name	Time	Method
Expanded Prostate Cancer Index (EPIC) urinary domain	Baseline to 2 years	Urinary Quality of life, 0/100 higher score better
Distant metastatic failure	Baseline to 3 years	Progression free survival measured as time to new or progressive bone metastases
Cause specific survival	Within 3 years of treatment	Death from prostate cancer
Cost effectiveness	3 years	Analysis of primary treatment costs and secondary treatment costs at time of progression
Biochemical failure (time to increase in prostate specific antigen (ng/ml) to 50% > nadir	Baseline to 3 years	Progression free survival measured as time to Prostate Specific Antigen (PSA) rise by 50% \> nadir
EPIC bowel domain	Baseline to 2 years	Bowel quality of life, 0/100, higher score better. Series of validated questions concerning urgency, frequency, consistency, leakage, presence of blood and pain with bowel movements and then rates how big a problem each symptom was (0-5)
EPIC sexual domain	Baseline to 2 years	Sexual quality of life, 0/100, higher score better. Series of validated questions concerning frequency and quality of erections, presence of morning erections, ability to engage in sexual activity or intercourse, rates ability and then rates importance of each issue to the patient.
Nodal progression	Baseline to 3 years	Progression free survival measured as new or progressive adenopathy on imaging
Overall survival	3 years	Overall survival regardless of cause of death

Trial Locations

Locations (4)

British Columbia Cancer Agency Center for the Southern Interior; 🇨🇦 Kelowna, British Columbia, Canada

Fraser Valley Cancer Center; 🇨🇦 Surrey, British Columbia, Canada

Vancouver Cancer Center; 🇨🇦 Vancouver, British Columbia, Canada

Vancouver Island Cancer Center; 🇨🇦 Victoria, British Columbia, Canada