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

British Columbia Cancer Agency

Status: Enrolling

Conditions: Oligometastatic Prostate Cancer

Treatments: Radiation: High dose rate brachytherapy; Radiation: Stereotactic body radiotherapy; Radiation: Permanent seed implant; Radiation: Hypofractionated external beam radiotherapy

Study type: Interventional

Funder types: Other

Identifiers

NCT04610372

H20-01207

Details and patient eligibility

About

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.

Full 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.

Enrollment: 168 estimated patients

Sex: Male

Ages: 18+ years old

Volunteers: No Healthy Volunteers

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)
• Patient is able and willing to complete the quality of life questionnaires, and other assessments that are a part of this study

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

Contraindications to brachytherapy including:

• Medically unfit for anesthesia,
• International Prostate Symptom Score (IPSS) greater than 20
• Poor urinary flow 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

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: None (Open label)

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168 participants in 4 patient groups

standard

Active Comparator group

Description:

External beam radiotherapy to deliver 5500 centiGray (cGy) in 20 fractions to the prostate over 4 weeks

Treatment:

Radiation: Hypofractionated external beam radiotherapy

High dose rate brachytherapy

Experimental group

Description:

A single fraction of 19 Gray (Gy) is delivered to the prostate under anesthesia as an out patient.

Treatment:

Radiation: High dose rate brachytherapy

Permanent seed implant brachytherapy

Experimental group

Description:

A single permanent implant of radioactive Iodine-125 seeds is performed under anesthesia as an out patient to deliver 125 Gy to the prostate

Treatment:

Radiation: Permanent seed implant

Stereotactic body radiotherapy

Experimental group

Description:

36.25 Gy is delivered to the prostate in 5 fractions given either weekly or every second day, using a SABR technique.

Treatment:

Radiation: Stereotactic body radiotherapy