Stereotactic Body Radiotherapy or Standard of Care for Prostate Oligoprogressive Cancer

Phase 2

Not yet recruiting

• Conditions: Castrate Resistance Prostate Cancer; OligoProgressive Metastatic Disease

• Registration Number: NCT06927635
• Lead Sponsor: University Health Network, Toronto

Brief Summary

This is a single centre, interventional, randomized Phase II, two-arm prospective trial investigating if Stereotactic Body Radiotherapy (SBRT) to all sites of Oligopressive (OP) disease while remaining on current Systemic Therapy (ST) will improve biochemical control compared to Standard of Care (SoC) (which involves a change in ST) for patients with OP Castrate Resistance Prostate Cancer (CRPC).

Detailed Description

The current standard of care for patients with metastatic Oligopressive (OP) Castrate Resistance Prostate Cancer (CRPC) is a change in Systemic Therapy (ST). We propose that Stereotactic Body Radiotherapy (SBRT) to Oligopressive sites, while maintaining patients on their current Systemic Therapy, may allow for biochemical control of disease while maintaining patient Quality of Life and avoiding the toxicities associated with changing Systemic Therapy. We have proposed an initial prospective feasibility study, followed by a larger phase II prospective study to investigate the efficacy of SBRT in Oligopressive Castrate Resistance Prostate Cancer.

Study Timeline

• Study First Submitted: 2025-03-03
• Study First Submitted QC: 2025-04-14
• Study First Posted: 2025-04-15
• Status Verified: 2025-05
• Last Update Submitted: 2025-05-22
• Last Update Posted: 2025-05-23
• Study Start: 2025-06
• Primary Completion: 2030-06
• Study Completion: 2030-06

Recruitment & Eligibility

• Status: NOT_YET_RECRUITING
• Sex: Male
• Target Recruitment: 75

Inclusion Criteria

• Age >18 years
• Able to provide informed consent
• Histologic diagnosis of prostate adenocarcinoma
• Castrate Resistance Prostate Cancer
• Radiographic evidence of <10 sites of extra-cranial OP metastatic lesions
• Receiving any line of ST for >3 months
• All sites of OP disease are amenable to and can be safely treated with SBRT
• ECOG performance status 0-3

Exclusion Criteria

• Evidence of spinal cord compression
• Contraindication to radiotherapy

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Primary Outcome Measures

Name	Time	Method
Study Feasibility	Within 18 months of study activation.	Determine the feasibility of enrolling 21 patients patients onto a study randomizing patients to either MDT using SBRT plus remaining on current ST versus SoC (change in Systemic Therapy) by measuring the rate accrual (number of patients per month for 18 months).
Change in Prostate-Specific Antigen (PSA)	Enrollment to 12 months post-enrollment.	Assess by standard PSA blood testing if the proportion of patients having a \>50% change in PSA compared to baseline (PSA50) is improved with MDT using SBRT plus remaining on current ST versus SoC.

Secondary Outcome Measures

Name	Time	Method
Time to next Systemic Therapy	Enrollment to 12-months post-enrollment.	Defined as the time from when the study intervention has been commenced until commencement of any next systemic anti-cancer therapy (including a change to best supportive care) or date of last follow up, whichever occurs first, which will be assess by the treating oncologist.
Radiographic Local Control of Oligopressive Lesions	Enrollment to 12 months-post enrollment.	Radiographic local control of the index OP lesions will be assessed by treating oncologist.
Radiographic Distant Control of Oligopressive Lesions	Enrollment to 12-months post-enrollment.	Defined by growth of non-Oligoprogressive metastatic sites and/or the development of new sites of metastatic disease, as assessed by treating oncologist.
Differences in Toxicity	Enrollment to 12-months post-enrollment.	Toxicity will be assessed to determine whether SBRT compared to SoC results in patient- and/or physician-reported toxicity differences. Toxicity will be collected using CTCAE v5.0
Progression Free Survival (PFS)	Enrollment to 12-months post-enrollment.	Defined as the time from randomization to death from any cause, progression of disease, or date of last follow-up, whichever occurs first. PFS will be assessed by the treating oncologist.
Differences in Quality of Life	Enrollment to 12-months post-enrollment.	Quality of Life (QoL) will be assessed to determine whether SBRT compared to SoC results in patient- and/or physician-reported QoL differences. QoL will be collected using the EORTC QLQ-C30 questionnaire.