Post-Prostatectomy Linac-Based Ultrahypofractionated Radiotherapy for Patients With Localized Prostate Cancer (PLUTO)

Post-Prostatectomy Linac-Based Ultrahypofractionated Radiotherapy for Patients With Localized Prostate Cancer: A Treatment Feasibility and Outcomes Study

Radical prostatectomy is a common treatment for localized prostate cancer. More than 30% of men who undergo surgery will subsequently develop recurrence, particularly in patients with adverse features where the risk may be even higher. Recurrence typically manifests as a rise in serum-level of prostate-specific antigen (PSA), referred to as biochemical recurrence. Post-operative radiotherapy is a potentially curative option for many patients, as shown in multiple prior randomized studies. A standard course of post-operative radiation requires 6 to 6 and half weeks of treatment, 5 days a week; however, new high-precision radiation techniques with image guidance, termed stereotactic body radiotherapy (SBRT), can deliver an equivalent or higher dose of treatment in 5 visits. Our group, amongst others, have demonstrated in previous studies, that the new 5-treatment technique was safe, convenient and effective in patients with intact prostates. Currently, limited data exists on this approach after prostatectomy. This study will be one of the first to assess the side effect profile and efficacy of SBRT in patients with localized prostate cancer who are considered candidates for post-prostatectomy radiation.

Study Overview

• Status: Active, not recruiting
• Conditions: Radical Prostatectomy; SBRT
• Intervention / Treatment: Radiation: SBRT

• Study Type: Interventional
• Enrollment (Estimated): 30
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Canada
  • Ontario
    • Toronto, Ontario, Canada, M4N3M5
      • Sunnybrook Health Sciences Centre

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child; Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• • Histologically confirmed diagnosis of adenocarcinoma of the prostate

  • Completed written informed consent
  • Able and willing to complete self report questionnaires
  • Pathologic stage T3 or T4 (without any gross residual disease), NX-0, M0, and/or +ve surgical margins, and/or a rising PSA post-radical prostatectomy on at least 2 consecutive measurements

Exclusion Criteria:

• • Gross residual disease

  • Histological or radiological node +ve (N1) or distant metastases (M1)
  • Prior pelvic radiotherapy
  • Contraindications to radical pelvic radiotherapy (e.g. connective tissue disease or inflammatory bowel disease)
  • Hip prosthesis

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: SBRT post operative; Stereotactic Body Radiotherapy (SBRT) 30 Gy in 5 fractions, once weekly to prostate bed; / - 25 Gy in 5 fractions, once weekly simultaneously to pelvic lymph nodes; / - 6-24 months of androgen deprivation therapy (ADT)	Radiation: SBRT; Stereotactic body radiation therapy, or SBRT, is a cancer treatment that delivers extremely precise, very intense doses of radiation to cancer cells while minimizing damage to healthy tissue

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Acute genitourinary (GU) and gastrointestinal (GI) toxicities	Based on Common Terminology Criteria for Adverse Events (CTCAE) v5.0	Through accrual completion, up to 3 years

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Incidence of late GU and GI toxicities (≥6 months)	Using CTCAE v5.0	Through accrual completion, up to 3 years
Biochemical disease-free survival (bDFS)	Biochemical disease-free survival (bDFS)	Through study completion, up to 3 years

Collaborators and Investigators

• Sponsor: Sunnybrook Health Sciences Centre

Study record dates

Study Major Dates

• Study Start (Actual): November 7, 2019
• Primary Completion (Estimated): October 1, 2030
• Study Completion (Estimated): October 1, 2030

Study Registration Dates

• First Submitted: August 21, 2019
• First Submitted That Met QC Criteria: August 22, 2019
• First Posted (Actual): August 26, 2019

Study Record Updates

• Last Update Posted (Actual): May 18, 2025
• Last Update Submitted That Met QC Criteria: May 14, 2025
• Last Verified: May 1, 2025

More Information

Terms related to this study

• Keywords: Prostate cancer; SBRT; Radiation; PSA Rise; Ultrahypofractionated Radiotherapy
• Additional Relevant MeSH Terms: Urogenital Diseases; Genital Diseases; Genital Neoplasms, Male; Urogenital Neoplasms; Neoplasms by Site; Neoplasms; Genital Diseases, Male; Prostatic Diseases; Male Urogenital Diseases; Prostatic Neoplasms
• Other Study ID Numbers: PLUTO

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED
• IPD Plan Description: Undecided

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No