Radiation Treatment of the Prostate That is Specially Adjusted for Each Person

NCT07578519 | Not Yet Recruiting Phase 2 DMC

• 1 other identifier: DAPAR
• Study Type: interventional
• Target: 50
• Locations: 1 country
• Sites: 1

Brief Summary

A number of recent studies have successfully reduced the number of radiotherapy treatments used for prostate cancer from 39 daily treatments to as little as 5 treatments. This study is designed to determine how tumors inside the prostate respond during these 5 treatments on magnetic resonance imaging (MRI) and use that information to design 2 fraction radiotherapy treatments for prostate cancer. For these two fraction treatments, the first fraction of radiation will use extra radiation to any nodules in the prostate, and the second fraction of radiation will give extra radiation to the nodule(s) in the prostate based on how those nodules responded to the first fraction of radiation. This idea is a relatively old concept but has not been used in the treatment of cancer yet. This research includes a clinical trial that evaluates whether it is safe to design treatments like this.

Conditions

Prostate Cancer

Keywords

Radiotherapy; prostate cancer; treatment; radiation

Outcome Measures

Primary Outcomes (1)

• Incidence

  Cumulative incidence of acute common terminology criteria for adverse events (CTCAE) v6.0 ≥ grade 2 genitourinary (GU) toxicity

  Baseline 3 weeks (includes treatment period for Arm 1 and 2) 1 month (includes treatment period for Arm 1) 3 months 6 months 2 years

Secondary Outcomes (10)

• Incidence

  Baseline 3 weeks 1 month 3 months 6 months 2 years

• Incidence

  2 years

• Incidence

  2 years

• international index of erectile function (IIEF-5)

  Baseline 3 weeks 1 month 3 months 6 months 2 years

• expanded prostate cancer index composite (EPIC)

  1 month and 2 years post treatment

Study Arms (2)

Arm 1/Stage 1: 5 weeks

EXPERIMENTAL

The first group of 25 patients enrolled will receive 5 fractions of radiotherapy to their prostate with or without radiotherapy to their pelvic lymph nodes and an MRI midway through the treatment to assess the response of disease.

Radiation: radiotherapy

Arm 2/Stage 2: 3 weeks

EXPERIMENTAL

The second group of 25 patients enrolled in this study will receive a single fraction of radiation to the prostate +/- pelvis with extra radiation to any nodule(s)/tumors in the prostate identified on MR. They will then have a second MR after 3 weeks and based on that MR a second fraction of radiation to the prostate +/- pelvis will be delivered.

Radiation: radiotherapy

Interventions

radiotherapy RADIATION

External beam radiotherapy via stereotactic body radiotherapy (SBRT).

Arm 1/Stage 1: 5 weeks; Arm 2/Stage 2: 3 weeks

Eligibility Criteria

• Age: 18 Years+
• Gender Eligibility Details: biological male
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Histologically confirmed adenocarcinoma of the prostate
• NCCN risk grouping of intermediate or high risk prostate cancer
• Patients must be 18 years of age, or older on the day of signing informed consent and be willing and able to provide written informed consent/assent
• Identifiable lesion within the epithelium of the prostate as determined by the treating radiation oncologist
• Have a prostate imaging reporting and data system (PIRADS) 4 or 5 nodule noted on MRI
• Have not received prior pelvic radiotherapy
• Life expectancy greater than 10 years
• ECOG performance status \<3
• Eligible for SBRT to the prostate

You may not qualify if:

• No identifiable lesion within the prostate on 3T MRI
• Prior trans-urethral resection of the prostate
• Non-adenocarcinoma histology
• Meeting criteria for very high-risk risk or node positive prostate cancer
• Active inflammatory bowel disease
• Evidence of metastatic disease on CT or bone scan
• Declined radiotherapy
• Unlikely to be available for all follow-up appointments
• Having received androgen deprivation therapy or 5-alpha reductase therapy prior to trial therapy
• Extensive disease in the posterior prostate or aberrant anatomy that makes the safe delivery of boost irradiation not feasible
• Unable to understand or sign a study consent form after use of interpreter if required
• Has a relative contraindication to radiotherapy including systemic lupus erythematosus, TNM deficiency or scleroderma
• Unable to tolerate or ineligible for mpMR imaging
• Any condition or diagnosis, that could in the opinion of the treating physician or qualified investigator interfere with the participant's ability to comply with study instructions, might confound the interpretation of the study results, or put the participant at risk

Sponsors & Collaborators

• AHS Cancer Control Alberta: lead

Study Sites (1)

Jack Ady Cancer Centre

Lethbridge, Alberta, T1J 3H5, Canada

Location

MeSH Terms

Conditions

Prostatic Neoplasms

Interventions

Radiotherapy

Condition Hierarchy (Ancestors)

Genital Neoplasms, Male; Urogenital Neoplasms; Neoplasms by Site; Neoplasms; Genital Diseases, Male; Genital Diseases; Urogenital Diseases; Prostatic Diseases; Male Urogenital Diseases

Intervention Hierarchy (Ancestors)

Therapeutics

Central Study Contacts

Charlie Kirkby

CONTACT

403-388-6872; Charles.Kirkby@cancercarealberta.ca

Asongna Folefoc

CONTACT

Asongna.Folefoc@cancercarealberta.ca

Study Design

• Study Type: interventional
• Phase: phase 2
• Allocation: NON RANDOMIZED
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: SEQUENTIAL
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Model Details: This study is a prospective open label, phase II, two-arm, sequentially allocated non-inferiority cohort trial. This trial design is necessary to determine the multi-parametric magnetic resonance imaging (mpMRI) based treatment response thresholds necessary to inform the DAPAR dose received by patients in the second arm. The first arm and first phase of the study will enroll 25 patients to receive MR imaging-based evaluations of response to 5 fractions of once weekly prostate stereotactic body radiotherapy (SBRT) to a total dose of 4000cGy to the prostate and proximal seminal vesicles and 3625cGy in 5 fractions to a planning target volume (PTV) margin of 3-5mm. The MR response measurements will then be used to deliver 2300cGy in 2 fractions to a PTV margin of 3-5mm around the prostate and proximal seminal vesicles and between 2500cGy and 2900cGy in 2 fractions to the MR based dominant intraprostatic lesion (DIL), delivered 3 weeks apart.

Study Record Dates

• First Submitted: May 1, 2026
• First Posted: May 11, 2026
• Study Start (Estimated): June 1, 2026
• Primary Completion (Estimated): June 1, 2031
• Study Completion (Estimated): June 1, 2032
• Last Updated: May 11, 2026

Record last verified: 2026-05

Data Sharing

• IPD Sharing: Will not share

Locations

CA (1)