MRI-based Focal Intraprostatic Simultaneous Integrated Boost (SIB) Intensification With De-escalated Adaptive-risk SBRT for Patients With Low to Intermediate Risk Prostate Cancer
United States58 participantsStarted 2026-09
Plain-language summary
The goal of this clinical trial is to determine the safety of stereotactic body radiation therapy (SBRT) microboost technique in patients with low to intermediate risk prostate cancer. The main question it aims to answer is: Is microboost SBRT with whole gland de-escalation both safe and effective in managing patients with low to intermediate-risk prostate cancer while maintaining acceptable toxicity levels? All patients will receive microboost SBRT at a dose of 45 Gy delivered in 5 fractions in up to 4 MRI-defined lesions. Patients (Arm 1) with highest grade disease in the microboost target lesion in the absence of GG2-3 beyond the microboost target (only GG1 disease can be present outside of the microboost region) will receive whole gland de-escalation at a dose of 30 Gy delivered in 5 fractions. Patients (Arm 2) with highest grade disease outside of the target lesion will receive whole gland de-escalation at a dose of 35 Gy delivered in 5 fractions. Participants will be treated every other day over a two week period and then follow up after radiation treament for up to 5 years. Participants will be asked to complete questionnaires and provide blood and urine samples for research purposes.
Who can participate
Age range
18 Years
Sex
MALE
See this in plain English?
AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.
Inclusion criteria
. Patients age 18 or older.
. Patients with an Eastern Cooperative Oncology Group (ECOG) performance status of 0 to 2
. Patients with histologically confirmed adenocarcinoma of the prostate who have not received prior pelvic radiation therapy or prostatectomy.
. Patients with low to intermediate risk group defined by the NCCN (National Comprehensive Cancer Network) guidelines as follows:
. Patients with unfavorable intermediate risk prostate cancer defined by the NCCN guidelines are recommended to undergo a PSMA (Prostate-Specific Membrane Antigen) PET, then the PSMA PET must show localized disease.
. Patients must have preferably undergone a standard of care pretreatment MRI fusion biopsy\* to identify visible intraprostatic lesions and confirm the absence of regional or distant metastatic disease, with criteria as follows:
Questions worth asking your doctor
Bring these to your next appointment. They're a starting point for a shared conversation — not a sign you qualify or a recommendation to enrol.
1This trial uses MRI-guided radiation that focuses a higher dose specifically on the tumor inside the prostate while keeping doses lower elsewhere — how does that approach compare to the standard radiation treatment you'd recommend for my specific risk level?
2Since the trial is in Phase 2 and hasn't started recruiting yet, what does that mean for how much is already known about the safety and effectiveness of this particular combination of techniques in men like me?
3The trial's main goal is to track serious urinary side effects — given my current urinary health and symptoms, how concerned should I be about that risk, and how would side effects be monitored and managed if I joined?
4Because the trial isn't recruiting yet, what would the realistic timeline look like before I could even be considered, and is waiting for this trial a reasonable option given where my cancer is right now?
5For someone with my diagnosis — low to intermediate risk prostate cancer — would you consider active surveillance, surgery, or standard SBRT to be a better-established path first, and what would I give up or gain by pursuing this trial instead?
Generated to help you prepare — always confirm anything about your own eligibility and care with the study team and your doctor.
Questions for the trial coordinator
The trial coordinator is the person who runs the study day to day. These cover the practical side — logistics, costs, and what taking part would actually mean for your life. The study team confirms whether you meet the criteria; these are questions to ask, not a sign you qualify.
1What does taking part actually involve week to week — how many visits, where, and how long does each one take?
2What costs are covered by the study, and what might I have to pay for myself, including travel, parking, or time off work?
3What happens during screening, and what happens if the study team confirms I don't meet the criteria after those tests?
4Who pays for the scans, blood work, and other tests the trial requires — the study, my insurance, or me?
5How will being in the trial affect my regular care, and will my own doctor stay informed and involved?
6Can I leave the trial at any point if I change my mind, and what would happen to my care if I do?
A starting point for the conversation — always confirm anything about your own eligibility, costs, and care with the study team and your doctor.
What they're measuring
1
Incidence of acute grade 2 or higher genitourinary toxicity
Timeframe: during treatment through 90 days after radiation treatment
. Genitourinary function with a baseline score ≤20 as defined by any pre-treatment IPSS questionnaire.
. Patients are mandated to get a fiducial placement. Optional proper rectal spacer placement is recommended as determined by the treating radiation oncologist based upon whether there is overt rectal wall invasion from the hydrogel spacer or if there is minimal to no separation of the prostate-rectal interface measured at the prostate mid-gland.
Exclusion criteria
. Patients with evidence of disease Grade Group 4 (GG4) or higher.
. Patients with PSA \>20 ng/mL.
. Patients with evidence of clinical stage T3a+ or gross extracapsular extension on the diagnostic MRI.
. Patients who received prior or concurrent androgen deprivation therapy for prostate cancer.
. Patients with more than 4 disease foci identifiable on MRI.
. Patients with evidence of metastatic disease on imaging (e.g., bone scan, PSMA PET scan, or MRI/CT scan).
. Patients with ineligibility to undergo an MRI due to:
. Patients with an I-PSS score \>20 as defined by any pre-treatment IPSS questionnaire.