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LDR Brachytherapy for Prostate Cancer (PRIAPUS Trial)

Led By Lucas Mendez, MD
Research Sponsored by Lawson Health Research Institute
Eligibility Criteria Checklist
Specific guidelines that determine who can or cannot participate in a clinical trial
Must have
Biopsy-confirmed adenocarcinoma of the prostate
No contraindications to prostate LDR brachytherapy
Must not have
NCCN-defined unfavourable intermediate or high-risk prostate cancer
Core positivity in both lobes of the prostate with no DIL detected on mpMR
Screening 3 weeks
Treatment Varies
Follow Up until study completion with 5 years of follow up
Awards & highlights


This trial is testing a new, MR-guided 3D ultrasound technique to see if it can more effectively treat prostate cancer while sparing the surrounding nerves and vessels.

Who is the study for?
Men with biopsy-confirmed prostate cancer, where the disease is contained in one lobe of the prostate. They should have good erectile function and be sexually active, without severe urinary symptoms or any prior high-risk treatments for prostate cancer. Participants must be fit for anesthesia, under 75 years old, and not have inflammatory bowel disease or certain other medical conditions.Check my eligibility
What is being tested?
The trial is testing a new way to do LDR brachytherapy that uses MR fusion with 3D Ultrasound guidance. The goal is to treat prostate cancer while sparing important nerves and vessels near the prostate and penile bulb to preserve sexual function.See study design
What are the potential side effects?
Potential side effects may include discomfort at the implant site, temporary urinary issues like frequency or urgency, erectile dysfunction risks due to nerve damage during treatment, as well as typical risks associated with anesthesia.

Eligibility Criteria

Inclusion Criteria

You may be eligible if you check “Yes” for the criteria below
My prostate cancer was confirmed by a biopsy.
I have no health issues preventing prostate seed implant therapy.
My prostate cancer is considered low or favorable intermediate risk.

Exclusion Criteria

You may be eligible for the trial if you check “No” for criteria below:
My prostate cancer is at an intermediate or high risk level.
My prostate cancer is present in both lobes without aggressive features on MRI.
I have had radiation therapy to my pelvis before.
My MRI shows cancer spread beyond the prostate capsule or to the seminal vesicles.
My MRI shows signs of cancer in both lobes of my prostate.
I cannot undergo general or spinal anesthesia due to health reasons.
My cancer has spread to distant parts of my body and/or lymph nodes.
I am over 75 years old.
I have had a prostate surgery known as TURP.
I have had surgery to remove the rectum and anus.
I have inflammatory bowel disease.


Screening ~ 3 weeks
Treatment ~ Varies
Follow Up ~until study completion with 5 years of follow up
This trial's timeline: 3 weeks for screening, Varies for treatment, and until study completion with 5 years of follow up for reporting.

Treatment Details

Study Objectives

Outcome measures can provide a clearer picture of what you can expect from a treatment.
Primary outcome measures
Rate of patients receiving this experimental brachytherapy technique and achieving acceptable dose distribution at 1-month post-implant.
Secondary outcome measures
Acute and long-term GU and GI toxicity
Biochemical failure
Local recurrence
+2 more

Trial Design

1Treatment groups
Experimental Treatment
Group I: Prostate Cancer PatientsExperimental Treatment1 Intervention
Low- or favourable intermediate-risk prostate cancer patients

Research Highlights

Information in this section is not a recommendation. We encourage patients to speak with their healthcare team when evaluating any treatment decision.
Mechanism Of Action
Side Effect Profile
Prior Approvals
Other Research
The most common treatments for prostate cancer include surgery, radiation therapy, hormone therapy, and focal therapies like brachytherapy. MR fusion 3D Ultrasound guided Low dose rate (LDR) brachytherapy uses advanced imaging techniques to precisely place radioactive seeds within the prostate, delivering targeted radiation to cancer cells while sparing surrounding healthy tissue. This precision reduces side effects and improves the quality of life for patients. Accurate imaging and targeted radiation are crucial as they enhance treatment efficacy and minimize damage to critical structures such as the neurovascular bundles and penile bulb, which are important for maintaining urinary and sexual function.
Focal therapy for localized prostate cancer in the era of routine multi-parametric MRI.Improving prostate cancer care collaboratively - a multidisciplinary, formal, consensus-based approach.Supporting prostate cancer focal therapy: a multidisciplinary International Consensus of Experts ("ICE").

Find a Location

Who is running the clinical trial?

Lawson Health Research InstituteLead Sponsor
666 Previous Clinical Trials
414,256 Total Patients Enrolled
15 Trials studying Prostate Cancer
635 Patients Enrolled for Prostate Cancer
Lucas Mendez, MDPrincipal InvestigatorLondon Health Sciences Centre- London Regional Cancer Program

Media Library

UltraSound-guided Low-dose Rate Brachytherapy (Brachytherapy) Clinical Trial Eligibility Overview. Trial Name: NCT04718987 — N/A
Prostate Cancer Research Study Groups: Prostate Cancer Patients
Prostate Cancer Clinical Trial 2023: UltraSound-guided Low-dose Rate Brachytherapy Highlights & Side Effects. Trial Name: NCT04718987 — N/A
UltraSound-guided Low-dose Rate Brachytherapy (Brachytherapy) 2023 Treatment Timeline for Medical Study. Trial Name: NCT04718987 — N/A
~2 spots leftby Jul 2025