LDR Brachytherapy for Prostate Cancer

(PRIAPUS Trial)

Overseen By Robin Sachdeva, PhD

Age: 18+

Sex: Male

Trial Phase: Academic

Sponsor: London Health Sciences Centre Research Institute OR Lawson Research Institute of St. Joseph's

Must not be taking: 5 alpha-reductase inhibitors

Disqualifiers: Older than 75, Metastases, Inflammatory bowel disease, others

No Placebo Group All trial participants will receive the active study treatment (no placebo)

Approved in 2 Jurisdictions This treatment is already approved in other countries

Compensation: Varies

Number of Visits: 2

Duration: 1 month

10 Participants Needed

Trial Summary

What is the purpose of this trial?

This trial is testing a new internal radiation treatment for prostate cancer that uses advanced imaging to precisely target the cancer. It aims to reduce erectile dysfunction by avoiding damage to nearby nerves and blood vessels. The treatment is designed for patients with prostate-confined cancers.

Will I have to stop taking my current medications?

The trial does not specify if you need to stop taking your current medications, but it does exclude those using cytoreductive prostate treatments, including 5 alpha-reductase inhibitors.

Is LDR Brachytherapy safe for humans?

LDR Brachytherapy for prostate cancer is generally considered safe, with low rates of serious side effects affecting the urinary or digestive systems, typically between 1% and 4%. ^{1 2 3 4 5}

How is LDR Brachytherapy different from other prostate cancer treatments?

LDR Brachytherapy for prostate cancer is unique because it involves implanting tiny radioactive seeds directly into the prostate, allowing for precise radiation delivery to the tumor while minimizing exposure to surrounding tissues. This method is minimally invasive, often performed as a same-day procedure, and is effective as a standalone treatment for many patients with localized prostate cancer. ^{1 3 4 5 6}

What data supports the effectiveness of the treatment UltraSound-guided Low-dose Rate Brachytherapy for prostate cancer?

Research shows that Low-dose-rate brachytherapy (LDR) is effective for treating localized prostate cancer, with excellent long-term outcomes and minimal side effects. Studies indicate that it provides precise radiation delivery, leading to high survival rates and low toxicity, making it a recommended option for various risk groups of prostate cancer. ^{1 2 3 4 6}

Research Team

Lucas Mendez, MD

Principal Investigator

London Health Sciences Centre- London Regional Cancer Program

Eligibility Criteria

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.

Inclusion Criteria

No or mild erectile function impairment (score ≥18 in International Index of Erectile Function- 5 [IIEF-5] without PDE-5 inhibitor assistance)

My prostate cancer is confined to one lobe, or a recent scan shows a major lesion there.

My prostate cancer was confirmed by a biopsy.

Exclusion Criteria

My prostate cancer is at an intermediate or high risk level.

Significant artifact on MR-Scan (e.g. caused by hip prosthesis)

You are unable to undergo an MRI scan due to certain medical conditions.

Timeline

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

Treatment

Participants receive MR fusion 3D Ultrasound guided Low dose rate brachytherapy to treat prostate cancer

1 month

1 visit (in-person)

Follow-up

Participants are monitored for safety, effectiveness, and erectile function post-treatment

60 months

Regular visits at 1, 6, 12, 18, 24, 36, 48, 60 months post intervention

Long-term follow-up

Participants are monitored for long-term outcomes including local recurrence and biochemical failure

5 years

Treatment Details

Interventions

• UltraSound-guided Low-dose Rate Brachytherapy

Trial Overview 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.

Participant Groups

Group I: Prostate Cancer Patients Experimental Treatment 1 Intervention

Low- or favourable intermediate-risk prostate cancer patients

UltraSound-guided Low-dose Rate Brachytherapy is already approved in United States, European Union for the following indications:

Approved in United States as Low-dose Rate Brachytherapy for:

• Localized prostate cancer
• Low-risk prostate cancer
• Favorable intermediate-risk prostate cancer

Approved in European Union as Low-dose Rate Brachytherapy for:

• Localized prostate cancer
• Low-risk prostate cancer
• Favorable intermediate-risk prostate cancer

Who Is Running the Clinical Trial?

London Health Sciences Centre Research Institute OR Lawson Research Institute of St. Joseph's

Lead Sponsor

Trials

678

Recruited

421,000+

London Health Sciences Centre Research Institute and Lawson Research Institute of St. Joseph's

Lead Sponsor

Trials

686

Recruited

427,000+

Lawson Health Research Institute

Lead Sponsor

Trials

684

Recruited

432,000+

Findings from Research

In a study of 201 patients treated with low-dose-rate (LDR) brachytherapy for localized prostate cancer, there was a significant and persistent decline in prostate-specific antigen (PSA) levels over time, indicating effective cancer control.

After 10 years of follow-up, only 9 patients experienced tumor recurrence, and while some urinary symptoms were noted initially, they significantly decreased after 18 months, suggesting that LDR brachytherapy is both safe and effective with manageable side effects.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Low-dose-rate brachytherapy as a minimally invasive curative treatment for localised prostate cancer has excellent oncological and functional outcomes: a retrospective analysis from a single centre. D'hulst, P., Mattelaer, P., Darras, J., et al.[2022]

In a study of 195 patients treated with low-dose rate brachytherapy (LDR-BT) for low-risk prostate cancer, the five-year biochemical failure-free survival (BFFS) rate was an impressive 95.7%.

The study found that the dose delivered to the prostate (D90%) was significantly linked to BFFS, indicating that a dose range of 170-180 Gy leads to excellent treatment outcomes with manageable side effects.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Low-dose rate brachytherapy with I-125 seeds has an excellent 5-year outcome with few side effects in patients with low-risk prostate cancer. Rasmusson, E., Gunnlaugsson, A., Kjellén, E., et al.[2022]

Low dose rate (LDR) prostate brachytherapy is a highly effective radiation treatment for non-metastatic prostate cancer, showing excellent oncologic outcomes and low rates of severe side effects (1% to 4% for late grade 3 or 4 toxicity).

This technique, which uses precise image guidance for radioactive source placement, is endorsed by expert consensus groups for all risk groups and can be performed as a same-day procedure, making it both cost-effective and convenient.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Low dose rate prostate brachytherapy. Stish, BJ., Davis, BJ., Mynderse, LA., et al.[2020]

A study involving 2237 patients with early-stage prostate cancer showed that low-dose-rate brachytherapy (LDR-BT) is highly effective, with 5-year disease-specific survival rates at 99% and overall survival rates at 94%.

The quality of the treatment, indicated by the volume of the target receiving the prescribed dose (V100), was linked to better biochemical failure-free survival, especially in patients with low-risk cancer, highlighting the importance of careful patient selection and treatment planning.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Low dose rate brachytherapy (LDR-BT) as monotherapy for early stage prostate cancer in Italy: practice and outcome analysis in a series of 2237 patients from 11 institutions. Fellin, G., Mirri, MA., Santoro, L., et al.[2022]

In a study of 102 patients undergoing prostate low-dose-rate brachytherapy, the estimated intrarectal dose rates from radioactive seeds were found to be higher for (103)Pd compared to (125)I immediately after implantation, with average rates of 2.5 cGy/h and 2.1 cGy/h, respectively.

Radiation exposure from (103)Pd decreases more rapidly than from (125)I, suggesting that patients should limit receptive anal intercourse for 2 months after (103)Pd treatment and for 6 months after (125)I treatment to minimize radiation exposure.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Radiation safety of receptive anal intercourse with prostate cancer patients treated with low-dose-rate brachytherapy. Nasser, NJ., Cohen, GN., Dauer, LT., et al.[2018]

Low-dose rate brachytherapy (LDR-BT) showed similar biochemical recurrence-free survival rates compared to radical prostatectomy (RP) after 5 years, indicating that both treatments are equally effective in preventing cancer recurrence in localized prostate cancer.

LDR-BT had a significant advantage over RP in terms of urinary incontinence (0% vs. 18% incidence), while RP was associated with more urinary irritation (80% vs. 4.5% incidence), highlighting the differing side effect profiles of these treatments.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Low-dose rate brachytherapy for men with localized prostate cancer. Peinemann, F., Grouven, U., Hemkens, LG., et al.[2022]

References

1. Poland pubmed.ncbi.nlm.nih.gov

Low-dose-rate brachytherapy as a minimally invasive curative treatment for localised prostate cancer has excellent oncological and functional outcomes: a retrospective analysis from a single centre. [2022]

2. England pubmed.ncbi.nlm.nih.gov

Low-dose rate brachytherapy with I-125 seeds has an excellent 5-year outcome with few side effects in patients with low-risk prostate cancer. [2022]

3. China pubmed.ncbi.nlm.nih.gov

Low dose rate prostate brachytherapy. [2020]

4. England pubmed.ncbi.nlm.nih.gov

Low dose rate brachytherapy (LDR-BT) as monotherapy for early stage prostate cancer in Italy: practice and outcome analysis in a series of 2237 patients from 11 institutions. [2022]

5. United States pubmed.ncbi.nlm.nih.gov

Radiation safety of receptive anal intercourse with prostate cancer patients treated with low-dose-rate brachytherapy. [2018]

6. England pubmed.ncbi.nlm.nih.gov

Low-dose rate brachytherapy for men with localized prostate cancer. [2022]