Radiotherapy for Prostate Cancer

(PROMPT Trial)

Recruiting at 3 trial locations

Overseen By Juanita Crook, MD

Age: 18+

Sex: Male

Trial Phase: Academic

Sponsor: British Columbia Cancer Agency

Must be taking: LHRH agonists, Anti-androgens

Disqualifiers: High metastatic burden, Abnormal liver function, others

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

Compensation: Varies

Number of Visits: 6

Duration: 4 weeks

168 Participants Needed

What You Need to Know Before You Apply

What is the purpose of this trial?

This trial tests new methods for treating prostate cancer that has spread to a few other areas in the body. It compares different types of radiotherapy to determine if they are as effective as the standard method while being gentler on the body and more cost-effective. Participants will receive either the standard external beam radiotherapy or one of three experimental treatments: high dose rate brachytherapy (a type of internal radiotherapy), permanent seed implant brachytherapy, or stereotactic body radiotherapy. Men with prostate cancer that has not been heavily treated and who are planning to start or have started hormone therapy might be suitable for this trial. As an unphased trial, this study provides a unique opportunity to explore innovative treatments that could potentially enhance quality of life and treatment outcomes.

Will I have to stop taking my current medications?

The trial does not specify if you need to stop taking your current medications. However, it mentions that LHRH agonists or antagonists and anti-androgens must have started within a certain timeframe before randomization, suggesting that some medications related to prostate cancer treatment may need to be continued.

Is there any evidence suggesting that this trial's treatments are likely to be safe?

Research shows that high dose rate brachytherapy is generally safe for men with prostate cancer. Studies report fewer severe side effects, indicating low treatment-related risks. This treatment also reduces the need for frequent travel, offering a significant benefit.

For permanent seed implant brachytherapy, research indicates good safety results. Specifically, one study found that 85% of men with low-risk prostate cancer did not experience a recurrence within five years, suggesting the treatment is both effective and well-tolerated.

Stereotactic body radiotherapy (SABR) has also been studied for safety. Research shows no major differences in negative outcomes with different treatment schedules, indicating the treatment is generally safe and offers flexible timing.

Overall, these treatments have proven to be safe options for prostate cancer patients, with manageable side effects. ^{1 2 3 4 5}

Why are researchers excited about this trial's treatments?

Researchers are excited about these prostate cancer treatments because they offer innovative approaches to radiotherapy. High dose rate brachytherapy delivers a powerful single dose directly to the prostate, potentially reducing treatment time compared to traditional external beam radiotherapy. Permanent seed implant brachytherapy uses radioactive seeds for a long-lasting effect, which might offer continuous treatment without repeated hospital visits. Stereotactic body radiotherapy provides precise, high-dose radiation in just a few sessions, minimizing exposure to surrounding tissues and potentially reducing side effects. These methods promise more convenience and possibly better outcomes for patients compared to conventional options.

What evidence suggests that this trial's treatments could be effective for prostate cancer?

Research has shown that high dose rate brachytherapy, one of the treatments in this trial, effectively treats prostate cancer, achieving high rates of disease control and long-term survival. Some studies report an 8-year survival rate of 95%. Another treatment option in this trial, permanent seed implant brachytherapy, also proves effective, with survival rates comparable to other treatments. Stereotactic body radiotherapy (SABR), also under study in this trial, has demonstrated similar positive results, with long-term data supporting its success. Overall, these treatments offer promising options for managing prostate cancer, each with comparable effectiveness. ^{1 2 3 6 7}

Who Is on the Research Team?

Juanita Crook, MD

Principal Investigator

BCCancer

Are You a Good Fit for This Trial?

Men with newly diagnosed prostate cancer that has spread only a little (oligometastatic) can join. They should be planning long-term hormone therapy, in good health for treatment and follow-up, and have not had other prostate cancer treatments except hormone drugs started within the last 24 weeks.

Inclusion Criteria

My prostate cancer diagnosis was confirmed through a tissue examination.

I have only received hormone therapy for my prostate cancer.

I started hormone therapy for my cancer within the last 24 weeks.

Exclusion Criteria

I had a prostate surgery (TURP) within the last 12 weeks before brachytherapy.

My liver isn't working properly.

I cannot have external beam radiation due to conditions like inflammatory bowel disease or previous pelvic radiation.

Timeline for a Trial Participant

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

Treatment

Participants receive one of the following treatments: standard moderately hypofractionated external radiotherapy, stereotactic body radiotherapy, high dose rate brachytherapy, or permanent seed implant brachytherapy

4 weeks

Multiple visits for treatment sessions

Follow-up

Participants are monitored for urinary quality of life and other secondary endpoints such as progression-free survival and overall survival

2 years

Assessments at 6 different points during the first 2 years

Long-term follow-up

Participants are monitored for progression-free survival and overall survival

3 years

What Are the Treatments Tested in This Trial?

Interventions

• High dose rate brachytherapy
• Hypofractionated external beam radiotherapy
• Permanent seed implant
• Stereotactic body radiotherapy

Trial Overview The trial is testing if using focused radiation (SABR or brachytherapy) is as safe and well-tolerated as standard external beam radiotherapy for treating oligometastatic prostate cancer. It also looks at survival rates and cost-effectiveness compared to the standard approach.

How Is the Trial Designed?

Group I: Stereotactic body radiotherapy Experimental Treatment 1 Intervention

36.25 Gy is delivered to the prostate in 5 fractions given either weekly or every second day, using a SABR technique.

Group II: Permanent seed implant brachytherapy Experimental Treatment 1 Intervention

A single permanent implant of radioactive Iodine-125 seeds is performed under anesthesia as an out patient to deliver 125 Gy to the prostate

Group III: High dose rate brachytherapy Experimental Treatment 1 Intervention

A single fraction of 19 Gray (Gy) is delivered to the prostate under anesthesia as an out patient.

Group IV: standard Active Control 1 Intervention

External beam radiotherapy to deliver 5500 centiGray (cGy) in 20 fractions to the prostate over 4 weeks

High dose rate brachytherapy is already approved in European Union, United States, Canada, Japan for the following indications:

Approved in European Union as HDR Brachytherapy for:

• Localized prostate cancer
• Locally advanced prostate cancer
• Recurrent prostate cancer

Approved in United States as HDR Brachytherapy for:

• Localized prostate cancer
• Locally advanced prostate cancer
• Recurrent prostate cancer

Approved in Canada as HDR Brachytherapy for:

• Localized prostate cancer
• Locally advanced prostate cancer
• Recurrent prostate cancer

Approved in Japan as HDR Brachytherapy for:

• Localized prostate cancer
• Locally advanced prostate cancer
• Recurrent prostate cancer

Who Is Running the Clinical Trial?

British Columbia Cancer Agency

Lead Sponsor

Trials

181

Recruited

95,900+

Published Research Related to This Trial

High-dose-rate brachytherapy (HDR BRT) is gaining popularity as a treatment for prostate cancer, showing promise in both monotherapy and in combination with external beam radiation therapy (EBRT).

Long-term data indicates that HDR BRT provides effective oncologic outcomes while maintaining a manageable toxicity profile, supporting its use in various clinical scenarios.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

High-dose-rate brachytherapy for prostate cancer: Rationale, current applications, and clinical outcome. Strouthos, I., Karagiannis, E., Zamboglou, N., et al.[2022]

The combination of high-dose-rate (HDR) brachytherapy and external beam radiotherapy (EBRT) resulted in an 86% biochemical control survival rate after 4 years for localized prostate cancer patients, indicating effective treatment outcomes, especially for lower-risk groups.

While the treatment was generally safe, 5% of patients experienced significant complications, including grade 3 urinary retention and chronic genitourinary toxicities, highlighting the need for careful monitoring of side effects.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

High-dose-rate brachytherapy plus external beam radiotherapy for T1 to T3 prostate cancer: an experience in Taiwan. Chen, YC., Chuang, CK., Hsieh, ML., et al.[2007]

A systematic review of 40 studies found that combining external beam radiotherapy (EBRT) with high-dose rate (HDR) brachytherapy (EBTI) provides superior biochemical control and overall survival for prostate cancer patients.

Specifically, the risk of biochemical recurrence and overall survival was significantly better with EBTI compared to EBRT and EBSeeds, with hazard ratios indicating a 40% and 50% increased risk of recurrence and mortality, respectively, for EBRT compared to EBTI.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Comparison of three radiotherapy modalities on biochemical control and overall survival for the treatment of prostate cancer: a systematic review. Pieters, BR., de Back, DZ., Koning, CC., et al.[2018]

High-dose-rate (HDR) brachytherapy as a standalone treatment for low- and intermediate-risk prostate cancer demonstrated excellent efficacy, with 10-year PSA progression-free survival rates of 97.8% and overall survival rates of 76.7% based on a study of 448 men over a median follow-up of 6.5 years.

The treatment was found to be safe, with no late grade 3 to 4 rectal toxicities reported and a low incidence (4.9%) of late grade 3 to 4 genitourinary toxicity, indicating a favorable safety profile for patients.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

High-Dose-Rate Monotherapy for Localized Prostate Cancer: 10-Year Results. Hauswald, H., Kamrava, MR., Fallon, JM., et al.[2022]

In a clinical trial involving 42 men with intermediate-risk prostate cancer, a treatment combining a single 15 Gy HDR brachytherapy boost with a five-fraction external beam radiation therapy (EBRT) resulted in a high biochemical disease-free survival rate of 95.5% after a median follow-up of 36 months.

The treatment demonstrated low toxicity, with only one case of acute Grade 3 gastrointestinal and genitourinary toxicity, and no significant differences in health-related quality of life across urinary, bowel, or sexual domains, suggesting it is a safe and effective option for patients.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

A phase IB clinical trial of 15 Gy HDR brachytherapy followed by hypofractionated/SBRT in the management of intermediate-risk prostate cancer. Den, RB., Greenspan, J., Doyle, LA., et al.[2023]

In a study of 90 men with high-risk prostate cancer treated with high-dose-rate brachytherapy (HDR-BT) after external beam radiation therapy (EBRT), patients reported better physical functioning and global health compared to reference data, although social, role, and cognitive functioning were worse.

The treatment resulted in low toxicity rates (10% gastrointestinal and 12.2% genitourinary adverse effects, all Grade I), indicating that HDR-BT combined with EBRT is effective with minimal adverse effects, and PSA levels may help predict health-related quality of life outcomes.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Health-related quality of life and rates of toxicity after high-dose-rate brachytherapy in combination with external beam radiation therapy for high-risk prostate cancer. Huang-Tiel, HJ., Otto, I., Golka, K., et al.[2021]

Combination high dose rate brachytherapy (HDRB) with external beam radiation therapy is a feasible and effective treatment for localized prostate cancer, showing a 91% prostate-specific antigen progression-free survival rate in 82 patients over a median follow-up of 3 years.

The use of HDRB allows for a shorter overall treatment time and is advantageous both biologically and logistically, making it a practical option for facilities that can perform brachytherapy.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Treatment of localized prostate cancer using a combination of high dose rate Iridium-192 brachytherapy and external beam irradiation: initial Australian experience. Stevens, MJ., Stricker, PD., Saalfeld, J., et al.[2019]

In a study of 101 patients with localized prostate cancer, high-dose rate brachytherapy (HDR) combined with external beam radiation (EBRT) showed promising early efficacy, with 82% of patients free from cancer recurrence after a median follow-up of 56 months.

While there were some significant acute toxicities, such as clot retention and a few serious complications, the long-term side effects were relatively low, with only 8% experiencing late grade 2 genitourinary toxicity and no late grade 3 gastrointestinal toxicity observed.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

HDR brachytherapy combined with external beam radiation for localised prostate cancer: early experience from the Sydney Cancer Centre. Whalley, D., Patanjali, N., Jackson, M., et al.[2018]

In a study of 287 men with intermediate and high-risk prostate cancer, those treated with low dose rate external beam radiotherapy (LDR-EBRT) had a higher biochemical progression-free survival (bPFS) rate of 90.5% at 5 years compared to 77.6% for those treated with high dose rate external beam radiotherapy (HDR-EBRT).

Patients receiving HDR-EBRT were over twice as likely to experience biochemical progression compared to those receiving LDR-EBRT, indicating that LDR-EBRT may offer better long-term control of prostate-specific antigen (PSA) levels.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

A comparison of outcomes for patients with intermediate and high risk prostate cancer treated with low dose rate and high dose rate brachytherapy in combination with external beam radiotherapy. Slevin, F., Rodda, SL., Bownes, P., et al.[2022]

Citations

1. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC6043748/

High dose-rate brachytherapy in the treatment of prostate cancer In summary, HDR brachytherapy boost results in a high disease control rates for men with localized prostate cancer, with strong evidence that it provides ...

2. sciencedirect.com sciencedirect.com/science/article/pii/S2452109425001484

High-dose-rate brachytherapy boost for prostate cancer: A ... Overall, this study demonstrated the efficacy of EBRT-boosted brachytherapy in the treatment of intermediate- and high-risk prostate cancer, ...

3. thegreenjournal.com thegreenjournal.com/article/S0167-8140(24)00651-0/fulltext

Prostate high dose-rate brachytherapy as monotherapy for ... We report on the efficacy of a randomized Phase II trial comparing HDR monotherapy delivered as 27 Gy in 2 fractions vs. 19 Gy in 1 fraction with a median ...

4. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC12190164/

Long-Term Outcomes After High-Dose-Rate Brachytherapy ... These outcomes included lower biochemical recurrence-free survival at 5 and 8 years, lower OS, and lower prostate CSS compared to patients with ...

5. myhealthplanner.com myhealthplanner.com/web/public/brands/medicalpolicyhb/external-policies/high-dose-rate-temporary-prostate-brachytherapy/

High-Dose Rate Temporary Prostate Brachytherapy Long-term survival data are available from case series; 1 found an 8-year survival rate of 95% and another found an actutimes 10-year survival rate of 77%. The ...

6. frontiersin.org frontiersin.org/journals/urology/articles/10.3389/fruro.2025.1598726/full

High-dose-rate brachytherapy lowers travel burden for men ... HDR-BT monotherapy significantly reduces the travel burden compared with EBRT for localized prostate cancer, with minimal treatment-associated toxicity.

7. pubmed.ncbi.nlm.nih.gov pubmed.ncbi.nlm.nih.gov/38160102/

Safety of high-dose rate (HDR) brachytherapy for patients ... Conclusions: HDR-BT is a safe treatment for patients with prostate cancer who previously received RT for rectal cancer. Further studies are ...