SBRT for Prostate Cancer

Recruiting at 1 trial location

Overseen By Tatiana Carvalho

Age: 18+

Sex: Male

Trial Phase: Academic

Sponsor: Fabio Cury

Must not be taking: Finasteride, Dutasteride, Chemotherapy, others

Disqualifiers: Invasive malignancy, Metastases, Surgery, others

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

Approved in 4 Jurisdictions This treatment is already approved in other countries

Compensation: Varies

Number of Visits: 3

Duration: 1 day

12 Participants Needed

What You Need to Know Before You Apply

What is the purpose of this trial?

This trial tests a new method for treating low- and favorable intermediate-risk prostate cancer using a single, high-dose session of Stereotactic Body Radiation Therapy (SBRT). Before treatment, a gel is placed between the prostate and rectum to protect healthy tissue. The trial aims to determine if this one-time treatment is safe and effective. Suitable candidates have confirmed prostate cancer with a PSA level under 15 ng/dL and have not undergone prior prostate surgeries or treatments. As an unphased trial, it provides a unique opportunity to explore innovative treatment options for prostate cancer.

Do I need to stop my current medications to join the trial?

The trial requires stopping finasteride at least 30 days before joining and dutasteride at least 90 days before joining. The protocol does not specify other medications, so check with the trial team for more details.

What prior data suggests that this method is safe for prostate cancer treatment?

Research has shown that single-dose stereotactic body radiation therapy (SBRT) is generally safe for treating prostate cancer. Studies have found that patients usually tolerate it well, with many not requiring additional treatments for several years. A special gel creates space between the prostate and rectum, protecting nearby organs from radiation and potentially reducing side effects. Overall, this treatment appears to be a safe option for consideration. ^{1 2 3 4 5}

Why are researchers excited about this trial?

Researchers are excited about Single Fraction Stereotactic Body Radiation Therapy (SBRT) for prostate cancer because it offers a unique approach compared to traditional treatments like conventional radiation therapy or surgery. Unlike the standard treatments that often require multiple sessions over several weeks, SBRT delivers a precise, high dose of radiation in just one session lasting about 30 minutes. This method uses advanced imaging and intensity-modulated radiation therapy (IMRT) techniques to target the tumor accurately while sparing surrounding healthy tissue. Additionally, the use of a hydrogel spacer and a urinary catheter helps protect nearby organs, potentially reducing side effects. This streamlined approach could significantly improve patient convenience and quality of life.

What evidence suggests that SBRT is effective for prostate cancer?

Research shows that Stereotactic Body Radiation Therapy (SBRT) effectively treats prostate cancer. In this trial, participants will receive a single 19 Gy dose of SBRT, which studies have demonstrated can deliver precise, high-dose radiation to the prostate in just one session. Long-term research suggests that SBRT offers results comparable to other standard treatments, maintaining good disease control over several years. To protect nearby healthy tissue, such as the rectum, from radiation, a hydrogel spacer will be used in this trial. ^{1 3 5 6 7}

Who Is on the Research Team?

Fabio Cury, MD

Principal Investigator

McGill University Health Centre- Cedars Cancer Centre

Are You a Good Fit for This Trial?

Men over 18 with low to favorable intermediate-risk prostate cancer, a recent PSA under 15 ng/dL, Gleason score of 6 or 7(3+4), and good performance status. They must not have had previous radical prostate treatments, hormonal therapies, or chemotherapy for prostate cancer and should be free from distant metastases and severe health conditions.

Inclusion Criteria

I have been mostly active and able to carry on all pre-disease activities without restriction recently.

I am older than 18 years.

Patient must be able to provide study-specific informed consent prior to study entry.

Exclusion Criteria

My cancer has spread to distant parts of my body.

You have had prostate cancer treatment such as surgery, radiation therapy, or hormone therapy in the past.

I have been cancer-free for at least 5 years, except for non-melanoma skin cancer or in situ carcinoma.

Timeline for a Trial Participant

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

Pre-treatment

A gel is injected between the prostate and the rectum using a transrectal ultrasound, followed by a CT and MRI scan for treatment planning

1 week

2 visits (in-person)

Treatment

Participants receive a single fraction of SBRT with a hydrogel spacer and urinary catheter in place

1 day

1 visit (in-person)

Follow-up

Participants are monitored for safety and effectiveness, including assessment of GI and GU toxicity

3 months

Long-term follow-up

Participants are monitored for PSA control and late toxicity

5 years

What Are the Treatments Tested in This Trial?

Interventions

• SBRT

Trial Overview The trial is testing a one-time Stereotactic Body Radiation Therapy (SBRT) treatment in patients who've had SpaceOAR hydrogel inserted to increase space between the prostate and rectum. It's a phase I study focusing on safety for those with specific types of early-stage prostate cancer.

How Is the Trial Designed?

Group I: Single Fraction SBRT in the treatment of prostate cancer Experimental Treatment 1 Intervention

Prior to treatment, a hydrogel spacer will be inserted between the recutm and prostate. A urinary catheter will also be inserted in the bladder. A single dose of 19Gy will be delivered with an IMRT technique. The treatment should last approximately 30 minutes. After the treatment, the urinary catheter will be removed.

SBRT is already approved in United States, European Union, Canada, Japan for the following indications:

Approved in United States as SBRT for:

• Prostate cancer
• Lung cancer
• Liver cancer
• Pancreatic cancer
• Spinal tumors

Approved in European Union as SBRT for:

• Prostate cancer
• Lung cancer
• Liver cancer
• Pancreatic cancer
• Spinal tumors
• Bone metastases

Approved in Canada as SBRT for:

• Prostate cancer
• Lung cancer
• Liver cancer
• Pancreatic cancer
• Spinal tumors

Approved in Japan as SBRT for:

• Prostate cancer
• Lung cancer
• Liver cancer
• Pancreatic cancer

Who Is Running the Clinical Trial?

Fabio Cury

Lead Sponsor

Trials

1

Recruited

10+

Boston Scientific Corporation

Industry Sponsor

Trials

758

Recruited

867,000+

Michael F. Mahoney

Boston Scientific Corporation

Chief Executive Officer since 2016

MBA from Wake Forest University, BBA in Finance from the University of Iowa

Kenneth Stein

Boston Scientific Corporation

Chief Medical Officer since 2020

MD from Harvard Medical School, MMSc in Clinical Investigation from Harvard-MIT Division of Health Sciences and Technology

Published Research Related to This Trial

Stereotactic body radiotherapy (SBRT) for localized prostate cancer shows promising results, with studies indicating that ultra-hypofractionated schedules (like 42.7 Gy in 7 fractions) are non-inferior to standard treatments in terms of 5-year biochemical recurrence-free survival and have similar tolerability.

Current evidence suggests that two-fraction SBRT may be the shortest effective treatment schedule, but caution is advised against single-fraction SBRT due to concerns about inferior efficacy, highlighting the need for ongoing trials to determine optimal fractionation schedules.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

The march toward single-fraction stereotactic body radiotherapy for localized prostate cancer-Quo Vadimus? Ong, WL., Loblaw, A.[2023]

A study involving 803 patients analyzed the quality of life (QOL) impacts of SBRT, IMRT, and brachytherapy for localized prostate cancer, showing that all treatments resulted in good QOL two years post-treatment.

SBRT demonstrated similar outcomes to IMRT in urinary and sexual domains, but showed a significant improvement in bowel symptoms compared to brachytherapy, suggesting it may be a safer option with fewer side effects.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Patient-reported quality of life after stereotactic body radiotherapy (SBRT), intensity modulated radiotherapy (IMRT), and brachytherapy. Evans, JR., Zhao, S., Daignault, S., et al.[2022]

Stereotactic body radiation therapy (SBRT) for localized prostate cancer showed a high two-year biochemical relapse-free survival rate of 99%, indicating its efficacy in controlling the disease.

The treatment was well tolerated, with low rates of gastrointestinal (1%) and genitourinary (31%) toxicities, and most patients who were sexually potent before treatment maintained their potency two years later.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Stereotactic body radiation therapy (SBRT) for clinically localized prostate cancer: the Georgetown University experience. Chen, LN., Suy, S., Uhm, S., et al.[2022]

In a prospective phase II trial involving 110 patients aged 70 and older with localized prostate cancer, stereotactic body radiotherapy (SBRT) demonstrated a severe toxicity rate of less than 5%, confirming its safety for this patient population.

The SBRT regimen resulted in a biochemical progression-free survival (bPFS) rate of 90% over a median follow-up of 36 months, indicating its efficacy in treating localized prostate cancer without negatively impacting patients' quality of life.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Prospective validation of stringent dose constraints for prostatic stereotactic radiation monotherapy: results of a single-arm phase II toxicity-oriented trial. Nguyen, P., Harzée, L., Retif, P., et al.[2022]

Stereotactic body radiation therapy (SBRT) is a promising treatment for prostate cancer, offering a shorter treatment course and potentially more effective tumor cell killing compared to conventional radiation therapy, but long-term safety and efficacy data are still lacking.

Current studies show encouraging results for SBRT in terms of biochemical control and late toxicity, but due to limitations like short follow-up and small patient numbers, SBRT should only be used in clinical trials at this time.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Stereotactic body radiation therapy for prostate cancer: is the technology ready to be the standard of care? Zaorsky, NG., Studenski, MT., Dicker, AP., et al.[2013]

Stereotactic body radiotherapy (SBRT) is shown to be safe and effective for treating node-positive prostate cancer, with a median follow-up of 30 months revealing no severe gastrointestinal toxicities and manageable genitourinary side effects.

In a study of 60 patients, SBRT resulted in a 3-year overall survival rate of 89% and a biochemical failure-free survival rate of 77%, indicating promising long-term outcomes even in patients with advanced disease.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Safety and Efficacy of Ultra-hypofractionation in Node-positive Prostate Cancer. Telkhade, T., Murthy, V., Kanala, TS., et al.[2021]

Stereotactic body radiation therapy (SBRT) for localized prostate cancer showed similar 5-year survival rates (90.8% for SBRT vs. 88.1% for IMRT) and comparable freedom from biochemical failure (FFBF) rates, indicating its efficacy is on par with intensity-modulated radiation therapy (IMRT).

Both treatment methods had low toxicity, with no severe (grade 3 or higher) side effects reported, suggesting that SBRT is a safe alternative that offers the benefits of shorter treatment duration and lower costs.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Propensity score matched comparison of SBRT versus IMRT for the treatment of localized prostate cancer. Oliai, C., Bernetich, M., Brady, L., et al.[2022]

Stereotactic ablative radiation (SAbR) at a dose of 45 Gy in 5 fractions shows a promising safety profile for treating localized prostate cancer, with acute urinary and gastrointestinal toxicity rates of 20.4% and 7.3%, respectively, and low rates of late toxicity after 2 years.

The treatment demonstrated excellent efficacy, with a biochemical failure-free survival rate of 100% at 1 year and 98.7% at 2 years, indicating strong disease control outcomes for patients.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Dose-Intensified Stereotactic Ablative Radiation for Localized Prostate Cancer. Chen, L., Gannavarapu, BS., Desai, NB., et al.[2022]

Stereotactic body radiotherapy (SBRT) shows a high local control rate of 98.1% in treating oligorecurrent prostate cancer limited to lymph nodes, based on a systematic review of 363 patients across nine studies with a median follow-up of 19.23 months.

The treatment demonstrated a low incidence of toxicity, with only 5.6% of patients experiencing grade ≥2 adverse effects, and no cases of grade 4 toxicity, suggesting that SBRT is a safe option for this patient group.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Exploring All Avenues for Radiotherapy in Oligorecurrent Prostate Cancer Disease Limited to Lymph Nodes: A Systematic Review of the Role of Stereotactic Body Radiotherapy. Ponti, E., Lancia, A., Ost, P., et al.[2022]

In a study of 84 low-risk prostate cancer patients treated with Stereotactic Ablative Body Radiotherapy (SABR), long-term quality of life (QOL) outcomes were generally positive, with a median follow-up of 50.8 months, although some patients reported declines in urinary (17.9%), bowel (26.2%), and sexual (37.5%) QOL domains.

Dosimetric factors such as rectal D1cc and penile bulb V35 were identified as significant predictors of worse QOL, highlighting the importance of adhering to strict dosimetric constraints to minimize side effects from treatment.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Dosimetric and patient correlates of quality of life after prostate stereotactic ablative radiotherapy. Elias, E., Helou, J., Zhang, L., et al.[2018]

In a study of 152 men with intermediate risk prostate cancer, weekly stereotactic ablative radiotherapy (SABR) resulted in better short-term bowel and urinary quality of life compared to every other day treatment, but there were no significant differences in late toxicity or long-term quality of life outcomes after 62 months.

Both treatment regimens showed similar rates of biochemical failure and overall survival, indicating that while weekly SABR may reduce acute side effects, it does not compromise long-term efficacy or safety.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Accelerating prostate stereotactic ablative body radiotherapy: Efficacy and toxicity of a randomized phase II study of 11 versus 29 days overall treatment time (PATRIOT). Alayed, Y., Quon, H., Ong, A., et al.[2021]

A single session of stereotactic ablative body radiotherapy (SABR) for oligometastatic prostate cancer was found to be feasible and safe, with only one significant adverse event (a vertebral fracture) reported among 33 patients over a 2-year follow-up period.

The treatment resulted in high local progression-free survival rates of 97% at 1 year and 93% at 2 years, with nearly half of the patients (48%) avoiding the need for androgen deprivation therapy at the 2-year mark, indicating effective disease control and maintained quality of life.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Stereotactic Abative Body Radiotherapy (SABR) for Oligometastatic Prostate Cancer: A Prospective Clinical Trial. Siva, S., Bressel, M., Murphy, DG., et al.[2022]

Stereotactic ablative radiotherapy (SABR) has been shown to be feasible and well tolerated for low- and intermediate-risk prostate cancer patients, with promising results from large randomized studies comparing it to conventional treatments.

While SABR shows potential benefits and cost-effectiveness, there is currently insufficient data to recommend its use for high-risk prostate cancer patients outside of clinical trials.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Stereotactic Ablative Body Radiotherapy for Intermediate- or High-Risk Prostate Cancer. Loblaw, A.[2021]

In a study comparing two different fractionation schedules of stereotactic ablative radiotherapy (SABR) for prostate cancer, the 2-fraction treatment (26 Gy/2) showed significantly better quality of life (QOL) outcomes in the bowel domain compared to the 5-fraction treatment (40 Gy/5), with a lower rate of clinically important changes in bowel function.

Both treatment groups had low five-year biochemical failure rates (3.3% for 2-fraction and 4.6% for 5-fraction), indicating that the 2-fraction SABR is not only effective but also well tolerated, warranting further randomized trials to confirm these findings.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Two versus five stereotactic ablative radiotherapy treatments for localized prostate cancer: A quality of life analysis of two prospective clinical trials. Alayed, Y., Quon, H., Cheung, P., et al.[2020]

Citations

1. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC6460234/

Single-fraction Stereotactic Body Radiation Therapy versus ... This study aimed to compare outcomes of patients with prostate cancer with bone metastases treated with stereotactic body radiation therapy ...

2. sciencedirect.com sciencedirect.com/science/article/pii/S2405632424000209

Stereotactic body radiation therapy (SBRT) for prostate ... Very accurate dose delivery was achieved with the three arrangements, with mean γ passing rates >96.5 % (2 %/2 mm criteria). Slightly but significantly higher γ ...

3. ro-journal.biomedcentral.com ro-journal.biomedcentral.com/articles/10.1186/s13014-025-02713-9

PRO-FAST single-fraction ablative, urethral-sparing, HDR-like ... A 2018 phase I/II study tested a single 19 Gy SBRT fraction [32], though 19 Gy HDR-BT showed lower 5-year biochemical control (66–73%) [5, 6, 33 ...

4. jamanetwork.com jamanetwork.com/journals/jamanetworkopen/fullarticle/2723641

Long-term Outcomes of Stereotactic Body Radiotherapy for ... This cohort study of pooled individual patient data assesses long-term outcomes after stereotactic body radiotherapy for low-risk and ...

5. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC6043737/

Stereotactic ablative body radiotherapy in patients with ... Efficacy for SABR appears to be similar to brachytherapy including positive biopsy rates 2–3 years post treatment, biochemical failure (BF) rates out to 10-year ...

6. sciencedirect.com sciencedirect.com/science/article/abs/pii/S0360301620343996

Safety, Efficacy, and Patterns of Failure After Single ... Conclusion. SF SBRT is safe and effective, and a significant proportion of patients remain free from systemic therapy for several years after SBRT. After ...

7. thegreenjournal.com thegreenjournal.com/issue/S0167-8140(25)X0003-7?pageStart=26

May 2025 Prostate cancer focal boost versus no boost in 20 fraction external beam radiotherapy: a prospective cohort on dosimetry, toxicity and quality of life