Targeted Radiotherapy for Prostate Cancer

Overseen By Murtuza Saifuddin, M.S.

Age: 18+

Sex: Male

Trial Phase: Academic

Sponsor: Sunnybrook Health Sciences Centre

Disqualifiers: Inflammatory bowel disease, Hip replacement, others

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

Approved in 3 Jurisdictions This treatment is already approved in other countries

Compensation: Varies

Number of Visits: 4

Duration: 5 fractions

20 Participants Needed

What You Need to Know Before You Apply

What is the purpose of this trial?

This trial aims to determine if a new targeted radiotherapy, called MR Linac delivered Radiotherapy, can reduce side effects for men with intermediate-risk localized prostate cancer. Participants will undergo five sessions of focused radiation, adjusted using MRI scans to precisely target the cancer. The main goal is to find a treatment method that reduces unwanted side effects while monitoring for cancer recurrence and changes in sexual health or urinary and digestive issues. Men with prostate cancer confirmed by biopsy, a specific tumor grade, and visible tumors on MRI scans might be suitable for this trial. As an unphased trial, this study provides participants the chance to contribute to innovative research that could enhance future prostate cancer treatments.

Will I have to stop taking my current medications?

The trial does not specify if you need to stop taking your current medications. However, if you are on androgen deprivation therapy (a treatment to lower male hormones), you may continue it for less than 6 months if your doctor agrees.

What prior data suggests that this protocol is safe?

Research has shown that MR Linac radiotherapy is generally well-tolerated by patients with localized prostate cancer. This method uses MRI to precisely target the cancer, reducing the risk of severe side effects immediately after treatment.

One study found that MR Linac technology results in a favorable side effect profile, with most patients experiencing only mild or manageable side effects. Another study highlighted that this technology allows for better visualization and tracking during treatment, which helps protect nearby healthy tissues.

Overall, evidence suggests that MR Linac therapy is safe for many patients, with a low risk of severe side effects. However, individual experiences may vary, so discussing potential risks with a healthcare provider is important. ^{1 2 3 4 5}

Why are researchers excited about this trial?

Most treatments for prostate cancer use conventional radiotherapy, which can sometimes affect healthy tissues surrounding the tumor. However, researchers are excited about MR Linac delivered radiotherapy because it combines an MRI scanner with a linear accelerator in a single device. This allows for real-time imaging and precise targeting of the cancerous tissue, potentially minimizing damage to surrounding healthy cells. This precision could lead to fewer side effects and improved outcomes, making it a promising advancement in prostate cancer treatment.

What evidence suggests that MR Linac delivered Radiotherapy is effective for prostate cancer?

Research has shown that MR Linac radiotherapy, which participants in this trial will receive, holds promise for treating prostate cancer. This method combines MRI (a scan using magnets) with precise radiation, enabling doctors to target cancer more accurately while protecting healthy tissue. Studies have found that this approach can improve survival rates and reduce side effects compared to traditional treatments. MR Linac also allows for adaptive treatments, meaning the radiation plan can be adjusted on the spot if the tumor or patient's body changes. This precision aims to reduce harm to nearby organs and enhance overall quality of life. ^{2 6 7 8 9}

Who Is on the Research Team?

Danny Vesprini, MD

Principal Investigator

Sunnybrook Health Sciences Centre

Are You a Good Fit for This Trial?

Men aged 18 or older with intermediate risk localized prostate cancer, Gleason score between 3+3 and 4+3, MRI stage T2 or less. They must have a visible tumor on MRI that's less than half the size of the prostate and PSA <20 ng/ml. Short-term hormone therapy is allowed.

Inclusion Criteria

Your PSA level is less than 20 ng/ml before starting treatment.

My prostate tumor is visible on MRI and occupies less than half of my prostate.

My MRI shows a tumor with a grade 3 or higher rating.

Timeline for a Trial Participant

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

Treatment

Participants receive 5 fraction SBRT to the prostate with dose variations based on mpMRI, PSA, and histology

5 fractions

Scans before and during radiotherapy on the MR-linac

Follow-up

Participants are monitored for safety and effectiveness after treatment, with assessments at 4 and 12 weeks, and 6, 12, and 24 months

24 months

Assessments at 4 and 12 weeks, and 6, 12, and 24 months

Long-term follow-up

Participants are followed up for recurrence/biochemical failure as per standard care

Beyond 24 months

What Are the Treatments Tested in This Trial?

Interventions

• MR Linac delivered Radiotherapy

Trial Overview The trial tests a new way to give radiotherapy for prostate cancer using an MR Linac machine. It aims to tailor the radiation dose specifically to each patient's tumor, potentially reducing side effects by either increasing or decreasing the dose as needed.

How Is the Trial Designed?

Group I: Interventional Experimental Treatment 1 Intervention

All radiotherapy will be delivered on the MR-linac

MR Linac delivered Radiotherapy is already approved in European Union, United States, Canada for the following indications:

Approved in European Union as Stereotactic Body Radiation Therapy (SBRT) for:

• Localized prostate cancer
• Intermediate-risk prostate cancer
• High-risk prostate cancer

Approved in United States as Stereotactic Body Radiation Therapy (SBRT) for:

• Localized prostate cancer
• Intermediate-risk prostate cancer
• High-risk prostate cancer

Approved in Canada as Stereotactic Body Radiation Therapy (SBRT) for:

• Localized prostate cancer
• Intermediate-risk prostate cancer
• High-risk prostate cancer

Who Is Running the Clinical Trial?

Sunnybrook Health Sciences Centre

Lead Sponsor

Trials

693

Recruited

1,569,000+

Published Research Related to This Trial

The use of a magnetic resonance linear accelerator (MR-Linac) for adaptive radiation therapy allowed for precise targeting and significant inter-fraction tumor regression in a patient with advanced prostate cancer, with a notable 49% reduction in tumor volume during treatment.

The patient experienced improved urinary symptoms and pain relief, highlighting the efficacy and safety of MR-guided adaptive radiation therapy in delivering high-dose palliative treatment while minimizing radiation exposure to surrounding healthy tissues.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Case Report: MR-Guided Adaptive Radiotherapy, Some Room to Maneuver. Li, W., Winter, J., Padayachee, J., et al.[2022]

In a study of 200 prostate cancer patients treated with MR-guided stereotactic body radiotherapy (SBRT), the treatment demonstrated low acute toxicity, with the most common side effect being mild urinary issues in 31% of patients.

The therapy resulted in a significant decrease in Prostate Specific Antigen (PSA) levels in 99% of patients, indicating effective treatment outcomes, while real-time MRI monitoring ensured precise targeting during the procedure.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Outcome of the first 200 patients with prostate cancer treated with MRI-Linac at Assuta MC. Gelbart Pridan, O., Ben David, MA., Zalmanov, S., et al.[2023]

In a study of 135 patients with prostate cancer, stereotactic body radiotherapy (SBRT) using 1.5-T MR-guided radiotherapy (MRgRT) was found to be feasible and safe, with similar rates of acute toxicity compared to conventional volumetric modulated arc therapy (VMAT).

While there was no significant difference in overall acute toxicity between MR-linac and conventional linac, MRgRT showed a potential trend towards reduced grade 2 gastrointestinal toxicity, suggesting it may be a safer option for patients.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Linac-based versus MR-guided SBRT for localized prostate cancer: a comparative evaluation of acute tolerability. Nicosia, L., Mazzola, R., Rigo, M., et al.[2023]

The use of MR-guided stereotactic body radiation therapy (SBRT) for prostate cancer has shown promising results in reducing acute genitourinary (GU) toxicities, making it a safer option compared to traditional CT-guided methods, as demonstrated in the MIRAGE trial.

A new phase II trial is underway to compare the efficacy and toxicity of delivering MR-guided SBRT in 2 fractions versus 5 fractions, with 136 men participating, aiming to determine if fewer treatment sessions can maintain similar safety profiles over a 2-year period.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

A randomized phase II trial of MR-guided prostate stereotactic body radiotherapy administered in 5 or 2 fractions for localized prostate cancer (FORT). Wolfe, S., Diven, MA., Marciscano, AE., et al.[2023]

The study demonstrated the feasibility of using a 1.5 T MRI-linear accelerator (MR-Linac) for salvage radiotherapy (SRT) in 16 prostate cancer patients, with a high success rate of 94.6% for treatment fractions and no patient-sided treatment failures.

Patients reported high tolerability of the treatment, with low rates of acute toxicity observed during and three months after radiotherapy, indicating that this method is safe and well-suited for clinical use.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

First Experience and Prospective Evaluation on Feasibility and Acute Toxicity of Online Adaptive Radiotherapy of the Prostate Bed as Salvage Treatment in Patients with Biochemically Recurrent Prostate Cancer on a 1.5T MR-Linac. Wegener, D., Thome, A., Paulsen, F., et al.[2022]

A meta-analysis of 29 studies involving 2547 patients found that MRg-A-SBRT significantly reduces the risk of acute grade 2 or higher genitourinary (GU) toxicity by 44% and gastrointestinal (GI) toxicity by 60% compared to CT-SBRT.

MRg-A-SBRT offers a safer alternative for prostate cancer treatment by minimizing short-term side effects, although further research is needed to assess long-term toxicity and disease control outcomes.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Acute toxicity comparison of magnetic resonance-guided adaptive versus fiducial or computed tomography-guided non-adaptive prostate stereotactic body radiotherapy: A systematic review and meta-analysis. Leeman, JE., Shin, KY., Chen, YH., et al.[2023]

Citations

1. redjournal.org redjournal.org/article/S0360-3016(24)03520-X/abstract

Enhancing Delivery Efficiency on the Magnetic Resonance ... This work aims for significantly enhancing the delivery efficiency on the magnetic resonance linear accelerator (MR-linac) by introducing ...

2. targetedonc.com targetedonc.com/view/mr-linac-provides-greater-precision-with-adaptive-radiation-across-cancers

MR-LINAC Provides Greater Precision With Adaptive ... MR-LINAC (magnetic resonance-guided linear accelerator) is a new technology that provides greater precision of radiation treatment via adaptive treatment ...

3. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC8978250/

MR-guided radiotherapy for prostate cancer - PubMed Central This review summarises the potential and current evidence for MRI-guided radiotherapy, with a predominant focus on prostate cancer.

4. sciencedirect.com sciencedirect.com/science/article/pii/S2405630824000193

MRI-guided radiotherapy in twenty fractions for localised ... To our knowledge, this is the first paper which assesses the outcomes of moderately hypofractionated radiotherapy on a 1.5 T MR-Linac for prostate cancer.

5. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC12268278/

Stereotactic total ablative radiotherapy with MR-LINAC for ... MRgSTAR demonstrates promising early survival outcomes and a favorable toxicity profile in synchronous OMPC, warranting further investigation to ...

6. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC10544147/

A randomized phase II trial of MR-guided prostate stereotactic ... MR-LINAC technology facilitates improved visualization of the prostate, real-time intrafraction tracking of prostate and organs-at-risk (OAR), ...

7. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC10813892/

MR-LINAC, a New Partner in Radiation Oncology To investigate the tolerability of MR-LINAC based stereotactic ablative radiotherapy (MRL-SBRT) for patients with localized prostate cancer.

8. frontiersin.org frontiersin.org/journals/oncology/articles/10.3389/fonc.2025.1607610/full

Stereotactic total ablative radiotherapy with MR-LINAC for ... MRgSTAR demonstrates promising early survival outcomes and a favorable toxicity profile in synchronous OMPC, warranting further investigation to confirm its ...

9. jamanetwork.com jamanetwork.com/journals/jamanetworkopen/fullarticle/2818117

Safety and Tolerability of Online Adaptive High-Field ... The findings of this study suggest that online adaptive MR-guided radiotherapy is associated with a low risk of high-grade acute toxic effects.