MR-guided Radiotherapy for Recurrent Prostate Cancer

Overseen By Alejandro Berlin, MD

Age: 18+

Sex: Male

Trial Phase: Academic

Sponsor: University Health Network, Toronto

Must not be taking: Hormonal therapy

Disqualifiers: Non-skin malignancy, Metastatic disease, 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: 1

Duration: 6 months

100 Participants Needed

What You Need to Know Before You Apply

What is the purpose of this trial?

This trial aims to assist men with prostate cancer that has returned after surgery and radiation by using advanced imaging techniques. It combines a special PET scan with MRI to pinpoint cancer locations that traditional scans might miss. Once identified, these cancer spots will receive treatment with a highly focused form of radiation called stereotactic ablative radiotherapy (also known as Stereotactic Body Radiotherapy or Stereotactic Ablative Body Radiotherapy), which aims to eradicate the tumors with minimal side effects. Men who have experienced a rise in PSA levels (a protein linked to prostate cancer) after surgery and radiation, and have not recently used hormonal therapy, might be suitable candidates for this trial. As an unphased trial, this study offers a unique opportunity to explore cutting-edge imaging and treatment techniques for prostate cancer recurrence.

Will I have to stop taking my current medications?

The trial does not specify if you need to stop taking your current medications, but you cannot have used any form of hormonal therapy in the past 12 months or plan to start it when enrolling.

What prior data suggests that this MR-guided radiotherapy technique is safe for recurrent prostate cancer?

Research has shown that stereotactic ablative radiotherapy (SABR) is generally well-tolerated for treating prostate cancer. Studies have found that administering SABR in specific doses, such as 40 Gy in 5 sessions, results in few additional side effects. Most side effects are mild and manageable for patients.

However, some reports indicate a higher risk of more serious side effects, like grade 3 toxicity, which can impact daily life. These cases are uncommon and often depend on individual patient factors.

In summary, SABR is generally safe, with most patients experiencing mild side effects. However, a small risk of more serious side effects exists for some individuals. ^{1 2 3 4 5}

Why are researchers excited about this trial?

Researchers are excited about MR-guided radiotherapy for recurrent prostate cancer because it offers a more targeted approach compared to traditional treatments like external beam radiotherapy or hormone therapy. This technique uses advanced imaging, specifically [18F] DCFPyL PET/MRI, to precisely locate cancer lesions, allowing stereotactic ablative radiotherapy (SABR) to focus directly on the affected areas while sparing healthy tissue. This precision can potentially reduce side effects and improve outcomes by delivering high doses of radiation to cancer sites with pinpoint accuracy. By enhancing the accuracy of treatment, researchers hope to improve the effectiveness of radiotherapy for patients with recurrent prostate cancer.

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

Research has shown that stereotactic ablative radiotherapy (SABR) effectively treats prostate cancer. Studies indicate that 96% of patients showed no signs of cancer in biopsies taken three years after receiving SABR. Another study found that 87.6% of patients had their cancer under control in the treated area two years post-treatment. Additionally, many patients did not require further hormone therapy five years after SABR. In this trial, lesions identified through [18F] DCFPyL PET/MRI will receive treatment with either SABR or surgery. These findings highlight SABR as a promising method for precisely targeting and treating recurrent prostate cancer. ^{1 2 6 7 8}

Who Is on the Research Team?

Alejandro Berlin, MD

Principal Investigator

Princess Margaret Cancer Centre - University Health Network

Are You a Good Fit for This Trial?

This trial is for men with prostate cancer recurrence after surgery and radiotherapy, who have rising PSA levels but no visible metastases on scans. They should be in good health overall, able to lie still for imaging and treatment, not on hormone therapy recently or planning to start it, and without severe kidney issues or certain blood disorders.

Inclusion Criteria

My cancer has not spread to other parts of my body.

I will start hormone therapy when my PSA level is 6.0ng/ml or higher.

I don't have other major health issues that would prevent me from undergoing curative treatments.

Exclusion Criteria

I have never had cancer that wasn't skin cancer.

Timeline for a Trial Participant

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

Imaging and Localization

Participants undergo whole-body MR anatomical imaging combined with PSMA-targeted [18F]DCFPyL PET to map recurrent disease

1-2 weeks

1 visit (in-person)

Treatment

Identified lesions are treated with image-guided stereotactic ablative radiotherapy (SABR) or surgery

6 months

Follow-up

Participants are monitored for safety, effectiveness, and biochemical response after treatment

6 months

Multiple visits (in-person and virtual)

What Are the Treatments Tested in This Trial?

Interventions

• Stereotactic Ablative Radiotherapy

Trial Overview The study tests a new PET/MRI scan using [18F]DCFPyL to find tiny cancer spread post-prostatectomy that standard scans can't see. Men with detected cancer spots will then receive precise Stereotactic Ablative Radiotherapy (SABR) aimed at eradicating these tumors.

How Is the Trial Designed?

Group I: [18F] DCFPyL PET/MRI Experimental Treatment 2 Interventions

\[18F\] DCFPyL PET/MRI scans for patients with recurrent disease after radical prostatectomy and adjuvant/salvage radiotherapy. Lesions identified through \[18F\] DCFPyL PET/MRI will be treated with stereotactic ablative radiotherapy (SABR) or surgery.

Stereotactic Ablative Radiotherapy is already approved in European Union, United States, United Kingdom for the following indications:

Approved in European Union as Stereotactic Ablative Radiotherapy for:

• Early-stage non-small cell lung cancer
• Liver cancers
• Kidney cancers
• Bone metastasis
• Spinal metastasis
• Prostate cancers

Approved in United States as Stereotactic Ablative Radiotherapy for:

• Early-stage non-small cell lung cancer
• Liver cancers
• Kidney cancers
• Bone metastasis
• Spinal metastasis
• Prostate cancers

Approved in United Kingdom as Stereotactic Ablative Radiotherapy for:

• Early-stage non-small cell lung cancer
• Liver cancers
• Kidney cancers
• Bone metastasis
• Spinal metastasis
• Prostate cancers

Who Is Running the Clinical Trial?

University Health Network, Toronto

Lead Sponsor

Trials

1,555

Recruited

526,000+

Published Research Related to This Trial

Androgen deprivation therapy is the most common treatment for radio-recurrent prostate cancer, but it is only palliative and can have adverse effects due to testosterone suppression.

Stereotactic body radiation therapy (SBRT) offers a promising alternative by delivering high doses to tumors with precision, potentially reducing damage to surrounding tissues, although current data supporting its use is still limited.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Retreatment for prostate cancer with stereotactic body radiation therapy (SBRT): Feasible or foolhardy? Arcangeli, S., Agolli, L., Donato, V.[2020]

In a study involving 20 prostate cancer patients treated with Adaptive Stereotactic Body Radiotherapy (SBRT), the delivered dose was confirmed to be adequate, ensuring that the target area received at least 95% of the prescribed dose while minimizing exposure to surrounding organs.

The study demonstrated that both the daily re-computed doses and cumulative doses were consistent, indicating that the online MRI guidance effectively maintained treatment accuracy despite potential prostate motion during the longer session times.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Adaptive SBRT by 1.5 T MR-linac for prostate cancer: On the accuracy of dose delivery in view of the prolonged session time. Ruggieri, R., Rigo, M., Naccarato, S., et al.[2021]

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 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 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]

The study involving 12 patients with lymph node oligometastases demonstrated that hypofractionated radiotherapy using the 1.5T MR-linac system is feasible, with most pre-treatment plans meeting clinical dose criteria for different fractionation schemes.

However, the quality of treatment plans varied, with single fraction treatments (1x20 Gy) generally being of lesser quality compared to multiple fractions (5x7 Gy and 3x10 Gy), highlighting the importance of considering the target's location relative to critical structures when selecting a treatment plan.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Dosimetric feasibility of hypofractionation for SBRT treatment of lymph node oligometastases on the 1.5T MR-linac. Winkel, D., Werensteijn-Honingh, AM., Eppinga, WSC., et al.[2021]

This multicenter phase I/II study aims to evaluate the safety and efficacy of stereotactic body radiotherapy (SBRT) for patients with localized prostate cancer recurrence after previous radiotherapy, involving at least 47 participants.

The primary goal is to determine the optimal dose of SBRT while monitoring for dose-limiting toxicities, with the secondary aim of assessing the treatment's effectiveness in achieving biochemical relapse-free survival.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

GETUG-AFU 31: a phase I/II multicentre study evaluating the safety and efficacy of salvage stereotactic radiation in patients with intraprostatic tumour recurrence after external radiation therapy-study protocol. Pasquier, D., Le Deley, MC., Tresch, E., et al.[2020]

In a study of 26 patients with low- or intermediate-risk prostate adenocarcinoma, stereotactic body radiation therapy (SBRT) showed excellent biochemical control with no observed failures after a median follow-up of 59.5 months.

The treatment resulted in manageable late toxicity, with only 11.5% of patients experiencing significant genitourinary or gastrointestinal side effects, and patient-reported quality of life remained stable compared to pre-treatment levels.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Prostate Stereotactic Body Radiation Therapy With a Focal Simultaneous Integrated Boost: 5-Year Toxicity and Biochemical Recurrence Results From a Prospective Trial. Maas, JA., Dobelbower, MC., Yang, ES., et al.[2023]

In a study of 515 patients treated with stereotactic body radiation therapy (SBRT) for prostate cancer, the 7-year freedom from biochemical failure rates were excellent, with 95.8% for low-risk, 89.3% for intermediate-risk, and 68.5% for high-risk patients, indicating strong disease control.

The treatment was found to be safe, with no acute Grade 3 or 4 complications and low rates of late toxicity (4% for rectal and 9.1% for urinary Grade 2 toxicity), while quality of life measures returned to baseline within 2 years post-treatment.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Quality of Life and Toxicity after SBRT for Organ-Confined Prostate Cancer, a 7-Year Study. Katz, AJ., Kang, J.[2022]

In a study involving 51 prostate cancer patients treated with stereotactic body radiotherapy (SBRT), the treatment showed promising outcomes with manageable toxicity levels, as no patients experienced severe (grade 3+) side effects during the initial follow-up period.

The median follow-up of 14.5 months revealed a low prostate-specific antigen level of 1.3 ng/ml at 13-18 months post-treatment, indicating effective disease control in this cohort.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Prostate stereotactic body radiotherapy—first UK experience. Tree, AC., Ostler, P., Hoskin, P., et al.[2022]

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) demonstrated high local control rates (96.0% at 2 years) and was well tolerated among 75 patients with oligometastases of prostate cancer, indicating its efficacy and safety as a treatment option.

The study found that SBRT could effectively manage both metastatic hormone-sensitive prostate cancer (mHSPC) and metastatic castration-resistant prostate cancer (mCRPC), providing a potential alternative to delay androgen deprivation therapy (ADT) for mHSPC patients.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Short-Term Outcomes and Clinical Efficacy of Stereotactic Body Radiation Therapy (SBRT) for Oligometastases of Prostate Cancer in China. Xu, C., Zhao, X., Ju, X., et al.[2022]

Citations

1. jamanetwork.com jamanetwork.com/journals/jamaoncology/fullarticle/2763312

Outcomes of Observation vs Stereotactic Ablative ... Conclusions and Relevance Treatment with SABR for oligometastatic prostate cancer improved outcomes and was enhanced by total consolidation of ...

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

Stereotactic ablative body radiotherapy in patients with ... Early outcomes of SABR look very promising. In the pHART3 study, routine biopsies were done 3 years post-treatment. Seventy-one of 74 (96%) of eligible patients ...

3. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC9954604/

Long-Term Outcomes of Stereotactic Body Radiotherapy ... The 2- and 5-year LC were 87.6% and 47.9%, respectively; the 2- and 5-year FFDM were 72.7% and 42.8%, respectively; and the 2- and 5-year PFS ...

4. sciencedirect.com sciencedirect.com/science/article/pii/S0167814025052235

Stereotactic ablative body radiotherapy for PSMA-PET/CT ... A third of oligometastatic prostate cancer patients were ADT free at 5 years post SABR. •. Subsequent courses of SABR was shown to double ...

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

Stereotactic total ablative radiotherapy with MR-LINAC for ... The estimated 3-year OS and PFS rates were 100% and 95.2% (95% confidence interval: 89.0%–100%), respectively. No clinical factors, including ...

6. sciencedirect.com sciencedirect.com/science/article/abs/pii/S1879850025001511

Clinician- and Patient-Reported Outcomes of Stereotactic ... Conclusions. SABR delivering 40 Gy in 5 fractions is feasible and well-tolerated for high-risk prostate cancer, with minimal additional toxicity ...

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

8. 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 ...