Hormone Therapy + SBRT for Prostate Cancer

Overseen By Patrick Cheung

Age: 18+

Sex: Male

Trial Phase: Phase 1 & 2

Sponsor: Sunnybrook Health Sciences Centre

Must be taking: ADT

Disqualifiers: Castrate resistant, Recent malignancy, others

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

Compensation: Varies

Number of Visits: Unknown

Duration: 8 months

What You Need to Know Before You Apply

What is the purpose of this trial?

This trial tests whether a new, focused type of radiotherapy, called stereotactic radiotherapy, can enhance prostate cancer treatment when combined with hormone therapy. Researchers aim to determine if targeting all tumors identified by a special PSMA PET scan (a detailed imaging method) is more effective than using drugs alone. Suitable candidates include those with prostate cancer that has spread to a few areas, remains undetected by regular scans, and can be treated with this new radiotherapy. As a Phase 1, Phase 2 trial, this research examines how the treatment works in people and measures its effectiveness in an initial, smaller group.

Will I have to stop taking my current medications?

The trial information does not specify whether you need to stop taking your current medications. It's best to discuss this with the trial coordinators or your doctor.

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

Studies have shown that stereotactic body radiotherapy (SBRT) is both effective and safe for treating prostate cancer. Research indicates that even patients with aggressive prostate cancer tolerated SBRT well, experiencing few serious side effects. One study found that administering a specific SBRT dose of 45 Gy over 5 treatments is generally safe and well-tolerated by patients.

Hormone therapy is also part of this trial. It is a common treatment for prostate cancer and is usually well-tolerated. While side effects like tiredness or mood changes can occur, they are typically manageable.

Overall, existing research suggests that both SBRT and hormone therapy are safe options for many patients. However, every treatment can affect people differently, so discussing any concerns with a doctor is important. ^{1 2 3 4 5}

Why are researchers excited about this trial's treatments?

Researchers are excited about the combination of hormone therapy with Stereotactic Body Radiation Therapy (SBRT) for prostate cancer because it targets metastatic sites more precisely than standard treatments. While typical hormone therapy can control cancer growth systemically, SBRT allows for high-dose radiation targeting of specific metastatic sites, potentially leading to better control of the disease with fewer side effects. This approach could mean more effective management of prostate cancer that has spread, offering patients a treatment that could shrink tumors faster and improve quality of life.

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

Research has shown that stereotactic body radiotherapy (SBRT) is very promising for treating prostate cancer. In one study, 96% of patients experienced positive results three years after receiving SBRT. Another study found that SBRT is generally safe and causes few side effects, even for high-risk patients. Additionally, using SBRT for prostate cancer that has spread to a few areas (known as oligometastatic cancer) improved patient outcomes. In this trial, one group of participants will receive SBRT combined with hormone therapy, a well-known treatment that reduces or blocks hormones that help cancer grow. Another group will receive hormone therapy alone. Together, these treatments might effectively manage prostate cancer. ^{1 5 6 7 8}

Are You a Good Fit for This Trial?

Men over 18 with hormone-sensitive, oligometastatic prostate cancer visible on PSMA PET-CT but not on conventional imaging. They must have a good performance status (able to carry out daily activities), up to 3 areas of metastasis treatable by SBRT, and controlled primary tumor without progression. Excluded are those with castrate-resistant cancer, spinal cord compression, recent ADT for palliation or other cancers in the past 5 years.

Inclusion Criteria

My cancer has spread to no more than 3 areas, as shown by a PSMA scan.

Able to provide informed consent.

I am fully active or can carry out light work.

Exclusion Criteria

I have not had cancer, except for non-melanoma skin or in-situ cancer, in the last 5 years.

I have health issues that make hormone therapy or radiation unsuitable for me.

I have used hormone therapy for prostate cancer over a year ago with the aim to cure.

Timeline for a Trial Participant

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

Treatment

Intermittent hormone treatment with or without stereotactic body radiotherapy for a minimum of 8 months

8 months

Follow-up

Participants are monitored for safety and effectiveness after treatment

5 years

What Are the Treatments Tested in This Trial?

Interventions

• Hormone therapy
• Stereotactic Body Radiotherapy

Trial Overview The trial is testing if adding stereotactic body radiotherapy (SBRT) to hormone therapy improves outcomes in patients with specific types of advanced prostate cancer that's still responsive to hormones and has limited spread as seen on specialized scans.

How Is the Trial Designed?

Group I: Arm 2: SBRT to mets Experimental Treatment 2 Interventions

Intermittent Hormone treatment (minimum of 8 months) \+ SBRT to all sites of metastatic disease

Group II: Arm 1: Standard of Care Active Control 1 Intervention

Intermittent Hormone treatment (minimum of 8 months)

Who Is Running the Clinical Trial?

Sunnybrook Health Sciences Centre

Lead Sponsor

Trials

693

Recruited

1,569,000+

Published Research Related to This Trial

In a study of 230 men with early low-risk prostate cancer treated with stereotactic body radiotherapy (SBRT), the ten-year biochemical disease-free survival rate was an impressive 93%, indicating high efficacy of this treatment.

The treatment showed low toxicity, with only 10% of patients experiencing mild late urinary toxicity and 4% with late rectal toxicity, while quality of life scores for bowel and urinary function returned to baseline after initial declines.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Stereotactic Body Radiotherapy for Low-Risk Prostate Cancer: A Ten-Year Analysis. Katz, A.[2020]

In a study of 713 men treated with stereotactic body radiation therapy (SBRT) for localized prostate cancer, only 3% to 4% experienced significant long-term declines in health-related quality of life (HRQOL), indicating that SBRT has minimal long-term negative effects on overall well-being.

Factors such as lower baseline bowel HRQOL and depression were found to predict declines in HRQOL, suggesting that comorbid conditions may play a larger role in patient outcomes than the treatment itself.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Predictors of multidomain decline in health-related quality of life after stereotactic body radiation therapy (SBRT) for prostate cancer. Dess, RT., Jackson, WC., Suy, S., et al.[2022]

The use of stereotactic body radiation therapy (SBRT) for low and intermediate risk prostate cancer increased dramatically from 0.9% in 2004 to 19.5% in 2015, indicating growing acceptance of this treatment method.

SBRT has been shown to have a favorable toxicity profile and efficacy, leading to a significant decline in conventional fractionation treatments, which dropped from 96.3% to 75.8% during the same period.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Current use of stereotactic body radiation therapy for low and intermediate risk prostate cancer: A National Cancer Database Analysis. Malouff, TD., Stross, WC., Seneviratne, DS., et al.[2021]

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 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 of 44 prostate cancer patients treated with a combination of conventional pelvic radiation and an extreme hypofractionation SBRT boost, the five-year progression-free survival rate was an impressive 88.2%, indicating effective long-term control of the disease.

The treatment was associated with low rates of severe toxicity, with only 2.3% experiencing grade III or greater acute genitourinary and gastrointestinal side effects, suggesting that this approach is both effective and safe for patients with advanced prostate cancer.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Phase I/II Study of Extreme Hypofractionated Stereotactic Body Radiation Therapy Boost to Prostate for Locally Advanced, Node-Positive and Oligometastatic Cancer. Narang, K., Kadian, M., Venkatesan, K., et al.[2021]

Stereotactic body radiation therapy (SBRT) and high-dose-rate brachytherapy (HDRBT) are effective modern treatments for prostate cancer, allowing for higher doses of radiation to be delivered precisely to the tumor while protecting surrounding healthy tissue.

These treatments are particularly beneficial for men with low- and intermediate-risk prostate cancer, as they can potentially shorten treatment duration while maintaining effective oncological outcomes and minimizing toxicity.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Ablative Radiotherapy in Prostate Cancer: Stereotactic Body Radiotherapy and High Dose Rate Brachytherapy. Ma, TM., Lilleby, O., Lilleby, WA., et al.[2023]

Stereotactic body radiation therapy (SBRT) resulted in significantly lower post-treatment PSA levels compared to intensity-modulated radiation therapy (IMRT) at 2 and 3 years, indicating better efficacy in controlling prostate cancer.

Both SBRT and IMRT showed similar overall survival rates after 5 years, but SBRT offers advantages such as lower cost and easier application, making it a suitable alternative for treating localized prostate cancer.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

[Stereotactic body radiation therapy versus conventional intensity-modulated radiation therapy for the treatment of prostate cancer]. Gao, QN.[2022]

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]

Citations

1. 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 ...

2. 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 ...

3. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC6484596/

Long-term Outcomes of Stereotactic Body Radiotherapy for ... Comparative analysis of efficacy and safety of radiation treatment options for low- and intermediate-risk prostate cancer.

4. sciencedirect.com sciencedirect.com/science/article/pii/S2588931125000860

Long-term Oncological Outcomes in the Phase 2 PATRIOT ... This study suggests no significant differences in long-term cancer outcomes between EOD and QW schedules for five-fraction prostate SABR.

5. 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 ...

6. 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 ...

7. thegreenjournal.com thegreenjournal.com/article/S0167-8140(25)04545-1/fulltext

A site-specific analysis of the prospective, phase II ... Among patients with oligoprogressive prostate cancer, SBRT is an effective and safe intervention, including in patients with aggressive ...

8. frontiersin.org frontiersin.org/journals/oncology/articles/10.3389/fonc.2022.779182/full

Dose-Intensified Stereotactic Ablative Radiation for ... SAbR for PCa at 45 Gy in 5 fractions shows an encouraging safety profile. Prospective studies with longer follow-up are warranted to establish this dose ...