SBRT + Radium-223 for Prostate Cancer

Not currently recruiting at 9 trial locations

Overseen By Brandon Imber, MD

Age: 18+

Sex: Male

Trial Phase: Phase 2

Sponsor: Memorial Sloan Kettering Cancer Center

Must not be taking: Radionuclide agents

Disqualifiers: Castration resistant prostate cancer, others

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

Prior Safety Data This treatment has passed at least one previous human trial

Compensation: Varies

Number of Visits: Unknown

Duration: 8-10 weeks

What You Need to Know Before You Apply

What is the purpose of this trial?

This trial tests a new combination of treatments for prostate cancer that has spread to the bones. Some participants will receive both Radium dichloride, a study drug, and Stereotactic Body Radiation Therapy (SBRT), while others will receive only SBRT. The researchers aim to determine if adding Radium dichloride enhances the treatment's effectiveness compared to SBRT alone. Men who have previously treated prostate cancer but now have 1–3 active bone spots may be suitable for this study. As a Phase 2 trial, this research focuses on evaluating the treatment's effectiveness in an initial, smaller group of participants.

Do I need to stop my current medications for this trial?

The trial information does not specify if 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?

Research has shown that Radium-223 is generally well-tolerated by patients with prostate cancer that has spread to the bones. Studies have found that Radium-223 can improve quality of life and delay symptom progression. This indicates it is relatively safe, with many patients completing several treatment cycles.

For Stereotactic Body Radiation Therapy (SBRT), research indicates it is a safe treatment for prostate cancer. This precise form of radiation minimizes harm to nearby healthy tissues, and patients usually experience fewer harmful side effects.

Overall, studies have demonstrated that both Radium-223 and SBRT are well-tolerated treatments, providing reassurance about their safety for patients considering joining a clinical trial. ^{1 2 3 4 5}

Why are researchers excited about this study treatment for prostate cancer?

Researchers are excited about the combination of Radium-223 and Stereotactic Body Radiation Therapy (SBRT) for prostate cancer because it offers a unique dual approach. Radium-223 is a radiopharmaceutical that specifically targets bone metastases, delivering radiation directly to cancer sites while sparing healthy tissue, which is different from traditional hormone therapies that target cancer systemically. SBRT, on the other hand, delivers high doses of radiation with precision, minimizing damage to surrounding tissues. The integration of these treatments could enhance effectiveness by precisely targeting both the cancer cells in the bones and other metastatic sites, potentially leading to improved outcomes for patients with metastatic prostate cancer.

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

Research has shown that Radium (Ra-223) dichloride effectively treats men with prostate cancer that has spread and resists hormone therapy. Studies have found that it can delay severe bone pain and extend patients' lives. One important study demonstrated that patients receiving Radium-223 lived significantly longer than those who did not. Additionally, patients who underwent more treatments with Radium-223 tended to live even longer. Radium-223 is generally safe and has low rates of side effects. In this trial, participants in the experimental arm will receive Radium-223 followed by Stereotactic Body Radiation Therapy (SBRT), while those in the control arm will receive SBRT alone. SBRT is a precise radiation treatment that targets cancer with high doses while protecting nearby healthy tissue. ^{1 3 5 6 7}

Who Is on the Research Team?

Brandon Imber, MD, PhD

Principal Investigator

Memorial Sloan Kettering Cancer Center

Are You a Good Fit for This Trial?

Men over 18 with prostate cancer that has spread to bones (1-3 sites) and treated primary tumor. They must have a PSA level of 0.5-50 ng/mL, good performance status, normal organ function, and agree to contraception if needed. Excluded are those with certain prostate cancer types, more than three bone metastases, brain metastases or other serious conditions.

Inclusion Criteria

I can take care of myself and am up and about more than half of my waking hours.

My kidney function tests are within normal limits.

I am willing and able to follow the study's requirements.

Exclusion Criteria

I have not had any cancer in the past 3 years, except for treated skin cancer.

I do not have any serious illness or infections worse than a mild condition.

I experience loss of bowel control.

Timeline for a Trial Participant

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

Treatment

Participants receive two cycles of Radium (Ra-223) dichloride every 4 weeks followed by SBRT at a dose of 9 Gy per fraction for 3 fractions

8-10 weeks

Follow-up

Participants are monitored for safety and effectiveness after treatment

1 year

What Are the Treatments Tested in This Trial?

Interventions

• PET Scan
• Radium dichloride
• Stereotactic Body Radiation Therapy

Trial Overview The trial is testing the effectiveness of combining Stereotactic Body Radiation Therapy (SBRT) with Radium (Ra-223) dichloride versus SBRT alone in treating prostate cancer that has spread to the bones.

How Is the Trial Designed?

Group I: Experimental Arm Experimental Treatment 1 Intervention

Participants will receive two cycles of Radium (Ra-223) dichloride at 55 kBq/kg or 0.00149 mCi/kg or 1.49 uCi/kg every 4 weeks followed 2-3 weeks later by SBRT at a dose of 9 Gy per fraction for 3 fractions (total dose of 27 Gy) to all sites of radiographically apparent metastatic disease. SBRT to the target index lesion(s) should be completed within 30 days after simulation after completion of the 2nd infusion of Radium (Ra-223) dichloride. Specific dose constraints, dosing schedules, and management of SBRT to multiple sites will be at the discretion of the treating Radiation oncologist. The goal is to complete simulation and SBRT within 30 days. Only active or progressive disease is to be treated at the discretion of the treating investigator.

Group II: Control Arm: Active Control 2 Interventions

Participants will receive SBRT at a dose of 9 Gy per fraction for 3 fractions (total dose of 27 Gy) to all sites of radiographically apparent metastatic disease. SBRT fractions can be administered every day or every other day per institutional practice. SBRT should begin within 30 days (+/- 7 days) of randomization. Only active or progressive disease is to be treated at the discretion of the treating investigator.

Who Is Running the Clinical Trial?

Memorial Sloan Kettering Cancer Center

Lead Sponsor

Trials

1,998

Recruited

602,000+

Published Research Related to This Trial

The Cyberknife® system, used for stereotactic body radiation therapy (SBRT), shows promising efficacy in treating localized prostate cancer, with median PSA levels dropping significantly after treatment and biochemical progression-free survival rates ranging from 78.3% to 100% over a follow-up period of 4 to 60 months.

While the treatment is associated with mostly mild side effects (grade 1/2), there are reports of erectile dysfunction and some grade 3 toxicities, indicating a need for further long-term studies and randomized trials to establish its safety and effectiveness as a standard treatment.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Current role of image-guided robotic radiosurgery (Cyberknife(®) ) for prostate cancer treatment. Seisen, T., Drouin, SJ., Phé, V., et al.[2018]

Stereotactic ablative radiotherapy (SABR) is a safe and effective treatment for low and intermediate risk prostate cancer, with only a 2.25% failure rate observed in a study of 400 patients over a median follow-up of 15 months.

The treatment resulted in a significant decline in prostate-specific antigen (PSA) levels, with no severe late adverse effects reported, indicating that SABR could be considered for more advanced cases of prostate cancer.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Cyberknife Radioablation of Prostate Cancer – Preliminary Results for 400 Patients Miszczyk, L., Namysł Kaletka, A., Napieralska, A., et al.[2020]

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]

The study compared two SBRT techniques, isocentric RapidArc (RA) and non-isocentric CyberKnife (CK), in 20 patients with localized prostate cancer, finding that RA provided better target coverage and sparing of the rectum at lower doses.

RA also demonstrated improved delivery efficiency with fewer monitor units and shorter treatment times compared to CK, making it a more favorable option for prostate cancer treatment.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Treatment plan comparison between stereotactic body radiation therapy techniques for prostate cancer: non-isocentric CyberKnife versus isocentric RapidArc. Lin, YW., Lin, KH., Ho, HW., et al.[2014]

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]

CyberKnife stereotactic ablative radiotherapy (SABR) for treating intermediate- to very-high-risk prostate cancer showed a high 3-year biochemical relapse-free survival rate of 90.2%, indicating its efficacy in managing this condition.

The treatment was well-tolerated, with no patients experiencing severe toxicity (≥ grade 3), and only mild genitourinary and gastrointestinal side effects were reported, suggesting a favorable safety profile.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Stereotactic ablative radiotherapy with CyberKnife in the treatment of locally advanced prostate cancer: preliminary results. Fan, CY., Chao, HL., Huang, WY., et al.[2017]

Recent data indicate that CyberKnife SBRT (Stereotactic Body Radiation Therapy) for prostate cancer shows promising treatment outcomes with minimal toxicity, suggesting it could be a safe and effective option.

Despite ongoing controversy in the radiation oncology community, the radiobiologic characteristics of the prostate make it a strong candidate for SBRT, highlighting the need for further evaluation and acceptance of this treatment approach.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

CyberKnife radiosurgery for prostate cancer. Katz, AJ.[2022]

In a study of 29 prostate cancer patients treated with stereotactic body radiotherapy (SBRT) using a Cyberknife, PSA levels showed a significant decrease over time, with a median nadir of 0.329 ng/mL achieved after 23 months.

The treatment demonstrated a favorable safety profile, with only 3% of patients experiencing Grade 2 urinary toxicities and no severe late rectal toxicities reported, indicating that SBRT is a feasible option for prostate cancer treatment.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Stereotactic body radiotherapy for prostate cancer: a preliminary report. Lee, YH., Son, SH., Yoon, SC., et al.[2022]

Stereotactic ablative body radiation (SABR) is a promising non-invasive treatment for localized prostate cancer, showing similar efficacy to brachytherapy in terms of disease control and lower side effects, making it a potentially safer option.

SABR is also more cost-effective and resource-efficient compared to traditional radiation techniques, but further well-powered studies are needed to confirm its benefits before it can be considered standard care, especially for patients with metastatic disease.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Stereotactic ablative body radiotherapy in patients with prostate cancer. Loblaw, A., Liu, S., Cheung, P.[2023]

Citations

1. pubmed.ncbi.nlm.nih.gov pubmed.ncbi.nlm.nih.gov/38924042/

Real-world safety and effectiveness of radium-223 in ... Median OS was 15.7 months (95% confidence interval 12.13-19.51); patients receiving 5-6 223Ra injections and earlier 223Ra use had longer OS ...

2. sciencedirect.com sciencedirect.com/science/article/pii/S2588931125001725

Radium-223 in Men with Metastatic Castration-resistant ... According to the pivotal ALSYMPCA clinical trial, Ra-223 was found to prolong the time to first symptomatic skeletal event, improve quality of life or delay its ...

3. ascopubs.org ascopubs.org/doi/10.1200/JCO.2025.43.5_suppl.81

Effectiveness and safety of radium-223 in men with ... Findings highlight the survival benefits of early use of Ra-223 with the completion of 5 or more cycles, along with a favorable safety profile and low rates of ...

4. nature.com nature.com/articles/s41391-025-00969-6

Real-world utilization patterns and survival in men with ... Overall, median rwOS was 22.9 months. Median rwOS was longer in men who completed ≥5 Ra-223 cycles versus 1–4 cycles (30.3 versus 15.3 months) ...

5. nejm.org nejm.org/doi/full/10.1056/NEJMoa1213755

Alpha Emitter Radium-223 and Survival in Metastatic ... In this phase 3 study, radium-223 significantly prolonged overall survival in patients who had castration-resistant prostate cancer and bone ...

6. ascopubs.org ascopubs.org/doi/10.1200/JCO.2025.43.16_suppl.5048

Long-term safety of radium-223 (Ra-223) in metastatic ... Primary outcomes were the incidence of SPMs, short- (30 days) and long-term (7 years) safety events, and bone marrow suppression (BMS) ...

7. thelancet.com thelancet.com/journals/eclinm/article/PIIS2589-5370(23)00170-0/fulltext

Clinical outcomes and treatment patterns in REASSURE Real-world outcomes of radium-223 dichloride for metastatic castration resistant prostate cancer. Future Oncol. 2020; 16:1371-1384. Crossref.