Stereotactic Radiotherapy for Prostate Cancer

(ADAPT-25 Trial)

Overseen By Cathy Tran

Age: 18+

Sex: Male

Trial Phase: Phase 2

Sponsor: British Columbia Cancer Agency

Must be taking: Androgen deprivation therapy

Disqualifiers: Stage cT3+, Gleason 8+, PSA 20+, 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: 2

Duration: 2 weeks

100 Participants Needed

Trial Summary

Will I have to stop taking my current medications?

The trial information does not specify whether you need to stop taking your current medications. However, if you are on Androgen Deprivation Therapy (ADT) for certain prostate cancer risks, you may continue it as part of the trial.

What data supports the effectiveness of the treatment Stereotactic Body Radiation Therapy (SBRT) for prostate cancer?

Research shows that SBRT is effective for treating localized prostate cancer, with studies indicating positive patient-reported outcomes and low rates of cancer recurrence over several years. ^{1 2 3 4 5}

Is stereotactic body radiation therapy (SBRT) generally safe for prostate cancer patients?

Research shows that SBRT for prostate cancer is generally safe, but there are concerns about potential side effects and impacts on quality of life. Studies have evaluated its safety and found it to be tolerable, though some patients may experience treatment-related toxicity. ^{6 7 8 9 10}

How is Stereotactic Body Radiation Therapy (SBRT) different from other treatments for prostate cancer?

Stereotactic Body Radiation Therapy (SBRT) for prostate cancer is unique because it delivers high doses of radiation in fewer sessions compared to traditional methods, which may be more effective and convenient for patients. This approach is particularly promising for localized prostate cancer and is being actively researched for its potential benefits. ^{11 12 13 14 15}

What is the purpose of this trial?

Prostate cancer is a common cancer, and a significant cause of cancer death in men. There are many potentially curative treatment options for prostate cancers that have not spread. A relatively recent option is called prostate stereotactic ablative radiotherapy (SABR). SABR is a form of external beam radiotherapy, where patients receive a small number (5-7) of treatments (also called fractions) of radiation delivered in a highly accurate and precise fashion. Standard prostate SABR is generally given in 5 fractions and has been shown to be at least as effective as conventional external beam radiotherapy. Disease control with SABR appears excellent, and it compares favorably to surgery in terms of side effects and quality of life. In theory, reducing the number of fractions from 5 to 2 may improve disease control and reduce side effects, in addition to providing added convenience for patients. Small studies suggest prostate SABR in 2 fractions may be highly effective and well tolerated. However, there is little available data comparing 2 and 5 fraction SABR head to head to tell us which is superior. Two fraction SABR involves delivery of 2 large dose fractions of radiotherapy which could result in significant side effects if proper precautions are not taken. The use of continuous tracking of the prostate gland position during treatment delivery reduces the risk of missing the prostate or overdosing organs near by. Such tracking has been shown to reduce bladder side effects. Also, the use of a rectal spacer placed between the prostate and rectum has been shown to reduce bowel side effects. Also, advanced artificial intelligence (AI)-directed computer applications could potentially improve the targeting of radiation during each treatment. The ADAPT-2 study is a randomized phase II trial comparing standard 5-fraction SABR with an experimental 2-fraction approach in men with intermediate risk prostate cancer. All treatment, whether 5 or 2-fractions, will use continuous prostate tracking (also called triggered imaging) and a rectal spacer (called Space OAR Hydrogel) to minimize side effects. The trial will also evaluate the potential of a new AI-guided dose guidance application to see if it can improve current methods of targeting SABR each day. This aspect of the study will be offline; that is, the AI application will not be used to actually target treatment for the trial patients. Rather, daily targeting of SABR will use standard conventional means, and the AI application will be studied in a simulated fashion to determine it is useful and can be incorporated into workflow. The main goal of the ADAPT-25 study is to compare the long-term side effects and quality of life between 5- and 2-fraction prostate SABR. Secondary goals will be to compare the long-term disease control between 5-and 2-fraction prostate SABR, and to evaluate whether a novel AI-directed dose guidance application can be used to better target SABR by reducing doses to neighboring organs, and whether it can be easily fit into prostate SABR workflow.

Research Team

Winkle Kwan

Principal Investigator

BC Cancer

Abraham Alexander

Principal Investigator

BC Cancer

Eligibility Criteria

Men with intermediate risk prostate cancer who haven't had their disease spread are eligible for this trial. It's not specified, but typically participants would need to be healthy enough for radiotherapy and meet certain medical criteria.

Inclusion Criteria

Able to provide informed consent

Life Expectancy > 5 years

PSA within 90 days prior to registration

Exclusion Criteria

My cancer has spread to the lymph nodes in my pelvis.

I have had radiation therapy to my pelvic area before.

PSA > 20ng/mL or greater

Timeline

Screening

Participants are screened for eligibility to participate in the trial

16 weeks

Treatment

Participants receive prostate stereotactic ablative radiotherapy (SABR) in either 2 or 5 fractions over 2 weeks

2 weeks

2-5 visits (in-person)

Follow-up

Participants are monitored for safety, quality of life, and disease control after treatment

5 years

AI Evaluation

Offline evaluation of AI-driven dose guidance/adaptive positioning application

3 years

Treatment Details

Interventions

• Stereotactic Body Radiation Therapy (SBRT)

Trial Overview The ADAPT-2 study is testing whether treating prostate cancer with just 2 large doses of radiation (SABR) is as effective and safe as the standard 5-dose treatment. Both methods use tracking technology and a rectal spacer to minimize side effects, while also evaluating an AI application in simulation.

Participant Groups

Group I: Two-Fraction Prostate SABR Experimental Treatment 1 Intervention

27Gy delivered to the prostate gland (CTV)in 2 fractions over 2 weeks

Group II: 5-fraction prostate SABR Active Control 1 Intervention

40Gy delivered to the prostate gland (CTV) in 5 fractions over 2 weeks.

Who Is Running the Clinical Trial?

British Columbia Cancer Agency

Lead Sponsor

Trials

181

Recruited

95,900+

Findings from Research

Between 2006 and 2020, there was a significant increase in publications and citations related to stereotactic body radiotherapy (SBRT) for prostate cancer, indicating growing interest and research in this treatment method.

The United States led the research output in this field, with a focus on SBRT applications in oligometastatic disease, reirradiation, and salvage therapy, highlighting key areas for future investigation.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Stereotactic Body Radiotherapy for Prostate Cancer: Where, When, and Who? A Bibliometric Analysis. Viani, GA., Gouveia, AG., Jacinto, AA., et al.[2023]

Stereotactic body radiotherapy (SBRT) for localized prostate cancer showed a 5-year biochemical relapse-free survival (bRFS) rate of 93% across 1100 patients, indicating its effectiveness as a treatment option.

The study found no significant differences in outcomes based on the use of androgen deprivation therapy or total radiation dose, suggesting that SBRT is a robust treatment regardless of these factors.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Stereotactic body radiotherapy for localized prostate cancer: pooled analysis from a multi-institutional consortium of prospective phase II trials. King, CR., Freeman, D., Kaplan, I., et al.[2022]

In a study of 174 hormone-naïve patients with localized prostate cancer treated with stereotactic body radiation therapy (SBRT), significant urinary symptoms were reported more frequently than bowel symptoms, with 51.6% of patients experiencing a clinically significant decline in urinary scores at 12 months.

The study indicates that while urinary and bowel symptoms initially increased after treatment, the proportion of patients reporting significant declines in these symptoms decreased from 12 to 36 months, suggesting potential late improvements in quality of life following SBRT.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Stereotactic Body Radiation Therapy for Prostate Cancer: What is the Appropriate Patient-Reported Outcome for Clinical Trial Design? Woo, JA., Chen, LN., Wang, H., 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 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]

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]

In a study of 23 patients with high-risk prostate cancer, stereotactic body radiation therapy (SBRT) was found to be feasible and well tolerated, with low rates of severe gastrointestinal (GI) and genitourinary (GU) toxicities.

The treatment resulted in acute grade 1 GI toxicities in only 9.1% of patients and grade 3 GU toxicities in 4.5%, indicating that serious side effects were uncommon, but further long-term follow-up is needed to assess ongoing safety and efficacy.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Early Tolerance Outcomes of Stereotactic Hypofractionated Accelerated Radiation Therapy Concomitant with Pelvic Node Irradiation in High-risk Prostate Cancer. Pinitpatcharalert, A., Happersett, L., Kollmeier, M., 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]

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]

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]

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]

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]

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 phase I/II study involving 91 patients with localized prostate cancer, stereotactic body radiation therapy (SBRT) demonstrated a remarkable prostate-specific antigen (PSA) control rate of 99% over a median follow-up of 42 months.

While the maximum-tolerated dose (MTD) was not reached, the study noted a concerning 10.6% incidence of high-grade rectal toxicity at the highest dose level of 50 Gray, prompting the need for dose constraints to reduce this risk in future trials.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Stereotactic Body Radiation Therapy for Prostate Cancer: Review of Experience of a Multicenter Phase I/II Dose-Escalation Study. Kim, DW., Straka, C., Cho, LC., et al.[2022]

References

1. United States pubmed.ncbi.nlm.nih.gov

Stereotactic Body Radiotherapy for Prostate Cancer: Where, When, and Who? A Bibliometric Analysis. [2023]

2. Ireland pubmed.ncbi.nlm.nih.gov

Stereotactic body radiotherapy for localized prostate cancer: pooled analysis from a multi-institutional consortium of prospective phase II trials. [2022]

3. Switzerland pubmed.ncbi.nlm.nih.gov

Stereotactic Body Radiation Therapy for Prostate Cancer: What is the Appropriate Patient-Reported Outcome for Clinical Trial Design? [2020]

4. United States 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. [2023]

5. England pubmed.ncbi.nlm.nih.gov

Prostate stereotactic body radiotherapy—first UK experience. [2022]

6. Ireland pubmed.ncbi.nlm.nih.gov

Patient-reported quality of life after stereotactic body radiotherapy (SBRT), intensity modulated radiotherapy (IMRT), and brachytherapy. [2022]

7. United States pubmed.ncbi.nlm.nih.gov

Early Tolerance Outcomes of Stereotactic Hypofractionated Accelerated Radiation Therapy Concomitant with Pelvic Node Irradiation in High-risk Prostate Cancer. [2022]

8. England pubmed.ncbi.nlm.nih.gov

Safety and Efficacy of Ultra-hypofractionation in Node-positive Prostate Cancer. [2021]

9. Germany 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. [2022]

10. United States pubmed.ncbi.nlm.nih.gov

Predictors of multidomain decline in health-related quality of life after stereotactic body radiation therapy (SBRT) for prostate cancer. [2022]

11. Germany pubmed.ncbi.nlm.nih.gov

The march toward single-fraction stereotactic body radiotherapy for localized prostate cancer-Quo Vadimus? [2023]

12. Netherlands 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. [2022]

13. England pubmed.ncbi.nlm.nih.gov

Stereotactic body radiation therapy (SBRT) for clinically localized prostate cancer: the Georgetown University experience. [2022]

14. Netherlands pubmed.ncbi.nlm.nih.gov

Long-term Outcomes from a Phase 1 Dose Escalation Study Using Stereotactic Body Radiotherapy for Patients with Low- or Intermediate-risk Prostate Cancer. [2023]

15. Switzerland pubmed.ncbi.nlm.nih.gov

Stereotactic Body Radiation Therapy for Prostate Cancer: Review of Experience of a Multicenter Phase I/II Dose-Escalation Study. [2022]