NCT05665738 · University of California, San Francisco
Two-fraction HDR Monotherapy for Localized Prostate Cancer
What this study is about
This is a single center single treatment group$1 forward-looking pilot study investigating the safety of high dose rate (HDR) brachytherapy as treatment given alone delivered in 2 fractions 3 hours apart. HDR treatment given alone has been established as safe and effective in this context, however previous studies have delivered 2 fractions on separate days, or at least 6 hours apart.
View original scientific description
This is a single center single arm prospective pilot study investigating the safety of high dose rate (HDR) brachytherapy as monotherapy delivered in 2 fractions 3 hours apart. HDR monotherapy has been established as safe and effective in this context, however previous studies have delivered 2 fractions on separate days, or at least 6 hours apart. Clinically, this regimen, if shown to be safe and effective in future studies, has the potential to reduce operative resources and logistical stresses on brachytherapy departments.
Interventions
RADIATION
High Dose Rate Monotherapy
High dose rate brachytherapy delivered in 13.5 Gy x 2 fractions over a single implant procedure 3 hours apart
Primary outcome measures
Proportion of participants with treatment-related adverse events
Time frame: Up to 6 months
The proportion of participants with reported grade 3 or higher genitourinary (GU) or gastrointestinal (GI) toxicities, as graded by the NCI Common Terminology Criteria for Adverse Events (CTCAE) version 5.0 will be reported.
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
Inclusion criteria
- Participants must have histologically or cytologically confirmed diagnosis of prostate adenocarcinoma.
- National Comprehensive Cancer Network low to intermediate risk stratification.
- No prior treatment for prostate cancer and no prior androgen deprivation therapy.
- Age \>=18 years.
- Eastern Cooperative Oncology Group (ECOG) performance status \<2 (Karnofsky \>60%.
- Eligible to undergo High dose rate (HDR) brachytherapy as monotherapy as determined by the treating radiation oncologist.
- Ability to understand and the willingness to sign a written informed consent document.
- Human immunodeficiency virus (HIV)-infected individuals on effective anti-retroviral therapy with undetectable viral load within 6 months are eligible for this trial.
- For participants with evidence of chronic hepatitis B virus (HBV) infection, the HBV viral load must be undetectable on suppressive therapy, if indicated.
- Individuals with a history of hepatitis C virus (HCV) infection must have been treated and cured. For individuals with HCV infection who are currently on treatment, they are eligible if they have an undetectable HCV viral load.
- Individuals with a prior or concurrent malignancy whose natural history or treatment does not have the potential to interfere with the safety or efficacy assessment of the investigational regimen are eligible for this trial.
Exclusion criteria
- Any prior treatment for prostate cancer.
- Any prior androgen deprivation therapy.
- Is currently receiving any other investigational agents.
- Abnormal pre-brachytherapy assessment raising concern for undergoing HDR brachytherapy procedure.
- Contraindications to general anesthesia.
- Contraindications to radiotherapy.
- Prior cryosurgery or cryotherapy to the prostate.
- Prior transurethral resection of the prostate within the previous 6 months.
Where
- San Francisco, California
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Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced Jun 5, 2026 · Source of record for eligibility and locations