A Phase II Trial of Focal Ultrahypofractionated Stereotactic Radiation Therapy for the Treatment of Unifocal Prostate Cancer

• Status: Not yet recruiting
• Trial end date: 2028-12-01
• Target enrollment: 0
• Participant gender: Male

Summary

Background:

• Prostate cancer is the most common cancer among American men.

• The best current validated treatment options include whole gland radiotherapy and radical prostatectomy.

• Based on recent advances in imaging, focal ablative therapies are under investigation in attempts to deliver comparable rates of tumor control with less side effects.

• Thus far, focal therapies such as cryotherapy, high-intensity focused ultrasound, or focal laser ablation have resulted in poor local control with the exception of implanted radiation sources which have shown in-field control rates > 90%.

• As such, the proposed trial is designed to investigate the efficacy of a novel form of focal stereotactic body radiation therapy (SBRT) for the treatment of localized, unifocal prostate cancer.

• Prostate specific membrane antigen (PSMA) targeted PET imaging was recently FDA approved for imaging men with suspected prostate cancer metastases who are potentially curable by radiation or surgery. 18F-DCFPyL, a second generation PSMA PET agent that binds with high affinity to PSMA yet clears rapidly from the blood pool will be used in this study.

Objective:

-To determine whether localized, tumor-directed SBRT can produce biopsy-confirmed tumor response at 24 months in participants with unifocal prostatic adenocarcinoma.

Eligibility:

• Histologically confirmed, low or intermediate risk prostatic adenocarcinoma verified by biopsy.

• Unifocal prostate cancer defined as a single focus of prostate cancer on imaging which is correlated with a positive targeted biopsy.

• Age >= 18.

• No concurrent systemic Androgen Deprivation Therapy (ADT) is planned.

Design:

• This is a single-arm phase II trial designed to measure the efficacy of a novel application of SBRT guided with advanced prostate-specific imaging techniques.

• Participants will initially undergo a treatment planning CT, multiparametric MRI (mpMRI), 18F-DCFPyL PET/CT imaging, a biopsy, quality of life (QoL) questionnaires and laboratory evaluations. SBRT will be administered at 26Gy in two fractions on two separate days.

• Following completion of treatment, participants will be followed for up to 2 years through clinical evaluation, laboratory evaluations (including a complete blood count (CBC), prostate specific antigen (PSA) and testosterone measurements), QoL assessments, mpMRI, 18FDCFPyL PET/CT imaging, and a biopsy.

• The accrual ceiling is set to 42 participants with the goal of recruiting 30 evaluable

participants.

• Phase: Phase 2
• Accepts Healthy Volunteers?: No

Details

• Lead Sponsor: National Cancer Institute (NCI)

Criteria

• INCLUSION CRITERIA:

• Participants must have histologically confirmed, low or intermediate risk prostatic adenocarcinoma verified by biopsy (NIH Laboratory of Pathology confirmation is required).

• Unifocal prostate cancer defined as a single focus of prostate cancer on MRI and PSMA PET/CT imaging which is correlated with a positive targeted biopsy.

• Age >=18 years.

• ECOG performance status <=2 (Karnofsky >60%).

• Men must agree to use highly effective contraception with their partner (barrier method of birth control; abstinence) for the duration of study participation and up to 120 days after the last radiation treatment.

• Ability of individual to understand and the willingness to sign a written informed consent document.

EXCLUSION CRITERIA:

• Participants with NCCN high-risk prostate cancer features (Gleason score >=8, >cT2a, or PSA >= 20 ng/mL).

• Participants with prostate biopsies which show >= grade group 2 adenocarcinoma determined to be outside of the radiographically visible lesion (systematic biopsies which map to a radiographically detected lesion are not an exclusion criterion).

• Participants in whom concurrent systemic Androgen Deprivation Therapy (ADT) or chemotherapy is planned.

• Participants who are receiving any other investigational agents.

• Participants found to have pelvic or distant metastases on pre-treatment staging studies.

• Participants with an AUA-SI/IPSS score > 18.

• Participants who have previously received curative treatment for a prior or the current diagnosis of prostate cancer.

• Active urinary tract infection assessed by urinalysis.

• Human immunodeficiency virus (HIV)-infected individuals who are not on effective anti-retroviral therapy with undetectable viral load within the 6 months prior to registration are eligible for this trial.

• Participants with hepatitis B virus (HBV) infection who have not been treated and cured.

• Participants with chronic HBV at screening must have an undetectable HBV viral load on suppressive therapy.

• Participants with hepatitis C virus (HCV) infection who have not been treated and cured.

• Participants with HCV infection who are currently on treatment, are eligible if they have an undetectable HCV viral load at screening.

• Anatomic relationship between the tumor and adjacent normal tissues judged to be unfeasible for the planned treatment by the PI.

• Participants with connective tissue diseases.

• Participants with radiation hypersensitivity syndromes.

• Ongoing active irritable bowel disease within the radiation field.

• Participants with prior medical comorbidity or surgical history involving the low pelvis which is expected to confer a high risk of toxicity to the experimental radiation regimen.

• Ineligibility or unwillingness to undergo a contrast-enhanced MRI due to inadequate renal function (eGFR < 30), severe claustrophobia, a weight above tolerance of the scanner (> 350 lbs.), a body size unable to fit into the scanner, or implanted devices incompatible with an MRI (implanted cardiac devices, surgical hardware, retained shrapnel, cerebral aneurysm clips, or other incompatible objects.

• Unwillingness to undergo an 18F-DCFPyL PET/CT or known allergy to the 18FDCFPyL tracer.

• Contraindication or inability to undergo fiducial marker implantation.

• History of prior radiotherapy overlapping with the intended radiation field.

• Uncontrolled intercurrent illness, factors, or social situations that would limit compliance with study requirements.