Short-course pelvic radiotherapy with a focused high-dose microboost for high-risk prostate cancer

Hypofractionated Radiotherapy With a Focal Microboost for High-Risk and Locally Advanced Prostate Cancer

This tests whether a shorter course of pelvic radiotherapy combined with a focused high-dose 'microboost' is safe and effective for men with previously untreated high-risk, very high-risk, or pelvic lymph node–positive prostate cancer.

Quick facts

• Phase: PHASE2
• Study type: Interventional
• Enrollment: 46 (estimated)
• Ages: 18 Years and up
• Sex: Male
• Sponsor: Medical University of South Carolina (other)
• Drugs / interventions: chemotherapy, radiation
• Locations: 1 site (Charleston, South Carolina)
• Trial ID: NCT07325721 on ClinicalTrials.gov

What this trial studies

This Phase 2 interventional study delivers hypofractionated pelvic radiotherapy with an added focal microboost to the dominant tumor area in men with high-risk or locally advanced prostate cancer. Participants receive standard-of-care visits along with trial-specific questionnaires and blood draws, with optional banking of blood and existing biopsy tissue. The active treatment course lasts about six weeks, with follow-up visits every three months for two years and then twice yearly through year five. The trial is single-site and designed to monitor safety and early effectiveness outcomes of combining these two radiation techniques.

Who should consider this trial

Good fit: Adult men with previously untreated prostate cancer classified as high risk, very high risk, or non-metastatic pelvic lymph node–positive who are able to undergo pelvic radiotherapy are ideal candidates.

Not a fit: Men with prior definitive prostate radiation or other prior local cancer treatments, those with metastatic disease beyond pelvic lymph nodes, or those who cannot tolerate pelvic radiotherapy are unlikely to benefit from this protocol.

Why it matters

Potential benefit: If successful, this approach could shorten overall treatment time and improve local tumor control while maintaining acceptable side effects.

How similar studies have performed: Hypofractionation is already commonly used for prostate cancer and focal boost techniques have shown promising early results, but combining them is relatively novel and remains under study.

Eligibility criteria

Inclusion Criteria:

1. Provision of signed and dated informed consent form.
2. Stated willingness to comply with all study procedures and availability for the duration of the study.
3. Biologically male patients aged 18 years and older.
4. Ability to receive pelvic radiotherapy and be willing to adhere to the protocol regimen.
5. Previously untreated prostate cancer (with cytotoxic chemotherapy, cryotherapy, ablative treatment, surgical or radiation therapy). Prior transurethral resection of prostate (TURP) is permitted if 90 days or more prior to the start of radiotherapy.
6. Localized or locally advanced prostate cancer meeting NCCN criteria for high risk, very high risk or non-metastatic, pelvic lymph node positive defined as having at least one or more of the following:

   1. PSA \>20 ng/mL prior to starting ADT.
   2. cT3a-T4 by digital exam or imaging.
   3. Gleason score of 8-10 (grade group 4 or 5).
   4. Staged as N1M0 by the treating investigator (pelvic lymph node positive, below the aortic bifurcation) based on soft tissue imaging within 120 days prior to registration (may include CT, MRI or PSMA PET/CT, of fluciclovine choline PET/CT).
7. History and physical exam within 120 days prior to registration.
8. ECOG performance status 0-2.
9. Be able to undergo MRI of the prostate and/or pelvis as a component of RT planning.
10. Have at least one MRI visible target for microboost (PI-RADS≥ 4 version 2.0).
11. Bone and soft tissue imaging as clinically indicated for staging within 120 days prior to registration.
12. For males: use of condoms or other methods to ensure effective contraception with partner during radiation and for six months after completion of radiation.
13. Adequate hematologic function within 120 days prior to registration as defined by:

    1. hemoglobin \>=9.0 g/dL independent of transfusion, and
    2. platelet count \>= 100,000 x 10 \^9/microliter independent of transfusion.
14. Adequate hepatic function within 120 days prior to registration defined as total bilirubin \<2 x institutional upper limits of normal (ULN is 1.2 mg/dL). If labs are done at outside institution, total bilirubin should be \<2.4.
15. Agreeable and eligible to receive long term (defined as 12-36 months) ADT as a standard component of prostate cancer therapy.

Exclusion Criteria:

* 1\. Concurrent use of testosterone supplementation unless discontinued by time of registration.

  2\. Definitive radiologic evidence of metastatic disease outside of the pelvic nodes on conventional imaging (bone scan, CT scan, MRI).

  3\. Prior pelvic radiotherapy. 4. Pre-existing conditions or overall health status which disqualifies the patient from curative intent-RT. Patients with life expectancy less than 5 years are not eligible.

  5\. Treatment with another investigational prostate cancer therapy within 12 months.

  6\. Prior total prostatectomy, cryotherapy, high-intensity focused ultrasound, irreversible electroporation, MRI ablation, laser ablation, transurethral ultrasound ablation, aquablation directed towards the prostate for any prostate disease or condition.

  7\. Prior or concurrent invasive pelvic malignancy (except non-melanomatous skin cancer) or lymphomatous or hematogenous malignancy, unless disease free for a minimum of 5 years.

  8\. Any condition that, in the opinion of the investigator, would preclude participation in this study.

  9\. Prior pharmacologic androgen ablation for prostate cancer is allowed only if the onset of androgen ablation (both LHRH agonist and oral anti-androgen) is ≤ 90 days prior to registration.

  10\. Inability to undergo implantation of gold fiducial markers or rectal spacer gel.

  11\. Patients with a prior or concurrent malignancy whose natural history or treatment has the potential to interfere with the safety or efficacy assessment of the investigational regimen.

Where this trial is running

Charleston, South Carolina

• Medical University of South Carolina Hollings Cancer Center — Charleston, South Carolina, United States (RECRUITING)

Study contacts

• Study coordinator: Harriet Eldredge-Hindy Eldredge-Hindy, MD

Conditions: Prostate Cancer, Prostate Cancer Patients Treated by Radiotherapy, Prostate cancer, Microboost, hypofractionated