Main Session
Sep 29
PQA 06 - Genitourinary Cancer, Gynecological Cancer, and Health Care Access and Engagement

3233 - FocaSaBra: A Prospective Phase II Trial of Focal Salvage Brachytherapy for Locally Recurrent Prostate Cancer after Radiotherapy

02:15pm - 03:30pm ET
Poster Hall - Exhibit Hall A
Screen: 22
POSTER

Presenter(s)

Adam Kluska, MD, PhD - Greater Poland Cancer Center, Poznan, Greater Poland

W. Burchardt1,2, A. Kluska1, A. Chyrek1,2, A. Chichel1, G. Bieleda2,3, and G. Zwierzchowski2,3; 1Greater Poland Cancer Centre, Poznan, Brachytherapy Department, Poznan, Poland, 2Poznan University of Medical Sciences, Electroradiology Department, Poznan, Poland, 3Greater Poland Cancer Centre, Poznan, Medical Physics Department, Poznan, Poland

Purpose/Objective(s): Biochemical recurrence after primary radiotherapy for localized prostate cancer represents a major clinical challenge. Approximately 30–55% of post-radiotherapy failures are initially classified as true isolated intraprostatic recurrences [1,2]. Salvage radical prostatectomy (SRP) and whole-gland salvage reirradiation with brachytherapy (BT) or external beam radiotherapy/stereotactic body radiotherapy (EBRT/SBRT) offer potentially curative treatment options. Reported recurrence-free survival (RFS) rates range from 75.0% to 78.5% at a median follow-up of 18–35 months for SRP. Two-year RFS rates are 84.0% (95% CI: 67.0–93.0%) for BT and 69.0% (95% CI: 42.0–87.0%) for SBRT. Severe genitourinary (grade =3) toxicity after whole-gland salvage treatment has been reported at approximately 5.6% after SBRT, 9.6% after HDR brachytherapy, 9.1% after LDR brachytherapy, and 20% after SRP [4]. Reported rates of severe gastrointestinal toxicity are 11% after SRP, 3% after BT, and 4% after EBRT [4].

Materials/Methods: FocaSaBra is a prospective, single-center, phase II study enrolling 100 patients with histologically confirmed, imaging-localized intraprostatic recurrence at least 2 years after completion of prior radiotherapy. The eligibility criteria include prostate-specific antigen (PSA) <10 ng/mL, PSA doubling time >6 months, International Prostate Symptom Score (IPSS) <20, performance status =2, and absence of distant metastases confirmed preferentially by PSMA PET (Figure 1). The intervention consists of focal salvage brachytherapy directed to the dominant intraprostatic lesion (DIL) with a 5–10 mm intraprostatic margin (0–3 mm extracapsular margin where appropriate). The clinical target volume (CTV) must not exceed 50% of the total prostate volume. Depending on prior radiation modality, patients receive either ultra–low-dose-rate (uLDR) brachytherapy with iodine-125 (145 Gy) or high-dose-rate (HDR) brachytherapy with iridium-192 (26 Gy delivered in 2 fractions)

Results:

The primary endpoint is the incidence of acute and late grade =3 genitourinary and gastrointestinal toxicity assessed using CTCAE v4.0 and RTOG scales. Secondary endpoints include PSA progression-free survival and longitudinal quality-of-life outcomes measured using EORTC QLQ-C30 and QLQ-PR25 questionnaires, as well as IPSS and International Index of Erectile Function (IIEF) scores.

Follow-up is conducted at 1 month after treatment and every 6 months thereafter for up to 5 years. Enrollment has commenced and is ongoing; data analysis has not yet been performed. Clinical trial registration: NCT05715502.

Conclusion: The FocaSaBra trial was designed to evaluate the safety and feasibility of focal salvage brachytherapy (FsBT) in carefully selected patients with recurrence following prior radiotherapy. The aim is to maintain or improve oncologic efficacy while reducing treatment-related toxicity

  1. Zumsteg J Urol 2015
  2. Jansen Eur Urol Oncol 2020,
  3. Creta PCPD 2025
  4. Valle Eur Urol 2020