Main Session

Sep 29

PQA 06 - Genitourinary Cancer, Gynecological Cancer, and Health Care Access and Engagement

3264 - Long-Term Outcomes and Toxicity Following Salvage Whole Gland or Focal HDR Brachytherapy for Recurrent Prostate Cancer: A Single-Institution Experience

02:15pm - 03:30pm ET

Poster Hall - Exhibit Hall A

Screen: 8

POSTER

Presenter(s)

Dina Elhabashy, MD, MS - Corewell Health William Beaumont University Hospital, Royal Oak, MI

D. H. Elhabashy¹, A. Limbacher², E. Sebastian², A. Thompson², S. R. Nandalur², and D. J. Krauss³; ¹Department of Radiation Oncology, Corewell Health William Beaumont, Royal Oak, MI, ²Department of Radiation Oncology, Corewell Health William Beaumont University Hospital, Royal Oak, MI, ³Department of Radiation Oncology, Corewell Health Beaumont University Hospital, Royal Oak, MI

Purpose/Objective(s):

Management of locally recurrent prostate cancer after definitive radiation therapy (RT) remains challenging, with limited curative options. Salvage high-dose-rate (HDR) brachytherapy is a targeted, organ-preserving treatment option that can provide durable disease control while minimizing toxicity.

Materials/Methods:

We retrospectively reviewed 33 patients who underwent salvage HDR brachytherapy between April 2014 and September 2025 for locally with or without regionally recurrent prostate cancer following prior RT. Primary endpoints included biochemical control and treatment-related toxicity.

Results:

Median follow-up from salvage treatment was 27 months, and the median interval from initial diagnosis to salvage treatment was 73.8 months. The majority of patients initially received brachytherapy (82%), with the remainder treated with EBRT or combined modality therapy. Median PSA at recurrence was 3.7 ng/mL with a median PSA doubling time of 21 months. PET imaging was performed in 79% of patients with no cases showing distant metastatic disease.

Salvage treatment consisted of focal (55%) or whole-gland (45%) HDR brachytherapy delivered in either 2 or 4 treatment fractions. Androgen deprivation therapy (ADT) was administered in 76% of patients for a median duration of 6 months (range 3–24).

Median time to PSA nadir after salvage was 5.6 months. Biochemical failure occurred in 27% (n=9) of patients, with a median time to failure of 35 months. Patterns of failure included local (56%), nodal (11%), combined local and nodal (11%), and distant disease (22%).

Treatment was well tolerated with no acute or late gastrointestinal (GI) toxicity observed. Acute grade 2 genitourinary (GU) toxicity was observed in 39% of cases. Late grade 2 GU toxicity was observed in 24% and grade 3 in 9%, including urinary retention requiring intervention (n=2) and severe erectile dysfunction (n=1). Median IPSS increased from 5 at baseline to 7 post-treatment.

Among patients who underwent focal salvage brachytherapy, biochemical failure occurred in 28% (n=5), including local (n=2), nodal (n=1), combined local and nodal (n=1), and distant failure (n=1), with median time to failure was 12 months. Twelve patients (67%) received ADT with a median duration of 6 months (range 3–16). No patients experienced grade =3 acute GU toxicity. Grade 3 late GU toxicity occurred in 2 patients, including urinary retention requiring intervention (n=1) and severe erectile dysfunction (n=1).

Conclusion: Salvage HDR brachytherapy provides durable biochemical control with acceptable toxicity in patients with recurrent prostate cancer. Both focal and whole-gland approaches demonstrated favorable urinary outcomes with no GI toxicity observed. Outcomes in the focal salvage subgroup were comparable, with low rates of severe toxicity, supporting focal therapy as a feasible treatment strategy in appropriately selected patients.