Salvage Magnetic Resonance Imaging–guided Transurethral Ultrasound Ablation for Localized Radiorecurrent Prostate Cancer: 12-Month Functional and Oncological Results

Abstract

<div><h3>Background</h3><p>Up to half of all men who undergo primary radiotherapy for localized prostate cancer (PCa) experience local recurrence.</p></div><div><h3>Objective</h3><p>To evaluate the safety and early functional and oncological outcomes of salvage magnetic resonance imaging–guided transurethral ultrasound ablation (sTULSA) for men with localized radiorecurrent PCa.</p></div><div><h3>Design, setting, and participants</h3><p>This prospective, single-center phase 1 study (<a href="https://clinicaltrials.gov/show/NCT03350529">NCT03350529</a>) enrolled men with biopsy-proven localized PCa recurrence after radiotherapy. Multiparametric magnetic resonance imaging (mpMRI) and 18F prostate-specific membrane antigen-1007 (18F PSMA-1007) positron emission tomography (PET)-computed tomography (CT) were used to confirm organ-confined disease localization. Patients underwent either whole-gland or partial sTULSA, depending on their individual tumor characteristics.</p></div><div><h3>Outcome measurements and statistical analysis</h3><p>Patients were followed at 3-mo intervals. Adverse events (AEs, Clavien-Dindo scale), functional status questionnaires (Expanded Prostate Cancer Index [EPIC]-26, International Prostate Symptom Score, International Index of Erectile Function-5), uroflowmetry, and prostate-specific antigen (PSA) were assessed at every visit. Disease control was assessed at 1 yr using mpMRI and 18F-PSMA-1007 PET-CT, followed by prostate biopsies.</p></div><div><h3>Results and limitations</h3><p>Eleven patients (median age 69 yr, interquartile range [IQR] 68–74) underwent sTULSA (3 whole-gland, 8 partial sTULSA) and have completed 12-mo follow-up. Median PSA was 7.6 ng/ml (IQR 4.9–10) and the median time from initial PCa diagnosis to sTULSA was 11 yr (IQR 9.5–13). One grade 3 and three grade 2 AEs were reported, related to urinary retention and infection. Patients reported a modest degradation in functional status, most significantly a 20% decline in the EPIC-26 irritative/obstructive domain at 12 mo. A decline in maximum flow rate (24%) was also observed. At 1 yr, 10/11 patients were free of any PCa in the targeted ablation zone, with two out-of-field recurrences. Limitations include the nonrandomized design, limited sample size, and short-term oncological outcomes.</p></div><div><h3>Conclusions</h3><p>sTULSA appears to be safe and feasible for ablation of radiorecurrent PCa, offering encouraging preliminary oncological control.</p></div><div><h3>Patient summary</h3><p>We present safety and 1-yr functional and oncological outcomes of magnetic resonance imaging–guided transurethral ultrasound ablation (TULSA) as a salvage treatment for local prostate cancer recurrence after primary radiation. Salvage TULSA is safe and shows the ability to effectively ablate prostate cancer recurrence, with acceptable toxicity.</p></div>