MRI-directed Ultrasound-guided Transperineal Focal Laser Ablation (TPLA) for Prostate Cancer: one year follow-up of 158 patients

Tuesday, April 1, 2025

3:00 PM – 3:09 PM CT

Location: Music City Center, 204

Presenting Author(s)

Eric M. Walser, MD, FACR (he/him/his)

Professor and Chairman of Radiology
UTMB, United States

Author/Co-author(s)

KD

Katelijne De Bie, MD

Department of Urology
Vrije Universiteit, Amsterdam, Netherlands
FC

Francois Cornud, MD

Department of Radiology
Clinique de l'Alma, France
LV

LAMJG Van Riel, MD

Department of Urology
Vrije Universite it Amsterdam, Netherlands
SR

S Regusci, MD

Radiologist
Swiss International Prostate Center, Switzerland
MM

M Martins Favre, MD

Radiologist
Swiss International Prostate Center, Switzerland
MG

M Galiano, MD

urologist
Clinique de l'Alma, France
JO

JR Oddens, MD

urologist
Vrije Universiteit Amsterdam, Netherlands

Purpose: This study investigates the safety and one-year functional and oncological outcomes of MRI-directed US-guided transperineal focal laser ablation (TPLA) for patients with organ-confined prostate cancer (PCa).

Materials and Methods:

This study is based on a registry of patients treated with TPLA for localised PCa at three clinics in Europe and the USA. Included patients were treated between 2018 and 2023, and were followed-up for a minimum of one year. The EchoLaser system, operating at 1064 nm, was used in single or multi-fibre mode for PI-RADS ≥ 3 lesions under ultrasound (US) guidance. Before treatment, MRI-delineated target volumes were fused with US imaging. Follow-up included PSA every six months, MRI scans at six or twelve months, and biopsies as indicated (PSA rise and/or MRI lesions) in two clinics, or standard biopsies at 12 months in the third clinic.

Results:

A total of 158 patients received TPLA on 170 PI-RADS ≥3 lesions. The median age was 69 years (IQR 62-73), initial PSA level was 7.5 ng/mL (IQR 5.0-10), prostate volume was 40 cc (IQR 30-60), and tumour diameter was 12 mm (IQR 10-15 mm). Among these patients, 44/158 (28%) had ISUP 1, 79 (50%) ISUP 2, 23 (14.6%) ISUP 3, and 7 (4.4%) ISUP 4 disease. Between one to four fibers were used per patient in one or two treatment cycles, with a median treatment time of 15 minutes (IQR 11-15) and a median energy delivery of 3827 Joules (IQR 2400-7208).

At the 6-month follow-up, PSA levels decreased from a median of 7.5 ng/mL (IQR 5.0-10) to 3.3 ng/mL (IQR 1.9-6.6) (p< 0.001). There were no significant changes in erectile function (IIEF) or urinary symptoms (IPSS) at 12 months compared to baseline. Post-FLA, one patient experienced a Clavien-Dindo (CD) Grade 3 complication (a recto-prostatic fistula requiring surgery). CD Grade 1 complications occurred in 32/158 patients (19%) and CD Grade 2 complications in 13/158 patients (8%).

At 12 months, PSA levels increased compared to the 6-month mark (median 4.5 ng/mL (IQR 2.5-14) vs. 3.3 ng/mL (IQR 1.9-6.6), p< 0.001). MRI scans were performed in 134 patients, with 40/134 (30%) showing positive MRI lesions in the treated area. Biopsies were conducted on 82 patients (including all MRI-positive patients), and 42/82 (51%) had positive biopsies, confirming in-field recurrence. Therefore, initial TPLA treatment was successful in 116/158 (74%) of patients.

Conclusion:

At the one-year follow-up, nearly three-quarters of patients remained recurrence-free after TPLA for localised PCa. The therapy was safe and did not affect erectile function or urinary symptoms.