Reliable Visualization of the Treatment Effect of Transperineal Focal Laser Ablation in Prostate Cancer Patients by Magnetic Resonance Imaging and Contrast-enhanced Ultrasound Imaging

Luigi A M J G van Riel; Rob A A van Kollenburg; Jan Erik Freund; Mitra Almasian; Auke Jager; Marc R W Engelbrecht; Ruth S Smit; Elise Bekers; Jakko A Nieuwenhuijzen; Pim J van Leeuwen; Henk van der Poel; Theo M de Reijke; Harrie P Beerlage; Jorg R Oddens; Daniel M de Bruin

doi:10.1016/j.euros.2023.06.002

Reliable Visualization of the Treatment Effect of Transperineal Focal Laser Ablation in Prostate Cancer Patients by Magnetic Resonance Imaging and Contrast-enhanced Ultrasound Imaging

Eur Urol Open Sci. 2023 Jun 29:54:72-79. doi: 10.1016/j.euros.2023.06.002. eCollection 2023 Aug.

Authors

Luigi A M J G van Riel^{1

2

3}, Rob A A van Kollenburg^{1

2

3}, Jan Erik Freund^{4

5}, Mitra Almasian², Auke Jager^{1

3}, Marc R W Engelbrecht^{6

7}, Ruth S Smit^{6

7}, Elise Bekers⁸, Jakko A Nieuwenhuijzen³, Pim J van Leeuwen⁹, Henk van der Poel^{3

9}, Theo M de Reijke^{1

3}, Harrie P Beerlage^{1

3}, Jorg R Oddens^{1

3}, Daniel M de Bruin^{1

3}

Affiliations

¹ Department of Urology, Amsterdam UMC Location University of Amsterdam, Prostate Cancer Network in the Netherlands, Amsterdam, The Netherlands.
² Department of Biomedical Engineering and Physics, Amsterdam UMC Location University of Amsterdam, Prostate Cancer Network in the Netherlands, Amsterdam, The Netherlands.
³ Department of Urology, Cancer Center Amsterdam, Amsterdam UMC Location Vrije Universiteit Amsterdam, Amsterdam, The Netherlands.
⁴ Department of Pathology, UMC Utrecht, Utrecht, The Netherlands.
⁵ Department of Pathology, Amsterdam UMC Location University of Amsterdam, Prostate Cancer Network in the Netherlands, Amsterdam, The Netherlands.
⁶ Department of Radiology and Nuclear Medicine, Amsterdam UMC Location University of Amsterdam, Prostate Cancer Network in the Netherlands, Amsterdam, The Netherlands.
⁷ Department of Radiology & Nuclear Medicine, Cancer Center Amsterdam, Amsterdam UMC Location Vrije Universiteit Amsterdam, Amsterdam, The Netherlands.
⁸ Department of Pathology, Netherlands Cancer Institute, Prostate Cancer Network in The Netherlands, Amsterdam, The Netherlands.
⁹ Department of Urology, Netherlands Cancer Institute, Prostate Cancer Network in The Netherlands, Amsterdam, The Netherlands.

Abstract

Background: Transperineal focal laser ablation (TPLA) treatment for prostate cancer (PCa) is an experimental focal ablative therapy modality with low morbidity. However, a dosimetry model for TPLA is lacking.

Objective: To determine (1) the three-dimensional (3D) histologically defined ablation zone of single- and multifiber TPLA treatment for PCa correlated with magnetic resonance imaging (MRI) and contrast-enhanced ultrasound (CEUS) and (2) a reliable imaging modality of ablation zone volumetry.

Design setting and participants: This was a prospective, multicenter, and interventional phase I/II pilot study with an ablate-and-resect design. TPLA was performed in 12 patients with localized prostate cancer divided over four treatment regimens to evaluate potential variation in outcomes.

Intervention: TPLA was performed approximately 4 wk prior to robot-assisted radical prostatectomy (RARP) in a daycare setting using local anesthesia.

Outcome measurements and statistical analysis: Four weeks after TPLA, ablation zone volumetry was determined on prostate MRI and CEUS by delineation and segmentation into 3D models and correlated with whole-mount RARP histology using the Pearson correlation index.

Results and limitations: Twelve office-based TPLA procedures were performed successfully under continuous transrectal ultrasound guidance using local perineal anesthesia. No serious adverse events occurred. A qualitative analysis showed a clear demarcation of the ablation zone on T2-weighted MRI, dynamic contrast-enhanced MRI, and CEUS. On pathological evaluation, no remnant cancer was observed within the ablation zone. Ablation zone volumetry on CEUS and T2-weighted MRI compared with histology had a Pearson correlation index of r = 0.94 (95% confidence interval [CI] 0.74-0.99, p < 0.001) and r = 0.93 (95% CI 0.73-0.98, p < 0.001), respectively.

Conclusions: CEUS and prostate MRI could reliably visualize TPLA ablative effects after minimally invasive PCa treatment with a high concordance with histopathological findings and showed no remnant cancer.

Patient summary: The treatment effects of a novel minimally invasive ablation therapy device can reliably be visualized with radiological examinations. These results will improve planning and performance of future procedures.

Keywords: Focal laser therapy; Magnetic resonance imaging; Prostatic neoplasms; Ultrasonography.