MRI-guided focal laser ablation of prostate cancer: a prospective single-arm, single-center trial with 3 years of follow-up

Abstract

Purpose: We aimed to assess post-interventional and 36-month follow-up results of a single-center, single-arm, in-bore phase I trial of focal laser ablation (FLA) guided by multiparametric magnetic resonance imaging (mpMRI).

Methods: FLA procedures were done in-bore MRI using a transperineal approach. Primary endpoints were feasibility and safety expressed as lack of grade 3 complications. Secondary endpoints were changes in international prostate symptom score (IPSS), sexual health inventory for men (SHIM), quality of life (QoL) scores, and serum prostate specific antigen (PSA) levels. Treatment outcomes were assessed by combined mpMRI-ultrasound fusion-guided and extended sextant systematic biopsy after 12, 24, and optionally after 36 months.

Results: Fifteen participants were included. Seven patients (46.67%) had Gleason 3+3 and 8 patients (53.33%) had Gleason 3+4 cancer. All patients tolerated the procedure well, and no grade 3/4 complications occurred. All grade 1 and 2 complications were transient and resolved completely. There was no significant change in mean IPSS from baseline (-1, p = 0.460) and QoL (0, p = 0.441) scores following FLA but there was a significant drop in mean SHIM scores (-2, p = 0.010) compared to pretreatment baselines. Mean PSA significantly decreased after FLA (-2.5, p < 0.001). Seven out of 15 patients (46.67%) had residual cancer in, adjacent, or in close proximity to the treatment area (1 × 4+3=7, 1 × 3+4=7, and 5 × 3+3=6). Four out of 15 patients (26.67%) underwent salvage therapy (2 repeat FLA, 2 radical prostatectomy).

Conclusion: After 3 years of follow-up we conclude focal laser ablation is safe and feasible without significant complications.

Conflict of interest statement

Conflict of interest disclosure

The authors declared no conflicts of interest.

Figures

Figure 1

Box and whisker plots of IPSS, SHIM, QoL scores and PSA level at baseline. IPSS, international prostate symptom score; SHIM, sexual health inventory for men; QoL, quality of life; PSA, prostate specific antigen.

Figure 2

Change of IPSS, SHIM, QoL and PSA from baseline until receipt of salvage treatment or the end of follow-up if no salvage treatment was received. IPSS, international prostate symptom score; SHIM, sexual health inventory for men; QoL, quality of life; PSA, prostate specific antigen.

Figure 3

Change from baseline until receipt of salvage treatment or the end of follow-up if no salvage treatment was received. Per patient change of IPSS, SHIM, QoL and PSAS depicted in the boxplot was calculated as the average difference between outcomes measured at baseline and each follow-up visit. IPSS, international prostate symptom score; SHIM, sexual health inventory for men; QoL, quality of life; PSA, prostate specific antigen.

Figure 4

A 75-year-old male with a serum PSA of 6.2 ng/mL at the time of the baseline prostate MRI, which revealed a left mid anterior transition zone lesion with a resultant targeted biopsy indicating Gleason 3+4 prostate cancer (arrows). MRI follow-up scans at 6 months, 12 months and 36 months after in-bore MRI-guided focal laser ablation demonstrate band-like appearance suggesting fibrosis on T2-weighted MRI and ADC map with no focal enhancement on DCE MRI (arrows).