Two-year Outcomes Following Focal Laser Ablation of Localized Prostate Cancer

Background: There is no consensus regarding how to assess oncological control following focal ablation of prostate cancer.

Objective: To assess quality of life and in-field recurrence following focal laser ablation (FLA).

Design, setting, and participants: Of 34 men participating in a prospective outcomes study following FLA, 32 underwent prostate-specific antigen (PSA) testing and magnetic resonance imaging (MRI) at 6 mo and 2 yr. All underwent assessment of urinary and sexual function at 1 yr.

Intervention: FLA and MRI-targeted biopsy of the ablation zone.

Outcome measurements and statistical analysis: The American Urological Association Symptom Score and the Sexual Health Inventory for Men at baseline and 12 mo were compared using a two-sided Wilcoxon signed-rank test with a significance level of p=0.05. The percentage of positive and negative in-field biopsies was calculated for suspicious and nonsuspicious post-ablation MRI scans.

Results and limitations: FLA was associated with no adverse impact on urinary or sexual function. For men with suspicious MRI (MRI+) findings, in-field disease recurrence of intermediate and low risk disease was detected in 75% and 25% of cases, respectively. For men with nonsuspicious MRI (MRI-) findings, in-field disease recurrence of intermediate- and low-risk disease was detected in 22.4% and 50% of cases, respectively. The change in PSA from baseline did not discriminate cases with MRI- findings with and without cancer at 2 yr.

Conclusions: MRI reliably identifies in-field recurrence of only intermediate-risk prostate cancer at 2 yr after FLA. A biopsy of the ablation zone must be performed for MRI+ findings. The decision to perform an ablation-zone biopsy for men with MRI- scans should be influenced by whether detection of low-risk disease would influence management.

Patient summary: Our study provides compelling evidence that men should undergo interval magnetic resonance imaging to assess the probability of intermediate-risk disease in the ablation zone following focal laser ablation of localized prostate cancer.