Initial Experience of Targeted Focal Interstitial Laser Ablation of Prostate Cancer with MRI Guidance

To develop and evaluate a technique of 3.0 Tesla magnetic resonance (MR) guided laser ablation based on 3-dimentional mapping biopsy (3DMB) for low risk prostate cancer.

The study was approved by the institutional review board and was the Health Insurance Portability and Accountability Act compliant. The prospective study was performed on seven 3DMB proven low risk prostate cancer patients. In the first phase of the procedure the patient's prostate was aligned to a position concordant with prior 3DMB using the transperineal grid and fiduciary golden marker coordinates. In the second phase ablation was performed using MR thermometry to determine the ablation endpoint and lesion coverage. Immediately after treatment dynamic contrast-enhanced MR imaging was done. Prostate-specific antigen testing was performed 3 and 12 months after the treatment and compared by ANOVA test. A follow up biopsy was done one year following ablation.

The entire procedure took less than 2 hours and all patients tolerated the procedure well. There was a significant difference in prostate-specific antigen value before and 3 months after the treatment (p = 0.005). Four out of 6 patients had positive follow up biopsy for cancer.

This study verifies the feasibility and safety of treating low risk prostate cancer with laser therapy guided by 3.0T MR imaging based on 3DMB.