Phase 1 Study of MRI Targeted Focal Laser Thermal Therapy of Prostate Cancer

This is a single center, single arm, open-label study to evaluate the safety and feasibility of MRI guided focal prostate cancer laser ablation in patients with a focus of prostate cancer who has not yet received treatment for their cancer. Patients fulfilling the inclusion criteria and having none of the clinical exclusion criteria will be enrolled into the study after they (or their legal representative) have signed the informed consent form. No control group will be utilized and all patients will receive MRI guided FLA for their focal prostate cancer. As part of the screening process, patients will provide a medical history and undergo a physical examination, including a digital rectal examination (DRE). At the first visit, patients will also be given a copy of the informed consent, and a copy of quality of life and performance questionnaires to assess urinary, rectal, and erectile functions (IPSS questionnaire for urinary, IIEF5 questionnaire for erectile function, for all). MR imaging at visit 2 will serve to determine if a single site of prostate cancer can be localized. At visit 3, 12 cores transrectal us guided prostate biopsy will confirm yet again that this is a unilateral, unifocal histologically proven tumour in the site recognized on the MRI. On preoperative examination (visit 4) - blood and urine samples will be taken prior to procedure. Visit 5 - the focal treatment will be performed under regional or general anesthesia, or conscious sedation, (as determined by the anesthesiologist) in the TGH research 1.5T MRI suite. MR guided FLA procedure is similar to MR guided brachytherapy, with fibers and probes inserted transperineally outside the bore of the MR and then the patient is moved inside the bore to verify position before deploying the laser. The treatment is expected to last 2-3 hours, and patients expected to have no pain during the whole procedure. Laser ablation will be monitored using MR thermometry14, 15.An MRI scan will be done immediately after the ablation, as initial assessment for ensuring complete treatment of the target volume, as well as ensuring that treatment does not extend to critical structures.

The size and location of the lesion will be compared to the planned target volume and the proximity of the lesion to the urethra and rectum. If the lesion does not encompass the target volume, and is still a safe distance from either critical structure, FLA may be continued.

On day 3, 7, 30, and 120 following the procedure, patients will be assessed for clinical signs of urinary, rectal, and erectile complications and will complete validated self-assessment tools on these functions. Free/Total PSA will be monitor on visit -1 and after the treatment on day 7, 30 and 120, in order to try to understand the effect of FLA on PSA. Four months after the focal procedure, a further 12 cores biopsy, plus 2 cores aimed to the ablated lesion will then be preformed to verify the oncological effectiveness of the treatment.