Presentation Authors: John Feller*, Bernadette Greenwood, Steven Gunberg, Jeffrey Herz, Wesley Jones, Indian Wells, CA, Robert Toth, Parlin, NJ
Introduction: In the United States alone, new prostate cancer cases for 2018 were estimated at 164,690 and deaths at 29,430. Focal therapies for prostate cancer are increasingly being explored and new treatments for salvage patients are being studied. Our objective is to investigate the efficacy of using MR-guided laser focal therapy for MR-visible prostate cancer utilizing a transrectal approach for laser applicator placement and therapy delivery in an outpatient setting. Lasers have been used for soft tissue necrotization for decades. A commercially available MR-guided biopsy system allows insertion of a laser fiber into biopsy-proven cancer for ablation of MR-visible tumor.
Methods: All MRI-guided therapy was delivered using a 1.5 Tesla Philips Achieva XR system (Philips Healthcare, Best, The Netherlands) for both image acquisition and real-time thermometry. DynaCAD and DynaLOC (Invivo, Orlando, FL, USA) software were used for image analysis and laser fiber placement planning. Laser focal therapy was delivered using a Visualase (Medtronic, Minneapolis, MN, USA) 15W, 980 nm diode laser. Visualase (saline-cooled) fibers or Tranberg Clinical Laserthermia (CLS Americas, Framingham, MA, USA)(non-cooled) fibers were introduced transrectally. MR imaging and MR-thermometry were used to monitor energy deposition and coagulation necrosis.
Results: Under IRB-approved, HIPAA-compliant protocol, 130 men and 198 cancer foci were treated. Total procedure time was between 1.5 and four hours MRI volume of coagulation necrosis ranged from 0.6 to 38 cc (mean 7.2 cc, median 6.2 cc). No serious adverse events or morbidity were reported. Of the 131 lesions (in 94 men) for which we had 6 mo. biopsies of the treatment regions available, 27/131 of lesions (21%) in 20/95 of men (21%) were positive and clinically significant*, while 83/131 of lesions (63%) in 61/95 of men (65%) were negative. We observed a 40% decrease in mean PSA at 12 months post therapy and no statistically significant change in IPSS and SHIM scores._x000D_
*Excludes Gleason score 3+3=6
Conclusions: Our data indicate that outpatient, transrectally-delivered MRI-guided laser focal therapy for prostate cancer is both safe and feasible. The precision and controllability achieved under MRI-guidance may have favorable results for cost effectiveness and quality of life without eliminating the possibility of whole-gland treatment in the patient's future. We will continue to follow these men for twenty years as part of an IRB-approved clinical trial (NCT#02243033).