Image Guided Photothermal Focal Therapy for Localized Prostate Cancer: Phase I Trial U. Lindner,* R. A. Weersink, M. A. Haider, M. R. Gertner, S. R. H. Davidson, M. Atri, B. C. Wilson, A. Fenster and J. Trachtenberg From Surgical Oncology, Urology Division (UL, JT), Division of Biophysics and Bioimaging (RAW, MRG, SRHD, BCW), Joint Department of Medical Imaging (MAH, MA), University Health Network, University of Toronto, Toronto, and Imaging Research Laboratories, Robarts Research Institute, London (AF), Ontario, Canada Purpose: We ascertained the feasibility and safety of image guided targeted photothermal focal therapy for localized prostate cancer. Materials and Methods: Twelve patients with biopsy proven low risk prostate cancer underwent interstitial photothermal ablation of the cancer. The area of interest was confirmed and targeted using magnetic resonance imaging. Three- dimensional ultrasound was used to guide a laser to the magnetic resonance to ultrasound fused area of interest. Target ablation was monitored using thermal sensors and real-time Definity® contrast enhanced ultrasound. Followup was performed with a combination of magnetic resonance imaging and prostate bi- opsy. Validated quality of life questionnaires were used to assess the effect on voiding symptoms and erectile function, and adverse events were solicited and recorded. Results: Interstitial photothermal focal therapy was technically feasible to per- form. Of the patients 75% were discharged home free from catheter the same day with the remainder discharged home the following day. The treatment created an identifiable hypovascular defect which coincided with the targeted prostatic lesion. There were no perioperative complications and minimal morbidity. All patients who were potent before the procedure maintained potency after the procedure. Continence levels were not compromised. Based on multicore total prostate biopsy at 6 months 67% of patients were free of tumor in the targeted area and 50% were free of disease. Conclusions: Image guided focal photothermal ablation of low risk and low volume prostate cancer is feasible. Early clinical, histological and magnetic resonance imaging responses suggest that the targeted region can be ablated with minimal adverse effects. It may represent an alternate treatment approach to observation or delayed standard therapy in carefully selected patients. Further trials are required to demonstrate the effectiveness of this treatment concept. Key Words: prostatic neoplasms, ablation techniques, ultrasonography, magnetic resonance imaging Abbreviations and Acronyms 3-D  3-dimensional AS  active surveillance CEUS  contrast enhanced ultrasound IIEF  International Index of Erectile Function I-PSS  International Prostate Symptom Score MR  magnetic resonance MRI  magnetic resonance imaging PCa  prostate cancer PSA  prostate specific antigen TRUS  transrectal ultrasound US  ultrasound Submitted for publication February 5, 2009. Study received Research and Ethics Institu- tional Board approval. Supported by the Muzzo Fund of the Princess Margaret Hospital Foundation. * Correspondence: Surgical Oncology, Urology Division, University Health Network, 601 University Ave., Toronto, Ontario M5G 2M9 Canada (tele- phone: 647-8019043; FAX: 416-2609236; e-mail: lindneruri@gmail.com). PROSTATE cancer remains the most common, noncutaneous human malig- nancy with an estimated 186,320 new cases diagnosed in 2008 in the United States. 1 Autopsy studies show that cancer cells can be found in the pros- tate of 30% to 40% of men at age 60 years, increasing to 60% to 70% by age 80 years. However, the lifetime risk of clinically significant and fatal prostate cancer of a 50-year-old Amer- ican man is estimated to be only 9.5% 0022-5347/09/1824-1371/0 Vol. 182, 1371-1377, October 2009 THE JOURNAL OF UROLOGY ® Printed in U.S.A. Copyright © 2009 by AMERICAN UROLOGICAL ASSOCIATION DOI:10.1016/j.juro.2009.06.035 www.jurology.com 1371