Abstract
INTRODUCTION: Focal therapy (FT) for localized prostate cancer (PC) aims to achieve cancer control and maintain quality of life. Microwave tissue coagulation (MTC) is a tissue-coagulation thermotherapy that has been used to treat solid tumors such as kidney, liver, and lung tumors. However, the use of this technology in lesion-targeted FT for PC has not been established. METHODS: We will perform a prospective multi-center, single-arm, clinical study to evaluate the efficacy and safety of lesion-targeted focal MTC for localized PC. In eight centers with expert urologists for performing magnetic resonance imaging (MRI)/ultrasound (US) fusion biopsy, patients will be evaluated prospectively after lesion-targeted MTC. The target sample size is 65. This study was registered with the Japan Registry of Clinical Trials and ClinicalTrials.gov. Inclusion criteria were patients who had a single MRI-visible lesion with Prostate Imaging Reporting and Data System (PI-RADS) category 3 or 4 that was proven as Gleason score of 7 or 8 cancer by enrollment biopsy or patients who had a single MRI-visible lesion with PI-RADS category 4 or 5 that was proven as Gleason score of 6 or 7 by enrollment biopsy. The primary endpoint is the disappearance of the targeted cancer lesion at 6 months after microwave coagulation, evaluated by a combined response in prostate-specific antigen, MRI, and prostate biopsy. DISCUSSION: The importance of this clinical trial is to establish a new ablative treatment option for lesion-targeted FT in PC.