TRANSPERINEAL RADIOFREQUENCY INTERSTITIAL TUMOR ABLATION OF THE PROSTATE - CORRELATION OF MAGNETIC-RESONANCE-IMAGING WITH HISTOPATHOLOGIC EXAMINATION

Objectives. Radiofrequency (RF) energy has recently been employed to d estroy human tissue in vivo. The purpose of this study was to investig ate the safety of this approach in localized carcinoma of the prostate (CaP) and specifically, the predictability of lesions obtained with r adiofrequency interstitial tumor ablation (RITA). Methods. Using RITA, a total of 21 lesions were induced in 10 patients with localized CaP (mean age 70.4 years). RF was delivered transperineally under transrec tal ultrasound (TRUS) guidance. All patients underwent endorectal magn etic resonance imaging (MRI) before and after treatment. Radical prost atectomy was performed in all patients 1 to 7 days after RITA. Three o f the patients were treated with local anesthesia only. The predictabi lity of the thermal lesion was assessed by correlating the findings of intraoperative TRUS, pre- and post-RITA endorectal MRI, and the histo logic examination of the specimen. Results. Postoperatively, patients were catheterized for an average of 1.8 days (1 to 3 days), Lesions of 2 x 2 x 2 cm were targeted. Average lesion diameters obtained on MRI were 2.08 +/- 0.23 x 2.09 +/- 0.36 x 2.28 +/- 0.21 cm. Average lesion diameters defined by coagulative necrosis at histologic examination we re 2.20 +/- 0.25 x 2.10 +/- 0.31 x 2.38 +/- 0.14 cm. There were no sta tistically significant differences (P = 0.377) between average lesion volume on MRI (5.37 +/- 1.83 cm(3)) and average lesion volume at histo logy (5.86 +/- 1.63 cm(3)). No complications or adverse events were no ted. Conclusions. In this Phase I study, RITA was shown to be safe and feasible, and to result in lesions that were predictable in size and location. MRI accurately visualized and verified the area of coagulati ve necrosis as documented at histology. The procedure is technically s imple and can even be performed under local anesthesia. (C) 1997, Else vier Science Inc. All rights reserved.