Postoperative MRI in patients undergoing interstitial laser coagulation thermotherapy of benign prostatic hyperplasia

Objective: We conducted MRI of the effects of laser-induced thermal therapy (LITT) in benign prostatic hyperplasia (BPH). Materials and Methods: Eighteen patients (average age 64 years) were examined with MRI 24-48 h before and after LITT of BPH. Sagittal and axial T2-weighted FSE MR images were evaluated for signs of coagulation necrosis in the prostate gland and the presence of intra- and extraprostatic edema. Results: Coagulation areas showed as a hypointense central core with a hyperintense rim. Intraprostatic edema led to a volume increase of 18-108% both in the central and in the total gland. Periprostatic edema was severe in preprostatic and prevesical tissue as well as lateral to the prostate, moderate in the presacral space, and mild perirectally and dorsal to the prostate. Follow-up examinations 2 weeks to 6 months after LITT in five patients showed decrease of coagulation necrosis volume, prostate size, and edema. Conclusion: MRI appears to be a reliable method to monitor LITT effects in patients with BPH.