582 MR-guided focal cryoablation of prostate cancer recurrence following radiotherapy: A feasibility study

582

MR-guided focal cryoablation of prostate cancer recurrence following radiotherapy: A feasibility study Eur Urol Suppl 2013;12;e582

Futterer J.1, Bomers J.1, Yakar D.1, Van Lin N.J.T.2, Vergunst H.3, De Lange F.4, Barentsz J.O.4, Sedelaar J.P.5 1

Radboud University Nijmegen Medical Centre, Dept. of Radiology, Nijmegen, The Netherlands, 2Radboud University

Nijmegen Medical Centre, Dept. of Radiotherapy, Nijmegen, The Netherlands, 3CWZ, Dept. of Urology, Nijmegen, The Netherlands, 4Radboud University Nijmegen Medical Centre,, Dept. of Radiology, Nijmegen, The Netherlands, 5

Radboud University Nijmegen Medical Centre,, Dept. of Urology, Nijmegen, The Netherlands

INTRODUCTION & OBJECTIVES: Cryosurgery of prostate cancer (PCa) under transrectal ultrasound (TRUS) guidance has been performed for several years for salvage treatment purposes after radical prostatectomy or radiotherapy. However, high complication rates are not uncommon, due to poor visibility. Magnetic resonance (MR) imaging guided cryosurgery of the prostate may reduce these high complication rates, because of the excellent soft tissue contrast. Furthermore, MR image guidance enables both accurate lesion targeting as well as three-dimensional monitoring of iceball growth. The purpose of our study was to assess the feasibility and safety of MR image-guided focal cryoablation of recurrent PCa after radiotherapy. MATERIAL & METHODS: Since May 2011, ten patients with histopathologically proven local recurrence of PCa and without evidence for distant metastases were treated under general anesthesia in a 1.5 Tesla MR system. An urethralwarmer was inserted in the urethra. A transperineal plate, attached to a flexible arm was placed against the perineum. Cryoneedles were inserted with real-time MR image guidance. A rectal warmer was inserted in the rectum. Both warmers were flushed with warm water to protect the tissue from freezing. Iceball formation and tissue coverage was continuously monitored under near real-time MR image guidance. Two freeze- and thaw cycles were performed. Treatment time was defined as from the moment the first MR image was performed until the last MR image was finished. Follow-up consisted of PSA-level measurement every 3 months and a multi-parametric MRI after 3, 6 and 12 months. RESULTS: MR-guided focal cryoablation was technically feasible in all patients. In one patient the urethral-warmer could not be inserted. This procedure was cancelled and successfully repeated 2 months later. Median age of the patients at the time of treatment was 67 years (range 52 – 76), median PSA level was 3.7 ng/mL (range 0.9 – 8.7) and Gleason scores varied between 7 - 10. Per patient 2 – 4 cryoneedles were used and median treatment time was 133 minutes (range 91 – 242). Median hospitalization time was 2 days (range 2 – 3). Two patients suffered from mild urine retention and one had hematospermia. Three months follow-up is known for the first 6 patients: their PSA level decreased to a median of 1.3 (range 0.3 – 5.9) and their multi-parametric MRI showed no presence of recurrent tumor. After 6 months, 1 out of 3 assessed patients had a histopathologically proven local recurrence just above the area previously treated. He was retreated with MR-

guided cryoablation. Follow-up is not known yet. CONCLUSIONS: Transperineal focal MR-guided cryoablation of recurrent PCa after radiotherapy was technically feasible and safe. Initial short-term results are promising, but more patients have to be included.