Ablation of stage T1/T2 prostate cancer with permanent interstitial temperature self-regulating rods

Purpose: To determine if stage T-1/T-2 prostate cancer can be treated safely and effectively with interstitial thermal ablation. Patients and Methods: Twenty patients with biopsy-confirmed prostate cancer were enrolled in the protocol. The average age was 71.0 years, and the pretreatment prostate specific antigen (PSA) concentration ranged from 2.5 to 10.7 ng/mL and the Gleason sum from 3 to 7. An array of small biocompatible magnetic alloy rods was placed in the patients percutaneously in a procedure analogous to the placement of brachytherapy seeds. Rods were placed end-to-end and no further than I cm apart; rods extended to the capsule and were placed at the capsule in the rectal grove. The rods are temperature self-regulating and heat to 70 degrees C when placed in an alternating magnetic field. Each patient was treated in a coil system that supplies a uniform magnetic field throughout the patient's pelvis for a single 60-minute session. Urethral cooling and rectal temperature monitoring was performed. Serial PSA was followed, and biopsy was performed I year post-treatment. Results: Immediately after treatment, most PSA values increased dramatically but then fell to <1.0 ng/mL within 8 weeks. After I year, five patients had positive biopsies; these patients had significantly lower rod-implant densities. Eight patients reported erectile dysfunction, but none reported incontinence. Other complications were minor. Conclusion: The data suggest that this technique is well tolerated and safe and may be useful in certain patients with T-1/T-2 prostate cancer.