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

To determine if stage T(1)/T(2) prostate cancer can be treated safely and effectively with interstitial thermal ablation.

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 1 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 1 year post-treatment.

Immediately after treatment, most PSA values increased dramatically but then fell to <1.0 ng/mL within 8 weeks. After 1 year, five patients had positive biopsies; these patients had significantly lower rodimplant densities. Eight patients reported erectile dysfunction, but none reported incontinence. Other complications were minor.

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.