Some interesting information was presented at the Society of Interventional Radiology’s 35th Annual Scientific Meeting just held in Tampa, Fl. A potential future use of magnetic resonance (MR)-guided heat (laser interstitial thermal therapy) or cold (cryoablation) to treat the recurrence of prostate cancer after the surgical removal of the prostate gland (and in some cases after the failure of salvage radiation) was disclosed.
“Magnetic resonance-guided ablation may prove to be a promising new treatment for prostate cancer recurrences; it tailors treatment modality (imaging) and duration to lesion size and location and provides a less invasive and minimally traumatic alternative for men,” said David A. Woodrum, M.D., Ph.D., an interventional radiologist at the Mayo Clinic in Rochester, Minn. “The safe completion of four clinical cases using MR-guided ablation therapy to treat prostate cancer in patients who had failed surgery demonstrates this technology’s potential,” he said, stressing, however, that the application for using ablation therapy in treating prostate cancer is relatively new.
In the study four men with recurrent prostate cancer had previously been treated with a radical prostatectomy. The men then underwent salvage therapy using either MR-guided laser interstitial thermal therapy, which uses high temperatures generated by local absorption of laser energy, or cryoablation, generating freezing with extremely cold gas destroying cancerous tissue. The use of MR imaging with temperature mapping and/or ice ball growth monitoring, the researchers were able to tailor the individual treatments to specific lesion size and location. “Immediately after treatment, we found no definite residual tumor. The treatment preserved the patients’ baseline sexual and urinary function and had no major complications,” added Woodrum.
In this very small retrospective review, each of the four men was found to have post surgical recurrent prostate cancer detected by MR imaging. Two were treated with MR-guided laser interstitial thermal therapy; the other two were treated with cryoablation. Biopsy-proven cancer lesions ranged in size from 6 millimeters and were located in the prostate bed just inferior to the bladder and anterior to the rectum, where the prostate gland had previously resided. The men had no detectable metastases at the time of treatment. For both ablation methods, two to three probes or applicators were used in each case. Intermittent MR imaging was employed during the procedures for placement of the probes/applicators and to actively monitor ablation size during treatment to completely cover the lesion.
This type of treatment remains in the very early stages so additional study is needed to identify which men will be best suited for the ablation procedure and to follow up to evaluate its long term efficacy.
Abstract 156: “MR-Guided Trans-perineal Laser and Cryoablation of Locally Recurrent Prostate Adenocarcinoma Following Radical Prostatectomy,” D.A. Woodrum, L.A. Mynderse, A. Kawashima, K.R. Gorny, T.D. Atwell, K.K. Amrami, H. Bjarnason, M.R. Callstrom and E.F. McPhail, all at Mayo Clinic, Rochester, Minn.; and B. Bolster, Siemens, Rochester, Minn., SIR 35th Annual Scientific Meeting March 13, 2010, Tampa, Fla.
Joel T Nowak, MA, MSW