SIR: MR-guided therapy offers hope for prostate cancer recurrence

Using MRI-guided laser interstitial thermal therapy or cryoablation methods may serve as new treatment options for cancer recurrence after surgical removal of the prostate gland, according to research presented at the 35th annual Society of Interventional Radiology (SIR) scientific meeting in Tampa, Fla. This is because improved detection of early prostate cancer recurrence is best seen through MRI, researchers said.

Marking the first known patient cases treated by this method, David A. Woodrum, MD, an interventional radiologist at Mayo Clinic in Rochester, Minn., said: “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.”

For the retrospective study, four men with post-surgical recurrent prostate cancer detected by an MRI were recruited. According to the researchers, two men underwent salvage therapy treatment with MR-guided laser interstitial thermal therapy, a method that utilizes high temperatures generated by local absorption of laser energy. The remaining two patients underwent cryoablation, a process that generates freezing conditions with extremely cold gas that destroys cancerous tissue.

The authors tailored MR treatments to lesion size and location within the patients, by way of temperature mapping and/or ice ball growth monitoring and they employed intermittent MR imaging during the procedures in order to correctly place the probes and to actively monitor ablation size during treatment to completely cover the lesion. For both interstitial thermal therapy and cryoablation, two to three probes were used for each patient, Woodrum and colleagues said.

Within the location inside the body were the prostate gland had been prior to surgical resection, the researchers found biopsy-proven cancer lesions in the four study participants. However, Woodrum noted, "immediately after treatment, we found no definite residual tumor. The treatment preserved the patients' baseline sexual and urinary function and had no major complications.”

Despite the findings, Lance A. Mynderse, MD, a urologist at Mayo, noted that the treatment method remains in the formative stages and additional studies will be required to learn what patients will be best suited for the ablation procedure, as well as to examine the middle- and long-term results for efficacy.

"MR-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," concluded Woodrum.