Rad-15. Percutaneous MRI guided and monitored cryosurgery of bone tumors.

The purpose of this study is to develop a minimally invasive image guided treatment for painful benign primary and malignant secondary bone tumors that might substitute or replace current therapies. Patients with painful primary bone tumors who were poor surgical candidates due to the likelihood of complications secondary to anatomy, or patients with painful secondary bone tumors were enrolled in this Investigational Review Board approved study. Preoperatively diagnostic imaging consisted of a CT or a MRI along with plain film x-rays. Treatment goal was relief of pain. Most patients were not candidates or had failed traditional palliative therapies. Fifteen patients underwent 16 IMRI guided and monitored percutaneous cryosurgeries with general anesthesia (13), spinal anesthesia (1), and deep sedation (2). Eighteen lesions were treated. Tumor locations included the spine, sternum, sacrum, scapula, long bones, and iliac bones. Malignant tumor cell types included renal cell carcinoma, sarcoma, breast adenocarcinoma, colon adenocarcinoma, non-small cell lung cancer, and carcinoid tumor. Benign cell type was osteoid osteoma. Follow-up ranges from 3-30 months with a mean of 20 months. Short-term results demonstrated excellent and immediate relief of pain. Long-term results find 10 patients alive with continued pain relief although one patient with a large (6 cm) scapular lesion required a second treatment. The other five patients achieved long-term pain relief but have died from disease progression outside of the cryosurgery site. Complications consisted of foot drop in two patients, both of which had large destructive lesions involving the sacrum. Excellent and sustained pain relief was achieved in a variety of tumors, many of which were located such that traditional palliative treatments were not an option. The multiplanar imaging and thermal event imaging capabilities of MRI were critical in minimizing morbidity and maximizing success.

Patrick E. Sewell, Jr, MD, and Gurmeet Dhillon, MD. University of Mississippi Medical School, Department of Radiology, Division of Image Guided Minimally Invasive Surgery, Jackson MI.