Cryoablation of a bone metastatic lesion form renal cell caner. In cryoablation, a small freezing probe is insertead through the skin, and its tip is placed into the cancerous tissue using CT and ultrasound guidance. Retrospective studies suggest an around 95% success rate. Subsequent MRI or CT scans are used to evaluate the ablation, with diminution of the tumor in the cryolesion and lack of contrast enhancement considered a favorable result, and increase of the tumor in the cryolesion or interval growth considered signs of inadequate treatment. A percutaneous biopsy, a standard resection, or retreatment with cryoablation can then occur. The mechanism leading to tumor destruction is uncertain and may be a combination of direct cytotoxicity and damage to vascular elements leading to ischemic necrosis.
Cryoablation is employed and studied in various organs. Percutaneous cryoablation is beginning to emerge as a useful method of image-guided ablation of musculoskeletal metastases; however, only case reports and series are available in the literature. A prospective trial in bone concluded: ”
Our findings suggest that cryoablation is a safe and effective treatment for the palliation of painful metastatic lesions that are refractory to standard therapies. Most important, the activities of daily living for these patients are improved with this therapy. Prospective comparison studies of cryoablation and radiation therapy may be useful to distinguish the relative benefits of these therapies for palliation of painful metastatic lesions.”
It remains an E/I procedure pending more studies.
Steven R. Ullrick, MD, Jeffrey J. Hebert, MDb, Kirkland W. Davis,
Cryoablation in the Musculoskeletal System, Current porblems in diagnostic radiology, Volume 37, Issue 1, Pages 39-48 (January 2008)
Matthew R. Callstrom, MD, PhD, Thomas D. Atwell, MD, J. William Charboneau, MD, Michael A. Farrell, MD, Matthew P. Goetz, MD, Joseph Rubin, MD, Jeff A. Sloan, PhD, Paul J. Novotny, MS, Timothy J. Welch, MD, Timothy P. Maus, MD, Gilbert Y. Wong, MD and Kathy J. Brown, BS
Painful Metastases Involving Bone: Percutaneous Image-guided Cryoablation—Prospective Trial Interim Analysis Radiology, 241, 572-580 2006
Tuncali K, Morrison PR, Winalski CS, et al. MRI-guided percutaneous cryotherapy for soft-tissue and bone metastases: initial experience. AJR Am J Roentgenol 2007; 189:232–239.