Hyun Jung Bang MD, Abstract Co-Author: Nothing to Disclose

Peter John Littrup MD, Presenter: Co-founder, Cryomedix, LLC Co-founder, CryoDynamics LLC Research support, HealthTronics, Inc

Barbara A. Adam BA, Abstract Co-Author: Nothing to Disclose

Monica D'Agostini, Abstract Co-Author: Nothing to Disclose

Yasmin Habibi MPH, Abstract Co-Author: Nothing to Disclose

Dylan Goodrich, Abstract Co-Author: Nothing to Disclose

Hussein D. Aoun MD, Abstract Co-Author: Nothing to Disclose

To assess complications, recurrences, median survival rate and ablation zone resorption following cryoablation of soft tissue tumors in non-organ locations.

164 CT and/or US-guided, percutaneous cryotherapy procedures were performed for 195 tumors in 100 patients. Tumor location was grouped according to regional sites: retroperitoneal, superficial, intraperitoneal, and bone. Protection of adjacent crucial tissues (e.g. skin, bowel) from cytotoxic temperatures (e.g., <-20C) was achieved by saline injection, balloon interposition and/or direct skin warming. Complications were graded according to Common Toxicity Criteria for Adverse Events Version 3.0 (CTCAE). Patients were followed by CT or MRI and local recurrence was defined as any asymmetric nodular enhancement of the cryozone and/or ablation site enlargement. Resorption was calculated from ablation zone measurements grouped into 1, 3, 6, 12, 18, and 24+ month statistical bins.

Tumor and procedure numbers for each site are: 38,32 - retroperitoneal; 63,49 - superficial; 60,54 - intraperitoneal; 34,31 - bone. The cryotherapy zone was well defined by CT as a hypodense ice ball with an average ablation diameter of 5.5 cm, while average tumor diameter was 3.4 cm. Major complications (CTCAE Grade >3) occurred after 8 procedures (5%). After an average follow-up of 12 months (range: 0-80), a total of 17 local recurrences of 195 tumor sites (9%) were noted, of which 10 (59%) occurred within the ablation zone and 7 (41%) were satellite lesions (i.e., <10mm beyond). Therefore, true procedure failure rate of only 5% (10/195), which occurred with an average time to recurrence of 4.1 months, suggested excellent local cancer control for difficult-to-treat patients. Application of the Kaplan-Meier estimator determined that the median survival rate of patients in this study was 25.1 months. By 24 months, ablation volume reduction was 94%.

Intermediate data suggests that CT-guided percutaneous cryoablation is an effective modality in the local control of soft tissue tumors with an average ablation volume reduction of 94% at 24 months. Procedures are well tolerated in these variable locations if proper visualization is obtained and if appropriate precautions are taken on a case by case basis.

CT-guided percutaneous cryoablation is a effective modality in the local control of soft tissue metastasis.

Bang, H, Littrup, P, Adam, B, D'Agostini, M, Habibi, Y, Goodrich, D, Aoun, H, Soft Tissue Cryotherapy: Intermediate Follow-up in Retroperitoneal, Intraperitoneal, Superficial, and Bone Locations.  Radiological Society of North America 2010 Scientific Assembly and Annual Meeting, November 28 - December 3, 2010 ,Chicago IL. http://archive.rsna.org/2010/9013066.html