Ritu Randhawa MBBS, Presenter: Nothing to Disclose

Eric vanSonnenberg MD, Abstract Co-Author: Nothing to Disclose

Palma Dileo MD, Abstract Co-Author: Nothing to Disclose

Sridhar Shankar MD, Abstract Co-Author: Nothing to Disclose

Paul Richard Morrison MS, Abstract Co-Author: Nothing to Disclose

Rashmi Thottathil Nair MD, Abstract Co-Author: Nothing to Disclose

Stuart George Silverman MD, Abstract Co-Author: Nothing to Disclose

Kemal Tuncali MD, Abstract Co-Author: Nothing to Disclose

Annick D. Van Den Abbeele MD, Abstract Co-Author: Nothing to Disclose

Jeffery A Morgan MD, Abstract Co-Author: Nothing to Disclose

George D Demetri MD, Abstract Co-Author: Nothing to Disclose

et al, Abstract Co-Author: Nothing to Disclose

To evaluate the therapeutic efficacy and safety of percutaneous RFA in the treatment of solitary progressive lesions in patients with metastatic GIST refractory to gleevec.

Nine patients (M: F =7:2), mean age of 59 years, treated with gleevec for a median of 25 months (range 18-36 m) underwent CT-guided percutaneous RFA for single or limited site(s) of progressive disease. 8/9 treated lesions were liver metastases, and 1/9 in a soft tissue lesion. Progression of disease was manifested by a new “nodule within a mass” in 5/9 patients, and/or increase in size of the pre-existing lesions or development of a new lesion in 4/9 patients. Mean lesion diameter was 4.95 cm (range, 2.7 –8.5 cm). All patients had staging with CT or MRI, as well as functional imaging with 18-FDG-PET scans, both before and after the RFA. Successful treatment was defined as lack of enhancement of the treated lesion on a follow up CT or MRI. Biopsies of the target lesions were performed prior to the procedure. An internally cooled electrode was used in 4 sessions, and a cluster electrode was used for 5 treatments.

With median follow-up of 15.1 months (range 7- 24 months), all nine patients had their lesions ablated successfully. Mean number of RF applications per lesion was 1.5 (range, 1-2 applications); average time per application was 13 minutes (range, 9- 15 minutes). All treated lesions continue to be 18 FDG – PET negative with median follow-up 15.1 months. 5/9 patients progressed systemically, prompting an increase in their gleevec dosage (from 400 or 600mg/d to 800mg/d); this resulted in disease control for an additional 1-6 months (median 3.5 months). 4/9 patients remain systemically stable on continued treatment with gleevec (median follow-up 15.1 months). No patients developed early or late complications from the procedure.

Percutaneous CT-guided RFA shows promise in local control of metastatic GIST refractory to gleevec therapy

E.v.: Consultant for Cook and Boston Scientific.A.D.V.: Reasearch support grant from Novartis and Pfizer.

Randhawa, R, vanSonnenberg, E, Dileo, P, Shankar, S, Morrison, P, Nair, R, Silverman, S, Tuncali, K, Van Den Abbeele, A, Morgan, J, Demetri, G, et al, , Safety and Efficacy of Percutaneous Radiofrequency Ablation (RFA) in Patients with Metastatic Gastrointestinal Stromal Tumor (GIST) with Oligoclonal Evolution of Lesions Refractory to Imatinib Mesylate (Gleevec).  Radiological Society of North America 2004 Scientific Assembly and Annual Meeting, November 28 - December 3, 2004 ,Chicago IL. http://archive.rsna.org/2004/4414374.html