Abstract No. 508 Recalcitrant aneurysmal bone cysts: does cryoablation help?

Abstract

Aneurysmal bone cysts (ABC) are most commonly seen in children and can be very aggressive and locally destructive. The described treatments for ABCs are curettage, resection, intracystic steroid injections, arterial embolization and sclerotherapy. The recurrence rate after traditional surgical treatments ranges from 12% to 71% (71% in children<10 years) with 90% detected within 2 years of surgical treatment. Response to sclerotherapy is gradual, unpredictable and may also fail. Several sessions of percutaneous sclerotherapy is often needed to gain control over rapidly progressive ABCs. We studied the efficacy and safety of cryoablation as a novel approach in treating resistant, rapidly progressive or relapsed ABCs. Eight patients (4 yr to 23 yr (mean 13.7 yr); 5 female pts) with symptomatic and recurrent progressive ABCs post percutaneous sclerotherapy and/or surgical resection underwent percutaneous image-guided cryoablation. ABCs were expansile, aggressive appearing on imaging and in challenging locations: fibula (n=3), tibia (n=2), pelvic bones (n=2), metacarpal (n=1). Patients were evaluated by the orthopedics and interventional radiology before being referred for cryoablation. Percutaneous image-guided (ultrasound and cone-beam CT) cryoablation was performed using Argon and Helium gases in a single or staged sessions. Neuromonitoring was used when lesion was close to major nerves. Pre procedure and follow up clinical and imaging evaluation was done to assess outcome. Following cryoablation, there was significant improvement in symptoms with tumor size regression and bone stabilization in all patients followed over 6 months to 3 years. Two patients had transient nerve injury which self-resolved. Percutaneous image-guided cryoablation is an effective novel modality to treat challenging and recalcitrant aneurysmal bone cysts and should be considered early in such cases.