Cryoablation of sternal metastases for pain palliation and local tumor control

Purpose: To determine safety and effectiveness of cryoablation of sternal metastases for pain palliation and local tumor control. Materials and Methods: A tumor ablation database was retrospectively reviewed for sternal cryoablation procedures performed between January 2005 and June 2013, which yielded 15 procedures to treat 12 sternal metastases in 12 patients (five men). Median patient age was 57 years (range, 38-80 y). Metastases arose from five primary sites (breast, lung, kidney, ampulla, and thyroid), and median tumor size was 3.8 cm (range, 2.2-7.5 cm). Seven patients (58%) underwent cryoablation for pain palliation, and five (42%) underwent cryoablation for local tumor control of oligometastatic disease. Clinical outcomes (including complications, local tumor control, and pain response) were evaluated retrospectively. Results: Mean pain scores decreased from 7.0 ± 1.9 (median, 7; range, 4-10) at baseline to 1.8 ± 1.2 (median, 1.5; range, 0-4) following cryoablation (P = .00049). Two patients had durable pain palliation, and four had greater than 1 month of pain relief, with a median duration of 5.7 months (range, 1.5-14.7 mo). Two patients in whom recurrent pain developed underwent repeat cryoablation, with durable pain relief. Allowing for a single repeat treatment local tumor control was achieved in four of five patients (80%) treated for this indication, with median follow-up of 8.4 months (range, 2.6-13.6 mo). In one patient (8%), an infectious complication developed that was successfully treated with antibiotics on an outpatient basis. Conclusions: Cryoablation is a safe and potentially effective treatment for patients with painful sternal metastases and can achieve local tumor control in select patients.