Ultrasound-guided percutaneous microwave ablation assisted by a three-dimensional visualization preoperative treatment planning system for larger adrenal metastasis (D ≥ 4 cm): Preliminary results

Objective: The objective of this study is to assess the clinical effect and safety of ultrasound-guided percutaneous microwave ablation (US-PMWA) assisted by three-dimensional (3D) visualization operative treatment planning system in larger adrenal metastasis (LAM) (D ≥ 4 cm). Materials and Methods: From Dec 2011 to Dec 2017, 12 consecutive LAM patients with pathologically proven with a mean diameter of 5.2±1.3cm (range 4.1-7.6) were treated. Artificial ascites and thermal monitoring system as ancillary technique were used. The patients were followed up with imagings and complications were recorded. Results: The median follow-up period was 31 months (ranged 6–52 m). All LAM achieved completely ablation according to the 3D planning preoperation. Complete ablation was achieved in 10 (10/12, 83.3%) patients by one session and 2 patients (2/12, 16.7%) by two sessions. Recurrence was detected at the treated site in 3 patients (3/12, 25.0%) at 5, 9, and 13 months after ablation and received another ablation. Progression of metastasis disease at extra-adrenal sites occurred in 9 patients (9/12, 75%). Seven (7/12, 58.3%) patients died during the follow-up period. Therefore, the 1-, 2-, and 3-year local tumor control rates were 83.3%, 75.0%, and 75.0%, and 1-, 2-, 3- and 4-year overall survival rates were 91.7%, 75.0%, 50.0%, and 41.7%, respectively. No severe complications related to ablation occurred, except 3 (3/12, 25%) patients developed hypertension during ablation. Conclusions: US-PMWA assisted by 3D visualization preoperative treatment planning system maybe a safe and efficient therapy for LAM, which could promote ablation precision, improve the clinical outcomes