Local control, safety, and survival following image-guided percutaneous microwave thermal ablation in primary lung malignancy

AIM: To determine local control, safety, and survival following percutaneous computed tomography (CT)-guided high-power microwave ablation (MWA) in the treatment of primary lung malignancy at a single institution. MATERIAL AND METHODS: From July 2010 to June 2016, 52 patients (mean age 76.3 years, range 55-91 years) with 61 unresectable primary lung cancers of mean diameter 23.8 mm (range 26-55 mm) underwent MWA in 55 ablation sessions. Tumours were diagnosed at biopsy, or positron-emission tomography (PET) avidity (mean SUV max = 10.51) and interval growth. Statistical analysis was performed by Kaplan-Meier modelling and Cox and logistic regression. RESULTS: Local tumour progression (LTP) was diagnosed in six lesions (10%). Median time to local recurrence was 3 months (range 2-14 months). There was a near 12-fold increased odds of local recurrence if the lesion size was >3 cm (95% confidence interval [CI]: 1.84-75.14; p=0.009). The median inpatient stay was 1 day, with no intra-procedural deaths and a 0% 30-day post-ablation mortality rate. Pneumothorax requiring drain was the most serious complication, occurring in 22% (n=12) of patients. Presence of severe emphysema and predicted forced expiratory volume in 1 second (FEV1) of <50% were found to predict future requirement of a drain (odds ratio [OR] 8.17, 95% CI: 1.62-41.37, p=0.01 and OR: 5.14, 95% CI: 1.28-20.68, p=0.02 respectively), when adjusted for age and gender. Tumour size >3 cm had a hazard ratio of 4.37 compared with tumour size <= 3 cm (95% CI: 1.45-13.17, p=0.009) of risk of cancer death at any time, by Cox regression. CONCLUSION: MWA for primary lung malignancy is a safe and effective treatment for primary lung tumours with outcomes that may be comparable to stereotactic body radiation therapy. (C) 2018 Published by Elsevier Ltd on behalf of The Royal College of Radiologists.