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.