CLINICAL STUDY Outcomes of an Algorithmic Approach to Management of Pneumothorax Complicating Thermal Ablation of Pulmonary Neoplasms Nour-Eldin Nour-Eldin, MD, MSc, EDiR, Nagy N.N. Naguib, MSc, Ahmed M. Tawfik, MSc, Karen Koitka, MBBCh, Ahmed S. Saeed, MD, and Thomas J. Vogl, MD ABSTRACT Purpose: To investigate the outcomes of an algorithm for treatment of pneumothorax in association with radiofrequency (RF) and microwave (MW) ablation of pulmonary neoplasms. Materials and Methods: This retrospective study included data from 248 ablation sessions for lung tumors in 164 patients (92 men; mean age, 59.7 y  9.8): 200 RF ablations (80.6%) and 48 MW ablations (19.4%). Pneumothorax was classified as mild, moderate, or severe. Twelve patients developed mild pneumothorax and were observed for further complications, and 33 developed moderate or severe pneumothorax and were managed with percutaneous aspiration of the pneumothorax. The decision to abort or continue ablation was determined based on clinical response to percutaneous aspiration, clinical distress, and feasibility of applying the applicator within the lesion. Results: Incidence of pneumothorax was 18.1% (45 of 248 sessions), with four (8.9%) occurrences during MW ablation and 41 (91.1%) during RF ablation. Pneumothoraces were mild in 12 sessions (26.7%), moderate in 27 (60%), and severe in six (13.3%). Complete evacuation of the pneumothorax was achieved in 25 of 33 sessions (75.8%). Intercostal tube drainage was indicated in eight sessions (24.2%), including six severe and two moderate pneumothoraces. Pneumothorax evolved immediately after thoracic puncture in 10 patients. Ablation therapy was aborted in two sessions in which severe pneumothorax occurred, and an intercostal chest tube was inserted. Conclusions: Mild pneumothorax can be managed by close observation without interruption of ablation therapy. Manual evacuation was an effective strategy for management of moderate pneumothorax and allowed for adequate positioning of the electrode, but did not suffice for severe and progressive pneumothorax, which required placement of an intercostal chest tube. ABBREVIATIONS MW = microwave, RF = radiofrequency Thermal ablation may be used to treat a variety of thoracic malignancies, including primary lung cancer, recurrent pri- mary lung cancer, metastatic disease, chest wall masses, and painful, bony thoracic metastases (1–14). As the use of this modality becomes more widespread, it is vital that asso- ciated complications be considered and evidence-based man- agement protocols established for situations in which they arise. Pneumothorax is the most frequent serious complication of thoracic thermal ablation, with a reported mean incidence of 28% (1–12). There is a need for evidence-based knowledge regarding the factors associated with pneumothorax develop- ment and appropriate management protocols. Most scientific research has focused on therapy efficacy and complications of thermal ablation, but there are currently no protocols to guide the management of these associated complications. The purpose of the present study was to inves- tigate the outcomes of an algorithm for the treatment of pneu- mothorax occurring in association with thermal ablation of lung neoplasms. From the Diagnostic and Interventional Radiology Institute (N.E.N.E., N.N.N.N., A.M.T., T.J.V.), Johann Wolfgang Goethe University Hospital, The- odor-Stern-Kai 7, Frankfurt, Hessen 60590, Germany; Department of Internal Medicine (K.K.), Toowoomba Base Hospital, Toowoomba, Australia; and Di- agnostic and Interventional Radiology Department (N.E.N.E, A.S.S.), Cairo University Hospital, Cairo, Egypt. Received January 19, 2009; final revision received May 24, 2011; accepted May 31, 2011. Address correspondence to N.E.N.E.; E-mail: nour410@hotmail.com None of the authors have identified a conflict of interest. © SIR, 2011 J Vasc Interv Radiol 2011; 22:1279 –1286 DOI: 10.1016/j.jvir.2011.05.014