Radiofrequency ablation of non-small-cell carcinoma of the lung under real-time FDG PET CT guidance.

Radiofrequency ablation (RFA) is a well-established method in treatment of patients with lung carcinomas who are not candidates for surgical resection. Usually computed tomographic (CT) guidance is used for the procedure, thus enabling needle placement and permitting evaluation of complications such as pneumothorax and bleeding. (18)F-fluorodeoxyglucose (FDG) positron emission tomography (PET) is generally used for tumor activity assessment and is therefore useful in follow-up after tumor treatment. A method that provides real-time image-based monitoring of RFA to ensure complete tumor ablation would be a valuable tool. In this report, we describe the behavior of preinjected FDG during PET CT-guided RFA of a non-small-cell lung carcinoma and discuss the value of FDG as a tool to provide intraprocedure monitor ablation. The size and the form of the activity changed during ablation. Ablation led to increase of the size and blurring and irregularity of the contour compared to pretreatment imaging. The maximal standardized uptake value decreased only slightly during the procedure. Therefore, before RFA, FDG PET can guide initial needle placement, but it does not serve as a monitoring tool to evaluate residual viable tissue during the procedure.