Lung tumor RFA: An atlas of periprocedural FDG PET-CT (within 24 hrs) in evaluating residual tumor

1077 Learning Objectives The objective is to demonstrate the utility of periprocedural PET-CT in early evaluation of residual tumor following RFA of lung cancer. Introduction: RFA (radiofrequency ablation) of surgically unresectable lung tumors is an increasingly accepted treatment modality, and its role is still evolving. Although morphologic imaging with CT (and less so MRI) play an important role in the pre-RFA evaluation of patients with suspected lung malignancy, their role in evaluating residual tumor in the periprocedural (within 24 hours post RFA) period is limited due to difficulties in distinguishing malignancy from posttreatment inflammatory morphologic changes. However, recent experience in animal models and patients undergoing hepatic tumor ablation suggest that periprocedural PET-CT may allow earlier detection of residual tumor post ablation, particularly when timed to surmount post-procedure inflammatory responses. Methods: RFA was performed using an AngioDynamic9s StarBurst RFA System (RFA electrode and generator), with all ablations done in accordance with the company9s protocol. Periprocedural PET-CT was performed within 24 hours of RFA, 45-60 minutes following the intravenous administration of 10-15 mCi FDG (370-555 MBq). Images were processed on the MIMvista workstation. Results: The pictorial atlas will emphasize the utility of the seven periprocedural PET-CT scans and its ability to identify residual tumor in the immediate periprocedural time frame. Correlative pre-, peri-, and post-procedural diagnostic CT and PET-CT findings and clinical follow-up will also also be presented. Conclusions: Our observations suggest a very promising role for early evaluation of the adequacy of ablation. Potential benefits include earlier planning for repeat ablations of residual tumor indentified on periprocedural PET-CT