Utility of PET-CT in CT-guided biopsy of lung masses

Full text: CT guided transthoracic biopsies of lung masses is routinely performed, the diagnostic yield in large masses/lesions noted on CT may be decreased due to sampling of necrotic cores, non viable tumor areas, scar or fibrotic tissue. Targeting metabolically active tumor foci could potentially decrease the sampling errors. We sought to retrospectively evaluate the role of PET-CT, in CT guided trans-thoracic biopsies of lung masses greater than 3 cms. Materials and Methods: Retrospective analysis of all patients with lung Ca. undergoing PET-CT scanning followed by CT guided trans-thoracic biopsies of lung masses greater than 3 cms. A total of 33 patients were identified by chart reviews, the findings on histopathology were correlated with those of PET-CT findings, statistical analysis were performed on a Excel database. Results: The statistical analysis of PET-CT findings were as follows: Sens=92%, Spec.13%, Acc.=73%, PPV=77%, NPV=33%. The estimated specificity and negative predicative values were low in our series, since only few lesions with absent or metabolically mild lesions on PET were biopsied, while significant number of false positives on FDG PET due chronic inflammation were sampled. Conclusion: Our results suggest that the findings on PET-CT would be helpful in pre-procedural target identification and navigation during CT guided trans-thoracic biopsy of suspected lung masses. In future co registration of PET-CT with diagnostic CT and respiratory gated PET would be helpful in precise targeting. CLINICAL RELEVANCE/APPLICATION In future co registration of PET-CT with diagnostic CT and respiratory gated PET would be helpful in precise targeting