Can PET-CT predict diagnostic success in ultrasonography-guided transthoracic fine needle aspiration biopsies in lung cancers?

Objective: To examine any correlations between tumor maximum standard uptake values (SUVmax) in positron emission tomography-computed tomography (PET-CT) and homogeneous/heterogeneous tumor FDG uptake in PET-CT, and the diagnostic success of the procedure in thoracic ultrasonography (US)-guided transthoracic fine needle aspiration biopsy (TFNAB). Methods: The files of patients who underwent thoracic US-guided TFNAB between 2013 and 2018 were examined. Patients who underwent thoracic US-guided TFNAB and were diagnosed as having primary lung cancer were considered as the US-TFNAB diagnostic group. Patients whose disease was diagnosed as primary lung cancer using a different diagnostic method (e.g. CT-guided biopsies, fiberoptic bronchoscopy) due to a tack of diagnosis despite undergoing thoracic US-guided TFNAB were allocated to the US-TFNAB non-diagnostic group. The clinical and radiologic characteristics and PET-CT parameters of the two groups were compared. Results: A total of 104 patients were included in the study; 79 (76%) patients whose disease was diagnosed using US-guided TFNAB, and 25 (24%) patients whose primary lung cancer could not be diagnosed with US-guided TFNAB. The mean SUVmax value of the US-TFNAB diagnostic group was 19.5 +/- 10.1, whereas it was 15.1 +/- 8.9 in the US-TFNAB non-diagnostic group (p =0.016). Whether a lesion showed homogeneous or heterogeneous FDG uptake did not effect diagnostic success (p = 0.289). SUVmax value was the only effective independent factor in the diagnostic success of the procedure (p =0.035). Conclusions: High SUVmax values in PET-CT in lung cancers may increase the diagnostic success of US guided-TFNAB procedures. (C) 2020 Sociedade Portuguesa de Pneumologia. Published by Elsevier Espana, S.L.U.