Differences between TNM classification and 2-[18F]FDG PET parameters of primary tumor in NSCLC patients

BACKGROUND: The aim of the study was to compare the TNM classification with 2-[ 18 F]FDG PET biological parameters of primary tumor in patients with NSCLC. MATERIALS AND METHODS: Retrospective analysis was performed on a group of 79 newly diagnosed NSCLC patients. PET scans were acquired on Gemini TF PET/CT scanner 60–70 min after injection of 2-[ 18 F]FDG with the mean activity of 364 ± 75 MBq, with the area being examined from the vertex to mid-thigh. The reconstructed PET images were evaluated using MIM 7.0 Software for SUV max , MTV and TLG values. RESULTS: The analysis of the cancer stage according to TNM 8 th edition showed stage IA2 in 8 patients, stage IA3 — 6 patients, stage IB — 4 patients, IIA — 3 patients, 15 patients with stage IIB, stage IIIA — 17 patients, IIIB — 5, IIIC — 5, IVA in 7 patients and stage IVB in 9 patients. The lowest TLG values of primary tumor were observed in stage IA2 (11.31 ± 15.27) and the highest in stage IIIC (1003.20 ± 953.59). The lowest value of primary tumor in SUV max and MTV were found in stage IA2 (6.8 ± 3.8 and 1.37 ± 0.42, respectively), while the highest SUV max of primary tumor was found in stage IIA (13.4 ± 11.4) and MTV in stage IIIC (108.15 ± 127.24). CONCLUSION: TNM stages are characterized by different primary tumor 2-[ 18 F]FDG PET parameters, which might complement patient outcome.