Preoperative PET-CT SUVmax and predominant histological pattern in resected lung adenocarcinoma: a retrospective cohort study of 166 patients.

Objectives

We investigated whether preoperative maximum standardized uptake value (SUVmax) on PET-CT tracks the predominant histological pattern of resected lung adenocarcinoma and lymphovascular invasion (LVI).

Methods

We retrospectively reviewed 166 consecutive patients resected between 2014 and 2026. Tumours were classified by predominant pattern (IASLC/ATS/ERS 2011) using descriptive labels, not grade terms: lepidic-predominant (n = 49), acinar/papillary-predominant (n = 59), solid/micropapillary/cribriform-predominant (n = 47) and invasive mucinous adenocarcinoma (n = 8). PET-CT was available in 94 (56.6%), who were compared with the 72 without. Pairwise comparisons were Holm-corrected and logistic models included age, sex and pleural invasion.

Results

Imaged and non-imaged patients did not differ in any recorded variable (p ≥ 0.10). Median SUVmax rose stepwise across the three non-mucinous groups (8.80, 12.60, 15.40; Kruskal-Wallis p = 0.034, ε²=0.080); after Holm correction only the lepidic- versus solid/micropapillary/cribriform-predominant contrast remained significant (p = 0.042). Mucinous tumours showed low uptake (median 2.70; five imaged cases, descriptive only) and SUVmax was higher when LVI was present (13.10 vs 7.35; p = 0.001). Discrimination was modest: area under the curve 0.648 (95% CI 0.513-0.783) for an aggressive pattern and 0.698 (0.593-0.803) for LVI, with specificity below 50%. Adjusted for tumour size, age, sex and pleural invasion, SUVmax remained associated with LVI (odds ratio 1.12; 95% CI 1.05-1.21; p = 0.002).

Conclusions

SUVmax shows a graded association with the predominant histological pattern and with LVI, but discrimination is modest. Our thresholds are two to three times higher than those from screen-detected series, indicating that published cut-offs are not transferable across populations, and SUVmax complements rather than replaces clinical and radiological assessment.