Current Thoracic Surgery

Background: The aim of this study is two-fold; first is to investigate the determinants of malignancy from the clinical and radiological results of patients operated on solitary pulmonary nodules (SPN) and second is to determine the SUVmax threshold value for predicting malignancy based on nodule size. While the literature tends to focus on many variables as a group for understanding the SPNmalignancy link, this study asks whether we could weigh size more compared to other factors to decide on malignancy potential. The fact that the incidental finding of SPNs is on rise means timely prediction and cure are within our reach.

Materials and Methods: Patients operated in our clinic due to SPN between January 2018 and December 2022 were categorized into two groups according to their histopathologic diagnoses as malignant and benign. The clinical and radiological characteristics of the two groups were then analysed.

Results: Among the 522 patients included in the study, 385 (74%) were male and the mean age was 61 ± 10.5 years. The high SUVmax value of the nodule and the presence of lobulation and spiculation were found to be determinant factors for malignancy (p<0.05, for all). In addition, SUVmax values of 1.75 for nodules <1 cm in diameter, 2.24 for nodules between 1-2 cm, and 2.55 for nodules >2 cm were determined as malignancy predictors.

Conclusions: High SUVmax and the presence of lobulation and spiculation are positive predictive factors for malignancy in SPNs. We believe that the SUVmax value is discretely (by itself) critical in predicting malignancy according to the diameter of the nodule. As size is a relatively straightforward variable to measure and SPN is largely curable with timely intervention, the capacity of size to be a predictor would be highly convenient. In this respect, to better exploit the SUVmax indicator in practice during prognosis, more sensitive cut-off values in an ascending/descending order of the module diameter could be defined.