Diagnostic value of ¹⁸F-FDG-PET/CT in benign lung diseases

Introduction
There are many diseases which, despite not being malignant, show high metabolic activity and cause false-positive results.

Aim
To evaluate the results of positron emission tomography (PET) in patients who underwent resection after preliminary diagnosis of malignancy based on fluorodeoxyglucose (FDG) uptake value, in whom the lesions were later classified as pathologically benign.

Material and methods
The analysis included the records of 106 (12.3%) patients out of 862 patients who underwent surgery between January 2012 and December 2015 after being initially diagnosed with malignant lung lesions based on PET-CT results, in whom the lesions were later classified as pathologically benign. Diagnoses, PET findings, types of surgery, and demographic data of the patients were recorded.

Results
The mean age of the patients was 55.5 (26–79) years. The mean diameter and SUVmax of the lesions were 2 ±2.14 (0.5–13) and 3.55 ±4.35 (0–22.2) cm, respectively. The pathology results were analyzed in five different groups. The SUVmax in the hamartoma group was significantly lower than in the other groups (p < 0.001), while the SUVmax in the granulomatous disease group was significantly higher than in the other groups (p < 0.001).

Conclusions
The possibility of false positive PET results must be kept in mind when diagnosing and treating lung cancer. In particular, in the case of suspected granulomatous disease, all available pre- and intraoperative diagnostic procedures must be used.