18F-FDG PET/CT characteristics of solitary fibrous tumour of the pleura: single institution experience

To date, published studies have shown that 18F-FDG PET/CT and CT have limited value in differentiating benign and malignant solitary fibrous tumours of the pleura (SFTP). This study aimed to determine whether the metabolic and morphological characteristics of 18F-FDG PET/CT can be a valuable addition to diagnostic tools for SFTPs. From January 2016 to November 2021, we performed a retrospective review in 32 SFTPs patients who underwent 18F-FDG PET/CT scan. All the SFTP diagnoses were confirmed by surgical resection or biopsy samples. The metabolic parameters (including SUVmax, SUVmean, MTV, TLG, and SULmax) were obtained from 18F-FDG PET/CT images. Thirty-two patients with SFTP were consecutively identified. The malignant SFTPs have higher Ki-67 expression (P = 0.005). The study observed that tumour heterogeneity without contrast injection (P = 0.001) and intratumor blood vessels (P = 0.047) were morphological features associated with malignant SFTP. Malignant SFTP was more frequently observed with higher SUVmax values (P = 0.001), higher SUVmean values (P = 0.001), higher TLG values (P = 0.006), and higher SULmax values (P < 0.001). For predicting malignant SFTP, the AUC values of SUVmax, SUVmean, TLG, and SULmax obtained by the area under curve analysis were 0.970 (95% CI 0.907–1.000; P = 0.001), 0.874 (95% CI 0.675–1.000; P = 0.009), 0.807 (95% CI 0.654–0.961; P = 0.031), and 0.911 (95% CI 0.747–1.000; P = 0.004), respectively. The study showed that metabolic and morphological features were useful for distinguishing malignant from benign SFTPs.