F-18 fluorodeoxyglucose positron emission computed tomography in the diagnosis of pleural metastases from breast carcinoma

ABSTRACT

Background: This study aimed to investigate the feasibility of F-18 fluorodeoxyglucose (FDG) positron emission computed tomography (PET/CT) in identifying the pleural invasion of metastatic breast cancers.Methods: A retrospective study was conducted to include 75 patients with untreated breast cancer who had undergone thoracoscopy to drain pleural effusions and to perform pleural biopsies. Whole group of patients were evaluated in terms of age, type of primary breast cancer, macroscopic appearance of pleura during thoracoscopy, maximum standardized FDG uptake value (SUV) reported by PET/CT scan in addition to presence of malignancy detected in pleura and/or pleural effusion.Results: All of 75 patients were female and mean age was 56.12±11.70. Metastatic disease was diagnosed in the pleura of 40 (53.3%) and in the pleural effusion of 43 (57.3%) patients. The sensitivity and specificity of PET/CT in detecting pleural metastases of breast carcinoma was calculated as 88.2% and 96.2% whereas PET/CT demonstrated sensitivity of 91.9% and specificity of 91.3% in identifying malignant pleural effusion. Cut-off values of FDG uptake were 4.25 for pleural metastases and 3.85 for malignant pleural effusions. PET/CT also indicated a false negative rate of 12.5%, a false positive rate of 16.28% and an overall accuracy rate of 85.33% in the diagnosis of pleural metastasis of breast carcinoma.Conclusions: PET/CT reporting an FDG uptake over 4 in the pleura or pleural effusion is beneficial in managing the patients with the suspicion of pleural metastases from breast cancer.