Objective To evaluate the clinical value of ¹⁸F-FDG PET-CT in diagnosis of the pleural or peritoneal carcinomatosis.

Methods A total of 37 patients with pleural effusion or ascites of unknown origin were analyzed retrospectively. All patients underwent whole body ¹⁸F-FDG PET-CT. The ¹⁸F-FDG distributional pattern and the maximum standardized uptake value(SUV_max) of lesions were analyzed. The final diagnosis of all cases were established based on the results of catamnestic analysis, tumor markers assay, histopathology or clinical follow-up.

Results Of all the 37 cases, 29 had positive findings on ¹⁸F-FDG PET-CT, of which 26 were pleural or peritoneal carcinomatosis and 3 were pleural or peritoneal tuberculosis; 8 patients had negative findings on ¹⁸F-FDG PET-CT, of which 6 were pleural or peritoneal benign lesions and 2 were peritoneal carcinomatosis. The sensitivity, specificity, accuracy, positive predictive value, negative predictive value of ¹⁸F-FDG PET-CT in diagnosis of peritoneal carcinomatosis were 92.9%, 66.7%, 86.5%, 89.7% and 75.0% respectively. The SUV_max between the ring-form and strip-type lesions were significantly different(5.97±3.39 vs. 2.89±0.92, t=2.93, P < 0.05).

Conclusions ¹⁸F-FDG PET-CT is simple, noninvasive and high sensitive in detecting pleural or peritoneal carcinomatosis, and may be an ideal technique of highly clinical usefulness in the diagnosis of the pleural or peritoneal carcinomatosis.