Prognostic Value of 18 F-FDG Standard Uptake Value by Integrated PET/CT in the Staging of Malignant Pleural Mesothelioma

Malignant pleural mesothelioma (MPM) is a rare and aggressive tumor with generally disappointing results in terms of survival, however, there are occasional long-term survivors probably due to the biologic characteristics of the disease. Standard uptake value (SUV) of [¹⁸F] Fluorodeoxyglucose (FDG) evaluated by photon emission tomography (PET) is now widely accepted as an indicator of biologic behavior in several malignancies. The aim of this study was to verify whether SUV_max and SUV_mean are inversely associated with the prognosis of patients with MPM and whether there was a correlation between grading/disease stage and SUV value. Patients with histologically proven MPM underwent integrated PET and computed tomography (CT) scanning. Patients fasted and received 5.18 MBq of FDG per kilogram of body weight. Based on the maximum Chi-Square method, a SUV_max of 4.21 (range: 2.30–14.74) and a SUV_mean of 2.78 (range: 1.80–7.00) were used to classify patients as having a good or poor prognosis, respectively. From January 2004 to March 2010, 27 patients were analyzed: median age was 65 years (range: 54–77) and histologic MPM subtypes were epithelioid (23 patients) and biphasic (4 patients). At a median follow-up of 23 months (range: 1–52), there was no difference in median survival for either high or low SUV_max [26 months (range: 11-not reached) vs.19 months (range: 12-not reached); p = 0.811] or for high or low SUV_mean [26 months (range: 8-not reached) vs.19 months (range: 11-not reached); p = 0.831]. High SUV_max (p = 0.018) was statistically correlated with high-stage disease. There was only a trend towards statistical significance between high-grade disease and high SUV_mean (p = 0.083); no such trend was found between advanced stages and SUV_max (p = 0.268). We observed a significant correlation only between high SUV_max and high-grade disease. No other relationships between SUV_max and SUV_mean with biologic and clinical parameters were found. This is probably due to the patient characteristics and to the non-routine use of ¹⁸F-FDG PET/CT to stage rare tumors such as MPM.