Clinical implications of 18F-fluorodeoxyglucose positron emission tomography/computed tomography at delayed phase for diagnosis and prognosis of malignant pleural mesothelioma

Abstract

Abstract. Malignant pleural mesothelioma (MPM) has a poor prognosis, and conventional imaging modalities do not reflect the prognosis of MPM. In this study, the clinical significance of 18 F-fluorodeoxyglucose positron emission tomography/ computed tomography fusion imaging ( 18 F-FDG PET/CT) was evaluated for the differential diagnosis, staging and prognosis in MPM patients. Ninety patients who underwent 18 F-FDG PET/CT scanning due to a clinical diagnosis or suspicion of MPM prior to therapy were reviewed. Of 90 patients, 31 were pathologically diagnosed as MPM. Maximum standardized uptake values (SUVmax) were semi-quantitatively obtained from PET/CT 60 min (early phase) and 120 min (delayed phase) after injection of 18 F-FDG, and the clinicopathological correlations with the level of SUVmax obtained from PET/CT were examined. The survival curves of MPM patients were plotted according to the methods of Kaplan-Meier. The prognostic implications of the level of SUVmax were estimated by t-test. PET/CT scan showed intense abnormal FDG uptake (SUVmax >2.0) in the pleural lesions of all 31 MPM patients at delayed phase, while it showed abnormal FDG uptake in 30 (97%) patients at early phase. In all 31 MPM patients, the values of SUVmax at delayed phase were higher than those at the early phase. PET/CT also indicated metastasis in the lymph node in 7 patients (23%) and in the systemic lesions in 8 patients (26%) with MPM. Twenty-three MPM patients with high SUVmax, whose prognosis was apparent, showed significantly poorer prognosis in both early and delayed phase (respectively, p=0.03 and p=0.01, t-test). The results showed that 18 F-FDG PET/CT at delayed phase is very useful for the diagnosis of pleural diseases, and SUVmax on PET/CT in the delayed phase is a more reliable prognostic factor than that in the early phase. High uptake of 18 F-FDG PET/CT may be a predictive factor of prognosis in MPM patients. IntroductionThe most common cause of pleural effusion is nonspecific pneumonia which can be successfully treated with proper antibiotic therapy. However, pleural effusion may persist and require further examinations in some cases in spite of proper therapy. Computed tomography (CT) provides detailed information on morphological changes, but on its own cannot differ entiate between benign and malignant diseases. Also, invasive pro cedures are frequently required for a definitive diagnosis (1). Many studies have reported the value of 18 F-FDG PET/CT would thus be more informative for diagnosis of pleural diseases than examination with 18 F-FDG PET (7). The incidence of malignant pleural mesothelioma (MPM) in many countries including Japan is rising, as predicted (8,9),

Malignant Peritoneal Mesothelioma in a 16-Year-Old Girl: Presentation of a Rare Disease

“…Though, this area had been FDG positive in PET imaging during the treatment, enhanced glucose metabolism was only seen at the time of relapse. FDG PET is known to be a sensitive diagnostic method for staging of mesothelioma in adults and a high uptake is correlated with an unfavorable prognosis [ 1 ] . Final prognosis is diffi cult to predict for our patient as reliable survival data for pediatric patients do not exist.…”

18F-Fluorodeoxyglucose PET/CT and dynamic contrast-enhanced MRI as imaging biomarkers in malignant pleural mesothelioma

“…A number of previous studies [9,[13][14][15][16][17][18][19][20], mostly retrospective and observational, have considered the relationship between survival and PET measurements at baseline. Of these, 8 studies [13][14][15][16][17][18][19][20] with a total of 594 patients found that high SUVmax or TLG at baseline indicated worse survival, and one with 41 patients [9] found no relationship. Three studies have considered percentage change in SUVmax, TLG and MTV after chemotherapy; two [9,12] with a total of 64 patients found that a percentage reduction in TLG was indicative of better OS, while one [20] with 131 patients found a percentage reduction in SUVmax was related to longer OS.…”

18F-FDG PET/CT oncologic imaging at extended injection-to-scan acquisition time intervals derived from a single-institution 18F-FDG-directed surgery experience: feasibility and quantification of 18F-FDG accumulation within 18F-FDG-avid lesions and background tissues

“…In these numerous studies, attempts have been made to qualify and quantify the impact of the length of the injection-to-scan time interval on differentiating malignant processes from benign processes. As one might expect, the findings reported amongst these various investigators have been highly variable, with some supporting the use of delayed phase and dual-time-point diagnostic 18 F-FDG PET imaging approaches [66-77,81-84,86,87,91-93,95-100,103-108,110,111,113,114,117-122,124-128,131,133,134,136,138,141,143,146,149,152,153,155,157,160-163,165,167,169], and with others not [65,78,89,90,94,101,102,109,115,116,123,129,130,132,135,137,139,140,147,148,150,151,156,158,164,166,168]. …”