High SUVmax on FDG-PET Indicates Pleomorphic Subtype in Epithelioid Malignant Pleural Mesothelioma Supportive Evidence to Reclassify Pleomorphic as Nonepithelioid Histology
ABSTRACT We have recently proposed to reclassify the pleomorphic subtype of epithelioid malignant pleural mesothelioma (MPM) as nonepithelioid (biphasic/sarcomatoid) histology because of its similarly poor prognosis. We sought to investigate whether preoperative maximum standardized uptake value (SUVmax) on F-fluorodeoxyglucose (FDG) positron emission tomography (PET) correlates with histologic subtype in MPM.
Clinical data were collected for 78 patients with MPM who underwent preoperative FDG-PET. We retrospectively classified the epithelioid tumors into five subtypes: trabecular, tubulopapillary, micropapillary, solid, and pleomorphic. Tumors were categorized by SUVmax into two groups: low (<10.0) and high (≥10.0).
The median overall survival of epithelioid tumors with high SUVmax (n = 12) was significantly shorter (7.1 months) than that of epithelioid tumors with low SUVmax (n = 54, 18.9 months, p < 0.001) and comparable to nonepithelioid tumors (n = 12, 7.2 months). Epithelioid tumors with pleomorphic subtype (n = 9) had marginally higher SUVmax (mean ± SD: 10.6 ± 5.9) than epithelioid nonpleomorphic subtype (n = 57, 6.5 ± 3.2, p = 0.050), and were comparable to that of nonepithelioid tumors (n = 12, 9.1 ± 4.8). Among the epithelioid tumors with high SUVmax (n = 12), 50% (n = 6) showed pleomorphic subtype. In contrast, among epithelioid tumors with low SUVmax (n = 54), 6% (n = 3) showed epithelioid pleomorphic subtypes (p = 0.001). A positive correlation between mitotic count and SUVmax was observed (r = 0.30, p = 0.010).
Pleomorphic subtype of epithelioid MPM showed higher SUVmax than the epithelioid nonpleomorphic subtype and was similar to nonepithelioid histology. Preoperative SUVmax on FDG-PET in epithelioid MPM can indicate patients with pleomorphic subtype with poor prognosis, supporting their reclassification as nonepithelioid.
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ABSTRACT: Malignant pleural mesothelioma (MPM) is a disease with poor prognosis despite multimodal therapy but there is variation in survival between patients. Prognostic information is therefore potentially valuable in managing patients, particularly in the context of clinical trials where patients could be stratified according to risk. Therefore we have evaluated the prognostic ability of parameters derived from baseline 2-[(18)F]fluoro-2-deoxy-D-glucose positron emission tomography/computed tomography ((18)F-FDG PET/CT). In order to determine the relationships between metabolic activity and prognosis we reviewed all (18)F-FDG PET/CT scans used for pretreatment staging of MPM patients in our institution between January 2005 and December 2011 (n = 60) and measured standardised uptake values (SUV) including mean, maximum and peak values, metabolic tumour volume (MTV) and total lesion glycolysis (TLG). Overall survival (OS) or time to last censor was recorded, as well as histological subtypes. Median follow-up was 12.7 months (1.9-60.9) and median OS was 14.1 months (1.9-54.9). By univariable analysis histological subtype (p = 0.013), TLG (p = 0.024) and MTV (p = 0.038) were significantly associated with OS and SUVmax was borderline (p = 0.051). On multivariable analysis histological subtype and TLG were associated with OS but at borderline statistical significance (p = 0.060 and 0.058, respectively). No statistically significant differences in any PET parameters were found between the epithelioid and non-epithelioid histological subtypes. (18)F-FDG PET/CT parameters that take into account functional volume (MTV, TLG) show significant associations with survival in patients with MPM before adjusting for histological subtype and are worthy of further evaluation to determine their ability to stratify patients in clinical trials.European Journal of Nuclear Medicine 09/2013; 41(2). DOI:10.1007/s00259-013-2561-1 · 4.53 Impact Factor
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ABSTRACT: A 50-year-old woman presented with upper abdominal pain for 2 months. Abdominal enhanced CT showed multiple hypodense cystic tumors in the liver with heterogeneous enhanced septations. FDG PET/CT showed hypermetabolic peripheral regions and internal septations of the tumors with SUVmax of 6.3. Multiple hepatic cystadenocarcinomas were suspected. The patient underwent resection of the tumors. Epithelial mesothelioma was confirmed by pathology. This case indicates primary hepatic mesothelioma should be added to the differential diagnosis of FDG-avid malignant hepatic tumors.Clinical nuclear medicine 03/2013; DOI:10.1097/RLU.0b013e31828da61d · 2.86 Impact Factor
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ABSTRACT: The authors report two cases of pseudomesotheliomatous lung cancer (PLC) detected by (18)F-FDG PET/CT scan. (18)F-FDG PET/CT clearly revealed the extent of the disease in both cases, a case of adenocarcinoma of the lung and a case of squamous cell carcinoma of the lung. Intense (18)F-FDG uptake by the diffusely thickened pleurae and primary lesion was observed in both cases, and increased (18)F-FDG uptake by a pelvic bone metastasis was observed in the case of squamous cell carcinoma. Although PLC is indistinguishable from malignant pleural mesothelioma on (18)F-FDG PET/CT scans, (18)F-FDG PET/CT was helpful in identifying the primary focus of the PLCs and in staging the disease. Diagnostic image interpreters should be familiar with the (18)F-FDG PET/CT findings in PLC.Japanese journal of radiology 04/2013; DOI:10.1007/s11604-013-0210-z · 0.74 Impact Factor