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To determine the usefulness of positron emission tomography (PET) with 11C-acetate (AC) for imaging lung adenocarcinoma and evaluating its tumor aggressiveness, AC- and 18F-fluorodeoxyglucose (FDG)-PET were compared. One hundred and sixty-nine adenocarcinomas with clinical stage IA and 53 benign nodules were examined by both AC- and FDG-PET before surgery. The sensitivity and specificity for discriminating benign/adenocarcinoma were compared between AC- and FDG-PET. The AC and FDG uptakes were examined to determine the relationship with tumor aggressiveness, i.e., pathological tumor stage, lymphatic, vascular, or pleural involvement, and proliferative activity determined by Ki-67 staining score. While the sensitivity of AC-PET was significantly higher than FDG-PET for bronchioloalveolar carcinoma (BAC) and well-differentiated (W/D) adenocarcinoma ( p < 0.001 and 0.006, respectively), there was no significant difference for moderately or poorly differentiated adenocarcinoma. The specificity was not different between them. While FDG uptakes were significantly higher in tumors with pathological advanced stages or those with lymphatic, vascular and/or pleural involvements than in tumors with pathological stage IA or those without these tumor involvements ( p = 0.04 to p < 0.001), AC uptake did not show significant differences between the respective sub-groups except according to the tumor stage. While both AC and FDG uptakes showed a significant correlation with Ki-67 staining scores ( p = 0.03 and p < 0.001, respectively), the correlation coefficient of former was lower than that of latter ( p = 0.07). While AC-PET can image BAC and W/D adenocarcinoma with a higher sensitivity than FDG-PET, it cannot evaluate tumor aggressiveness of clinical stage IA lung adenocarcinoma as well as FDG-PET. [ABSTRACT FROM AUTHOR]

The article presents the study which clarified the usefulness of emission tomography using F-flourodeoxyglucose (FDG) in predicting histologic type and tumor invasiveness of thymoma. The result indicates that FDG as well as the carbon 11-labeled acetate (AC) are useful in predicting the histologic types of thymoma despite the fact that they do not predict the invasiveness of thymomas assessed by tumor. FDG also differed significantly between stages I/II tumors and stage III/IV tumors.

A 79-year-old man with chronic myeloid leukemia was referred to our department because of dry cough and low-grade fever, 272 days after commencing imatinib mesylate (Gleevec). High resolution computed tomography (HRCT) showed tiny scattered centrilobular nodules and ground-glass opacities throughout both lung fields, suggesting drug-induced pneumonitis. A thoracic video-assisted thoracoscopic surgery (VATS) biopsy specimen from the centrilobular nodules in the right upper lobe demonstrated patchy distribution of epithelioid cell granulomas and intra-alveolar organization. Most of those lesions were predominantly located in the alveolar spaces, which implicated non-transbronchial distribution. Following drug cessation alone, the patient's general condition and radiological abnormalities improved.

Background: The efficacy of fluorodeoxyglucose-positron emission tomography (FDG-PET) for predicting pathological tumor response and prognosis after neoadjuvant chemoradiotherapy followed by surgery in locally advanced nonsmall cell lung cancer (NSCLC) was compared to the predictive value of tumor size as determined by computed tomography (CT)., Methods: Thirty-seven consecutive NSCLC patients who received FDG-PET and CT scans both before and after neoadjuvant chemoradiotherapy were enrolled in this study. The percentage point changes in maximum standard uptake value (SUV) on PET and tumor size on CT after neoadjuvant treatment were defined as the SUV ratio and the size ratio, respectively, and were compared with pathological tumor response and prognosis after surgery. A major pathological response was defined as residual viable tumor cells corresponding to less than one-third the size of the original tumor., Results: Nineteen and 18 patients showed major and minor pathological responses, respectively, after neoadjuvant treatment. The optimal cutoff values for predicting a major pathological response were 0.6 for the SUV ratio and 0.79 for the size ratio. The SUV ratio predicted the pathological tumor response with higher accuracy than the size ratio did (P = 0.04). Neither the SUV ratio nor the size ratio predicted prognosis after surgery., Conclusion: For predicting the pathological tumor response after neoadjuvant chemoradiotherapy, the SUV ratio on FDG-PET is superior to the size ratio on CT in patients with NSCLC. However, neither the SUV ratio nor the size ratio could predict prognosis.

A 50-year-old female complained of back pain. Computed tomography showed a well-defined spindle-shaped mass 3.4 x 1.0 cm in size in the left paravertebral posterior mediastinum at the Th 3-4 level. The tumor was completely resected via thoracoscopic surgery, which showed no invasion into the surrounding tissue. It consisted of a cyst with a tiny mural solid element. By means of histological and immunohistochemical examinations, we diagnosed the tumor as ependymoma, and the patient remains alive 59 months after resection. As far as we know, 8 reported cases with primary mediastinal ependymoma have been reported. They had the following specific characteristics: (1) All patients were adult females; (2) The tumors were usually located at the paravertebral upper mediastinum; (3) Most of the tumors consisted of cystic and solid elements; (4) The tumors usually made no invasion into the surrounding tissues, though 2 cases had lymph-node metastases.