''Serial review on clinical PET tracers''. Diagnostic value of 11C-acetate-PET for non-small cell lung cancer

18F-fluorodeoxy-glucose (FDG)-positron-emission tomography (PET) often shows negative for tumors with low grade malignancy. On the other hand, 11C-acetate (AC)-PET has been known to be able to detect well-differentiated lung adenocarcinoma, prostate cancer, and well-differentiated hepatocellular carcinoma, which are often negative for FDG-PET. Here, we show our recent study which compare the detection rate and ability for prediction of malignancy grade of lung adenocarcinoma between acetate and FDG-PET. Two hundred and twenty seven Non-small cell lung cancer (NSCLC) and 56 benign nodules were examined by both AC- and FDG-PET before surgery. The sensitivity and specificity for discriminating benign/NSCLC were compared between AC- and FDG-PET. The AC- and FDG-uptakes were examined to determine the relationship with tumor aggressiveness, id est (i.e.) pathological tumor stage, lymphatic, vascular, or pleural involvement. Acetate or FDG uptake was calculated by the ratio of SUV (SUV-CR) between the tumor the corresponding point of contralateral normal lung. The sensitivity for detection of NSCLC was 0.71 with AC-PET, which was significantly higher than 0.57 with FDG-PET (p<0.001). There was no significant difference of specificity between the two. In the 146 lung adenocarcinoma, the sensitivity for detection of adenocarcinoma was 0.62 with AC-PET, which was significantly higher than 0.37 with FDG-PET (p<0.001). However, there was no significant difference of sensitivity between the two in 51 moderately differentiated adenocarcinoma and 30 poorly differentiated adenocarcinoma. In 169 clinical T1N0M0 adenocarcinoma, while tumors with lymphatic or vascular invasion showed higher FDG-uptake than those without (p=0.04-<0.001), AC-uptake did not show significant difference between tumors with and without lymphatic or vascular invasion. While AC- and FDG-PET were similar for the detection of moderately- or poorly-adenocarcinomas, the former was superior to the latter for the detection of well-differentiated adenocarcinomas. For prediction of tumor aggressiveness of clinical stage IA lung adenocarcinoma, AC-PET was inferior to FDG-PET. (author)