Diagnostic accuracy of FDG-PET cancer screening in asymptomatic individuals: use of record linkage from the Osaka Cancer Registry.

[Background]Whole-body cancer screening with multimodalities including [18F]-fluorodeoxyglucose positron emission tomography (FDG-PET) detects a wide range of tumors. This program has been recognized as an option for opportunistic screening, particularly in Japan. However, reports on diagnostic accuracy have been limited. We aimed to evaluate the detectability and related properties of this screening program among asymptomatic individuals in a community setting. [Methods]The study participants were 1, 762 residents of Osaka Prefecture, Japan, who underwent opportunistic cancer screening at Higashitemma Clinic for the first time between November 2004 and December 2005. FDG-PET cancer screening was performed with several imaging modalities (e.g., FDG-PET, computed tomography, magnetic resonance imaging and ultrasonography) and fecal occult blood test. Screening records were linked to the Osaka cancer registry within 1 year after the screening to determine sensitivity, specificity and positive predictive values. [Results]After excluding 12 participants with cancer detected before the screening, 33 were identified by the cancer registry to have primary cancers. Of these, the present screening program found that 28 were positive (6 prostate, 5 lung, 5 colorectal, 5 thyroid, 3 liver and 4 others). Sensitivity, specificity and positive predictive values were 84.8 % (28/33, 95 % confidence interval 69.1–93.3), 86.8 % (1, 491/1, 718, 85.1–88.3) and 10.1 % (28/277, 6.4–12.9), respectively. [Conclusions]FDG-PET cancer screening with multimodalities reasonably and accurately detects existing asymptomatic cancer. However, the numbers of false negatives and false positives were not insignificant. Facilities that provide the screening should inform participants of relevant information, including the limitations of this program

Facile synthesis of both enantiomers of (pyrrolidin-2-yl)phosphonate from l-proline

Diastereoselective introduction of phosphono groups into l-proline derivatives at the 5-position was achieved with suitable selection of N-protecting group. N-Benzoyl-l-prolinate preferentially gave trans-phosphorylated products, which could be easily transformed into (S)-(pyrrolidin-2-yl)phosphonates. On the other hand, N-benzyloxycarbonyl-l-prolinate reacted with phosphite to give cis-substituted products, which could be easily transformed into (R)-(pyrrolidin-2-yl)phosphonates