A considerable percentage of the subjects with emphysema as detected by CT screening had GOLD stage 0. CT screening assists in detecting early-stage emphysema.

In a selected group of PCNSL and GBM with similar MRI findings, the addition of quantitative FDG-PET to MRI may improve their differentiation. ADC measurement did not allow further discrimination.

We were able to clarify the performance profile of "FDG-PET for cancer screening" on the basis of a Japanese nationwide survey. The number of facilities possessing PET is increasing steadily, highlighting the necessity of evaluating the usefulness of "FDG-PET cancer screening" as soon as possible by undertaking long-term investigations of large series of subjects.

ObjectiveThe aim of this study was to survey the 18F-fluorodeoxyglucose-positron emission tomography (FDG-PET) cancer screening program conducted in Japan.MethodsThe “FDG-PET cancer screening program” included both FDG-PET and positron emission tomography with computed tomography (PET/CT) with or without other combined screening tests that were performed for cancer screening in asymptomatic subjects. A total of 155,456 subjects who underwent the FDG-PET cancer screening program during 2006–2009 were analyzed.ResultsOf the 155,456 subjects, positive findings suggesting possible cancer were noted in 16,955 (10.9 %). The number of cases with detected cancer was 1,912 (1.23 % of the total screened cases, annual range 1.14–1.30 %). Of the 1,912 cases of detected cancer, positive findings on FDG-PET were present in 1,491 cases (0.96 % of the total number of screened cases). According to the results of further examinations, the true positive rate for subjects with suggested possible cancer (positive predictive value) was 32.3 % with FDG-PET. Cancers of the colon/rectum, thyroid, lung, and breast were most frequently found (396, 353, 319, and 163 cases, respectively) with high PET sensitivity (85.9, 90.7, 86.8, 84.0 %, respectively). Prostate cancer and gastric cancer (165 and 124 cases, respectively) had low PET sensitivity (37.0 and 37.9 %, respectively). The Union for International Cancer Control (UICC) clinical stage of cancer found with the FDG-PET cancer screening program was mainly Stage I.ConclusionsThe FDG-PET screening program in Japan has detected a variety of cancers at an early stage. However, several cancers were found in repeated FDG-PET cancer screening program, indicating the limitation of a one-time FDG-PET cancer screening program. The value of the FDG-PET cancer screening program is left to the judgment of individuals with regard to its potentials and limitations.

BACKGROUND: The objective of this study was to clarify the usefulness of positron emission tomography (PET) using18F‐fluorodeoxyglucose (FDG) and carbon 11‐labeled acetate (AC) for predicting the histologic types and tumor invasiveness of thymoma in a multicenter study. METHODS: Forty thymomas were examined using both FDG‐PET and AC‐PET before surgery. The histologic types were type A in 1 thymoma, type AB in 12 thymomas, type B1 in 11 thymomas, type B2 in 7 thymomas, type B3 in 6 thymomas, and type C in 3 thymomas. Tumor invasiveness was assessed by pathologic tumor stage and was identified as stage I in 17 tumors, stage II in 17 tumors, stage III in 4 tumors, and stage IV in 2 tumors. FDG and AC uptake was measured as the maximum standard uptake value (SUV). RESULTS: The FDG‐SUV in type C thymomas was significantly higher than that in the other types (A‐B3; P = .001 – P = .048). The AC‐SUV in type A/AB thymomas was significantly higher than that in the other tumor types (B1‐C; P < .001 – P = .002). All 3 type C tumors had an FDG‐SUV ≥6.3, and all 13 type A/AB tumors had an FDG‐SUV <6.3 and an AC‐SUV ≥5.7. All 17 thymomas that had an FDG‐SUV <6.3 and an AC‐SUV <5.7 were type B1, B2, or B3. Neither the FDG‐SUV nor the AC‐SUV differed significantly between the stages I/II tumors and stage III/IV tumors. CONCLUSIONS: Although neither the FDG‐SUV nor the AC‐SUV can predict the invasiveness of thymomas assessed by tumor stage, they are useful for predicting histologic types of thymoma. Thymomas with an FDG‐SUV <6.3 and an AC‐SUV ≥5.7 almost certainly are types A/AB, which is of considerable prognostic and management significance. Cancer 2009. © 2009 American Cancer Society.