The purpose of this study was to identify the functional fields activated in relation to the NO-GO decision. Nine healthy subjects participated in the study which consisted of two test positron emission tomography (PET) scans (GO/NO-GO task and response selection task) and one control scan. In the response selection task, subjects were asked to flex their thumb of the right hand when a light emitting diode (LED) placed 60 cm from their eyes turned on red and to flex their index finger of the right hand when LED turned on green. In the GO/NO-GO task, subjects were asked to flex their thumb when the LED turned on red, however, they were asked not to move their fingers when LED turned on green. In the control state, they were asked simply to look at the LED without any movement of finger during the course of the scan. The mean regional cerebral blood flow (rCBF) change images for each task minus control and task minus task were calculated and fields of significant rCBF changes were identified. Several fields in the prefrontal cortex of the right hemisphere were specifically activated in relation to the GO/NO-GO task. The results indicate that the prefrontal cortex of the right hemisphere may be a key structure to make a decision not to move.

Autoimmune pancreatitis (AIP) has been recently proposed as a disease entity, and an elevated serum IgG4 level is a characteristic finding in it. This disease is sometimes associated with other inflammatory diseases, such as retroperitoneal fibrosis and sclerosing cholangitis. To elucidate the clinicopathological characteristics of AIP-associated prostatitis (AIP-P), the clinicopathological findings of AIP-P patients were evaluated, and the immunohistochemical expression of the IgG subclasses (IgG1, IgG2, IgG3, and IgG4) in six AIP-P patients was compared with that in 10 control patients who were clinically diagnosed as suspicious for carcinoma but who had focal inflammation without adenocarcinoma on histological examination of the prostate. All AIP-P patients had the characteristic findings of AIP, and their lower urinary tract symptoms (LUTS) improved after steroid therapy. In four of five AIP-P patients, digital rectal examination indicated prostate enlargement. Histologically, AIP-P had lymphoplasmacytic and scattered eosinophilic infiltration and obliterative phlebitis accompanying gland atrophy with dense fibrosis. Immunohistochemically, the IgG4-positive plasma cell/mononuclear cell ratio was significantly higher in the AIP-P group than in the control group (P = 0.0011). AIP-P is a distinct clinicopathological entity, and a mechanism similar to that implicated in AIP may be involved in it as well.

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BackgroundThis study aimed to compare the detection of bone metastases from breast cancer on F-18 fluorodeoxyglucose positron emission tomography (FDG-PET) and bone scintigraphy (BS). An explorative search for factors influencing the sensitivity or uptake of BS and FDG-PET was also performed.MethodsEighty-eight patients with bone metastases from breast cancer were eligible for this study. Histological confirmation of bone metastases was obtained in 31 patients. The bone metastases were visually classified into four types based on their computed tomography (CT) appearance: osteoblastic, osteolytic, mixed, and negative. The sensitivity of BS and FDG-PET were obtained regarding CT type, adjuvant therapy, and the primary tumor characteristics. The FDG maximum standardized uptake value (SUVmax) was analyzed.ResultsThe sensitivities of the three modalities (CT, BS, and FDG-PET) were 77, 89, and 94%, respectively. The sensitivity of FDG-PET for the osteoblastic type (69%) was significantly lower than that for the other types (P < 0.001), and the sensitivity of BS for the negative type (70%) was significantly lower than that for the others. Regarding tumor characteristics, the sensitivity of FDG-PET significantly differed between nuclear grade (NG)1 and NG2–3 (P = 0.032). The SUVmax of the osteoblastic type was significantly lower than that of the other types (P = 0.009). The SUVmax of NG1 was also significantly lower than that of NG2–3 (P = 0.011). No significant difference in FDG uptake (SUVmax) was detected between different histological types.ConclusionAlthough FDG-PET is superior to BS for the detection of bone metastases from breast cancer, this technique has limitations in depicting osteoblastic bone metastases and NG1.

Since April 2010, the Japanese Public Health Insurance System has covered the costs incurred for performing 18 F-fluoro-2-deoxyglucose positron emission tomography (FDG-PET) imaging for patients with advanced gastric cancer. The aim of this review was to evaluate the clinical impact of PET for patients with gastric cancer. A systematic literature search was performed in PubMed/MEDLINE using the keywords ''gastric cancer'' and ''PET'' to search for relevant articles published from January 2000 to September 2010. The clinical impact of selected articles was assessed by the authors to evaluate the following: (a) tumor staging, (b) diagnosis for recurrent disease, (c) evaluation of treatment response, and (d) screening for gastric cancer. FDG uptake increases in papillary adenocarcinoma, tubular adenocarcinoma, and solid-type poorly differentiated adenocarcinoma. This uptake is also associated with glucose transporter 1 expression. The sensitivity and specificity of FDG-PET for metastatic lymph node detection were 21-40% and 89-100%, respectively. The sensitivity and specificity for distant metastasis detection were 35-74% and 74-99%, respectively. Treatment response can be detectable at an earlier stage by PET than by computed tomography (CT), because FDG uptake by cancer cells decreases according to the treatment response. In summary, although PET has limitations such as frequent false-negative cases in signetring cell carcinoma and non-solid type poorly differentiated carcinoma, it can contribute to the selection of a more appropriate treatment modality by detecting distant metastases and treatment response.