Radiation exposure and risk–benefit analysis in cancer screening using FDG-PET: results of a Japanese nationwide survey

Objective

The aim of this study was to estimate radiation exposure and evaluate the risks and benefits of 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) in cancer screening.

Methods

A nationwide survey of FDG-PET cancer screening was conducted in 2006, and the results were analyzed with a common index, “extension/shortening of the average life expectancy.”

Results

The average estimated effective dose was 4.4 mSv (male 4.7 mSv; female 4.0 mSv) for dedicated PET and 13.5 mSv (male 14.2 mSv; female 12.8 mSv) for PET/computed tomography (CT). The risk–benefit break-even age from the viewpoint of radiation exposure was in the 40s for men and 30s for women for dedicated PET and in the 50s for men and 50s (variable injection dose) or 60s (constant injection dose) for women for PET/CT.

Conclusions

FDG-PET cancer screening is beneficial for examinees above the break-even ages. The risks and benefits should be explained to examinees because of the larger radiation used in cancer FDG-PET screening compared with other X-ray tests.     

Intrapartum late deceleration develops more frequently in pre-eclamptic women with severe proteinuria

AIM: Our purpose was to investigate the effect of proteinuria associated with pre-eclampsia on intrapartum fetal heart rate patterns. METHODS: A retrospective study was performed involving 79 pregnant women with pre-eclampsia and 19 pregnant women with gestational hypertension (GH). Pre-eclampsia was then classified into two groups according to the degree of proteinuria (> or = or < 3 + dipstick), which was classified as severe urinary protein (UP; n = 35) and mild UP (n = 44) at delivery. Intrapartum fetal heart rate (FHR) monitoring was classified as either no deceleration, moderate variable deceleration, severe variable deceleration (sVD), prolonged deceleration (PD), occasional deceleration or recurrent late deceleration (rLD). We evaluated the prevalence of non-reassuring FHR (sVD, PD or rLD), the prevalence of intrauterine growth restriction (IUGR), and cord blood gas status in the three groups. The prevalence of non-reassuring FHR and cord blood gas status of these three groups was also compared with their prevalence in 65 women with low-risk pregnancies. Multiple logistic regression analysis was performed to determine the association between rLD and maternal-fetal parameters. RESULTS: Levels of systolic and diastolic blood pressure were similar among the three groups. Severe UP was diagnosed significantly earlier, was associated with significantly lower gestational age, and infants with lighter birth weight (P < 0.05) compared with GH and mild UP. The prevalence of IUGR in severe UP was higher than in GH (54%v. 21%, P < 0.05); however, no differences were found in the prevalence of IUGR between mild and severe UP (43%v. 54%, P = 0.33). The prevalence of non-reassuring FHR in GH was not statistically significant in the low-risk pregnancies (5%v. 9%, P = 0.58). In mild and severe UP, the non-reassuring FHRs were more predominant (30% and 43%, respectively) than in low-risk pregnancies and GH (P < 0.05). The rLD was more common in the group with severe UP and accounted for 40% of all FHR patterns. There was no difference in the incidence of low pH among the groups. However, fetuses in pregnancies involving severe UP were significantly hypoxemic when compared with others. Multiple logistic regression analysis showed that worsening proteinuria (odds ratio [OR], 5.5; 95% confidence interval [CI], 2.4-12.9) and IUGR (OR, 3.8; 95% CI, 1.2-11.5) increased the risk of rLD. Rates of preterm birth at less than 32 weeks (OR, 0.7; 95% CI, 0.2-2.5) and severe hypertension (OR, 0.5; 95% CI, 0.2-1.3) were not significant. CONCLUSION: In pre-eclampsia, the presence of severe proteinuria is associated with an increased likelihood of rLD.     

Preoperative evaluation of perigastric vascular anatomy by 3-dimensional computed tomographic angiography using 16-channel multidetector-row computed tomography for laparoscopic gastrectomy in patients with early gastric cancer

PURPOSE: The purpose of this study was to evaluate the efficacy of 3-dimensional computed tomographic angiography (3D CTA) using 16-channel multidetector-row helical computed tomography (MDCT) in the preoperative visualization of laparoscopic gastrectomy for early gastric cancer. MATERIALS AND METHODS: Twenty consecutive patients with early gastric cancer who underwent computed tomographic (CT) examination using 16-channel MDCT (0.625 mm x 16) before surgery were included in this study. At a rate of 4 mL/s, 2 mL/kg of 300 mg I/mL contrast material was intravenously injected. Timing for arterial phase scanning was determined by using a test bolus injection. Portal phase imaging was performed 70 seconds after the start of bolus injection. By using volume rendering and maximum intensity projection techniques, 3D CT angiograms of perigastric vessels were reconstructed from CT images of 0.625-mm thickness on computer workstations. RESULTS: In all cases, the left gastric artery (LGA) and the right gastric artery were correctly identified on 3D CTA, and the left gastric vein was also depicted on 3D CTA in all cases. In 2 cases, the aberrant left hepatic artery from LGA was correctly identified on 3D CTA. In 1 case, the accessory LGA from the left hepatic artery was correctly identified on 3D CTA. The variations of the veins included the left gastric vein flowing into the portal vein in 10 cases: the splenic vein in 9 and the junction of the portal and splenic veins in 1. CONCLUSIONS: A 3D CTA reconstructed from 16-channel MDCT images clearly revealed perigastric vascular anatomy in all cases, which is important for laparoscopic gastrectomy. Three-dimensional CTA is useful for the preoperative visualization of laparoscopic gastrectomy.     

FDG PET and PET/CT monitoring of autoimmune pancreatitis associated with extrapancreatic autoimmune disease

We report a series of FDG PET findings of a 69-year-old male patient with autoimmune pancreatitis (AIP) associated with extrapancreatic disease. The first FDG PET revealed diffuse uptake of FDG in AIP and retroperitoneal fibrosis (RF). The second FDG PET after cessation of steroid treatment indicated subsiding of disease activity in AIP, continuous disease activity in RF, and new extrapancreatic lesions, including enlargement of a right salivary gland, nephritis, and lymphadenopathy. The last FDG PET under steroid treatment revealed reduced FDG uptake in the above abnormal FDG uptake lesions. A series of these FDG PET findings suggest the usefulness of FDG PET for the diagnosis and monitoring of AIP associated with extrapancreatic autoimmune diseases.     

Cationic liposomes induce apoptosis through p38 MAP kinase-caspase-8-Bid pathway in macrophage-like RAW264.7 cells

We have demonstrated that cationic liposomes composed of stearylamine (SA-liposomes) induce apoptosis in a variety of cells, but the mechanism responsible for the cellular death is not clear. In this paper, we investigated the signaling pathways implicated in SA-liposome-induced apoptosis in the macrophage-like cell line RAW264.7. Treatment with SA-liposomes caused the activation of mitogen-activated protein kinases (MAPKs), especially p38 and c-jun N-terminal kinase, and apoptosis was only inhibited upon the addition of a specific inhibitor for p38. N-acetylcysteine, a scavenger of reactive oxygen species (ROS), effectively inhibited the activation of p38 and cellular death, indicating that the activation induced by ROS is an initial step in the process of apoptosis triggered by SA-liposomes. Caspase-8 was activated by p38, and caspase-8-dependent cleavage of Bid was also observed. No down-regulation of bcl-2 expression, and no cleavage of Bax protein were observed. Taken together, our results suggest that apoptosis of RAW264.7 by SA-liposomes was mediated by the MAPK p38 and a caspase-8-dependent Bid-cleavage pathway. Moreover, we found that ROS can contribute intimately to the SA-liposome-induced cell death in RAW264.7.     

Autopsy case of disseminated Trichosporon inkin infection identified with molecular biological and biochemical methods

Trichosporon species are usually opportunistic pathogens. Disseminated trichosporonosis is uncommon but is increasingly reported with a high mortality rate, especially in immunocompromised patients. Although Trichosporon asahii and T. mucoides are known as the most common pathogens of disseminated trichosporonosis, cases of systemic infection due to T. inkin have been reported recently. However, no autopsy case of disseminated T. inkin infection has been reported. Herein is presented an autopsy case of disseminated trichosporonosis caused by T. inkin in a 30-year-old man with allogenic peripheral blood stem cell transplantation for acute myelocytic leukemia. In the present case, identification of T. inkin was performed with morphological, molecular biological and biochemical methods. It is difficult to make a diagnosis of Trichosporon infection on only histological examination; therefore, molecular biological and biochemical methods are needed in a diagnosis of disseminated trichosporonosis.     

Reconstruction of Critical‐Sized Bone Defect in Dog Skull by Octacalcium Phosphate Combined with Collagen

Purpose: The present study was designed to investigate whether synthetic octacalcium phosphate (OCP) combined with collagen (OCP/collagen) can repair a critical‐sized defect in dog skull. OCP/collagen has been shown to biodegrade and to tend to be replaced by newly formed bone if implanted in rat calvaria defects. Materials and Methods: An OCP/collagen disk was prepared from pepsin‐digested atelocollagen isolated from porcine dermis and synthetic OCP. Two critical‐sized defects (20 mm in diameter) were made in a dog skull. Ten disks of OCP/collagen or collagen (control) were implanted in the bone defects and resected with surrounding tissues at 3, 6, or 12 months after the implantation. The specimens were analyzed radiographically, crystallographically, histologically, and histomorphometrically. Results: X‐ray diffraction and FTIR analyses showed that OCP tended to convert to a poorly crystallized hydroxyapatite, similar to that of biological apatite, by 3 months. Radiographic and histologic analyses showed that the implantation of OCP/collagen disks initiated new bone formation in the defects at 3 months after implantation. However, there was no promotion of bone formation by control collagen disks even with prolonged implantation up to 12 months. Histomorphometric analysis revealed that the percentage of newly formed bone in the defect implanted with OCP/collagen increased significantly, from 30.91 ± 6.65 at 3 months to 51.22 ± 5.99 at 12 months, although the value tended to reach a plateau at 6 months (44.49 ± 3.34). On the other hand, the percentage of remaining OCP was estimated at approximately 10% at 3 months and remained nearly unchanged thereafter. Conclusion: The results suggest that bone regeneration of a critical‐sized bone defect of dog calvaria by OCP/collagen can be enhanced for 3 to 6 months and that OCP/collagen holds potential as a bone substitute material.     

Survival and quality of life for patients with peripheral type chronic thromboembolic pulmonary hypertension.

BACKGROUND: The validity of pulmonary thromboendarterectomy for treatment of relatively peripheral type of chronic thromboembolic pulmonary hypertension (CTEPH) remains uncertain. The survival and quality of life (QOL) of patients with relatively peripheral type of CTEPH was investigated at follow up. METHODS AND RESULTS: Between April 1999 and March 2006, 83 consecutive patients with CTEPH were evaluated for surgical indication and underwent computed tomography angiography. The extent of central disease was scored (ie, CD score), and a CD score of 相似文献