Tetsuya Tsujikawa

Bio: Tetsuya Tsujikawa is an academic researcher from University of Fukui. The author has contributed to research in topics: Medicine & Standardized uptake value. The author has an hindex of 20, co-authored 82 publications receiving 1152 citations.

Accuracy of PET for Diagnosis of Solid Pulmonary Lesions with 18F-FDG Uptake Below the Standardized Uptake Value of 2.5

Abstract: Benign and malignant pulmonary lesions usually are differentiated by 18F-FDG PET with a semiquantitative 18F-FDG standardized uptake value (SUV) of 2.5. However, the frequency of malignancies with an SUV of

Cytosolic acetyl-CoA synthetase affected tumor cell survival under hypoxia: the possible function in tumor acetyl-CoA/acetate metabolism

Abstract: Understanding tumor-specific metabolism under hypoxia is important to find novel targets for antitumor drug design. Here we found that tumor cells expressed higher levels of cytosolic acetyl-CoA synthetase (ACSS2) under hypoxia than normoxia. Knockdown of ACSS2 by RNA interference (RNAi) in tumor cells enhanced tumor cell death under long-term hypoxia in vitro. Our data also demonstrated that the ACSS2 suppression slowed tumor growth in vivo. These findings showed that ACSS2 plays a significant role in tumor cell survival under hypoxia and that ACSS2 would be a potential target for tumor treatment. Furthermore, we found that tumor cells excreted acetate and the quantity increased under hypoxia: the pattern of acetate excretion followed the expression pattern of ACSS2. Additionally, the ACSS2 knockdown led to a corresponding reduction in the acetate excretion in tumor cells. These results mean that ACSS2 can conduct the reverse reaction from acetyl-CoA to acetate in tumor cells, which indicates that ACSS2 is a bi-directional enzyme in tumor cells and that ACSS2 might play a buffering role in tumor acetyl-CoA/acetate metabolism.

Uterine tumors: pathophysiologic imaging with 16alpha-[18F]fluoro-17beta-estradiol and 18F fluorodeoxyglucose PET--initial experience.

Abstract: Purpose: To clarify prospectively the relationship between estrogen receptor (ER) expression and glucose metabolism by using 16α-[18F]fluoro-17β-estradiol (FES) and fluorine 18 (18F) fluorodeoxyglucose (FDG) positron emission tomography (PET) in patients with benign and malignant uterine tumors. Materials and Methods: The institutional review board approved this study, and informed consent was obtained from all subjects. FES and FDG PET studies were performed in 38 patients (mean age, 54.1 years ± 14.0 [standard deviation]) with benign and malignant uterine tumors to compare differences in tracer accumulation. Regional values of tracer uptake were evaluated by using standardized uptake value (SUV), a normalized value corrected by using injection dose and body weight. Results: Patients with endometrial carcinoma showed significantly greater mean SUV for FDG (9.6 ± 3.3) than for FES (3.8 ± 1.8) (P < .005). Patients with endometrial hyperplasia showed significantly higher mean SUV for FES (7.0 ± 2.9) than fo...

Functional Images Reflect Aggressiveness of Endometrial Carcinoma: Estrogen Receptor Expression Combined with 18F-FDG PET

Abstract: The grade of histologic differentiation is one of the most important prognostic factors in patients with endometrial carcinoma and postoperative staging. The aim of this study was to investigate whether 16a- 18 F-fluoro-17b-estradiol ( 18 F-FES) and 18 F-FDG PET reflect clinicopathologic features in patients with endometrial tumors. Methods: A total of 22 patients with endometrial adenocarcinoma and 9 with endometrial hyperplasia (mean age, 56.0 6 15.3 y) underwent 18F-FES PET for estrogen receptor imaging and 18 F-FDG PET. Regional values of tracer uptake were evaluated using standardized uptake value (SUV) and the SUV ratio of 18 F-FDG to 18 F-FES. The accuracy for predicting tumor aggressiveness defined as high-risk carcinoma (International Federation of Gynecology and Obstetrics [FIGO] stage $ Ic or histologic grade $ 2), low-risk carcinoma (FIGO stage # Ib and grade 1), and hyperplasia was compared for each PET parameter using receiver-operating-characteristic (ROC) analysis. The diagnostic accuracy of MRI findings for clinical staging was also compared. Results: Although the SUV for 18 F-FDG was significantly lower in endometrial hyperplasia than in carcinoma, a significant difference between high-risk and low-risk carcinoma was observed only in SUV for 18F-FES. High-risk carcinoma showed a significantly greater 18 F-FDG‐to‐ 18 F-FES ratio (3.6 6 2.1) than did low-risk carcinoma (1.3 6 0.5, P , 0.01) and hyperplasia (0.3 6 0.1, P , 0.005). Low-risk carcinoma showed a significantly higher 18F-FDG‐to‐18F-FES ratio than hyperplasia (P , 0.0001). In ROC analysis, the most accurate diagnostic PET parameter for predicting high-risk and low-risk carcinoma was the 18 F-FDG‐to‐ 18 F-FES ratio. The optimal 18 F-FDG/ 18 F

Lipid metabolism in cancer

Abstract: Lipids form a diverse group of water-insoluble molecules that include triacylglycerides, phosphoglycerides, sterols and sphingolipids. They play several important roles at cellular and organismal levels. Fatty acids are the major building blocks for the synthesis of triacylglycerides, which are mainly used for energy storage. Phosphoglycerides, together with sterols and sphingolipids, represent the major structural components of biological membranes. Lipids can also have important roles in signalling, functioning as second messengers and as hormones. There is increasing evidence that cancer cells show specific alterations in different aspects of lipid metabolism. These alterations can affect the availability of structural lipids for the synthesis of membranes, the synthesis and degradation of lipids that contribute to energy homeostasis and the abundance of lipids with signalling functions. Changes in lipid metabolism can affect numerous cellular processes, including cell growth, proliferation, differentiation and motility. This review will examine some of the alterations in lipid metabolism that have been reported in cancer, at both cellular and organismal levels, and discuss how they contribute to different aspects of tumourigenesis.

Preoperative staging of non-small-cell lung cancer with positron-emission tomography.

Abstract: Background Determining the stage of non–small-cell lung cancer often requires multiple preoperative tests and invasive procedures. Whole-body positron-emission tomography (PET) may simplify and improve the evaluation of patients with this tumor. Methods We prospectively compared the ability of a standard approach to staging (computed tomography [CT], ultrasonography, bone scanning, and, when indicated, needle biopsies) and one involving PET to detect metastases in mediastinal lymph nodes and at distant sites in 102 patients with resectable non–small-cell lung cancer. The presence of mediastinal metastatic disease was confirmed histopathologically. Distant metastases that were detected by PET were further evaluated by standard imaging tests and biopsies. Patients were followed postoperatively for six months by standard methods to detect occult metastases. Logistic-regression analysis was used to evaluate the ability of PET and CT to identify malignant mediastinal lymph nodes. Results The sensitivity and sp...

The multifaceted roles of fatty acid synthesis in cancer

Abstract: Lipid metabolism, in particular the synthesis of fatty acids (FAs), is an essential cellular process that converts nutrients into metabolic intermediates for membrane biosynthesis, energy storage and the generation of signalling molecules. This Review explores how different aspects of FA synthesis promote tumorigenesis and tumour progression. FA synthesis has received substantial attention as a potential target for cancer therapy, but strategies to target this process have not yet translated into clinical practice. Furthermore, efforts to target this pathway must consider the influence of the tumour microenvironment.

British Thoracic Society guidelines for the investigation and management of pulmonary nodules: accredited by NICE

Abstract: This guideline is based on a comprehensive review of the literature on pulmonary nodules and expert opinion. Although the management pathway for the majority of nodules detected is straightforward it is sometimes more complex and this is helped by the inclusion of detailed and specific recommendations and the 4 management algorithms below. The Guideline Development Group (GDG) wanted to highlight the new research evidence which has led to significant changes in management recommendations from previously published guidelines. These include the use of two malignancy prediction calculators (section ‘Initial assessment of the probability of malignancy in pulmonary nodules’, algorithm 1) to better characterise risk of malignancy. There are recommendations for a higher nodule size threshold for follow-up (≥5 mm or ≥80 mm3) and a reduction of the follow-up period to 1 year for solid pulmonary nodules; both of these will reduce the number of follow-up CT scans (sections ‘Initial assessment of the probability of malignancy in pulmonary nodules’ and ‘Imaging follow-up’, algorithms 1 and 2). Volumetry is recommended as the preferred measurement method and there are recommendations for the management of nodules with extended volume doubling times (section ‘Imaging follow-up’, algorithm 2). Acknowledging the good prognosis of sub-solid nodules (SSNs), there are recommendations for less aggressive options for their management (section ‘Management of SSNs’, algorithm 3). The guidelines provide more clarity in the use of further imaging, with ordinal scale reporting for PET-CT recommended to facilitate incorporation into risk models (section ‘Further imaging in management of pulmonary nodules’) and more clarity about the place of biopsy (section ‘Non-imaging tests and non-surgical biopsy’, algorithm 4). There are recommendations for the threshold for treatment without histological confirmation (sections ‘Surgical excision biopsy’ and ‘Non-surgical treatment without pathological confirmation of malignancy’, algorithm 4). Finally, and possibly most importantly, there are evidence-based recommendations about the information that people …