title: Significance of chronic marked hyperglycemia on FDG-PET: is it really problematic for clinical oncologic imaging?
abstract: OBJECTIVE
  The purpose of this study was to evaluate the adverse effects of chronic marked hyperglycemia on clinical diagnostic performance of positron emission tomography (PET) using (18)F-fuorodeoxyglucose (FDG).
  
  
  METHODS
  Fifty-seven scans of 54 patients, who received FDG-PET for the diagnosis of various cancer(s), and who showed high plasma glucose level of more than 200 mg/dl at the time of administration of FDG in spite of at least 4-h fasting, were retrospectively analyzed. In the clinical follow-up, this high plasma glucose was confirmed as chronic hyperglycemia derived from uncontrolled diabetes (n = 32) and untreated diabetes (n = 25). Based on the final diagnosis of malignancy obtained by histopathology or clinical follow-up for at least 6 months, the diagnostic performance of visual PET analysis was evaluated.
  
  
  RESULTS
  Excluding nine scans of nine patients without sufficient follow-up, final diagnosis was obtained in 48 scans of 45 patients. In 36 scans of 36 patients, at least one malignant lesion was finally confirmed, and true-positive and false-negative results were obtained in 30 and six cases, respectively. Six cases showed false-negative results due to low FDG-avid pathological characteristics (hepatocellular carcinoma, etc.), chemotherapeutic effect or small tumor size. Overall, the patient-based sensitivity, specificity, positive predictive value, negative predictive value and diagnostic accuracy were 83, 83, 94, 63 and 83%, respectively. In lesion-based diagnosis, 56 of 75 lesions (74%) were depicted by PET, while 19 lesions were negative on PET, also due to low FDG-avid characteristics or small size (less than 15 mm).
  
  
  CONCLUSIONS
  At the time of chronic hyperglycemia (not acute hyperglycemia), the adverse effect caused by high plasma glucose level was minimum. The FDG uptake of the tumor maintained a sufficiently high level for visual clinical diagnosis in most cases, except in the cases of low FDG-avid tumors or small lesions (15 mm in size).
authors: Department of Diagnostic Imaging and Nuclear Medicine, Kyoto University Graduate School of Medicine, Kyoto, Japan.
authors: Tadashi
authors: T
authors: Hara
authors: Tatsuya
authors: T
authors: Higashi
authors: Yuji
authors: Y
authors: Nakamoto
authors: Tsuyoshi
authors: T
authors: Suga
authors: Tsuneo
authors: T
authors: Saga
authors: Takayoshi
authors: T
authors: Ishimori
authors: Koichi
authors: K
authors: Ishizu
authors: Hidekazu
authors: H
authors: Kawashima
authors: Shigeto
authors: S
authors: Kawase
authors: Keiichi
authors: K
authors: Matsumoto
authors: Kaori
authors: K
authors: Togashi
mesh_terms: D000328:Adult; D000368:Aged; D001786:Blood Glucose / Q000378:metabolism; D002908:Chronic Disease; D048909:Diabetes Complications / Q000097:blood / Q000150:complications; D005188:False Negative Reactions; D005189:False Positive Reactions; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D006943:Hyperglycemia / Q000097:blood / Q000150:complications / Q000000981:diagnostic imaging; D008297:Male; D008875:Middle Aged; D009369:Neoplasms / Q000097:blood / Q000150:complications / Q000000981:diagnostic imaging*; D049268:Positron-Emission Tomography; D012189:Retrospective Studies
chemical_list: D001786:Blood Glucose; D019788:Fluorodeoxyglucose F18