title: [Usefulness of metabolic volume and total lesion glycolysis for predicting therapeutic response in cancer therapy by 18F-FDG PET/CT].
abstract: OBJECTIVE
  The current study was done to evaluate the usefulness of predicting capability of FDG PET/CT indices in therapeutic response of malignant tumor.
  
  
  METHODS
  Series of FDG PET/CT were performed at both pre- and after therapy for 70 lesions of 58 patients with malignant tumor. Three months after the 2nd PET/CT, follow up CT was performed for determining the final therapeutic effect. We calculated various indices including SUVmax, the metabolic volume (MV) and the total lesion glycolysis (TLG). We calculated four kinds of indices, TLG50, TLG75, MV50 and MV75 based on the different threshold. Then we calculated deltaSUVmax, deltaMV50, deltaMV75, deltaTLG50 and deltaTLG75 from a change of these indices. Finally, we compared the predictive capability of these five indices in therapeutic response of malignant tumor.
  
  
  RESULTS
  In the cancer therapy effect prediction, both deltaTLG75 and deltaTLG50 were significantly higher than SUVmax by using receiver operating-characteristic (ROC) curve analysis. The prognostic capability of deltaSUVmax for therapeutic response with sensitivity, specificity, positive predictive value, negative predictive value and accuracy were 85.7%, 59.5%, 58.5%, 86.2% and 70.0%; deltaTLG75 96.4%, 69.0%, 67.5%, 96.7% and 80.0%; and deltaTLG50 96.4%, 76.2%, 73.0%, 97.0% and 84.3%, respectively. By the use of deltaTLG75 or deltaTLG50, the predictive ability for therapeutic response improved significantly compared to that by the use of deltaSUVmax.
  
  
  CONCLUSIONS
  In the prediction for therapeutic response of various cancers by using FDG PET/CT, Total lesion glycolysis (TLG) was the most useful index.
authors.affiliation: Department of Radiology, School of Medicine, Miyazaki University.
authors.forename: Shogo
authors.initials: S
authors.lastname: Kiyohara
authors.forename: Shigeki
authors.initials: S
authors.lastname: Nagamachi
authors.forename: Hideyuki
authors.initials: H
authors.lastname: Wakamatsu
authors.forename: Ryuichi
authors.initials: R
authors.lastname: Nishii
authors.forename: Seigo
authors.initials: S
authors.lastname: Fujita
authors.forename: Shigemi
authors.initials: S
authors.lastname: Futami
authors.forename: Shozo
authors.initials: S
authors.lastname: Tamura
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D005260:Female; D019788:Fluorodeoxyglucose F18; D006019:Glycolysis; D006801:Humans; D008297:Male; D008875:Middle Aged; D009369:Neoplasms / Q000000981:diagnostic imaging* / Q000378:metabolism*; D049268:Positron-Emission Tomography; D019275:Radiopharmaceuticals
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18