title: Using SUV as a guide to 18F-FDG dose reduction.
abstract: This article explores how one can lower the injected (18)F-FDG dose while maintaining validity in comparing standardized uptake values (SUVs) between studies. Variations of the SUV within each lesion were examined at different acquisition times.
  
  
  METHODS
  Our protocol was approved by either the Human Investigation Committee or the Institutional Review Board. All 120 PET datasets were acquired continuously for 180 s per bed position in list mode and were reconstructed to obtain 30-, 60-, 90-, 120-, 150-, and 180-s-per-bed-position PET images with registration to a single set of nondiagnostic CT images. Qualitative assessment of the images was performed separately for correlation. The SUV measurements of each lesion were computed and normalized to the 180-s acquisition values to create a stabilization factor. These stabilization factors were used to demonstrate a predictable trend of stabilization over time. The variances of the stabilization factors over the entire dataset, composed of several tumor types over a range of sizes, were compared for each time point with the corresponding 150-s time point using a 2-sided F test, which has similar values to the 180-s time point.
  
  
  RESULTS
  The variance of the data decreased with increasing acquisition time and with increasing dose but leveled off for sufficiently long acquisitions.
  
  
  CONCLUSIONS
  Through the statistical analysis of SUVs for increasing acquisition times and visual evaluation of the plots, we developed and hereby propose an algorithm that can be used to seek the maximum reduction in administered (18)F-FDG dose while preserving the validity of SUV comparisons.
authors.affiliation: Sidra Medical and Research Center, Department of Diagnostic Imaging, Doha, Qatar dcheng@sidra.org.
authors.forename: David W
authors.initials: DW
authors.lastname: Cheng
authors.affiliation: Yale University School of Medicine, Department of Diagnostic Radiology, New Haven, Connecticut.
authors.forename: Devrim
authors.initials: D
authors.lastname: Ersahin
authors.affiliation: Yale University School of Medicine, Department of Diagnostic Radiology, New Haven, Connecticut.
authors.forename: Lawrence H
authors.initials: LH
authors.lastname: Staib
authors.affiliation: Fondazione Toscana Gabriele Monasterio per la Ricerca Medica e di Sanità Pubblica, CNR-Regione Toscana, Massa, Italy; and.
authors.forename: Daniele
authors.initials: D
authors.lastname: Della Latta
authors.affiliation: Fondazione Toscana Gabriele Monasterio per la Ricerca Medica e di Sanità Pubblica, CNR-Regione Toscana, Pisa, Italy.
authors.forename: Assuero
authors.initials: A
authors.lastname: Giorgetti
authors.affiliation: Yale University School of Medicine, Department of Diagnostic Radiology, New Haven, Connecticut.
authors.forename: Francesco
authors.initials: F
authors.lastname: d'Errico
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D004305:Dose-Response Relationship, Drug; D005260:Female; D019788:Fluorodeoxyglucose F18 / Q000008:administration & dosage* / Q000493:pharmacokinetics*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D008875:Middle Aged; D009369:Neoplasms / Q000175:diagnosis / Q000000981:diagnostic imaging; D049268:Positron-Emission Tomography; D019275:Radiopharmaceuticals / Q000008:administration & dosage* / Q000493:pharmacokinetics*; D012016:Reference Values; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed; D055815:Young Adult
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18
keywords: 18F-FDG; SUV; acquisition time; dose reduction; standardized uptake value