title: 18F-FDG PET/CT oncologic imaging at extended injection-to-scan acquisition time intervals derived from a single-institution 18F-FDG-directed surgery experience: feasibility and quantification of 18F-FDG accumulation within 18F-FDG-avid lesions and background tissues.
abstract: BACKGROUND
  18F-fluorodeoxyglucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) is a well-established imaging modality for a wide variety of solid malignancies. Currently, only limited data exists regarding the utility of PET/CT imaging at very extended injection-to-scan acquisition times. The current retrospective data analysis assessed the feasibility and quantification of diagnostic (18)F-FDG PET/CT oncologic imaging at extended injection-to-scan acquisition time intervals.
  
  
  METHODS
  (18)F-FDG-avid lesions (not surgically manipulated or altered during (18)F-FDG-directed surgery, and visualized both on preoperative and postoperative (18)F-FDG PET/CT imaging) and corresponding background tissues were assessed for (18)F-FDG accumulation on same-day preoperative and postoperative (18)F-FDG PET/CT imaging. Multiple patient variables and (18)F-FDG-avid lesion variables were examined.
  
  
  RESULTS
  For the 32 (18)F-FDG-avid lesions making up the final (18)F-FDG-avid lesion data set (from among 7 patients), the mean injection-to-scan times of the preoperative and postoperative (18)F-FDG PET/CT scans were 73 (± 3, 70-78) and 530 (± 79, 413-739) minutes, respectively (P < 0.001). The preoperative and postoperative mean (18)F-FDG-avid lesion SUV(max) values were 7.7 (± 4.0, 3.6-19.5) and 11.3 (± 6.0, 4.1-29.2), respectively (P < 0.001). The preoperative and postoperative mean background SUV(max) values were 2.3 (± 0.6, 1.0-3.2) and 2.1 (± 0.6, 1.0-3.3), respectively (P = 0.017). The preoperative and postoperative mean lesion-to-background SUV(max) ratios were 3.7 (± 2.3, 1.5-9.8) and 5.8 (± 3.6, 1.6-16.2), respectively, (P < 0.001).
  
  
  CONCLUSIONS
  (18)F-FDG PET/CT oncologic imaging can be successfully performed at extended injection-to-scan acquisition time intervals of up to approximately 5 half-lives for (18)F-FDG while maintaining good/adequate diagnostic image quality. The resultant increase in the (18)F-FDG-avid lesion SUV(max) values, decreased background SUV(max) values, and increased lesion-to-background SUV(max) ratios seen from preoperative to postoperative (18)F-FDG PET/CT imaging have great potential for allowing for the integrated, real-time use of (18)F-FDG PET/CT imaging in conjunction with (18)F-FDG-directed interventional radiology biopsy and ablation procedures and (18)F-FDG-directed surgical procedures, as well as have far-reaching impact on potentially re-shaping future thinking regarding the "most optimal" injection-to-scan acquisition time interval for all routine diagnostic (18)F-FDG PET/CT oncologic imaging.
authors.affiliation: Division of Surgical Oncology, Department of Surgery, Arthur G, James Cancer Hospital and Richard J, Solove Research Institute and Comprehensive Cancer Center, The Ohio State University Wexner Medical Center, Columbus, OH 43210, USA. stephen.povoski@osumc.edu.
authors.forename: Stephen P
authors.initials: SP
authors.lastname: Povoski
authors.forename: Douglas A
authors.initials: DA
authors.lastname: Murrey
authors.forename: Sabrina M
authors.initials: SM
authors.lastname: Smith
authors.forename: Edward W
authors.initials: EW
authors.lastname: Martin
authors.forename: Nathan C
authors.initials: NC
authors.lastname: Hall
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016208:Databases, Factual; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008297:Male; D008875:Middle Aged; D009369:Neoplasms / Q000175:diagnosis* / Q000601:surgery; D049268:Positron-Emission Tomography / Q000379:methods; D011184:Postoperative Period; D057234:Preoperative Period; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed / Q000379:methods
chemical_list: D019788:Fluorodeoxyglucose F18