title: A comparison of FLT to FDG PET/CT in the early assessment of chemotherapy response in stages IB-IIIA resectable NSCLC.
abstract: BACKGROUND
  The aim of this study was to compare the percentage change in18F-fluorothymidine (FLT) standard uptake value (SUV) between baseline and after one cycle of chemotherapy in patients categorized by RECIST 1.1 computed tomography (CT) as responders or non-responders after two cycles of therapy. Change in18F-fluorodeoxyglucose (FDG) uptake was also compared between these time points. Nine patients with newly diagnosed, operable, non-small cell lung cancer (NSCLC) were imaged with FDG positron emission tomography/CT (PET), FLT PET/CT, and CT at baseline, following one cycle of neoadjuvant therapy (75 mg/m2docetaxel + 75 mg/m2cisplatin), and again after the second cycle of therapy. All patients had a biopsy prior to enrollment and underwent surgical resection within 4 weeks of post-cycle 2 imaging.
  
  
  RESULTS
  Between baseline and post-cycle 1, non-responders had mean SULmax (maximum standard uptake value adjusted for lean body mass) increases of 7.0 and 3.4% for FDG and FLT, respectively. Responders had mean decreases of 44.8 and 32.0% in FDG and FLT SULmax, respectively, between baseline and post-cycle 1 imaging. On post-cycle 1 imaging, primary tumor FDG SUL values were significantly lower in responders than in non-responders (P = 0.016). Primary tumor FLT SUL values did not differ significantly between these groups. Using the change from baseline to post-cycle 1, receiver-operating characteristic (ROC) analysis showed an area under the curve (AUC) of 0.94 for FDG and 0.78 for FLT in predicting anatomic tumor response after the second cycle of therapy.
  
  
  CONCLUSIONS
  Fractional decrease in FDG SULmax from baseline to post-cycle 1 imaging was significantly different between anatomic responders and non-responders, while percentage changes in FLT SULmax were not significantly different between these groups over the same period of time.
authors.affiliation: Mallinckrodt Institute of Radiology, Washington University School of Medicine, 510 S. Kingshighway Blvd, Campus Box 8131, St. Louis, MO, 63110, USA.
authors.forename: John P
authors.initials: JP
authors.lastname: Crandall
authors.affiliation: Medical Imaging Department, King Fahad Specialist Hospital, P.O. Box 15215, Dammam, 31444-34, Saudi Arabia.
authors.forename: Abdel K
authors.initials: AK
authors.lastname: Tahari
authors.affiliation: Juravinski Cancer Centre, McMaster University, 699 Concession Street, Fourth, Hamilton, Ontario, L8V 5C2, Canada.
authors.forename: Rosalyn A
authors.initials: RA
authors.lastname: Juergens
authors.affiliation: Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University School of Medicine, 1650 Orleans St, CRB I Room G-94, Baltimore, MD, 21287, USA.
authors.forename: Julie R
authors.initials: JR
authors.lastname: Brahmer
authors.affiliation: Thoracic Oncology Service, Division of Solid Tumor Oncology, Department of Medicine, Memorial Sloan Kettering Cancer Center and Weill Cornell Medical College, 633 3rd Ave, New York, NY, 10017, USA.
authors.forename: Charles M
authors.initials: CM
authors.lastname: Rudin
authors.affiliation: Department of Radiology, Georgetown University Hospital, 3800 Reservoir Road NW CCC Bldg., Washington, DC, 20007, USA.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Esposito
authors.affiliation: Department of Medicine, Georgetown University Hospital, 3800 Reservoir Road NW LCCC Bldg., Second Floor Pod B, Washington, DC, 20007, USA.
authors.forename: Deepa S
authors.initials: DS
authors.lastname: Subramaniam
authors.affiliation: Department of Radiology, The Ohio State University, Wexner Medical Center, 395 W. 12th Ave., Room 430, Columbus, OH, 43210, USA.
authors.forename: Michael V
authors.initials: MV
authors.lastname: Knopp
authors.affiliation: Department of Radiology, Perelman School of Medicine, University of Pennsylvania, 116 Donner, HUP 3400 Spruce Street, Philadelphia, PA, 19104, USA.
authors.forename: Nathan C
authors.initials: NC
authors.lastname: Hall
authors.affiliation: The Johns Hopkins Wilmer Eye Institute, Johns Hopkins University School of Medicine, 600 N. Wolfe Street, Baltimore, MD, 21287, USA.
authors.forename: Prateek
authors.initials: P
authors.lastname: Gajwani
authors.affiliation: The Russell H. Morgan Department of Radiology, Johns Hopkins University School of Medicine, Nelson B1-160, 600 N. Wolfe St., Baltimore, MD 21287, USA.
authors.forename: Jeffrey P
authors.initials: JP
authors.lastname: Leal
authors.affiliation: The Russell H. Morgan Department of Radiology, Johns Hopkins University School of Medicine, Nelson B1-160, 600 N. Wolfe St., Baltimore, MD 21287, USA.
authors.forename: Martin A
authors.initials: MA
authors.lastname: Lodge
authors.affiliation: Department of Nuclear Medicine, Seoul St. Mary's Hospital, Catholic Medical Center, Seocho-gu, Banpo-daero 222, Seoul, 06591, Korea.
authors.forename: Joo H
authors.initials: JH
authors.lastname: O
authors.affiliation: Department of Pathology, Johns Hopkins University School of Medicine, 1550 Orleans Street, 304 CRB II, Baltimore, MD, 21287, USA.
authors.forename: Edward W
authors.initials: EW
authors.lastname: Gabrielson
authors.affiliation: National Cancer Institute, 6130 Executive Boulevard, MSC 7412, Bethesda, MD, 20892, USA.
authors.forename: Lalitha K
authors.initials: LK
authors.lastname: Shankar
authors.affiliation: Mallinckrodt Institute of Radiology, Washington University School of Medicine, 510 S. Kingshighway Blvd, Campus Box 8131, St. Louis, MO, 63110, USA. rwahl@wustl.edu.|The Russell H. Morgan Department of Radiology, Johns Hopkins University School of Medicine, Nelson B1-160, 600 N. Wolfe St., Baltimore, MD 21287, USA. rwahl@wustl.edu.
authors.forename: Richard L
authors.initials: RL
authors.lastname: Wahl
keywords: Early treatment response monitoring; FDG PET/CT; FLT PET/CT; Non-small cell lung cancer