title: The Feasibility of (18)F-Fluorothymidine PET for Prediction of Tumor Response after Induction Chemotherapy Followed by Chemoradiotherapy with S-1/Oxaliplatin in Patients with Resectable Esophageal Cancer.
abstract: OBJECTIVE
  The aim of this study was to determine whether (18)F-fluorothymidine (FLT) PET is feasible for the early prediction of tumor response to induction chemotherapy followed by concurrent chemoradiotherapy in patients with esophageal cancer.
  
  
  METHODS
  This study was prospectively performed as a collateral study of "randomized phase II study of preoperative concurrent chemoradiotherapy with or without induction chemotherapy with S-1/oxaliplatin in patients with resectable esophageal cancer". (18)F-FLT positron emission tomography (PET) images were obtained before and after two cycles of induction chemotherapy, and the percent change of maximum standardized uptake value (SUVmax) was calculated. All patients underwent esophagography, gastrofiberoscopy, endoscopic ultrasonography (EUS), computed tomography (CT) and (18)F-fluorodeoxyglucose (FDG) PET at baseline and 3-4 weeks after completion of concurrent chemoradiotherapy. Final tumor response was determined by both clinical and pathologic tumor responses after surgery.
  
  
  RESULTS
  The 13 patients for induction chemotherapy group were enrolled until interim analysis. In a primary tumor visual analysis, the tumor detection rates of baseline (18)F-FLT and (18)F-FDG PET were 85% and 100%, respectively. The tumor uptakes on (18)F-FLT PET were lower than those of (18)F-FDG PET. Among nine patients who completed second (18)F-FLT PET, eight patients were responders and one patient was a non-responder in the assessment of final tumor response. The percent change of SUVmax in responders ranged from 41.2% to 79.2% (median 57.1%), whereas it was 10.2% in one non-responder.
  
  
  CONCLUSIONS
  The percent change of tumor uptake in (18)F-FLT PET after induction chemotherapy might be feasible for early prediction of tumor response after induction chemotherapy and concurrent chemoradiotherapy in patients with esophageal cancer.
authors.affiliation: Department of Nuclear Medicine, Asan Medical Center, University of Ulsan College of Medicine, 388-1 Pungnap-2dong, Songpa-gu, Seoul, 138-736 South Korea.
authors.forename: Seol Hoon
authors.initials: SH
authors.lastname: Park
authors.affiliation: Department of Nuclear Medicine, Asan Medical Center, University of Ulsan College of Medicine, 388-1 Pungnap-2dong, Songpa-gu, Seoul, 138-736 South Korea.
authors.forename: Jin-Sook
authors.initials: JS
authors.lastname: Ryu
authors.affiliation: Department of Nuclear Medicine, Asan Medical Center, University of Ulsan College of Medicine, 388-1 Pungnap-2dong, Songpa-gu, Seoul, 138-736 South Korea.
authors.forename: Seung-Jun
authors.initials: SJ
authors.lastname: Oh
authors.affiliation: Department of Thoracic Surgery, Asan Medical Center, University of Ulsan College of Medicine, Seoul, 138-736 South Korea.
authors.forename: Seung-Il
authors.initials: SI
authors.lastname: Park
authors.affiliation: Department of Thoracic Surgery, Asan Medical Center, University of Ulsan College of Medicine, Seoul, 138-736 South Korea.
authors.forename: Yong Hee
authors.initials: YH
authors.lastname: Kim
authors.affiliation: Department of Internal Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, 138-736 South Korea.
authors.forename: Hoon-Yong
authors.initials: HY
authors.lastname: Jung
authors.affiliation: Department of Internal Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, 138-736 South Korea.
authors.forename: Gin Hyug
authors.initials: GH
authors.lastname: Lee
authors.affiliation: Department of Internal Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, 138-736 South Korea.
authors.forename: Ho Jun
authors.initials: HJ
authors.lastname: Song
authors.affiliation: Department of Radiation Oncology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, 138-736 South Korea.
authors.forename: Jong Hoon
authors.initials: JH
authors.lastname: Kim
authors.affiliation: Department of Diagnostic Radiology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, 138-736 South Korea.
authors.forename: Ho-Young
authors.initials: HY
authors.lastname: Song
authors.affiliation: Department of Pathology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, 138-736 South Korea.
authors.forename: Kyoung Ja
authors.initials: KJ
authors.lastname: Cho
authors.affiliation: Department of Internal Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, 138-736 South Korea.
authors.forename: Sung-Bae
authors.initials: SB
authors.lastname: Kim
keywords: 18F-FLT; Esophageal cancer; Induction chemotherapy; PET; Tumor response