title: (18)F-Fluorodeoxyglucose positron emission tomography ((18)F-FDG PET) for the early detection of response to neoadjuvant chemotherapy for locally advanced rectal cancer.
abstract: OBJECTIVE
  Early detection of a response to neoadjuvant chemotherapy for locally advanced rectal cancer may spare patients from additional toxic but ineffective chemotherapy. Using (18)F-fluorodeoxyglucose positron emission tomography ((18)F-FDG PET), we evaluated tumor response prospectively in the early course of preoperative chemotherapy.
  
  
  METHODS
  The subjects were 15 patients who received neoadjuvant chemotherapy (XELOX or XELOX plus bevacizumab) for locally advanced rectal cancer. Patients underwent (18)F-FDG PET before chemotherapy, at the end of the first cycle of chemotherapy, and before surgical resection. Magnetic resonance imaging (MRI) was performed before chemotherapy, after the second cycle of chemotherapy, and before resection. After resection, the SUVmax and diameter were compared and graded according to the tumor regression grade (TRG).
  
  
  RESULTS
  The TRG was assessed as TRG1 in one patient, TRG2 in five patients, and TRG3 in nine patients. We divided the patients into two groups: non-responders (NR) included the TRG1 and TRG2 patients, and responders (R) included the TRG3 patients. The tumor size before surgery was significantly smaller in the R group than in the NR group. The SUVmax at the end of the first cycle of chemotherapy and before surgical resection was significantly lower in the R group than in the NR group.
  
  
  CONCLUSIONS
  Performing (18)F-FDG PET at the end of the first cycle of chemotherapy allowed us to predict the pathological response of locally advanced rectal cancer.
authors.affiliation: Department of Gastroenterological Surgery, Osaka University, Graduate School of Medicine, Suita, Osaka, Japan.|Department of Surgery, Osaka Rosai Hospital, Sakai, Osaka, Japan.
authors.forename: Junichi
authors.initials: J
authors.lastname: Nishimura
authors.affiliation: Department of Surgery, Osaka Rosai Hospital, Sakai, Osaka, Japan. j-hasegawa@orh.go.jp.
authors.forename: Junichi
authors.initials: J
authors.lastname: Hasegawa
authors.affiliation: Department of Diagnostic Radiology, Hanwa Intelligent Medical Center, Sakai, Osaka, Japan.
authors.forename: Yoji
authors.initials: Y
authors.lastname: Ogawa
authors.affiliation: Department of Pathology, Osaka Rosai Hospital, Sakai, Osaka, Japan.
authors.forename: Hideaki
authors.initials: H
authors.lastname: Miwa
authors.affiliation: Department of Gastroenterological Surgery, Osaka University, Graduate School of Medicine, Suita, Osaka, Japan.
authors.forename: Mamoru
authors.initials: M
authors.lastname: Uemura
authors.affiliation: Department of Gastroenterological Surgery, Osaka University, Graduate School of Medicine, Suita, Osaka, Japan.
authors.forename: Naotsugu
authors.initials: N
authors.lastname: Haraguchi
authors.affiliation: Department of Gastroenterological Surgery, Osaka University, Graduate School of Medicine, Suita, Osaka, Japan.
authors.forename: Taishi
authors.initials: T
authors.lastname: Hata
authors.affiliation: Department of Gastroenterological Surgery, Osaka University, Graduate School of Medicine, Suita, Osaka, Japan.
authors.forename: Hirofumi
authors.initials: H
authors.lastname: Yamamoto
authors.affiliation: Department of Gastroenterological Surgery, Osaka University, Graduate School of Medicine, Suita, Osaka, Japan.
authors.forename: Ichiro
authors.initials: I
authors.lastname: Takemasa
authors.affiliation: Department of Gastroenterological Surgery, Osaka University, Graduate School of Medicine, Suita, Osaka, Japan.
authors.forename: Tsunekazu
authors.initials: T
authors.lastname: Mizushima
authors.affiliation: Department of Surgery, Osaka Rosai Hospital, Sakai, Osaka, Japan.
authors.forename: Riichiro
authors.initials: R
authors.lastname: Nezu
authors.affiliation: Department of Gastroenterological Surgery, Osaka University, Graduate School of Medicine, Suita, Osaka, Japan.
authors.forename: Yuichiro
authors.initials: Y
authors.lastname: Doki
authors.affiliation: Department of Gastroenterological Surgery, Osaka University, Graduate School of Medicine, Suita, Osaka, Japan.
authors.forename: Masaki
authors.initials: M
authors.lastname: Mori
mesh_terms: D000368:Aged; D017024:Chemotherapy, Adjuvant; D013505:Digestive System Surgical Procedures; D005260:Female; D005462:Fluorine Radioisotopes; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D020360:Neoadjuvant Therapy; D009367:Neoplasm Staging; D049268:Positron-Emission Tomography; D011300:Preoperative Care; D011446:Prospective Studies; D019275:Radiopharmaceuticals; D012004:Rectal Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology / Q000628:therapy*; D016896:Treatment Outcome
chemical_list: D005462:Fluorine Radioisotopes; D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18
keywords: FDG-PET; Neoadjuvant chemotherapy; Rectal cancer