title: [18F]fluoro-2-deoxyglucose-positron emission tomography for the assessment of histopathological response after preoperative chemoradiotherapy in advanced oral squamous cell carcinoma.
abstract: BACKGROUND
  [(18)F]fluoro-2-deoxyglucose-positron emission tomography (FDG-PET) is widely used to evaluate tumor metabolic activity. The aim of this study was to evaluate the usefulness of FDG-PET in assessing the histopathological response to preoperative concurrent chemoradiotherapy (CRT) in patients with oral squamous cell carcinoma (OSCC).
  
  
  METHODS
  Forty-five patients with resectable advanced OSCC who had received preoperative CRT followed by tumor ablative surgery between January 2004 and December 2011 were included in the study. All patients underwent FDG-PET before and after preoperative CRT. The maximum standardized uptake value (SUVmax) before (pre-SUV) and after preoperative CRT (post-SUV) and the SUVmax reduction rate (ΔSUV %) were used to evaluate the response to preoperative CRT. Correlations among SUVmax, histopathological response, and expression of cancer antigen Ki-67 and hypoxia-inducible factor-1α (HIF-1α) were analyzed.
  
  
  RESULTS
  Preoperative CRT significantly reduced intratumoral FDG uptake (P < 0.001). The pre-SUV and post-SUV were significantly lower in patients with a pathological complete response (pCR) than in those with a non-pCR (pre-SUV P = 0.037; post-SUV P = 0.001). ΔSUV % was higher in patients with pCR than in those with non-pCR (P = 0.029). The pre-SUV was significantly correlated with Ki-67 and HIF-1α expression in pretreatment biopsy specimens (Ki-67 P = 0.046, R = 0.292; HIF-1α P = 0.007, R = 0.385). The expression of both Ki-67 and HIF-1α was significantly lower in patients with pCR than in those with non-pCR (Ki-67 P < 0.001; HIF-1α P < 0.001).
  
  
  CONCLUSIONS
  Low pre-SUV and post-SUV and high ΔSUV % may predict a good histopathological response to preoperative CRT. Ki-67 and HIF-1α expression in pretreatment biopsy specimens were predictors of histopathological response to preoperative CRT.
authors.affiliation: Department of Oral and Maxillofacial Surgery, Nara Medical University, 804 Shijo-cho, Kashihara, Nara, 634-8522, Japan, hiroz@naramed-u.ac.jp.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Shimomura
authors.forename: Tomonori
authors.initials: T
authors.lastname: Sasahira
authors.forename: Yasutsugu
authors.initials: Y
authors.lastname: Yamanaka
authors.forename: Miyako
authors.initials: M
authors.lastname: Kurihara
authors.forename: Yuichiro
authors.initials: Y
authors.lastname: Imai
authors.forename: Shigehiro
authors.initials: S
authors.lastname: Tamaki
authors.forename: Nobuhiro
authors.initials: N
authors.lastname: Yamakawa
authors.forename: Norihisa
authors.initials: N
authors.lastname: Shirone
authors.forename: Masatoshi
authors.initials: M
authors.lastname: Hasegawa
authors.forename: Hiroki
authors.initials: H
authors.lastname: Kuniyasu
authors.forename: Tadaaki
authors.initials: T
authors.lastname: Kirita
mesh_terms: D000328:Adult; D000368:Aged; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D016190:Carboplatin / Q000008:administration & dosage; D002294:Carcinoma, Squamous Cell / Q000000981:diagnostic imaging* / Q000473:pathology / Q000628:therapy*; D059186:Chemoradiotherapy, Adjuvant; D019583:Dose Fractionation, Radiation; D005260:Female; D019788:Fluorodeoxyglucose F18; D005472:Fluorouracil / Q000008:administration & dosage; D006801:Humans; D051795:Hypoxia-Inducible Factor 1, alpha Subunit / Q000032:analysis; D019394:Ki-67 Antigen / Q000032:analysis; D008297:Male; D008875:Middle Aged; D009062:Mouth Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology / Q000628:therapy*; D020360:Neoadjuvant Therapy; D049268:Positron-Emission Tomography; D011300:Preoperative Care; D019275:Radiopharmaceuticals
chemical_list: C497442:HIF1A protein, human; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D019394:Ki-67 Antigen; D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18; D016190:Carboplatin; D005472:Fluorouracil