title: Changes in (18)F-fluorothymidine and (18)F-fluorodeoxyglucose positron emission tomography imaging in patients with head and neck cancer treated with chemoradiotherapy.
abstract: OBJECTIVE
  This study compared change of (18)F-fluorothymidine (FLT) uptake with that of (18)F-fluorodeoxyglucose (FDG) in head and neck squamous cell cancer (HNSCC) patients during and after treatment and evaluated the utility for early monitoring of response to chemoradiotherapy.
  
  
  METHODS
  Thirty patients with newly diagnosed HNSCCs treated with concurrent chemoradiotherapy underwent FLT and FDG PET in pre-treatment (PET1), mid-treatment (PET2) and post-treatment (PET3) stages. The PET images were evaluated quantitatively using maximum standardized uptake values (SUVs). Ratios between SUVs at PET2 and PET3 were also calculated.
  
  
  RESULTS
  According to the SUVs, no significant differences were found with primary site location, cellular differentiation and T category in all PET scans. About a 78 % median decrease in FLT SUV was observed at the total dose (TD) of 30 Gy and no apparent change was observed thereafter. About a 40 % decrease in FDG SUV was observed at TD 30 Gy and significant decreases were then found at the 4- and 6-week time points after the therapy. FLT PET demonstrated no recurrence regions in patients with a PET3/PET2 ratio of <1.5. In comparison, FLT SUVs in PET3 with recurrence were increased more than three times. However, no significant difference was found between the values with recurrence and those with no recurrence in FDG PET.
  
  
  CONCLUSIONS
  FLT PET signal change preceded FDG PET change and the increase of FLT uptake after the therapy can imply recurrence or a residual tumor. FLT PET seems promising for early evaluation of chemoradiation effects in HNSCCs.
authors: Department of Otolaryngology, Faculty of Medicine, Kagawa University, 1750-1, Ikenobe, Miki-cho, Kita-gun, Kagawa, 761-0793, Japan. hiro@kms.ac.jp
authors: Hiroshi
authors: H
authors: Hoshikawa
authors: Terushige
authors: T
authors: Mori
authors: Takehito
authors: T
authors: Kishino
authors: Yuka
authors: Y
authors: Yamamoto
authors: Ryuhei
authors: R
authors: Inamoto
authors: Kosuke
authors: K
authors: Akiyama
authors: Nozomu
authors: N
authors: Mori
authors: Yoshihiro
authors: Y
authors: Nishiyama
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D059248:Chemoradiotherapy; D015224:Dideoxynucleosides; D005260:Female; D019788:Fluorodeoxyglucose F18; D006258:Head and Neck Neoplasms / Q000000981:diagnostic imaging* / Q000628:therapy*; D006801:Humans; D008297:Male; D008875:Middle Aged; D049268:Positron-Emission Tomography / Q000379:methods*; D019275:Radiopharmaceuticals; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D016896:Treatment Outcome
chemical_list: D015224:Dideoxynucleosides; D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18; C002854:alovudine