title: PET/CT with 3'-deoxy-3'-[18F]fluorothymidine for lung cancer patients receiving carbon-ion radiotherapy.
abstract: OBJECTIVE
  The aim of this study was to investigate the clinical value of 3'-deoxy-3'-[F]fluorothymidine-positron emission tomography/computed tomography (FLT-PET/CT) for lung cancer patients receiving carbon-ion radiotherapy.
  
  
  METHODS
  Twenty consecutive patients with lung cancer underwent FLT-PET/CT before and after carbon-ion radiotherapy. Fifty minutes after intravenous injection of approximately 300 MBq of FLT, PET/CT data were acquired. Maximal standardized uptake value of the tumor was measured, from which the reduction rate of tumor FLT uptake was calculated. After treatment, the patients were followed (17-42 months for survivors) for the development of recurrence and survival.
  
  
  RESULTS
  Primary responses to carbon-ion radiotherapy were partial in 13 patients, stable disease in six patients, and nonevaluable in one patient. Although tumor FLT uptake significantly decreased after treatment (P < 0.001), the presence of radiation pneumonitis hampered its precise evaluation. During the follow-up period, nine patients developed recurrence, and seven patients died including two deaths from other causes. Pretreatment FLT uptake of patients who developed recurrence and who died of lung cancer were significantly higher than that of patients who did not (P = 0.008 and 0.007, respectively). Kaplan-Meier analysis using a cut-off value also supported the prognostic value of pre-carbon-ion radiotherapy FLT-PET/CT.
  
  
  CONCLUSIONS
  This investigation suggests that FLT-PET/CT is feasible in evaluating lung cancer patients undergoing carbon-ion radiotherapy. The presence of radiation pneumonitis can influence tumor FLT uptake and needs special attention. Pre-carbon-ion radiotherapy FLT-PET/CT seems to have a prognostic value and may contribute to decision-making on the treatment strategy.
authors.affiliation: Diagnostic Imaging Group bMolecular Probe Group, Molecular Imaging Center, National Institute of Radiological Sciences, Chiba, Japan.
authors.forename: Tsuneo
authors.initials: T
authors.lastname: Saga
authors.forename: Mitsuru
authors.initials: M
authors.lastname: Koizumi
authors.forename: Masayuki
authors.initials: M
authors.lastname: Inubushi
authors.forename: Kyosan
authors.initials: K
authors.lastname: Yoshikawa
authors.forename: Katsuyuki
authors.initials: K
authors.lastname: Tanimoto
authors.forename: Toshimitsu
authors.initials: T
authors.lastname: Fukumura
authors.forename: Tadaaki
authors.initials: T
authors.lastname: Miyamoto
authors.forename: Mio
authors.initials: M
authors.lastname: Nakajima
authors.forename: Naoyoshi
authors.initials: N
authors.lastname: Yamamoto
authors.forename: Masayuki
authors.initials: M
authors.lastname: Baba
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002244:Carbon / Q000627:therapeutic use*; D015224:Dideoxynucleosides; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D053208:Kaplan-Meier Estimate; D008175:Lung Neoplasms / Q000000981:diagnostic imaging* / Q000532:radiotherapy*; D008297:Male; D008875:Middle Aged; D049268:Positron-Emission Tomography / Q000379:methods*; D019275:Radiopharmaceuticals / Q000627:therapeutic use
chemical_list: D015224:Dideoxynucleosides; D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18; D002244:Carbon; C002854:alovudine