title: (18)F-fluorodeoxyglucose positron emission tomography to assess response after radiation therapy in anaplastic thyroid cancer.
abstract: OBJECTIVE
  To assess the interest of (18)F-fluorodeoxyglucose positron emission tomography ((18)F-FDG PET/CT) to evaluate the tumor response after radiotherapy (RT) in anaplastic thyroid cancer (ATC) patients.
  
  
  METHODS
  92 patients were treated for ATC at our institution from 1987 to 2012, out of which 64 (70%) received an aggressive multimodal treatment and 28 (30%) a palliative treatment. In the multimodal treatment group, curative-intended surgery, chemotherapy, and RT were delivered in 35 (55%), 59 (92%), and 56 (88%) patients. The maximum standardized uptake value (SUVmax) was determined in tumor (T), nodes (N) and metastases (M) in each available (18)F-FDG PET/CT.
  
  
  RESULTS
  The median follow-up was 3.2years. The 1-year actuarial overall survival (OS) was 18% (median: 5.2months) in the entire population and 27% (median: 7months) in the multimodal treatment group. In the multivariate analysis, RT, surgery, and pre-RT chemotherapy independently predicted for OS, with HRs respectively of 0.1, 0.3, and 0.5. Quantification of FDG uptake with SUVmax was assessable in 26 (40%), 19 (30%), and 25 (39%) of (18)F-FDG PET/CT performed initially (prior to any treatment), prior to RT, and after RT, respectively. Mean SUVmax significantly decreased in T (p<0.001), but not in N (p=0.1) and M (p=0.3) during the assessment period, which might be related to the local effect of RT. Comparing pre- and post-RT (18)F-FDG PET/CT, the T mean relative SUVmax decrease was lower (23±54%) in the 4 patients that had a local relapse (LR) as compared with others in the 12 others patients (62±33%; p=0.3). A relative SUVmax decrease inferior to 20% significantly predicted for LR (p=0.02).
  
  
  CONCLUSIONS
  The prognosis of ATC patients remains dismal despite an aggressive multimodal treatment. Although our results were not significant, (18)F-FDG PET/CT could potentially serve as a surrogate marker of treatment response in ATC.
authors.affiliation: Department of Radiation Oncology, Gustave Roussy, Paris Sud University, Villejuif, France; Univ Paris-Sud, Faculté de Médecine, Kremlin Bicêtre 94270, France.
authors.forename: Antonin
authors.initials: A
authors.lastname: Levy
authors.affiliation: Department of Nuclear Medicine and Endocrine Oncology, Gustave Roussy, Paris Sud University, Villejuif, France.
authors.forename: Sophie
authors.initials: S
authors.lastname: Leboulleux
authors.affiliation: Department of Nuclear Medicine and Endocrine Oncology, Gustave Roussy, Paris Sud University, Villejuif, France.
authors.forename: Charlotte
authors.initials: C
authors.lastname: Lepoutre-Lussey
authors.affiliation: Department of Nuclear Medicine and Endocrine Oncology, Gustave Roussy, Paris Sud University, Villejuif, France.
authors.forename: Eric
authors.initials: E
authors.lastname: Baudin
authors.affiliation: Department of Pathology, Gustave Roussy, Paris Sud University, Villejuif, France.
authors.forename: Abir Al
authors.initials: AA
authors.lastname: Ghuzlan
authors.affiliation: Department of Surgery, Gustave Roussy, Paris Sud University, Villejuif, France.
authors.forename: Dana
authors.initials: D
authors.lastname: Hartl
authors.affiliation: Department of Radiation Oncology, Gustave Roussy, Paris Sud University, Villejuif, France; Univ Paris-Sud, Faculté de Médecine, Kremlin Bicêtre 94270, France.
authors.forename: Eric
authors.initials: E
authors.lastname: Deutsch
authors.affiliation: Department of Nuclear Medicine and Endocrine Oncology, Gustave Roussy, Paris Sud University, Villejuif, France.
authors.forename: Désirée
authors.initials: D
authors.lastname: Deandreis
authors.affiliation: Department of Nuclear Medicine and Endocrine Oncology, Gustave Roussy, Paris Sud University, Villejuif, France.
authors.forename: Jean
authors.initials: J
authors.lastname: Lumbroso
authors.affiliation: Department of Radiation Oncology, Gustave Roussy, Paris Sud University, Villejuif, France.
authors.forename: Yungan
authors.initials: Y
authors.lastname: Tao
authors.affiliation: Department of Nuclear Medicine and Endocrine Oncology, Gustave Roussy, Paris Sud University, Villejuif, France; Univ Paris-Sud, Faculté de Médecine, Kremlin Bicêtre 94270, France.
authors.forename: Martin
authors.initials: M
authors.lastname: Schlumberger
authors.affiliation: Department of Radiation Oncology, Gustave Roussy, Paris Sud University, Villejuif, France; Univ Paris-Sud, Faculté de Médecine, Kremlin Bicêtre 94270, France. Electronic address: pierre.blanchard@gustaveroussy.fr.
authors.forename: Pierre
authors.initials: P
authors.lastname: Blanchard
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D019788:Fluorodeoxyglucose F18 / Q000008:administration & dosage*; D006801:Humans; D008297:Male; D008875:Middle Aged; D049268:Positron-Emission Tomography / Q000379:methods*; D065646:Thyroid Carcinoma, Anaplastic / Q000532:radiotherapy*; D013964:Thyroid Neoplasms / Q000532:radiotherapy*; D016896:Treatment Outcome
chemical_list: D019788:Fluorodeoxyglucose F18
keywords: (18)F-fluorodeoxyglucose positron emission tomography; Anaplastic thyroid cancer; Radiotherapy