TY - JOUR T1 - Usefulness of 3′-Deoxy-3′-<sup>18</sup>F-Fluorothymidine PET for Predicting Early Response to Chemoradiotherapy in Head and Neck Cancer JF - Journal of Nuclear Medicine JO - J Nucl Med SP - 1521 LP - 1527 DO - 10.2967/jnumed.111.099200 VL - 53 IS - 10 AU - Takehito Kishino AU - Hiroshi Hoshikawa AU - Yoshihiro Nishiyama AU - Yuka Yamamoto AU - Nozomu Mori Y1 - 2012/10/01 UR - http://jnm.snmjournals.org/content/53/10/1521.abstract N2 - This study compared the utility of 3′-deoxy-3′-18F-fluorothymidine PET (18F-FLT PET) with that of 18F-FDG PET for assessment of the early locoregional clinical outcomes of chemoradiotherapy for head and neck squamous cell carcinomas. Methods: From May 2006 to September 2010, 28 patients with head and neck squamous cell carcinomas underwent 18F-FLT and 18F-FDG PET before radiation therapy (RT), 4 wk after the initiation of RT, and 5 wk after completion of RT. PET images were evaluated qualitatively for regions of focally increased metabolism and were analyzed in relation to residual accumulation and local disease control. Results: During RT, 18F-FLT uptake decreased more significantly than 18F-FDG uptake. 18F-FLT accumulations disappeared in 34 of 54 lesions (63%), and negative predictive value was 97%. 18F-FDG PET during RT also had a high negative predictive value (100%), but only 9 lesions (16%) showed complete absence of accumulation. The specificity and overall accuracy of 18F-FLT PET were significantly higher than those of 18F-FDG PET both during and after RT. In particular, high significance was attributable to the results of the evaluations of primary lesions. There were significant differences in 3-y local control between the residual-accumulation and no-accumulation groups on both posttreatment 18F-FLT PET (P &lt; 0.0001) and posttreatment 18F-FDG PET (P = 0.0081). Conclusion: 18F-FLT PET during RT and early follow-up facilitates the selection of optimal further therapy and the prediction of outcomes. ER -