PT - JOURNAL ARTICLE AU - Vinod Malik AU - Julie A. Lucey AU - George J. Duffy AU - Lorraine Wilson AU - Leanne McNamara AU - Mary Keogan AU - Charles Gillham AU - John V. Reynolds TI - Early Repeated <sup>18</sup>F-FDG PET Scans During Neoadjuvant Chemoradiation Fail to Predict Histopathologic Response or Survival Benefit in Adenocarcinoma of the Esophagus AID - 10.2967/jnumed.110.079566 DP - 2010 Dec 01 TA - Journal of Nuclear Medicine PG - 1863--1869 VI - 51 IP - 12 4099 - http://jnm.snmjournals.org/content/51/12/1863.short 4100 - http://jnm.snmjournals.org/content/51/12/1863.full SO - J Nucl Med2010 Dec 01; 51 AB - This study evaluated the role of 18F-FDG PET as an early predictor of histopathologic response to neoadjuvant chemoradiotherapy and overall survival in patients with adenocarcinoma of the esophagus undergoing multimodal therapy. Methods: Thirty-seven patients with locally advanced adenocarcinoma of the esophagus underwent pretreatment and an intratreatment 18F-FDG PET scan in the second week of a 6-wk regimen of neoadjuvant chemoradiotherapy. Histopathologic response and overall survival were correlated with percentage change in 18F-FDG uptake (%Δmaximum standardized uptake value [%ΔSUVmax]). Results: In 16 patients (43%), treatment induced a histopathologic response (&lt;10% viable tumor cells), which was associated with a significant (P &lt; 0.05) survival benefit. The optimal reduction in 18F-FDG uptake, which separated histopathologic responders and nonresponders, was a −26.4% ΔSUVmax (receiver-operating-characteristic curve analysis). At this separation, sensitivity, specificity, positive predictive value, negative predictive value, and accuracy (area under the receiver operating characteristic curve) were 62.5%, 71.4%, 62.5%, 71.4%, and 67.4%, respectively, for intratreatment 18F-FDG PET scans. Kaplan–Meier survival analysis of 18F-FDG PET responders (&gt;26.4% reduction in SUVmax), compared with 18F-FDG PET nonresponders (&lt;26.4% reduction in SUVmax), revealed no survival benefit for responders (P = 0.6812). Conclusion: The %ΔSUVmax during the second week of induction chemoradiation did not correlate either with histopathologic response or with survival. Our results show that, in contrast to published reports on neoadjuvant chemotherapy, combined chemoradiotherapy in patients with adenocarcinoma of the esophagus lowers the predictive accuracy of early repeated 18F-FDG PET in identifying histopathologic responders and those with chances for increased survival below clinically applicable levels.