Predicting Pathologic Response of Esophageal Cancer to Neoadjuvant Chemotherapy: The Implications of Metabolic Nodal Response for Personalized Therapy

• DOI: 10.2967/jnumed.116.176313
• Publication Date: 2016-09-16T02:54:11Z
• Authors: John M. Findlay; Kevin M. Bradley; Lai Mun Wang; James M. Franklin; Eugene J. Teoh; Fergus V. Gleeson; Nicholas D. Maynard; Richard S. Gillies; Mark R. Middleton
• Keywords: Avidity; Standardized uptake value; Neoadjuvant Therapy

Only a minority of esophageal cancers demonstrates pathologic tumor response (pTR) to neoadjuvant chemotherapy (NAC). ¹⁸F-FDG PET/CT is often used for restaging after NAC and assess response. Increasingly, it during therapy identify unresponsive tumors predict pTR, using avidity the primary alone. However, definitions such metabolic (mTR) vary. We aimed comprehensively reevaluate assessment accepted parameters, as well novel concepts nodal stage (mN) (mNR). <b>Methods:</b> This was single-center retrospective U.K. cohort study. All patients with cancer staged before CT or undergoing resection from 2006 2014 were identified. pTR defined Mandard regression grade 1–3; imaging parameters included metrics (SUV_{max/mean/peak}), composites volume (including volume), SUV_max, our new mN mNR. <b>Results:</b> Eighty-two (27.2%) 301 demonstrated pTR. No pre-NAC PET predicted In 220 restaged by PET/CT, optimal ΔSUV_max threshold 77.8% reduction. sensitive current PERCIST 30% reduction, but more specific higher negative predictive value (<i>P</i> &lt; 0.001). Δlength independently composite avidity/spatial outperformed Although both mTR mNR associated in 82 ¹⁸F-FDG–avid nodes we observed 10 (12.2%) not demonstrating mTR. <b>Conclusion:</b> Current are suboptimal too simplistic. Composite avidity/volume measures improve prediction. may further assessment, specifically assessing metastatic subpopulations, likely responsible disease relapse, should be urgently assessed when considering aborting on basis