The value of endoscopic ultrasonography in a PET/CT upfront model in staging esophageal cancer with respect to treatment decision

25 Background: The optimal sequence of endoscopic ultrasonography (EUS) and positron emission tomography with computed tomography (PET/CT) in esophageal cancer (EC) is a matter of debate. The use of EUS with fine needle aspiration (FNA) after PET/CT seems to increase the efficacy of curative intended neoadjuvant or definitive chemoradiotherapy. Retrospectively, we assessed the impact of EUS in the PET/CT upfront model on the treatment decision making in EC patients. Methods: In the period 2009 to 2015, 298 EC patients were staged with hybrid PET/CT or PET with CT, and EUS if applicable, in a non-specific order to assess curability (T1-4a,N0-3M0). We determined the feasibility of EUS and whether the initial or additional EUS changed the primary decision suspicious incurable (T4b and M+) into curable disease or added extra nodal information leading to up/downstaging or exhibit suspected nodes at different lymph node stations. In addition, we assessed if EUS changed the radiation area (i.e. lymph nodes > 3.5 cm from the defined radiation target volumes) in the PET/CT “upfront model”. Results: EUS was complete in 185 (62.1%) and incomplete due to stricture from a relative obstructing tumor in 59 (19.8%) patients. Fifty-four patients (18.1%) did not receive EUS because of stenosis (n = 46; 15.4%), patient dependent reasons (n = 4; 1.3%) or other reasons (n = 4; 1.3%). EUS after hybrid PET/CT or PET with CT (n = 244) gave additional information in 166 patients (68.0%); it changed the curability in 4 (1.6%), lead to nodal up and downstaging in respectively, 81 (33.2%) and 27 (11.1%) patients, changed the number of or lymph node station of suspected lymph nodes in an additional 58 patients (n = 23.8%), and FNA gave additional information in 34 (13.9%) patients. EUS after PET/CT ”upfront” changed the treatment plan in 90 patients (36.9%), including alteration in the radiation field (86; 35.2%) and curability (4; 1.6%). Conclusions: EUS gave additional information after PET/CT “up front” and altered the radiation field in about one third of the EC patients, suggesting a better yield of “EUS on indication” after PET/CT upfront.