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

Abstract

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.

A national cross-sectional survey investigating the use of endoscopic ultrasound in the diagnosis and treatment of oesophageal cancer in the UK

“…It is generally accepted that the most appropriate order of investigations is PET-CT followed by EUS to assist treatment planning. 20 Despite this, a broadly equal proportion of centres request EUS regardless of PET-CT than proceed to EUS in light of PET-CT findings.…”

“…For most, EUS appeared to be used when there was uncertainty in nodal involvement or concerns about avidity on PET-CT. Less than a third used EUS for determining GTV despite reported differences compared to PET-CT when determining length of disease, with EUS previously recognised to change GTV in up to 29% of patients receiving radiotherapy. 20 Differences between modalities when measuring length of disease are considered attributable to a combination of submucosal disease not demonstrated on PET-CT, poor FDG-uptake in small but involved lymph nodes and anatomical differences in measurement between endoscopic and cross-sectional methods. 9,17 It is likely that individual clinician uncertainty regarding influence of EUS on overall patient outcomes, coupled with differences in sitespecific expertise, has contributed to this variation.…”