Impact of endoscopic ultrasonography with fine needle aspiration assessing clinical lymph node staging on radiotherapy treatment planning in esophageal cancer patients

Endoscopic ultrasound (EUS) combined with fine needle aspiration (FNA) can be of additional value to fluorine-18 labeled fluorodeoxyglucose positron emission tomography computed tomography (18FDG-PET-CT) for lymph node staging in esophageal cancer patients. The study objective was to evaluate the impact of routine EUS-FNA after 18FDG-PET-CT staging on radiotherapy planning. Patients with biopsy-proven esophageal carcinoma staged ≥cT2 and eligible for treatment with curative intent, including neoadjuvant chemoradiotherapy (nCRT) or definitive chemoradiotherapy (dCRT), were included. After March 2018, patients who were scheduled for dCRT or ASA 3 were excluded from routine EUS-FNA. The primary outcome was the impact of EUS-FNA after 18FDG-PET-CT on radiotherapy target volume delineation. Subsequently, radiotherapy field modifications were compared with surgical pathology when available. Between 2018 and 2023, 179 patients were included. In 61 patients (34%), the EUS scope was unable to pass through the tumor, limiting lymph node assessment. EUS-FNA altered radiotherapy treatment plans in 24 patients (13%), resulting in a number needed to treat of 7.5. Modifications included expansion of the radiation field in 17 cases, reduction in 6 cases, and both in 1 case. Among surgically resected patients, 10 lymph node stations were added to the radiation field based on EUS-FUNA results. Of these, 7 stations (70%) showed no positive or responsive lymph nodes in the resection specimen, while 3 stations (30%) had 2 positive nodes, and 1 with a complete response to nCRT. Four lymph node stations were with no positive nodes found in the resection specimen. Two patients were readmitted post-procedure, including one fatal case of mediastinitis potentially linked to EUS-FNA. Routine EUS-FNA after18FDG-PET-CT altered radiotherapy plans in only 13% of patients, with limited and uncertain impact on clinical outcomes, especially for those undergoing planned neoadjuvant therapy and surgery. These findings suggest that EUS-FNA may be best avoided in routine practice for such patients.