Endoscopic ultrasonography for defining primary tumor in esophageal radiotherapy / 中华消化内镜杂志

ABSTRACT

Objective To investigate the differences of measurement of gross target volume (GTV)between endoscopic ultrasonography ( EUS )-based ( GTVEUS ) and computed tomography ( CT ) -based (GTVCT) method for thoracic esophageal squamous cell carcinoma. Methods EUS was performed on 36consecutive patients with thoracic squamous cell carcinoma, and the superior and inferior boarders of the tumor defined by EUS were marked with hemoclips. The CT planning scan was then performed with the patient in supine position, and the GTVCT and GTVEUS were contoured respectively. The lengths ( LCT and LEUS) and spatial locations of longitudinal GTVCT and GTVEUS were compared. Results The mean LCT and LEUS were (7. 79 ± 3. 15 ) cm and (7. 42 ± 2. 72) cm, respectively ( t = 0. 82, P ＞ 0. 05 ), with a correlation coefficient of 0. 61 (P ＜0. 001 ). Locations of longitudinal GTVCT and GTVEUS were compared in 34cases, with 2 excluded for invisualization on CT. The mean conformal index (CI) was (0. 79 ± 0. 18 ), and spatial variations were found in 71% patients, with 8 patients at proximal end and 21 others at distal end.There was no clip placement associated complication. Conclusion Endoscopic hemoclips placement is safe and reliable. EUS can provide additional information to CT in defining longitudinal GTV in thoracic esophageal squamous cell carcinoma, especially in superficial and submucosal carcinomas.