Effectiveness Of Esophageal Gastric Junction Tumor Motion With And Without A Pneumatic Abdominal Compression In Precise IGRT Era

Abstract

To investigate the effect of a pneumatic abdominal compression belt (PACB) on suppressing the movement of primary lesions in the esophageal gastric junction (EGJ). Ten patients with EGJ adenocarcinoma were treated with preoperative concurrent chemoradiotherapy. Titanium clips A and B were placed on the upper and lower edges of the gross tumor with a gastroscope, respectively. Forty sets of images of the two titanium clips located in the EGJ were obtained by 4DCT in 10 patients in the supine position with and without a PACB. Of the 10 patients, 5 were treated with a PACB, and the other 5 were not. All patients received CBCT for the first 5 fractions and the 7th, 12th, 17th and 22nd fractions before treatment, and 90 sets of images were obtained for analysis. Paired t-tests and independent t-tests were used to test for differences. With and without a PACB, in the cranio-caudal (CC) direction, the internal motion of clip A was 0.0 ± 0.1 cm and 0.1 ± 0.1 cm (P = 0.001), respectively. With and without PACB, in the left-right (LR), anterior-posterior (AP) and cranio-caudal (CC) directions, the internal motion of clip B was (0.1 ± 0.1), (0.1 ± 0.1), and (0.1 ± 0.1) cm and (0.2 ± 0.1), (0.2 ± 0.1), and (0.5 ± 0.3) cm (P = 0.000, 0.000 and 0.000), respectively. The inter-fraction motion of clip B in the LR, AP and CC directions was (0.2 ± 0.2), (0.2 ± 0.2), and (0.2 ± 0.2) cm and (0.7 ± 0.8), (0.7 ± 0.7), and (0.5 ± 0.4) cm (P = 0.002, 0.002 and 0.005) with or without a PACB, respectively. To ensure that 90% of the tumor volume receives 95% of the prescription dose, 0.9, 0.9 and 0.9 cm ITV margins in the LR, AP and CC directions are suggested for EGJ lesions with PACB to better cover the tumor intra- and inter-fraction movements. A pneumatic abdominal compression belt can reduce the intra- and inter-fraction movements of EGJ tumors during preoperative radiotherapy.