Application of repeated enhanced 4DCT to detect the changes of heart volume during concurrent chemoradiotherapy for esophageal cancer / 中华放射肿瘤学杂志

ABSTRACT

Objective To detect the changes of heart volume during concurrent chemoradiotherapy for esophageal cancer based on repeated enhanced 4DCT.Methods Patients with squamous cell esophageal cancer underwent repeated enhanced 4DCT and 3DCT scans before and after 10,20 and 30 fractions of radiotherapy,respectively.The heart was contoured on 3DCT,end expiratory (EE) and maximum intensity projection (MIP) of 4DCTimages.The changes in theheart volume,blood pressure.and heart rate were statistically compared at different time points.Results A total of forty-six patients completed 4 fractions of 3DCT and enhanced 4DCT scans.Compared with the initial values,the heart volume was significantly decreased by 3.27％,4.45％ and 4.52％ after 10 fractions of radiotherapy,and reduced by 6.05％,5.64％ and 4.51％ following 20 fractions of radiotherapy on 3DCT,EE and MIP,respectively (P=0.000-0.027).The heart volume after 30 fractions of radiotherapy did not significantly differ from the initial volume (P＞ 0.05).After radiotherapy,there was a significant decrease inboth systolic and diastolic blood pressure (P =0.000 and P =0.009) and a significant ‖ increase in the heart rate (P=0.0 0 1) compared with those measured before radiotherapy.Conclusions Enhanced 4DCT scan can clearly reflect the changes of heart volume throughout concurrent chemoradiotherapy.The heart volume starts to shrink during the early stage of radiotherapy and continue to decrease until the middleand late-stage,whereas it restores to the initial volume after radiotherapy.Simultaneously,blood pressure declines and heart rate is accelerated during radiotherapy.