Comparison study of CT findings at different phases among pediatric hepatoblastoma patients based on PRETEXT system

Abstract

Objective To compare the CT findings of different phases in pediatric hepatoblastoma (HB) based on PRETEXT system in order to optimize pediatric HB CT scan protocol. Methods A total of 58 HB patients who were surgical and pathological diagnosed from January 2015 to December 2016 were analyzed. Pre-operation CT exams were analyzed respectively. Observing items included tumor size, intra-abdominal invasion, bleeding, intrahepatic metastasis, lymphatic metastasis, metastasis (except lymphatic in abdomen) main portal vein, three main hepatic vein, inferior vena cava (IVC) invasion, para-tumor hepatic arteries, and its branches. All image findings were compared to pathological and surgical findings to calculate the agreement rate. Exact Fisher test and R×C χ2 test were used. Results According to the surgery and pathological results, the agreement rate of tumor size was n=40 (68.9%) at non-contrast phase, n=43 (74.1%) at artery phase and n=52 (91.2%) at venous phase. Venous phase was adaptive for observing tumor size (χ2=8.16, P=0.018). For main portal vein, three main hepatic vein, and IVC invasion, none was found at both non-contrast and artery phase. N=12 (20.7%, P<0.001) was found at venous phase. For para-tumor hepatic arteries, and its branches, none was found at non-contrast phase. N=46 (79.3%) was found at artery phase. N=17 (29.3%) was found at venous phase. Artery phase was adaptive for observing (P<0.001). There was no statistical significant difference in intrahepatic metastasis, lymphatic metastasis and metastasis. Conclusions Suspected pediatric HB, artery and venous phase CT scan would meet the clinical requirement, there was no need for non-contrast pahse. Follow up cases, a single venous phase was enough. Venous phase contributed much more information on tumor size and high risk prognosis evaluation. Key words: Child; Liver neoplsams; Tomography, X-ray computed; Radiation dosage