Published online Jul 28, 2020. doi: 10.3748/wjg.v26.i28.4151
Peer-review started: April 6, 2020
First decision: April 26, 2020
Revised: May 8, 2020
Accepted: July 15, 2020
Article in press: July 15, 2020
Published online: July 28, 2020
Pancreatic ductal adenocarcinoma (PDA) is a malignancy with a high mortality rate and short survival time. The conventional computed tomography (CT) has been worldwide used as a modality for diagnosis of PDA, as CT enhancement pattern has been thought to be related to tumor angiogenesis and pathologic grade of PDA.
To evaluate the relationship between the pathologic grade of pancreatic ductal adenocarcinoma and the enhancement parameters of contrast-enhanced CT.
In this retrospective study, 42 patients (Age, mean ± SD: 62.43 ± 11.42 years) with PDA who underwent surgery after preoperative CT were selected. Two radiologists evaluated the CT images and calculated the value of attenuation at the aorta in the arterial phase and the pancreatic phase (VAarterial and VApancreatic) and of the tumor (VTarterial and VTpancreatic) by finding out four regions of interest. Ratio between the tumor and the aorta enhancement on the arterial phase and the pancreatic phase (TARarterial and TARpancreatic) was figured out through dividing VTarterial by VAarterial and VTpancreatic by VApancreatic. Tumor-to-aortic enhancement fraction (TAF) was expressed as the ratio of the difference between attenuation of the tumor on arterial and parenchymal images to that between attenuation of the aorta on arterial and pancreatic images. The Kruskal-Wallis analysis of variance and Mann-Whitney U test for statistical analysis were used.
Forty-two PDAs (23 men and 19 women) were divided into three groups: Well-differentiated (n = 13), moderately differentiated (n = 21), and poorly differentiated (n = 8). TAF differed significantly between the three groups (P = 0.034) but TARarterial (P = 0.164) and TARpancreatic (P = 0.339) did not. The median value of TAF for poorly differentiated PDAs (0.1011; 95%CI: 0.01100-0.1796) was significantly higher than that for well-differentiated PDAs (0.1941; 95%CI: 0.1463-0.3194).
Calculation of TAF might be useful in predicting the pathologic grade of PDA.
Core tip: The conventional computed tomography (CT) has been worldwide used as a modality for diagnosis of pancreatic ductal adenocarcinoma (PDA). In this study, the tumor-to-aortic enhancement fraction (TAF) values were statistically different among the well differentiated group, the moderately differentiated group and the poorly differentiated group (P < 0.05). It has been reported that TARarterial and TARpancreatic are related to histological finding of PDA, but in our study. there were no significant differences in TARarterial and TARpancreatic among the three groups. TAF can be obtained with conventional pancreatic CT, without additional radiation exposure and processing time, and this simple method could be useful for predicting prognosis of PDA.