Tumor vascularity at contrast-enhanced ultrasound (CEUS) of resectable ductal adenocarcinoma of the pancreas

Purpose: To evaluate the vascular patterns of resectable ductal adenocarcinoma of the pancreas at contrast-enhanced ultrasound (CEUS).

Materials and methods: CEUS of 42 resected ductal adenocarcinomas of the pancreas were retrospectly reviewed. All the lesions were studied with CEUS by using iv bolus injection of sulfur hexafluoride in the form of microbubbles (SonoVueBracco,Italy). The lesion enhancement was scored in comparison to the normal parenchyma and to the precontrastographic aspect of the lesion as: 1=poorly vascularized (more than 50% avascular) or 2=well vascularized (less than 50% avascular). All the lesions underwent pathological examination assesing tumor differentiation as: 1=undifferenziated (poorly differentiated) or 2=differentiated (moderately and well differentiated). The results of CEUS enhancement and pathology were compared by using Spearman's correlation test.

Results: All lesions were single. Diameter ranged between 1.2cm to 4.3cm (Mean=2.68cm; SD=0.66). There were 30 differentiated and 12 undifferentiated adenocarcinoma at pathology. CEUS revealed poor vascularization in 9 tumors. While 33 adenocarcinomas resulted well vascularized at CEUS.Moderate correlation was found between vascular pattern at CEUS and tumor differentiation (rs=0.70; p<0.0001). At CEUS 29/30 (97%) differentiated adenocarcinoma were well vascularized while 8/12 (67%) undifferentiated adenocarcinoma were poorly vascularized.

Conclusions: Correlation between vascular pattern of ductal adenocarcinoma at CEUS and tumor differentiation is not always present. Differentiated ductal adenocarcinoma of the pancreas is very often well vascularized at CEUS. Undifferentiated ductal adenocarcinoma of the pancreas is often poorly vascularized at CEUS.