Abstract
[Objectives] About half the number of pancreatic endocrine tumors is malignant, but preoperative diagnosis of malignancy is difficult and thus we have been performing operations according to those for cancer. The purpose of this study is to examine whether the use of FDG-PET for pancreatic endocrine tumors can offer preoperative information about malignancy of the tumor. [Subjects and methods] A total of seven patients who underwent surgical resection for non-functioning pancreatic endocrine tumor at our Cancer Center from April 2006 to March 2009 were enrolled. Pattern of FDG-PET and malignancy of the tumor were studied. [Results] Abnormal uptake of FDG was demonstrated in three out of three patients with well differentiated endocrine tumor and in two out of four patients with well differentiated endocrine cancer. A study of correlations between the tumors and the maximum SUV disclosed that the median SUV max was 27.46 for well differentiated endocrine tumors, versus 3.57 for well differentiated endocrine cancers. As for correlation between the tumor diameter and the SUV max, the median SUV max was 2.02 in three patients with the tumor less than 20mm in diameter, versus 22.65 in four patients with the tumor more than 20mm in diameter. [Conclusion] Abnormal uptake of FDG might strongly relate to the tumor diameter compared to the malignancy of it. It is concluded that we could not identify the usefulness of FDG-PET in evaluating the malignancy of pancreatic endocrine tumors.
