Fig. 3.

Representative cases of PanNET patients. (a) Preoperative AP CT images of a 64-year-old woman show a 1.8-cm homogeneously enhancing mass at the head of the pancreas (arrows). Regional lymph node metastasis is noted (arrowhead). This tumor was a WHO grade 2 PanNET with AJCC stage III. Although the initial tumor stage was high, the patient survived without recurrence until the last follow-up date (85.7 months after surgery). The R-score of this tumor was − 1.888. (b) Preoperative AP and PVP CT images of a 67-year-old man show a 1.9-cm mass at the tail of the pancreas. The mass shows heterogeneous enhancement, especially on AP images (arrows). This tumor was a WHO grade 2 PanNET with AJCC stage I. Despite the low AJCC stage, recurrence occurred at 4.7 months after surgery. The R-score of this tumor was 0.450, obviously higher than that of the patient in (a). AJCC, American Joint Committee on Cancer staging system; AP, arterial phase; OS, overall survival; PanNET, pancreatic neuroendocrine tumor; PVP, portal venous phase; RFS, recurrence-free survival; R-score, radiomics score; WHO, World Health Organization