Prediction of non-functioning pancreatic neuroendocrine tumor grades with fractal analysis of preoperative contrast-enhanced computed tomography images

• Published in: European journal of radiology 2021-08, Vol.141, p.109803-109803, Article 109803
• Main Authors: Nakano, Akira, Hayano, Koichi, Tochigi, Toru, Mashiko, Taro, Masuoka, Yoshihito, Yamamoto, Seiichiro, Ozawa, Soji, Nakagohri, Toshio
• Format: Article
• Language: English
• Subjects: Contrast-enhanced -computed tomography; Fractal analysis; Intratumoral heterogeneity; Ki-67 labeling index; Non-functioning tumor; Pancreatic neuroendocrine tumor
• ISSN: 0720-048X; 1872-7727
• DOI: 10.1016/j.ejrad.2021.109803

•Intra-tumoral heterogeneity of PNETs could be quantified with fractal analysis.•Fractal analysis of preoperative CE-CT could predict grades of PNETs.•Fractal analysis of CE-CT could help in choosing treatment options for patients. To assess intra-tumoral heterogeneity (ITH) via fractal analysis of preoperative contrast-enhanced computed tomography (CT) images to predict pathological grades in non-functioning pancreatic neuroendocrine tumors (NF-PNETs) and verify its impact on patient survival. This retrospective study enrolled 40 patients with NF-PNET resected in our institution during a period from July 2005 to December 2018, except functioning tumors, unidentified tumors in CT, patients without preoperative contrast-enhanced CT. CT images were analyzed using plugin software for calculating fractal dimension (FD), and the maximum value was denoted as “FDmax,” and compared with pathological grades and patient survival between G1 and G2/3 group separating according to two different Ki-67 index thresholds (3% and 5%). All CT images were acquired in three-phases and arterial phase images were examined. Ki-67 index and FDmax showed a direct correlation with significance (p