Case report: Pancreatic metastasis from small-cell lung cancer appears as primary G2 pancreatic neuroendocrine tumor on combined contrast PET imaging with three probes - Zhang, Huimin; Gao, Jie; Cong, Xiaofeng; Chen, Chen; Yin, Jiaxin; Xiong, Wenji; Liu, Ziling (Frontiers in Oncology, 2024)