In vivo proton MR spectroscopy of pancreatic neuroendocrine tumors in a multiple endocrine neoplasia type 1 conditional knockout mouse model

Purpose MR spectroscopy (MRS) can improve diagnosis and follow treatment in cancer. However, no study has yet reported application of in vivo ¹H-MRS in malignant pancreatic lesions. This study quantitatively determined whether in vivo ¹H-MRS on multiple endocrine neoplasia type 1 (Men1) conditional knockout (KO) mice and their wild type (WT) littermates could detect differences in total choline (tCho) levels between tumor and control pancreas. Methods Relative tCho levels in pancreatic tumors or pancreata from KO and WT mice were determined using in vivo ¹H-MRS at 9.4 T. The levels of Cho-containing compounds were also quantified using in vitro ¹H-NMR on extracts of pancreatic tissues from KO and WT mice, respectively, and on extracts of pancreatic tissues from patients with pancreatic neuroendocrine tumors (PNETs). Results tCho levels measured by in vivo ¹H-MRS were significantly higher in PNETs from KO mice compared to the normal pancreas from WT mice. The elevated choline-containing compounds were also identified in pancreatic tumors from KO mice and tissues from patients with PNETs via in vitro ¹H-NMR. Conclusion These results indicate the potential use of tCho levels estimated via in vivo ¹H-MRS in differentiating malignant pancreatic tumors from benign tumors. Magn Reson Med 74:1221-1226, 2015.