Abstract
A crucial point for the management of pancreatic ductal adenocarcinoma (PDAC) is the decrease of R1 resections. Our aim was to evaluate the combination of multispectral optoacoustic tomography (MSOT) with fluorescence guided surgery (FGS) for diagnosis and perioperative detection of tumour nodules and resection margins in a xenotransplant mouse model of human pancreatic cancer. The peptide cRGD, conjugated with the near infrared fluorescent (NIRF) dye IRDye800CW and with a trans-cyclooctene (TCO) tag for future click chemistry (cRGD-800CW-TCO), was applied to PDAC bearing immunodeficient nude mice. 27 days after orthotopic transplantation of human AsPC-1 cells into the head of the pancreas, mice were injected with cRGD-800CW-TCO and imaged with fluorescence- and optoacoustic devices before and 2h, 6h and 24h after injection, before they were sacrificed and dissected with a guidance of FGS imaging system. Fluorescence imaging of cRGD-800CW-TCO allowed detection of the tumour area but without information about the depth, whereas MSOT allowed high resolution 3D identification of the tumour area, in particular of small tumour nodules. Highly sensitive delineation of tumour burden was achieved during FGS in all mice. Imaging of whole-mouse cryosections, histopathological analysis and NIRF microscopy confirmed the localization of cRGD-800CW-TCO within the tumour tissue. In principle, all imaging modalities applied here were able to detect PDAC in vivo. However, the combination of MSOT and FGS provided detailed spatial information of the signal, and achieved a complete overview of the distribution and localization of cRGD-800CW-TCO within the tumour before and during surgical intervention. This article is protected by copyright. All rights reserved.
