Abstract CT156: Radiologic scoring method to define the therapeutic response and surgical candidacy

Purpose: The purpose of this study is to define the best CT perfusion analytical method for the surgical candidacy of pancreatic cancer patients in Neo-Adjuvant treated clinical trial population. Experimental Design: Study was designed to assess tumor perfusion status. This prospective study involved 24 adult patients with pancreatic adenocarcinoma (PDAC). Inclusion criteria included, patients with histologically or cytologically confirmed resectable, borderline resectable, or locally advanced (unresectable) PDAC. All patients received neoadjuvant therapy (paricalcitol, paclitaxel protein bound, cisplatin and gemcitabine) for up to 6 months Multi-phase CT was performed for most patients on a GE scanner using a standard pancreatic cancer protocol including a pre-injection phase, arterial phase, and porto-venous phase. The iodinated contrast agent Isovue 370 was dosed at 150 cc + 40 cc saline, and injected at a rate of 5 cc/sec into the antecubital vein. Volumetric analysis of images from 24 patients was conducted using 3D imaging software and perfusion scoring assessment was done on each case using 2D and 3D methodology. Regions of interest were drawn to define the volumetric tumor quantification. This work looked at the difference in density between arterial and venous phases, using the Marley equation. This data was then used to assess treatment response and ultimately whether or not a patient would be a surgical candidate. This surgical candidacy of these patients was defined by the “R” score. Results: The R score defines the number of vessels with tumor involvement. Each vessel that had any amount of tumor involvement was scored with a 1. Any patient with a score of 6 or higher was deemed not eligible for surgery while a score of 5 or less was eligible for surgery. 3D Tumor volumetric assessments were performed for the assessment of the treatment response that linked directly with the tumor perfusion.Conclusion: CT vessel perfusion using the R score method could be helpful to define the surgical candidacy of pancreatic cancer patients along with 3D tumor volumetric quantification. Citation Format: Syed Rahmanuddin, Daniel Von Hoff, Derek Cridebring, Jordyn Brase, Yuman Fong, Pejman Motarjem, Ron Korn, Kevin Choong, William Boswell, Erkut Borazanci. Radiologic scoring method to define the therapeutic response and surgical candidacy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-2