Perfusion Assessment in CEUS Imaging for Estimating Pancreatic Cancer Response to Sonoporation-Enhanced Chemotherapy

Accurate assessment of perfusion in vital organs like the pancreas is crucial for monitoring various pathologies, particularly tumors and their growth. While tumor growth inhibition usually results in decreased vascularization, current techniques for non-invasive and cost-effective perfusion assessment lack sufficient vessel separability for pancreatic applications, hindering optimal treatment selection and monitoring. Ultrasound (US) imaging offers advantages like low cost, rapid acquisition, non-invasiveness, and non-ionizing radiation. However, speckle, patient-related and acquisition-related motion artifacts, and limitations in distinguishing contrast-enhanced blood vessels, particularly in single frames, pose significant challenges. This study presents a novel solution utilizing image analysis of US contrast agents (UCAs) to characterize vascularization. The approach involves data denoising, selection of static frames, spatio-temporal registration, and deconvolution. The post-processed images are analyzed based on temporal intensity changes and normalized to extract trends. Data from 13 patients undergoing chemotherapeutic treatment with FOLFIRINOX or gemcitabine/abraxane were analyzed. Though no direct effects on vascularization are expected, the results suggest a correlation between derived vascularization trends (based on B-mode and CEUS data) and observed clinical treatment outcomes. Four patients exhibited negative slope (related to vascularization regression) aligned with clinical improvement, while six showed positive slope (related to increased vascularization) coinciding with treatment deterioration. Two patients displayed negative slopes without clinical improvement, and one patient displayed positive slope but had clinical improvement. These findings indicate the potential of this method to estimate treatment efficacy and guide personalized therapy, although the sample size is small and further investigation is warranted. Trial Registry Name: Sonoporation and Chemotherapy for the Treatment of Pancreatic Cancer. URL: https://clinicaltrials.gov/study/NCT04821284. Registration Number: NCT04821284.