Computed Tomography-Based Tumor Heterogeneity Analysis Reveals Differences in a Cohort with Advanced Pancreatic Carcinoma under Palliative Chemotherapy

Abstract

<b><i>Purpose:</i></b> Imaging in pancreatic cancer is a challenge, especially regarding therapy response evaluation. Tumor size, attenuation, and perfusion are widely used as parameters for computed tomography (CT) examinations, but are often limited due to blurry tumor borders and missing qualitative parameters. To improve monitoring of therapy response, we tested a new CT-based approach of tumor heterogeneity feature analysis. <b><i>Methods:</i></b> A total of 13 patients with pancreatic adenocarcinoma undergoing abdominal CT according to standard as baseline imaging with clinical follow-up and imaging (median time span 64 days) under systematic therapy (FOLFIRINOX/gemcitabine) were retrospectively analyzed. Progression was defined as new lesions and local tumor spread. Tumor heterogeneity analysis was performed using mintLesion®. Seven different image features referring to image heterogeneity were analyzed. Statistical analysis was performed with Spearman’s rank correlation and Mann-Whitney U test. <b><i>Results:</i></b> During follow-up, tumor volume did not significantly change between our groups with overall progression (local and systemic) and progression-free patients (<i>p</i> = 0.661). Mean positivity of pixel values were significantly higher in patients without progression compared to patients with progression (<i>p</i> = 0.030). There was a significant negative correlation between changes in kurtosis and time to local tumor spread (<i>p</i> = 0.008) or systemic progression (<i>p</i> = 0.017). <b><i>Conclusions:</i></b> Results suggest that analysis of tumor heterogeneity might provide valuable information from routine-acquired images regarding therapy response evaluation. This might help adjusting therapy regimes and could be easily integrated in clinical workflows. Furthermore, this procedure might possibly predict therapy response and, hence could lead the way to find a potential marker for progression-free survival.