Abstract
159
Objectives: Recent studies have indicated that some hematological inflammatory markers (HIMs) are valuable to predict prognosis in patients with various malignancies. The purpose of this study was to evaluate if HIMs were associated with texture features (TFs) or volumetric parameters (VPs) on FDG PET in patients with esophageal cancer and were useful in predicting treatment response of neoadjuvant chemotherapy (NAC) and recurrence after subsequent surgery. Methods: Pretreatment FDG PET/CT exams in 35 esophageal squamous cell carcinoma pts were analyzed retrospectively. HIMs evaluated in this study included white blood cell counts, neutrophil counts and percentages, neutrophil/lymphocyte ratio, platelet/lymphocyte ratio, lymphocyte/monocyte ratio, C-reactive protein (CRP) levels, and CRP/albumin (CRP/ALB) ratio at the time of PET/CT exams. TFs were obtained from a 3D ROI covering each esophageal lesion on PET. TFs evaluated were homogeneity, entropy, short- and long-run emphasis, and low- and high- gray-level zone emphasis as recommended by Orlhac J, et al. (J Nucl Med 2014). Metabolic tumor volume (MTV) and total lesion glycolysis (TLG) were obtained as VPs in addition to SUVmax. HIMs were compared to TFs and VPs. HIMs and PET parameters were compared to pathologic results of NAC response and recurrent status after subsequent surgery. Statistical significance was confirmed with Mann-Whitney U test, Spearman rank correlation test, and logistic regression analysis. Results: SUVmax ranged from 8.2 to 20.1 (13.2+/-3.4) and MTV from 12 to 191 (42+/-32) in esophageal cancer lesions. Elevation of white blood cell counts, neutrophil percentages, and CRP levels were observed in 5 (14%), 9 (26%), and 13 (37%) of the 35 pts, respectively. Homogeneity and TLG were significantly higher in pts with elevated neutrophil percentages than in pts without elevation. Moderate correlation was observed between HIMs and TFs or VPs as follows: neutrophil counts vs. SUVmax or TLG (rho: 0.34-0.4); neutrophil percentages vs. TLG (rho: 0.35); CRP levels or CRP/ALB ratio vs. entropy, MTV, or TLG (rho: 0.42-0.46). Good pathologic response (viable cancer cells: < 1/3 of specimens) was achieved in 5 (20%) pts and recurrence was observed in 17 (49%) of the 35 pts. Logistic regression analysis revealed none of HIMs was the statistically significant factor to predict pathologic response or recurrence. Low gray-level zone emphasis and MTV were demonstrated to be the predictors of recurrence in this study. Conclusion: The present study demonstrated associations between HIMs and TFs or VPs on FDG PET in esophageal cancer. Although HIMs failed to predict treatment response and recurrence in this study population, their connection to intratumoral heterogeneity or tumor burden may provide a new insight regarding characteristics of esophageal cancer.