Diagnostic utility of leukocyte volume, conductivity, and scatter (VCS) parameters in febrile neutropenia among pediatric oncology patients: A prospective observational study

Objectives: Early identification of infection is crucial for reducing morbidity and mortality in febrile neutropenia (FN). Conventional biomarkers, including C-reactive protein (CRP) and procalcitonin (PCT), have limitations in availability and additional cost. A complete blood count (CBC) performed by automated hematology analyzers provides volume, conductivity, and scatter (VCS) parameters for leukocytes, reflecting cellular morphometric and structural changes that may serve as rapid adjunctive markers for infection. Material and Methods: In this prospective observational study, 35 pediatric oncology patients (<18 years) with 50 FN episodes were analyzed at a tertiary cancer care center. VCS parameters of neutrophils and monocytes—mean neutrophil volume (MN-V-NE), conductivity (MN-C-NE), scatter (MN-S-NE), mean monocyte volume (MN-V-MO), and conductivity (MN-C-MO)—were recorded at a non-febrile state and during FN episodes. Correlations with blood culture, CRP, PCT, and clinical outcomes were assessed. Diagnostic accuracy was determined using receiver operating characteristic (ROC) analysis. Results: Significant elevations were observed during FN for MN-V-NE (p = 0.001), MN-V-MO (p = 0.009), and MN-C-MO (p = 0.028) compared to baseline. Blood cultures were positive in 28% of episodes, with equal proportions of Gram-positive and Gram-negative organisms, and 28.6% fungal isolates. CRP and PCT levels were significantly higher in culture-positive cases (p < 0.01). ROC analysis showed MN-V-NE had the highest diagnostic accuracy for FN (AUC = 0.78; sensitivity 94% at cutoff >142.5), followed by MN-C-MO [area under curve (AUC) = 0.63; specificity 84% at cutoff >117.5]. No VCS parameters correlated with mortality or discharge status. Conclusion: VCS parameters, particularly MN-V-NE and MN-C-MO, are rapid, cost-effective adjuncts for FN diagnosis in pediatric oncology patients but lack prognostic significance.