Using diffusion-weighted imaging and blood inflammatory markers to preoperatively differentiate between leiomyosarcoma and atypical leiomyomas.

OBJECTIVES

This study aims to compare apparent diffusion coefficient (ADC) findings between leiomyosarcoma (LMS) and atypical/degenerate leiomyoma (LM) and evaluate the usefulness of this biomarker for diagnosis. Additionally it will explore the potential of preoperative neutrophil-lymphocyte ratio (NLR) as a haematological marker to aid in the differentiation of LMS from atypical LM.

METHODS

Histologically proven LMS and LM patients between 2013 and 2023 were included. For all patients (191 LM, 18 LMS), the preoperative full blood count was analysed, and the NLR calculated. Whole volume of interest (VOI) and focal region of interest (ROI) areas were manually segmented on patients with DW-MRI sequences available (52 LM, 12 LMS). Mann-Whitney and Fishers exact test were used to assess statistical significance and receiver operating characteristic (ROC) curves for diagnostic performance.

RESULTS

VOI and ROI mean ADC values were significantly lower for LMS than LM, with ROI mean ADC demonstrating greater diagnostic accuracy (area under the curve, [AUC] 0.817 vs 0.755). Applying a threshold ROI mean ADC value of ≤1.00 × 10-3 mm2/s achieved a sensitivity and specificity of 88.3% and 65.4%, respectively. A higher NLR was suggestive of LMS (median 2.8 vs 1.7 for LM).

CONCLUSIONS

ADC, particularly a focal ROI is useful in differentiating LMS from LM. Differences in preoperative blood markers, suggest an inflammatory-malignancy relationship. Future risk stratification models of ADC and haematological parameters should be explored.

ADVANCES IN KNOWLEDGE: This study adds to few studies comparing using both ROI- and VOI-based methods, and no study has assessed both haematological markers and ADC metrics to aid differentiation.