The value of whole-lesion histogram analysis based on field‑of‑view optimized and constrained undistorted single shot...

This study aims to estimate the amount of axillary lymph node (ALN) involvement in early-stage breast cancer utilizing a field of view (FOV) optimized and constrained undistorted single-shot (FOCUS) diffusion-weighted imaging (DWI) approach, as well as a whole-lesion histogram analysis.

This retrospective analysis involved 81 individuals with invasive breast cancer. The patients were divided into three groups: N₀ (negative ALN metastasis), N_1-2 (low metastatic burden with 1-2 ALNs), and N_≥3 (heavy metastatic burden with ≥ 3 ALNs) based on their sentinel lymph node biopsy (SLNB) or axillary lymph node dissection (ALND). Histogram parameters of apparent diffusion coefficient (ADC) depending basically on FOCUS DWI were performed using 3D-Slicer software for whole lesions. The typical histogram characteristics for N₀, N_1-2, and N_{≥ 3} were compared to identify the significantly different parameters. To determine the diagnostic efficacy of significantly different factors, the area under their receiver operating characteristic (ROC) curves was examined.

There were significant differences in the energy, maximum, 90 percentile, range, and lesion size among N₀, N_1-2, and N_{≥ 3} groups (P < 0.05). The energy differed significantly between N₀ and N_1-2 groups (P < 0.05), and some certain ADC histogram parameters and lesion sizes differed significantly between N₀ and N_≥3, or N_1-2 and N_≥3 groups. For ROC analysis, the energy yielded the best diagnostic performance in distinguishing N₀ and N_1-2 groups from N_≥3 group with an AUC value of0.853. All parameters revealed excellent inter-observer agreement with inter-reader consistencies data ranging from0.919 to 0.982.

By employing FOCUS DWI method, the analysis of whole-lesion ADC histogram quantitatively provides a non-invasive way to evaluate the degree of ALN metastatic spread in early-stage breast cancer.