Shear-wave elastography contributes to accurate tumour size estimation when assessing small breast cancers

Area of Science:

• Breast cancer imaging
• Ultrasound elastography
• Tumour size assessment

Background:

• Accurate tumour size is crucial for breast cancer treatment planning.
• Grey-scale ultrasound (GSUS) may underestimate the size of small primary breast cancers (≤15 mm).
• Peritumoural stiffness (PTS) on shear-wave elastography (SWE) may provide additional information.

Purpose of the Study:

• To evaluate if PTS size on SWE correlates with size discrepancies between GSUS and final histology in small breast cancers.
• To determine if combining PTS size with GSUS improves tumour size estimation compared to final histology.

Main Methods:

• Retrospective analysis of 86 patients with small primary breast cancers (≤15 mm).
• Comparison of PTS size, GSUS size, and final histological size.
• Assessment of size discrepancies and the impact of combining PTS and GSUS measurements.

Main Results:

• PTS >3 mm was associated with larger final histological size (16 vs. 11.3 mm) and higher underestimation by GSUS (>5 mm, 63% vs. 18%).
• Combining PTS and GSUS measurements resulted in more accurate final tumour size estimation (p=0.03).
• PTS size was not significantly associated with margin involvement (p=0.27).

Conclusions:

• PTS size on SWE is a significant indicator of potential underestimation of tumour size by GSUS in small breast cancers.
• Incorporating PTS size into ultrasound assessments enhances the accuracy of tumour size estimation.
• Further research is needed to explore the relationship between SWE stiffness extent and margin status.