Ultrasound Microvessel Visualization in Cervical Cancer: Association Between Novel Ultrasound Techniques and...

The aim of the work described here was to evaluate the feasibility of superb microvascular imaging (SMI) and vascular endothelial growth factor receptor 2 (VEGFR2)-targeted microbubble (MB_VEGFR2)-based ultrasound molecular imaging (USMI) for visualizing microvessels in cervical cancer.

Hela cells were used to establish subcutaneous cervical cancer models. SMI and MB_VEGFR2-based USMI were performed, and the results were compared with intratumoral microvessel density (MVD) in four groups based on tumor diameter (<3 mm, 3-5 mm, 5-7 mm and ≥7 mm). The vascularization index (VI, %) was evaluated for SMI, and the normalized intensity difference (NID) for USMI.

Tumors with diameters ranging from 3 to 5 mm had the highest VI (39.07 ± 1.58) in SMI, and VI significantly decreased with increasing tumor size (all p values <0.001). The strongest signal intensity was observed in very early tumors (d < 3 mm: 43.80 ± 3.58%) after MB_VEGFR2 administration; the NID gradually decreased with increasing diameter of tumors (all p values = 0.007). However, no significant differences were observed in NID after administration of non-targeted (control) microbubbles (MB_Con) (all p values = 0.125). MB_VEGFR2-based USMI had the strongest correlation with MVD in displaying microvessels of cervical cancer compared with SMI and MB_Con (R² = 0.78 vs. R² = 0.40 and R² = 0.38).

These findings validate the superiority and accuracy of MB_VEGFR2-based USMI for microvessel imaging and monitoring of angiogenesis in cervical cancer compared with SMI and MB_Con. Nonetheless, SMI remains an alternative to microvessel imaging when ultrasonic contrast agent use is contraindicated.