Purpose
To evaluate the utility of in vivo imaging of a rabbit model of uveal melanoma utilizing high-frequency contrast-enhanced ultrasound (HF-CE-US) with 2- or 3- dimensional modes, and to correlate the sonographic findings with histopathologic characteristics.
Methods
Five New Zealand white rabbits were inoculated into their right eyes with aliquots of 92.1 human uveal melanoma cells. The rabbits were immune suppressed with subcutaneous cyclosporine 15mg/kg qd from three days prior to inoculation to four weeks after inoculation. Tumor-bearing eyes were imaged using HF-CE-US to determine the 2- and 3-dimensional tumor size and relative blood volume. The rabbits were sacrificed and their eyes with melanoma were histologically examined to determine melanoma size and mean vascular density (MVD).
Results
Melanoma grew in the choroid in all eyes. Utilizing HF-CE-US, melanomas were visualized as relatively hyperechoic regions in the images. The correlation coefficient of sonographic size or volume compared with histologic area were r square =0.72 and 0.70, respectively. The sonographic tumor relative blood volume correlated with histologic tumor vascularity (MVD) (r=0.92).
Conclusions
There is a positive correlation between in vivo sonographic tumor volume/size and histologic tumor size in our rabbit ocular melanoma model. HF-CE-US corresponds to microvascular density and blood volume. HF-CE-US is a real-time, non-invasive method for evaluation of intraocular melanoma tumor area and relative blood volume.
Keywords: 589 melanoma •
552 imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) •
637 pathology: experimental