Imaging angiogenesis: perspectives and opportunities in tumour research - a method display.

The growth of solid tumours necessitates angiogenesis. The aim of this paper is the presentation and evaluation of different ex vivo methods for analysing tumour angiogenesis. Oral squamous cell carcinomas (SCC) were induced in mice by subcutaneous injection of tumour cells in the groin region and processed for histology and microvascular corrosion casting. Vascularization was analysed light microscopically using CD31 immunochemistry. Corrosion casts were analysed by scanning electron microscopy (SEM), micro computed tomography (μCT) and synchrotron radiation-based micro computed tomography (SRμCT). Immunochemistry allows for a simple and authentic detection and stereological quantification of the SCC vascularization. μCT imaging of the corrosion casts gives a high-quality overview over the three-dimensional (3D) microvascular architecture. SEM and SRμCT allow a high-definition display of the vessel morphology, providing magnificent detail recognition down to the capillary level enabling imaging of different forms of tumour angiogenesis, e.g., sprouting and intussusceptive angiogenesis. Immunochemistry and SEM are regarded as suitable for most of the morphometrical and morphological assessments because of the simple procedure and the high explanatory power, especially in combination with each other. High resolution SRμCT helps answering specialized questions, however, requires sophisticated data processing for visualization and is of limited availability.