For many serous ovarian carcinomas, the indenti-fication of specific lymphatic endothelial markers has enabled the unambiguous characterisation of lymphangiogenesis during tumour progression.
Aims
To present an original technique of computerised segmentation of lymphatic vessels for their easy and unbiased quantification.
Methods
The method was implemented in the form of an original software package that calculates quantitative descriptors of lymphatic vessels. The input data are expected to be original histological images processed with the D2-40 endothelial marker while the results are the set of quantitative features of lymphangiogenesis.
Results
The computerised procedure of histological image analysis resulted in computing the following quantitative features.
(a)
The relative area occupied by the vessels is computed as the total amount of vessel pixels divided by the total number of pixels in the image.
(b)
The homogeneity of the distribution of vessels network over the image (tissue sample) space computing after the whole image is subdivided into 100 x 100 identical fragments. For each region the degree of distribution uniformity is calculated as the entropy value.
(c)
The relative area of small large and vessel. For computing this feature, the pixels belonging to the image boundary are removed by a standard erosion morphological operation. Then the ratio of the removed area to the original vessel area is calculated.
The above procedure was thoroughly tested on a test set containing 5000 images of histological samples of about 100 patients stained with the help of D2-40 endothelial marker.
Conclusion
Future studies are necessary to determine whether intratumoural lymphatics are restricted only to certain cancer types and whether their presence in tumours has prognostic significance.