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Computer-assisted image analysis of neovascularization in thyroid neoplasms from dogs

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  • 1 Veterinary Medical Teaching Hospital, School of Veterinary Medicine, University of California, Davis, CA 95616.
  • | 2 Departments of Pathology, Microbiology, and Immunology, School of Veterinary Medicine, University of California, Davis, CA 95616.
  • | 3 Surgical and Radiologic Sciences, School of Veterinary Medicine, University of California, Davis, CA 95616.
  • | 4 Veterinary Medical Teaching Hospital, School of Veterinary Medicine, University of California, Davis, CA 95616.
  • | 5 Surgical and Radiologic Sciences, School of Veterinary Medicine, University of California, Davis, CA 95616.

Abstract

Objective—To develop a computer-assisted image analysis procedure for quantitation of neovascularization in formalin-fixed paraffin-embedded specimens of thyroid gland tissue from dogs with and without thyroid gland neoplasia.

Sample Population—47 thyroid gland carcinomas, 8 thyroid gland adenomas, and 8 specimens of thyroid tissue from dogs without thyroid gland abnormalities (normal).

Procedure—Serial tissue sections were prepared and stained with antibodies against human CD31 or factor VIII-related antigen (factor VIII-rag). The areas of highest vascularity were identified in CD31- stained sections, and corresponding areas were then identified in factor VIII-rag-stained sections. Image analysis was used to calculate the total vascular density in each section, and neovascularization, expressed as a percentage, was determined as the absolute value of the total vascular density derived from factor VIII-rag-stained sections minus the vascular density derived from CD31-stained sections.

Results—Mean vascular density of thyroid gland carcinomas derived from CD31-stained sections was significantly greater than density derived from factor VIII-rag-stained sections. This incremental difference was presumed to represent degree of neovascularization. However, significant differences were not detected between vascular densities derived from CD31 and factor VIII-rag-stained sections for either normal thyroid gland tissue or thyroid gland adenomas. No significant correlations were found between vascular density in thyroid gland carcinomas and survival time following surgery.

Conclusion and Clinical Relevance—A computerassisted image analysis method was developed for quantifying neovascularization in thyroid gland tumors of dogs. This method may allow identification of dogs with tumors that are most likely to respond to treatment with novel antiangiogenesis agents. (Am J Vet Res 2002;63:363–369)

Abstract

Objective—To develop a computer-assisted image analysis procedure for quantitation of neovascularization in formalin-fixed paraffin-embedded specimens of thyroid gland tissue from dogs with and without thyroid gland neoplasia.

Sample Population—47 thyroid gland carcinomas, 8 thyroid gland adenomas, and 8 specimens of thyroid tissue from dogs without thyroid gland abnormalities (normal).

Procedure—Serial tissue sections were prepared and stained with antibodies against human CD31 or factor VIII-related antigen (factor VIII-rag). The areas of highest vascularity were identified in CD31- stained sections, and corresponding areas were then identified in factor VIII-rag-stained sections. Image analysis was used to calculate the total vascular density in each section, and neovascularization, expressed as a percentage, was determined as the absolute value of the total vascular density derived from factor VIII-rag-stained sections minus the vascular density derived from CD31-stained sections.

Results—Mean vascular density of thyroid gland carcinomas derived from CD31-stained sections was significantly greater than density derived from factor VIII-rag-stained sections. This incremental difference was presumed to represent degree of neovascularization. However, significant differences were not detected between vascular densities derived from CD31 and factor VIII-rag-stained sections for either normal thyroid gland tissue or thyroid gland adenomas. No significant correlations were found between vascular density in thyroid gland carcinomas and survival time following surgery.

Conclusion and Clinical Relevance—A computerassisted image analysis method was developed for quantifying neovascularization in thyroid gland tumors of dogs. This method may allow identification of dogs with tumors that are most likely to respond to treatment with novel antiangiogenesis agents. (Am J Vet Res 2002;63:363–369)