Preliminary study of plasma vascular endothelial growth factor (VEGF) during low- and high-dose radiation therapy of dogs with spontaneous tumors.
High plasma vascular endothelial growth factor (VEGF) concentrations are associated with radiation resistance and poor prognosis. After an exposure to ionizing radiation in cell culture an early phase and a late phase of increased VEGF have been documented. The activation was dependent on the radiation dose. Therefore, the purpose of this study was to measure baseline plasma VEGF and changes in VEGF over the course of fractionated radiation therapy in dogs with spontaneous tumors. Dogs with tumors had a significantly higher pretreatment plasma VEGF than did dogs without tumors. Immediately after irradiation no increased plasma VEGF was observed. Over the course of radiation therapy there was an increased plasma VEGF in dogs treated with low doses per fraction/high total dose, whereas plasma VEGF remained stable in dogs irradiated with high doses per fraction/low total dose. The regulatory mechanisms are very complex, and therefore the value of plasma VEGF measurements as an indirect marker of angiogenesis induced by radiotherapy is limited.
Wergin
Melanie C
MC
Section of Diagnostic Imaging and Radio-Oncology, Faculty of Veterinary Medicine, University of Zurich, Switzerland. mwergin@vetclinics.unizh.ch
Ballmer-Hofer
Kurt
K
Roos
Malgorzata
M
Achermann
Roger E
RE
Inteeworn
Natalie
N
Akens
Margarete K
MK
Blattmann
Hans
H
Kaser-Hotz
Barbara
B
D000818:Animals; D014408:Biomarkers, Tumor / Q000097:blood*; D016022:Case-Control Studies; D004283:Dog Diseases / Q000097:blood* / Q000532:radiotherapy*; D004285:Dogs; D005260:Female; D005354:Fibrosarcoma / Q000097:blood / Q000532:radiotherapy / Q000662:veterinary; D008297:Male; D008545:Melanoma / Q000097:blood / Q000532:radiotherapy / Q000662:veterinary; D009389:Neovascularization, Pathologic / Q000097:blood / Q000662:veterinary; D011829:Radiation Dosage; D012983:Soft Tissue Neoplasms / Q000097:blood / Q000532:radiotherapy / Q000662:veterinary*; D042461:Vascular Endothelial Growth Factor A / Q000097:blood*
D014408:Biomarkers, Tumor; D042461:Vascular Endothelial Growth Factor A