Evaluating Anti-VEGFR2 and Anti-Dll4 Antibodies in Tumor Radiotherapy

Animals with tumors approximately 100 mm³ in the chamber were administered with either anti-mouse vascular endothelial growth factor receptor 2 (VEGFR2) antibody [27 mg/kg; clone DC101 (37 (link)), BioXCell], anti-mouse Dll4 antibody (39 (link)) twice per week at a dose of 5 mg/kg (in two doses on the initial day of imaging and 3 days later), or one of two radiation treatments. For the radiation treatments, mice were anesthetized under inhalation with isoflurane and placed in an imaging-guided small animal radiation research platform (SARRP) irradiator (Xstrahl Ltd). A Cone Beam CT (computerized tomography) scan of each mouse was obtained, and the treatment was planned using MuriPlan (Xstrahl Ltd). The SARRP was used to deliver 15 Gy of x-rays (220–kilovolt peak copper-filtered beam with half-value layer of 0.93 mmCu) to the tumor at 2 Gy/min. This was given either in a single dose or at five daily fractionations of 3 Gy of x-ray radiation to the tumor. Dosimetry of the irradiator was performed as previously described (66 (link)).