Radiation therapy communication: Retreatment of multiple histologically confirmed oligodendroglioma drop metastasis with stereotactic radiotherapy in a dog

A 10-year-old female spayed boxer was treated with stereotactic radiotherapy (SRT) for a suspected glioma in the left piriform lobe. The intra-axial lesion was T2 hyperintense, T2 FLAIR hyperintense, T1 hypointense, and did not uptake contrast. Imaging was performed with an MRI every 3 months, and at the 6-month recheck, new lesions in the left hippocampus and right piriform lobe were evident without clinically apparent neurological progression. A second course of SRT was prescribed for the new lesions. Euthanasia was elected 14 months after the first course of SRT, and necropsy confirmed oligodendroglioma with drop metastasis.