Long-Term Survival in a Dog with Anaplastic Oligodendroglioma Treated with Radiation Therapy and CCNU

Abstract

ABSTRACT. A 9 year-old, neutered, male French Bulldog showing cluster seizures was diagnosed with a glioma in the right piriform cortex by MRI. Hypofractionated radiation therapy (RT) was performed using a linear accelerator. Although the lesion had involuted significantly at 2 months after RT, recurrence was observed at 4 months after RT. Chemotherapy was started using CCNU (60 mg/m 2 every 6-9 weeks) and was continued for one year. Follow-up MRI revealed involution of the lesion and the intervals of CCNU were increased to every 9-14 weeks. Two years after the first presentation, the dog suffered status epilepticus, followed by deficits of left sided postural reaction with cognitive dysfunction. The dog died on day 910, and histopathological diagnosis confirmed anaplastic oligodendroglioma. KEY WORDS: canine, CCNU, MRI, glioma, radiation therapy.doi: 10.1292/jvms.12-0058; J. Vet. Med. Sci. 74(11): 1517-1521, 2012 Gliomas such as oligodendrogliomas and astrocytomas are relatively common intracranial and intraparenchymal tumors in dogs [19]. In contrast to meningiomas, gliomas may be treated with megavoltage radiation therapy (RT) and/or chemotherapy (nitrosoureas) because of their location and infiltration [2,7,15,18]. Several reports have documented the results and prognosis of gliomas treated with RT [3,4] and chemotherapy [6,8,9]. However, detailed descriptions of individual cases are very limited.Here, we describe the long-term survival (2 years and 6 months) of a dog with glioma (final diagnosis: anaplastic oligodendroglioma) that was treated with megavoltage RT and CCNU (lomustine) therapy.A 9 year-old, 13.0 kg, neutered male French Bulldog presented with a complaint of cluster seizures that had started 2 weeks earlier. The seizures consisted of focal seizures (mastication, salivation, and vomiting) with secondary generalization. Although the neurological examination was normal and the seizures were controlled by phenobarbital (PB) (2 mg/kg, PO, BID), magnetic resonance imaging (MRI) was performed to evaluate intracranial disease. Cranial MRI (1.5 Tesla) revealed a lesion showing hyperintensity on T2-weighted (T2W) and fluid-attenuated inversion recovery (FLAIR) images, and hypointensity on T1-weighted (T1W) images without contrast enhancement (on gadolinium enhancement (Gd-) T1W) in the right piriform area (piriform cortex and amygdala) with mild mass effect (Fig. 1A, 1B). From these MRI findings, a glioma, likely a low-grade astrocytoma or oligodendroglioma, was diagnosed clinically (day 0).Because of the location of the lesion and by the owner's request, megavoltage radiation therapy (RT) using a 4 MV X-ray linear accelerator was started on day 14. The radiation treatment area was planned with software based on CT images. The lesion was treated with hypofractionated radiation that was 6 Gy per fraction from 4 directions (0°, 90°, 180° and 270°) once a week for 6 weeks (total 36 Gy). During the period of RT, no clinical signs, including seizures, occurred under PB therapy, and no problems associated with...

Anaplastic oligodendroglioma with leptomeningeal dissemination in a french bulldog

“…Intracranial neoplasms are common in dogs, with one study reporting an incidence of 14.5/100,000 [ 16 ], and another estimating a prevalence of 3.0% [ 23 ]. Gliomas such as astrocytoma and oligodendroglioma occur frequently in dogs [ 6 , 23 , 24 , 28 ], and depending on their location and infiltration, may be treated with radiation therapy (RT) and/or chemotherapy [ 6 , 10 , 17 , 19 ].…”

“…Several veterinary reports have documented the results and prognosis of gliomas treated with RT [ 1 , 2 , 10 , 30 ] and chemotherapy [ 5 , 7 , 8 , 10 , 11 , 29 ]. In one case, an oligodendroglioma was effectively reduced in size after RT (stereotactic ablative RT), though a new mass suspected as CSF drop metastasis was observed 5 weeks after therapy [ 30 ].…”

“…Although reduction of the new mass was observed following the second RT, ventral leptomeningeal enhancement had extended, and cervical lesions were observed [ 30 ]. In another case of anaplastic oligodendroglioma treated with RT (hypofractionated RT), the mass showed significant regression 2 months post-therapy, though clinical worsening and lesion regrowth was observed 4 months after RT [ 10 ]. Similarly, in the present case, although the lesion showed significant regression, regrowth was observed 8 months after RT.…”

Feline anaplastic oligodendroglioma: long-term remission through radiation therapy and chemotherapy

“…-May 7, 2013 OnlineFirst Version of Record >> - Nov 19, 2013 Version of Record Gliomas, such as oligodendrogliomas and astrocytomas, are frequent central nervous system tumours secondary to meningiomas in dogs, 1 and several reports have documented the results and prognoses of dogs with glioma treated with megavoltage radiation therapy (RT) and/or chemotherapy (nitrosoureas). [2][3][4] In contrast to canine gliomas, those in cats are rare, 5 and no study has described the long-term outcome in cats. Here, we report long-term remission of a cat with glioma (anaplastic oligodendroglioma) that was treated with RT followed by chemotherapy.…”

“…In contrast to cats, radio-and chemotherapy is often performed in humans and dogs for cases with where surgical resection would be difficult. [2][3][4][16][17][18][19][20] In a recent study of irradiation alone in 46 dogs with brain tumours of various types and uncertain histology, the median survival time was 699 days. 21 We reported long-term survival (910 days) in a dog with anaplastic oligodendroglioma, 2 and the RT protocol used in the present case was similar to that of the canine case.…”