Evaluation of intracranial meningioma resection with a surgical aspirator in dogs: 17 cases (1996–2004)

Abstract

Use of a surgical aspirator to resect intracranial meningiomas in dogs was associated with longer survival times than those achieved with traditional surgery alone or traditional surgery combined with radiation therapy. Dogs with meningothelial, psammomatous, or transitional intracranial meningioma subtypes appeared to have a better prognosis than dogs with other subtypes of meningioma.

Advances in Diagnostic and Treatment Modalities for Intracranial Tumors

“…In dogs with confirmed meningiomas, standard surgical cytoreduction alone generally has been reported to result in median survival times of approximately 4.5–7 months,144, 145, 146 with an improvement in median survival to 16.5–30 months with adjunctive radiation therapy 118, 145. However, use of cortical resection, ultrasonic aspiration, or endoscope‐assisted techniques has been reported to result in median survival times of 16, 41, and 70 months, respectively, for rostrotentorial meningiomas 146, 147, 148. Given the large variation in outcome for different surgical techniques in individual studies, it is difficult to make general recommendations for surgical treatment other than the observations that cytoreduction (particularly for rostrotentorial tumors) may be “curative” for many older animals with some surgeons and techniques and that adjunctive radiation therapy has an apparent beneficial effect (Fig 7).…”

“…A large retrospective study suggested no benefit for CT‐defined brain masses from lomustine (CCNU) chemotherapy compared to palliative care (93 days versus 60 days), but none of the 71 animals had a histologic diagnosis 142. Anecdotal histologically confirmed cases from published data show apparent survival benefits and occasional responses with survival of many months in some cases, but overall, chemotherapy alone appears to have limited value for intracranial tumors 147, 154, 166, 167, 168, 169. Temozolamide, a novel oral alkylating agent, has become the standard‐of‐care for adjuvant and monotherapy of high‐grade gliomas and other tumors in humans, although its use not been reported in dogs with clinical brain tumors.…”

Stereotactic Volume Modulated Arc Radiotherapy Protocol for Canine Intracranial Meningioma.

“…40 Conversely, recent work suggests that high doses of radiotherapy activates apoptosis through acid sphingomyelinase (ASM) pathway. 41 Since ASM concentration is significant higher in endothelial cells than in epithelial and neoplastic ones, high doses are likely to provoke tumor death damaging mainly microvasculature. Therefore this could explain how subtentorial necrosis and progressive sovratentorial impregnation coexist with volumetric stability in some of the cases exposed.…”

“…2 Gy per day) protocol and a high dose hypofractionated one. [40][41][42] Conventional fractionated treatment causes re-assortment of tumor cells into more radiosensitive phases and reoxygenation of hypoxic cells between fractions, as hypoxic cells are more radioresistant. Re-assortment and reoxygenetion lead to an improvement of the therapeutic ratio.…”

Characterization of Immune Cell Infiltration Into Canine Intracranial Meningiomas

“…Surgical excision of low-grade meningiomas usually results in long-term control or cure in cats and humans. 23,24,61 Despite some recent promising results with advanced surgical techniques including longterm survival in some cases, 27,35 many canine meningiomas have poorly defined margins and an unclear plane of dissection, making complete surgical removal challenging. 19,43 Therefore, adjunctive radiotherapy is often recommended to prolong survival, which results in additional adverse effects and a prolonged course of therapy, and it usually dramatically increases the expense of treatment.…”