Pilomyxoid astrocytoma: a review.

Pilomyxoid astrocytoma (PMA) is a recently described type of brain tumor. PMA shares similar features with pilocytic astrocytoma (PA), the most common central nervous system (CNS) tumor in the pediatric population, yet displays subtle histologic differences. Previous studies have shown PMA to behave more aggressively than PA, with shorter progression-free and overall survival as well as a higher rate of recurrence and CNS dissemination. These findings suggest that PMA may be a unique and distinct neoplasm. This review summarizes the histologic, clinical, and radiographic characteristics of PMA. In addition, the current treatment options and research endeavors involving this disease are described. Increased recognition of PMA within the medical community has the potential to affect the treatment and prognosis of pediatric low-grade astrocytomas.

Intra-arterial mitoxantrone delivery in rabbits: an optical pharmacokinetic study.

BACKGROUND: Several human studies have demonstrated the feasibility of intra-arterial delivery of mitoxantrone in systemic malignancies. Computational models predict that an intra-arterial bolus injection of mitoxantrone during transient cerebral hypoperfusion will enhance brain tissue drug deposition in comparison with injections during normal blood flow. OBJECTIVE: To assess whether transient reduction in cerebral blood flow would enhance the delivery of mitoxantrone. This is accomplished by obtaining real-time measurements of mitoxantrone concentrations in brain tissues by using a novel optical pharmacokinetics technique, based on reflectance spectroscopy. METHODS: The blood-brain barrier of anesthetized rabbits was disrupted by intracarotid injection of mannitol (8 mL, 25% over 40 seconds). Thereafter, animals received 3 mg of mitoxantrone injection during normal perfusion (n = 5) or cerebral hypoperfusion that was induced by contralateral arterial occlusion and systemic hypotension (n = 8). RESULTS: Cerebral hypoperfusion significantly decreased the cerebral blood flow, allowing a longer exposure time of the drug. It was determined that therapeutic concentrations of mitoxantrone were achieved in both groups; however, hypoperfusion did not increase the tissue concentrations of mitoxantrone after 20 minutes. CONCLUSION: These results demonstrate the effective delivery of mitoxantrone by the intra-arterial route, after blood-brain-barrier disruption, but the predicted benefits of flow reduction for improving intra-arterial deposition of mitoxantrone was not evident.