Hyperfractionated and accelerated-hyperfractionated radiotherapy for glioblastoma multiforme.

Because of promising radiobiological advantages allowing dose escalation and/or reduction of treatment time, hyperfractionated and accelerated-hyperfractionated radiotherapy (hf-rt, ahf-rt) were introduced as part of treatment of glioblastoma multiforme (gbm). In December 1988 we started a prospective study of hf-rt (total dose 78 Gy, two daily fractions of 1.3 Gy, interval between daily fractions 6 hr, treatment time 6 weeks, n = 34 patients).

[Classification and grading of gliomas and meningiomas].

GLIOMAS: As we demonstrated for supratentorial, diffuse gliomas in adults, a stratification into just two grades of malignancy, 'low' and 'high grade,' proved reliable and prognostically relevant. The discriminating histomorphological criterion for high-grade astrocytoma (WHO glioblastoma) as well as anaplastic oligodendroglioma and anaplastic oligoastrocytoma is endothelial hyperplasia/proliferation, which is usually associated with uptake of contrast medium in computed tomography and magnetic resonance imaging. As neoangiogenesis indicates glioma progression, it is worthwhile considering these radiographic features to judge the representativeness of the tumor samples critically.

[Grading of astrocytomas and oligodendrogliomas].

The histologic determination of the degree of tissue anaplasia and grade of malignancy of gliomas is based upon qualitative histological features (nuclear pleomorphism, mitoses, endothelial proliferation, tumor necrosis). This grading approach is influenced by the subjective interpretation of the pathologist, especially concerning the weighting of criteria (scant, moderate, pronounced). An observer-independent approach seems to be feasible by abandoning the concept of parameter weighting in favor of an binary approach noting only the presence or absence of these structure parameters.

[Meningioma. Classification and grading].

Meningiomas account for the most frequent primary intracranial neoplasms in adults. In 1993, the so-called atypical meningioma has additionally been introduced in the revised edition of the WHO Classification of Tumors of the Central Nervous System and should characterize meningiomas with an increased propensity to recur. Since the given qualitative histological criteria apply both to the "atypical" and anaplastic meningioma, mere histological grading appears somewhat critical.

Histologic and morphometric grading of gliomas. A comparative survival analysis.

Objective: A grading system based upon morphometrically assessed quantitative parameters (HOM system) was correlated with the results of classical histologic grading (St. Anne/Mayo system [SAMS], 1988, and World Health Organization classification, 1993). Validation was done by comparison with survival data.