Atypical and anaplastic meningiomas — does the new WHO-classification of brain tumours affect the indication for postoperative irradiation?

Abstract

We retrospectively analysed 13 patients (pts.) treated at the University of Tübingen from 1985 to 1993 to evaluate the results of radiation therapy (XRT) given as an adjuvant to totally or subtotally resected meningiomas. The overall survival was 38% at five years with a probability of relapse of 50% at this time. Reclassification of the tumours according to the new WHO-classification of brain tumours [14] revealed 10 grade-II-tumours (atypical meningioma) and 3 grade-III-tumours (anaplastic meningioma). Radiotherapy failed in all 3 pts. with macroscopically incomplete resection (Simpson's grade IV), who died with relapse between 4 and 51 months after radiotherapy. 5 out of 10 pts. with grade-II-tumours relapsed. All 3 pts. with grade-III-tumours died with relapse between 6 and 21 months after XRT. Morbidity was seen in 2 pts. after irradiation with 60 GY (ICRU dose specification). Complete surgical exstirpation offers the best possibility of tumour control. Grade-III-tumours should be irradiated whatever the extent of the primary surgery was. Our results might indicate a possible indication for XRT in pts. with atypical grade-II-tumours especially when radical surgery must be in doubt. Prospective multicentre trials are warranted to prove the prognostic value of the new WHO-classification for atypical and anaplastic meningiomas and to define the ultimate role of radiotherapy in this setting.

The Influence of Adjuvant Radiotherapy in Atypical and Anaplastic Meningiomas: A Series of 88 Patients in a Single Institution

“…Current literature is clearer about malignant meningiomas but has presented inconsistent outcomes in relation to the effects of adjuvant radiotherapy for atypical meningiomas, based on few small retrospective case series (3,9,21,23,24,33,37,41,42,47,54). Some retrospective reports(24) have made radiation fairly standard treatment for subtotally resected lesions at many Institutions.…”

The role of radiotherapy following gross-total resection of atypical meningiomas

“…17,49 Greater extent of resection was correlated with decreased recurrence rates in these initial series, 15,49 with a 5-year survival of up to 87% in small series.…”

“…Nevertheless, the majority of patients experienced recurrence after either surgery or postoperative radiotherapy, 9,17 with no improvement in PFS postradiotherapy. 26 Modern series that distinguish atypical meningioma from malignant meningioma report longer follow-up with low mortality rates 16 and recurrence-free survival of up to 89% at 5 years in patients treated with postoperative fractionated radiotherapy.…”

“…1,17,18,32,33,38,42 A recent case series suggested that the addition of postoperative radiation therapy may be associated with lower recurrence rates regardless of the extent of initial resection. 1 Our study aimed to further characterize the efficacy of postoperative radiotherapy in the prevention of recurrence and death after GTR of atypical meningiomas.…”

Relationship between malignant subtypes of meningioma and clinical outcome

“…The extent of resection is an important determinant of the risk of recurrence and the need for adjuvant therapy. 16 Postoperative radiotherapy is recommended in most cases, even though it has not been determined whether radiotherapy is beneficial. Surgery followed by radiation therapy has been reported to reduce the local recurrence of meningiomas compared to surgery alone.…”