MALIGNANT MENINGIOMA - AN INDICATION FOR INITIAL AGGRESSIVE SURGERY AND ADJUVANT RADIOTHERAPY

Malignant meningiomas constitute a rare subset of meningiomas and disp lay a marked propensity for postsurgical recurrence. This retrospectiv e study evaluates the various parameters which alter the recurrence ra te. The records of all malignant meningioma patients treated from 1984 through 1992 were reviewed, and the time to recurrence or current pat ient status was determined, and the influence of various patient and d isease parameters were analyzed. Thirty-eight patients were treated wi th 48 malignant meningioma resections performed (28 total and 20 subto tal), 25 at initial presentation and 23 for recurrent disease; 19 pati ents received postoperative radiotherapy. Subtypes included 32 anaplas tic meningioma, 11 hemangiopericytoma, 2 meningiosarcoma, and 3 papill ary meningioma. Followup ranged from 3 to 144 months, with five patien ts excluded from analysis. Actuarial disease free/progression free sur vival (DFS) at 5 years was 39% following total resection versus 0% aft er subtotal resection (p = 0.001). For all totally excised lesions, th e 5-yr DFS was improved from 28% for surgery alone to 57% with adjuvan t radiotherapy (p = NS). Adjuvant irradiation following initial resect ion increased the 5-yr DFS rates from 15% to 80% (p = 0.002). When adm inistered for recurrent lesions, adjuvant radiotherapy improved the 2- yr DFS from 50% to 89% (p = 0.015), but had no impact on 5-yr DFS. Mul tivariate analysis indicates extent of resection, adjuvant radiotherap y and recurrence status are independent prognostic factors. Malignant meningiomas display a tendency for post surgical recurrence, with recu rrence significantly increased for multicentric and recurrent disease. Complete surgical resection and the administration of adjuvant irradi ation following initial resection are crucial to long-term control.