Abstract
We reviewed the medical records of 392 patients who underwent initial surgery for
skull base meningiomas between 1983 and 2008. Among them, 32 (8.2%) showed tumor recurrence.
Risk factors for recurrence were analyzed clinically and biologically. Recurrent cases
were treated with radiotherapy, surgery, or both. In reoperation cases, pathological
and biological changes were analyzed and compared between groups with or without radiotherapy.
The recurrence rate was statistically high in cases of partial tumor removal and in
patients with tumor in the cavernous sinus, tumors with histological WHO (World Health
Organization) grade ≥ II or MIB-1 index > 3. The local control rate of postoperative
radiotherapy for recurrent cases was 66.7%. Malignant transformation and MIB-1 index
elevation was observed more frequently in patients who underwent reoperation after
radiotherapy than in the reoperation-only group. Risk factors for recurrence of skull
base meningiomas are as follows: (1) partial tumor removal, (2) tumor in the cavernous
sinus, (3) histological WHO grade ≥ II, or (4) MIB-1 index > 3. Postoperative radiotherapy
might be effective for tumor recurrence. However, the indications for radiotherapy
should be carefully considered because postsurgical radiotherapy may increase biological
activity, inducing malignant transformation.
Keywords
malignant transformation - MIB-1 index - radiotherapy - recurrence - skull base meningiomas
- surgery