Aims and background

To review the clinical, radiological and histological findings of 19 patients with radiation-induced intracranial meningiomas treated at our neurosurgical department between 1981 and 1996.

Method

The records of 18 patients with intracranial meningiomas who underwent low-dose radiation for tinea capitis in childhood, and of one patient irradiated for pituitary adenoma, were analyzed in respect of the previously reported features of postradiation meningiomas.

Results

The mean age of the patients with low-dose radiation-induced meningiomas was 58 years and the mean shortest onset latency was 48 years. The male to female ratio was 1.1:1. Forty-seven percent of patients presented with mental changes and/or focal neurological signs, 21% with signs of increased intracranial pressure and 26% with seizures. Calvarial location of the meningiomas was found in 54% of patients and in one patient the tumor arose from the skull base. Multiple tumors were present in 15% of patients and 29% of the meningiomas displayed malignant features on histological examination. A significantly lower meningioma recurrence rate was found in our series compared to the recurrence rate in the reported series of postradiation meningiomas. Five patients had a history of a second neoplasm other than meningioma.

Conclusion

Our series of low-dose radiation-induced meningiomas represents one of the largest of its kind in the English literature. The patients did not differ substantially in sex ratio, tumor localization, multiplicity and histological features from the previously reported postradiation meningioma patients, except for the significantly lower tumor recurrence rate. It would seem that over the next years we will be further witnessing the deleterious effects of low-dose radiation administered in childhood.