Long-term outcome and growth rate of subtotally resected petroclival meningiomas: experience with 38 cases.

Abstract

To evaluate the long-term outcome of a subtotally resected residual tumor and to assess its growth rate, we analyzed the records of 38 patients with residual petroclival meningioma. Clinical records and radiological findings of 38 cases of petroclival meningioma that were diagnosed and subtotally resected at Seoul National University Hospital between 1981 and 1997 were carefully reviewed. Follow-up imaging studies were reviewed, and Karnofsky performance scale scores at the last follow-up were recorded. The duration of follow-up ranged from 6 to 141 months (mean, 47.5 mo; median, 30 mo). Tumor progression and progression-free survival rates were assessed. The growth rate of a residual tumor was evaluated by measuring the equivalent diameter and the tumor volume serially; the tumor doubling time was calculated, and the predictive factors for determining the growth pattern in residual tumors and the prognosis were analyzed. In 33 (87%) of the 38 patients, Karnofsky performance scale scores at the last follow-up were 80 or above. The median progression-free survival time among patients with subtotally resected tumors was 66 months, and the 5-year progression-free survival rate was 60%. The growth rate of residual tumors was low (volume increase, 4.94 cc/yr; diameter increase, 0.37 cm/yr). The mean tumor doubling time was 8 years. Although there were no significant predictive factors, age and extent of tumor resection seemed to influence the progression-free survival rate. Significant factors affecting the growth rate were age and occurrence of menopause. Subtotal resection with or without radiation or radiosurgery should be considered as a suitable treatment option for patients with petroclival meningiomas, especially the elderly, because the growth rate of residual tumors is low.