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

OBJECTIVE: To evaluate the long-term outcome of a subtotally resected resid ual tumor and to assess its growth rate, we analyzed the records of 38 pati ents with residual petroclival meningioma. METHODS: Clinical records and radiological findings of 38 cases of petrocli val meningioma that were diagnosed and subtotally resected at Seoul Nationa l University Hospital between 1981 and 1997 were carefully reviewed. Follow -up imaging studies were reviewed, and Karnofsky performance scale scores a t 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 progre ssion-free survival rates were assessed. The growth rate of a residual tumo r was evaluated by measuring the equivalent diameter and the tumor volume s erially; the tumor doubling time was calculated, and the predictive factors for determining the growth pattern in residual tumors and the prognosis we re analyzed. RESULTS: In 33 (87%) of the 38 patients, Karnofsky performance scale scores at the last follow-up were 80 or above. The median progression-free surviv al time among patients with subtotally resected tumors was 66 months, and t he 5-year progression-free survival rate was 60%. The growth rate of residu al 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 signi ficant predictive factors, age and extent of tumor resection seemed to infl uence the progression-free survival rate. Significant factors affecting the growth rate were age and occurrence of menopause. CONCLUSION: Subtotal resection with or without radiation or radiosurgery sh ould be considered as a suitable treatment option for patients with petrocl ival meningiomas, especially the elderly, because the growth rate of residu al tumors is low.