The Efficiency of Radiation Therapy in the Treatment of Intracranial Oligodendrogliomas : Factors Influencing the Prognosis / 대한방사선종양학회지

ABSTRACT

PURPOSE: Oligodendrogliomas (ODG) are a rare, slow growing, tumor in the brain, which can be cured by complete surgical resection, but as yet it is not known if postoperative adjuvant radiation therapy (RT) is essential. We analyzed the treatment results of patients with irradiated ODG to investigate the efficacy of RT in terms of survival rates and other influencing prognostic factors. METHODS AND MATERIALS Between March 1983 and December 1997, 42 patients with ODG were treated with RT at our hospital. The RT was performed daily at a dose of 1.8~2.0 Gy, at 5 fractions per week, to a total dose of between 39.6 Gy and 64.8 Gy (mean 53.3 Gy). The ages of the patients ranged between 5 and 62 years, with a median age of 39 years. The mean follow-up period was 63.4 months (8-152 months). The Kaplan-Meier method was used to assess the survival, and 5 year survival rates (5-YSR). Log rank tests and Cox regression analyses were used to define the significance of prognostic factors. RESULTS: The majority of ODG in this study were located in the cerebral hemisphere (83.3%). ODG are slightly more common in men than women, and commonly occurs in middle age, between the 3rd and 4th decades. It has been recommended that RT is commenced within 4 weeks following surgery (5-YSR; 86% vs. 49%; p0.05). CONCLUSION: A local involved field irradiation with conventional fractionation, commencing within 4 weeks following surgical excision of the tumor, was beneficial for the 5-YSR, but a total radiation dose exceeding 60 Gy did not improve the 5-YSR.