Gamma Knife Radiosurgery for Juxtasellar Tumors

터어키안 주변종양에 대한 감마나이프 방사선 수술

Objective : Around the sellar area, there are many important structures. But, the optimal radiation dosage for minimal toxicity to surrounding neural tissue has not been firmly established. The purpose of this study is to evaluate the radiosurgical outcome of juxtasellar tumors and to investigate the relationship between radiation dosage and toxicity to neural tissue. Method : Between May 1992 and June 2000, we treated 65 juxtasellar tumors by using the Leksell Gamma Knife. Among them, 52 patients who could be followed more than 1 year were included in this study. The radiosurgical dosage to the optic pathway, cavernous sinus, Meckel's cave, hypothalamus, pituitary gland and stalk, and brain stem was analyzed and correlated with clinical outcome. The mean follow-up period was 33.5 months(range 12.2- 99.0 months). Result : The clinical response rate was 69.2%. The volume response rate was 61.0% and the radiologic control rate was 92.7%. There were 4 complications(7.7%) of 2 trigeminal neuropathy, 1 abducens nerve palsy, and 1 trigeminal and transient abducens nerve palsy. The optic apparatus appeared to tolerate doses greater than 10Gy. The risk of cranial nerve complications in cavernous sinus seemed to be related to doses of more than 16Gy. In 3 of 4 patients who received more than 16Gy to cavernous sinus, the abducens or trigeminal neuropathy occurred. Also, one patient who received more than 15Gy to the Meckel's cave, trigeminal neuropathy developed. The hypothalamus, pituitary gland and stalk, and brain stem were relatively tolerable to radiation. Conclusion : Gamma Knife radiosurgery seems to be an effective method to control the growth of juxtasellar tumors. To avoid injury to surrounding important neural tissue, careful dose planning and further study for radiation toxicity to neural tissue were needed.