Clinical Review And Discussion Of Stereotactic Radiosurgery Treatment For Acoustic Neuroma

OBJETIVE: To discuss influncing factors and clinical decisions for acoustic neuroma treated by stereotactic radiosurgery, by analyzing the outcome of 156 patients.METHODS: The study retrospectively analysed 156 cases acoustic neuroma treated by stereotactic radiosurgery in Gamma Knife Radiosurgery Center of Wuhan Union Hospital during 2010-2013,included 62 cases of males and 94 cases of females. The mean age is 50.8years old. We collected the full medical records of all cases Included in the study. The medical records included but not limited to tumor growth control rate, cranial nerves function preservation rate, procedure-related complications, and discuss the effect and influncing factors for acoustic neuroma treated by stereotactic radiosurgeryRESULT: The cases was followed up 24-71 months in this study,averaged 42 months. In 156 patients, tumors were significantly demonstrated regression in 45 cases, stable in 97 cases, enlargement in14 cases, the rate of tumor growth control was 91.02%. The tumor growth control rate of small tumor(maximum diameter <15mm) in 77 cases is 96.1%. The tumor growth control rate of medium-sized tumor(maximum diameter between 15mm~30mm) in 62 cases patients is88.71%. The tumor growth control rate of large tumor(maximum diameter >30mm) in 17 cases patients is 76.95%.The difference of tumor growth control rate between small-medium tumor and large tumor exists statistical significance(P=0.026). The facial nerve function preservation rate is 89.4% in 66 patients that margin doses ≥ 14 Gy, and98.6% in 73 patients that margin doses <14Gy. The difference of facial nerve function preservation rate between different margin dose exists statistical significance(P=0.02). The hearing preservation rate is72.41% in 29 patients that had GR Class I hearing before gamma knife radiosurgery treatment, and 47.37% in 57 patients that had GR Class II hearing before gamma knife radiosurgery treatment. The difference of hearing preservation rate exists statistical significance(P=0.027).CONCLUSION: Gamma Knife Stereotactic radiosurgery is an effective treatment of acoustic neuroma, could achieve satisfactory tumor growth control rate. Main factor influencing the tumor growth control rate after treatment is the size of tumor. Main factors influencing the hearing preservation rate and facial nerve function preservation rate are hearing grade before treatment and margin dose of the tumor,respectively.