專題討論1:腦瘤的放射手術治療

程 序 表

S1-1
加馬機放射手術治療顱底腦膜瘤
Gamma Knife Radiosurgery for skull base meningioma
孫銘希
Ming-hsi Sun, Hung-chuanPan, Hsu-tung Lee, Chiung-chyi Shen
台中榮民總醫院神經外科
Neurological Institute , Taichung Veterans General Hospital (VGHTC), Taichung, Taiwan

Background
  Meningioma growing at the skull base is usually prone to invading the surrounding critical neuro-vascular structure. This makes microsurgery a challenge of complete resection and post-op morbidity. Residue or delayed recurrence requiring further intervention is often. The stereotactic radiosurgery (SRS) has been an adjunct to microsurgery and also an alternative as primary treatment for the skull base meningioma.
Materials and methods
  To determine the efficacy of Gamma Knife radiosurgery (GKRS) in treating skull base meningioma at Taichung Veterans General Hospital, we performed a retrospective review of our patients between 2003 and 2011. Seventy-six patients with skull base meningioma treated with Gamma Knife radiosurgery were investigated and had at least one post-op radiographical follow-up..
The patients comprised 23 ( 30% ) male and 53 (70%) female , with average age of 63 years ( range 24-84 ) . Thirty-four (45 % ) patients had prior surgical resection followed by Gamma Knife radiosurgery and 42 ( 55%) patients were treated?? according to the radiographical diagnosis. The tumors involved the cavernous sinus in 38.2% and cerebello-pontine angle in 25% of patients mostly . The mean dose to the tumor margin was 12.9 Gy ( 10-16) and at 49.4% ( 40-60%) isodose line. The average radiation treated volume was 7.8 CC ( 0.357 – 41.9).
Results
  The mean follow –up is 38 months ( 6-127 ). The tumor volume post Gamma Knife radiosurgery decreased in 28 patients (36.8% ) , remained stable in 44 patients (57.9% ) , and increased as tumor progression in 4 patients (5.3% ). Overall control rate , tumor volume decreased and stable, was 94.7%. All four patients with tumor progression had prior surgical resection and diagnosed pathologically as atypical meningioma, WHO Gr. II. Two patients had radiation out-field recurrence underwent subsequent repeated Gamma Knife radiosurgery. The other two had both in- and out-field recurrence and underwent surgical resection. Six (7.8%) patients had post-radiation adverse effect around the tumor found on the follow-up MRI , but all were asymptomatic. New post-Gamma Knife related neurological symptoms of trigeminal and oculomotor nerve dysfunction were found in 3 patients.
Conclusion
  The Gamma Knife Radiosurgery provides high tumor control rate for benign meningioma at skull base and acceptable morbidity. However, the atypical meningioma has high potential of recurrence or progression.