432 - Gamma knife radiosurgery as a main modality in treating intracranial lesions of NF II patients

Date 28 September 2012
Event ESMO Congress 2012
Session Publication Only
Topics Central Nervous System Malignancies
Surgical Oncology
Radiation Oncology
Presenter Khaled Abdel Karim
Authors K. Abdel Karim1, N.M. Elmashad2, W. Reda3, A. El Shehaby3
  • 1Clinical Oncology, Nasser Institute, Cairo/EG
  • 2Clinical Oncology Department, Tanta University, Tanta/EG
  • 3Gamma Knife Center, Nasser Institute, Cairo/EG



Gamma knife radiosurgery GKS was used for the treatment of the patients with Neurofibromatosis type II (NFII) for years to achieve better tumor control and to avoid the post operative neurological deficits. This study aimed at exploring the effect of GKS on the tumor control rate, the avoidance of new neurological deficits, and the associated morbidity.


We revised the data of 50 intracranial NFII patients (either vestibular schwannomas or meningiomas) who were treated consequently between July 2001 and October 2009 in our center, the data of 43 patients were evaluable. The mean follow up period was 43.7 months (range 6 to 96). We treated 22 females (51.2%) and 21 males (48.8%) with a mean age of 27.6 years (range 9–53 years). Eight patients (18.6%) had a family history of NFII, 29 patients (67.4%) had previous surgeries. A hundred and seventy NFII lesions were treated in 169 treatment procedures, 83/170 were vestibular schwannomas and 87 were meningiomas. The mean number of treated lesions per patient was 3.97 (range 1–14). The mean marginal dose was 11.9 Gy (range 8 to 13 Gy), with a mean isodose of 52.5%, mean percent coverage was 95.7% (ranged 71-100%). The mean target volume was 11.1 cc (range 0.1 to 26.11 cc).


Regarding the overall radiological response, 16 lesions (9.4%) had regressed, 146 (85.9%) remained stable, and 8 (4.7%) had progressed. For 83 schwannomas, 7 lesions (8.4%) had regression, 72 (86.7%) remained stable, and 4 (4.8%) developed progression. For the 87 meningiomas, 9 (10.3%) had regressed, 74 (85.1%) were stable, and 4 (4.6%) had progressed. The Overall survival rate (OS) for all patients was 95.3% (only 2 died), the mean tumor control rate of 95.1%. The overall Freedom from neurological deficits was 97.7%. Only one patient complained of Grade III facial palsy which was temporary and resolved after medical treatment. Using a median dose of 12 Gy maintained serviceable hearing in 56.6% of ears.


Gamma knife radiosurgery for NFII patients can achieve good tumor control and preserved function with low risk of morbidity.


All authors have declared no conflicts of interest.