HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS REGISTER		Author Keyword(s) Vol Page [Advanced]

This Article Full Text Full Text (PDF) All Versions of this Article: jnnp.2007.119602v1 79/4/431    most recent Submit a response Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Services Email this link to a friend Similar articles in this journal Similar articles in PubMed Add article to my folders Download to citation manager Request Permissions Google Scholar Articles by Yang, S-Y Articles by Jung, H-W PubMed PubMed Citation Articles by Yang, S-Y Articles by Jung, H-W

Evaluation of tumour response after gamma knife radiosurgery for residual vestibular schwannomas based on MRI morphological features

¹ Department of Neurosurgery, DongGuk University International Hospital, Goyang, Gyeonggi-do, Republic of Korea
² Clinical Research Institute, Seoul National University Hospital, Seoul, Republic of Korea
³ Department of Neurosurgery, Seoul National University College of Medicine, Seoul, Republic of Korea
⁴ Department of Pathology, Seoul National University College of Medicine, Seoul, Republic of Korea

Correspondence to:
Dong Gyu Kim, MD, PhD, Professor, Department of Neurosurgery, Seoul National University College of Medicine, 28 Yeongon-dong, Jongno-gu, Seoul 110-744, Korea; gknife{at}plaza.snu.ac.kr

Methods: Sixty-one patients with histopathologically confirmed VS underwent GK radiosurgery with marginal tumour doses of 9.0–14.0 Gy (mean, 12.5). Mean tumour volume at GK radiosurgery was 3.65 ml (range, 0.52–15.50). GK radiosurgery was performed 0.3–95.7 months (median, 5.8) after microsurgery. Tumour volumes and half-reduction time were calculated using serial MRI. The morphological features of VS were documented by pre-microsurgical MRI. Histopathological investigation included Antoni-type dominance, the proliferation marker Ki-67 and tumour vascularity.

Results: Median duration of radiological follow-up was 53.7 months (range, 24.1–102.2) and the 8-year actuarial tumour control rate was 93.5%. No factor was associated with tumour control, although a cystic VS had borderline significance (p = 0.089). Mean tumour half-reduction time was 8.70 years (range, 0.57–79.89) and tumour half-reduction time in cystic VS proved to be significantly shorter than those in solid VS (p = 0.006). Thrombotic vessels (p = 0.015) and abnormal vessel proliferation (p = 0.003) were significantly more prominent in cystic VS than those in solid VS.

Conclusions: GK radiosurgery appeared to be an effective treatment modality for residual tumour control after microsurgery. Owing to having relatively abundant tumour vascularity, residual solid portions of cystic VS resulted in efficient shrinkage after GK radiosurgery. Therefore, GK radiosurgery was found to be a rewarding therapeutic approach to the residual solid portions of cystic VS.

Keywords: gamma knife radiosurgery; half-reduction time, tumour; vestibular schwannoma