TY - JOUR
T1 - Gamma Knife Radiosurgery for Vestibular Schwannomas: Identification of Predictors for Continued Tumor Growth and the Influence of Documented Tumor Growth Preceding Radiation Treatment
AU - Timmer, Ferdinand C. A.
AU - Mulder, Jef J. S.
AU - Hanssens, Patrick E J
AU - van Overbeeke, J. J.
AU - Donders, Rogier T.
AU - Cremers, Cor W. R. J.
AU - Graamans, Kees
PY - 2011/9
Y1 - 2011/9
N2 - Gamma knife radiosurgery (GKRS) has become an important treatment modality for vestibular schwannomas. The primary aim of this study was to investigate whether tumor growth at the moment of GKRS has any correlation with the outcome. The secondary aim was to identify clinical predictors of radioresistance in vestibular schwannoma patients treated with GKRS.One hundred vestibular schwannoma patients, treated with GKRS, were divided into two groups: 1) proven tumor growth preceding GKRS; and 2) previous history of growth unknown. GKRS outcome was defined in two ways. According to the first definition, GKRS was said to have failed when additional treatment had taken place. According to the second one, a volume decrease >20% after 2 years marked successful treatment.Correlations between outcome and growth status were determined with SPSS software. Furthermore, the study assessed how different variables (patient data, history, tumor characteristics, imaging, and audiovestibular examinations) correlated with the outcome of GKRS.No significant difference regarding success and failure of GKRS was found between the two patient groups. The mean reduction in tumor volume after GKRS was less pronounced in patients in whom tumor growth was demonstrated before treatment, but this finding was not significant. No significant predictors (P <.05) could be identified in this data set.This study found no indication that growth at the moment of GKRS influences therapeutic outcome, nor did it identify any predictors of the outcome after GKRS in vestibular schwannoma patients. The American Laryngological, Rhinological, and Otological Society, Inc.
AB - Gamma knife radiosurgery (GKRS) has become an important treatment modality for vestibular schwannomas. The primary aim of this study was to investigate whether tumor growth at the moment of GKRS has any correlation with the outcome. The secondary aim was to identify clinical predictors of radioresistance in vestibular schwannoma patients treated with GKRS.One hundred vestibular schwannoma patients, treated with GKRS, were divided into two groups: 1) proven tumor growth preceding GKRS; and 2) previous history of growth unknown. GKRS outcome was defined in two ways. According to the first definition, GKRS was said to have failed when additional treatment had taken place. According to the second one, a volume decrease >20% after 2 years marked successful treatment.Correlations between outcome and growth status were determined with SPSS software. Furthermore, the study assessed how different variables (patient data, history, tumor characteristics, imaging, and audiovestibular examinations) correlated with the outcome of GKRS.No significant difference regarding success and failure of GKRS was found between the two patient groups. The mean reduction in tumor volume after GKRS was less pronounced in patients in whom tumor growth was demonstrated before treatment, but this finding was not significant. No significant predictors (P <.05) could be identified in this data set.This study found no indication that growth at the moment of GKRS influences therapeutic outcome, nor did it identify any predictors of the outcome after GKRS in vestibular schwannoma patients. The American Laryngological, Rhinological, and Otological Society, Inc.
KW - Acoustic neuroma
KW - vestibular schwannoma
KW - gamma knife
KW - growth prediction
U2 - 10.1002/lary.21908
DO - 10.1002/lary.21908
M3 - Article
C2 - 22024833
VL - 121
SP - 1834
EP - 1838
JO - Laryngoscope
JF - Laryngoscope
SN - 0023-852X
IS - 9
ER -