Gamma knife radiosurgery for intracranial mature teratoma--long-term results and review of literature.
BACKGROUND
The purpose of this report is to present long-term outcomes of gamma knife radiosurgery for intracranial mature teratoma after debulking surgery.


METHODS
Three patients with intracranial mature teratoma had initial target volumes of 5.4, 18.7, and 5.1 cm(3), respectively, and were treated by gamma knife radiosurgery between 1993 and 2004. Marginal doses of 17, 12.5, and 13.5 Gy, respectively, were delivered to the tumors at isodose levels of 50%, 50%, and 62%, respectively. The first patient received radiosurgery after surgical removal and conventional radiotherapy. The second patient received similar management, including surgery and radiotherapy, with tumor recurrence. Two additional operations and subsequent radiosurgery were performed on this patient. Based on the favorable results of the first 2 patients, we performed radiosurgery instead of conventional radiotherapy after subtotal surgical removal in the last patient. By reviewing literatures concerning the therapeutic modalities and the long-term results of our 3 patients, we discuss the role of radiosurgery in treating intracranial mature teratoma.


RESULTS
A follow-up period of 121, 89, and 31 months, respectively, demonstrated tumor volume reduction rates of 70%, 89%, and 48%, respectively. No evidence of further tumor progression and no radiosurgery-related complication or morbidity was noted. The school performances of the affected children are all above average.


CONCLUSIONS
Gamma knife radiosurgery provides a safe and effective alternative as the adjuvant treatment of intracranial mature teratoma after surgical debulking. Previous conventional radiotherapy does not alter final tumor control. Radiosurgery should be considered when residual tumor growth continues with no related symptoms or evaluations of tumor markers during follow-up.
Chiu
Cheng-Di
CD
Department of Neurosurgery, Neurological Institute, Veterans General Hospital-Taipei, and National Yang-Ming University, Taipei, Taiwan 11217, Republic of China.
Chung
Wen-Yuh
WY
Pan
David Hung-Chi
DH
Wong
Tai-Tong
TT
Shih
Yang-Hsin
YH
Lee
Liang-Shong
LS
D000293:Adolescent; D024221:Antineoplastic Protocols; D001932:Brain Neoplasms / Q000473:pathology* / Q000532:radiotherapy / Q000601:surgery*; D002648:Child; D002675:Child, Preschool; D003663:Decision Trees; D004172:Diplopia / Q000209:etiology / Q000473:pathology / Q000601:surgery; D018450:Disease Progression; D006261:Headache / Q000209:etiology / Q000473:pathology / Q000601:surgery; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D009364:Neoplasm Recurrence, Local / Q000517:prevention & control / Q000532:radiotherapy; D016634:Radiosurgery / Q000379:methods* / Q000706:statistics & numerical data / Q000639:trends; D012985:Software Design; D013724:Teratoma / Q000473:pathology* / Q000532:radiotherapy / Q000601:surgery*; D016896:Treatment Outcome; D014839:Vomiting / Q000209:etiology / Q000473:pathology / Q000601:surgery