Combined Microsurgery Plus Gamma Knife By The Same Team For Large Skull Base Tumors: Towards Zero Mortality And Near Zero Morbidity In 381 CasesPing Chung Yu1, samuel cheong lun leung2, Chris Poon3, Yiu Wah Fan1, Ben Ng1, Josie Chan1, Robert Ho11Canossa Hospital 2neurosurgery department 3 Kwong Wah Hospital Keywords: skull base, outcome, gamma knife, resection, Microsurgery
In 1983, Professor Lars Leksell stated “the same individual can be a competent microsurgeon and also a stereotactic radiosurgeon.”
We applied this principle prospectively for treatment of large skull base tumors with the aim towards zero mortality and preservation of quality of life.
From 2000 Jan to 2009 July, 381 patients with large /symptomatic skull base tumors entered the protocol: 63 acoustic neuromas, 203 pituitary adenomas, 14 craniopharyngiomas, 78 skull base meningiomas, 8 chordomas and chondrosarcomas, and 15 other cranial nerve neuromas.
Large/symptomatic skull base tumors were targets of this study. The team included 3 senior neurosurgeons with expertise in skull base microsurgery and Gamma Knife surgery. The same neurosurgeon was always responsible for case selection, informed consent, operative microsurgery, and subsequent Gamma Knife surgery. Data was collected prospectively and same treatment protocol was followed in each case. We analyzed operative mortality, new post-operative neurological deficit, complications, and Glasgow outcome score at 3 months after microsurgery. Gamma Knife surgery follow up protocol included clinical, tumor volume mapping and neuro-endocrine assessment for relevant tumors.
There was no operative mortality due to microsurgery. 2 acoustic neuromas patients developed transient facial palsy. No permanent new cranial neuropathies occur after microsurgery. One patient with clivus chordoma had delayed nasal bleeding 7 days after transsphenoidal surgery. There were no cases of vascular injures, post-op CSF leak, infection, permanent diabetes insipidus, or new pituitary insufficiency. All patients who underwent microsurgery returned to their pre-operative status at 3 months post-op. No patient developed new cranial nerve or other neurological deficits after Gamma Knife. Mean follow up time after Gamma Knife was 70 months: Tumor volume response does not differ from those patients with small tumors that did not require combined treatment. 2 patients with craniopharyngiomas and 2 patients with chordomas required additional microsurgery/Gamma knife surgery. 11 acromegalics out of 40 required more than 1 Gamma knife session for persistent elevated growth hormone/IFG-1.
This is a retrospective study.
The same team combined approach for large skull base tumors gives excellent results with no procedural mortality, near zero new neurological deficit and preservation of quality of life.
We recommend all skull base neurosurgeons to undergo training in Gamma Knife surgery as part and parcel of their professional armamentarium. Project Roles:
P. Yu (), s. leung (), C. Poon (), Y. Fan (), B. Ng (), J. Chan (), R. Ho ()