One-day aspiration/GKS procedure is effective for metastatic brain tumor with cystic component.

Fumi Higuchi1, Shunsuke Kawamoto2, Keisuke Ueki3, Phyo Kim3

1Tochigi, Japan 2Tochighi, Japan 3Department of Neurosurgery,Dokkyo University School of Medicine

Keywords: brain metastasis, gamma knife, cyst, radiosurgery, outcome

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     GKS is an effective tool for the treatment of metastatic brain tumors. It covers multiple lesions in a single procedure and is less stressful for the patient. However, the tumor size amenable to GKS is limited to less than 3 cm in diameter, and cystic tumors frequently exceed this size limitation even if the solid portions are small. In order to avoid lowering the prescription dose sufficient for tumor control, the target volume should be decreased as much as possible. 
     For such lesions, we adopted a new strategy of performing stereotactic cyst aspiration prior to GKS on the same day. We investigated its efficacy in reducing target volume and tumor control.
     The 26 patient’s ages ranged 32 to 77 years (mean 58).
     Stereotactic aspiration followed by GKS was performed for 26 metastatic brain tumors in 25 patients at Department of Neurosurgery Dokkyo Medical University from February 2005 to April 2010.Their medical records were retrospectively reviewed. We collected data on target tumor volumes before and after aspiration, local control of the tumor and patients’ outcomes.
     Mean target volume was reduced from 20.0 cm3(range 8.0- 64.2 cm3 ) to 10.3 cm3 (range 8.0- 64.2 cm3) after aspiration. Volume reduction was approximately 50 %. Before aspiration there were 13 lesions exceeding 14 ml in volume, which is equivallent to a 3cm sphere. In 7 out of these 13 lesions, the target volume was reduced to less than 14ml by aspiration. Prescription dose of 20Gy was achievable in all except one case. Follow up periods were 1-27 months (median11). Seventy-six percent of tumors were well controlled at the end of the follow up or at the patient''s death by other causes. The 1- and 2-year actuarial survival rate was 43.1% and 14.4%.
     This was a retrospective series.
     One-day aspiration/GKS is effective for brain metastases with cystic component. 
     Aspiration procedure reduces the tumor volume significantly, and thereby warrants satisfactory tumor control by enabling safe delivery of sufficient treatment dose.


Project Roles:

F. Higuchi (), S. Kawamoto (), K. Ueki (), P. Kim ()