111Indium-octreotide brain scintigraphy: a prognostic factor in skull base meningiomas treated with gamma knife radiosurgery.

摘要

AIM: The purpose of this study is to prospectively investigate the prognostic role of somatostatin receptor scintigraphy (SRS) using an 111Indium-labelled somatostatin analogue, Octreotide, in skull base meningiomas (SBMs) treated with gamma knife (GK) radiosurgery. METHODS: From December 1997 to March 2000, SRS was performed both before and within 1 year of radiosurgery on 12 patients. Semi-quantitative data were calculated as SRS index; the index decrease was arbitrarily considered significant above 10. A potential correlation between the decrease in post/pre-GK SRS index and radiosurgical outcome was evaluated. RESULTS: The follow-up period was at least 30 months in the whole series (median, 43 months). In all 12 patients, the pre-GK SRS index was always >1, averaging 3.73+/-2.9. A decrease in the post-GK average SRS index (2.35+/-1.5) was observed. The difference between the pre- and post-GK average values was statistically significant (p10 was observed in 9 patients and 10, with stable imaging in the others (p=0.00024). Conclusion. Our preliminary findings suggest a prognostic correlation between a decrease in concentration of somatostatin receptors on meningioma cells within 1 year of radiosurgery and delayed meningioma shrinkage.