Endocrinological evaluation of growth hormone-secreting pituitary macroadenoma invading cavernous sinus treated by aggressive transsphenoidal resection followed by Gamma Knife radiosurgeryJong Hee Chang1, Min Cheol Oh2, Eun Jik Lee3, Sun Ho Kim21 2Department of Neurosurgery, Yonsei University Health System 3Department of Endocrinology, Yonsei University Health System Keywords: acromegaly, resection, hormone dysfunction, gamma knife, pituitary adenoma
Pituitary tumors involving the cavernous sinus pose difficult challenges, particularly for hormone-secreting tumors.
The authors would like to determine long-term effect of Gamma Knife
radiosurgery (GKS) for the treatment of remnant tumor in the cavernous
sinus (CS) after operation using transsphenoidal approach (TSA) of
growth hormone (GH)-secreting pituitary macroadenoma.
There were 13 women and 4 men with a mean age of 41.8 years (range 27-62).
Seventeen patients who failed to achieve biochemical remission after TSA were followed for a mean period of 70.2 months (range 17-180) after GKS. All patients underwent regular hormonal examination including serum GH, IGF-1, oral glucose tolerance test, and combined pituitary function test (CPFT). Magnetic resonance imaging (MRI) was performed 6 months after GKS and then subsequent one year interval. All patients had remnant tumor only in the CS and received hormone-suppressive medication, sandostatin LAR before or after GKS.
Ten patients( 58.8%) achieved hormonal remission with a mean time of 47 month (median 40, range 18-129) after GKS and mean radiation dose to tumor margin was 27.9 Gy (range 14-35). Mean tumor volume decreased from 5.2 ml (at pre-GKS MRI) to 3.6 ml (at the last follow-up MRI) (p=0.000). Actuarial rate of hormonal remission at 2, 4, and 6 years were 12.5%, 40%, and 64%, respectively. Intergroup comparison between remission and non-remission group those who had a minimum hormonal follow-up period of 48 months, showed both ‘serum level of GH’ and ‘degree of decreased GH percentile’ at 12 months after GKS showed significant difference (p=0.023), (p=0.014), respectively. A new pituitary hormone deficiency that has significant difference was found only in gonadal axis (p=0.032) based on last follow-up CPFT. A radiation necrosis was detected in 4 patients.
This was a retrospective series.
GKS for the remnant tumor only in the CS after maximal resection of sellar and suprasellar portion of GH-secreting pituitary macroadenomais effective, especially for minimizing newly developed post-GKS hypopituitarism.
However, careful dose planning and long-term follow-up should be
necessary in terms of prevention and effective management of
radiation-induced complications. Project Roles:
J. Chang (), M. Cheol Oh (), E. Jik Lee (), S. Ho Kim ()