The enlargement of nonfunctional pituitary adenomas after postoperative gamma knife radiosurgery is the consequence of hypothyroidism.

Nan Zhang1, Li Pan2, Han-feng Wu2, Bin-jiang Wang2, Ya-fei Dong2, Jia-zhong Dai2, En-min Wang2

1Xuhui District,Shanghai, China 2

Keywords: pituitary adenoma, gamma knife, hormone dysfunction, outcome, radiosurgery

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     Tumor enlargement after pituitary radiosurgery can be due to several outcomes.
     Our purpose was to evaluate the tumor control failure of nonfunctional pituitary adenomas associate with hypopituitarism after postoperative gamma knife radiosurgery.
     The median duration of follow up for the 67 patients after GKR was 38 months.
     The endocrine and image follow-up data of sixty-seven patients with residual or recurrence nonfunctional pituitary adenoma after operation treated with GKR between 2006 and 2009 were studied.
     The tumor control rate was 94%. New hormone deficiency after GKR was found in seven patients(10%). Six patients (9%) developed hypothyroidism and three patients (4%) developed cortisol deficiency. Four cases were found with enlargement of pituitary adenomas and new hypothyroidism. The median follow-up time of patients with new hormone deficiency after GKR was 47 months. Using Sodiumlevothyroxine(Euthyrox) as the replace treatment for the new hypopituitarism patients decreased the tumor volume which was found enlargement on the follow-up images without retreatment using GKR.
     This was a retrospective study.
     Gamma Knife is a safe and effective treatment for residual or recurrent nonfunctional pituitary adenomas. The enlargement of nonfunctional pituitary adenomas after GKR is the consequence of hypothyroidism and is not the failure outcome of GKR.
     Replacement therapyusing Euthyrox for hypothyroidism is effective in decreasing the enlargement tumor volume than retreatment using GKR.


Project Roles:

N. Zhang (), L. Pan (), H. Wu (), B. Wang (), Y. Dong (), J. Dai (), E. Wang ()