My father was diagnosed with Cushing's disease
Question from TJ:
My father was diagnosed with Cushing's disease and had transspheniodal surgery to remove the tumor. The MRI after surgery showed that all of the tumor was removed but his cortisol was still high (689). He then had Gamma Knife treatment four months ago. Two months after the treatment his number dropped to 203. Now four months after the treatment his number is 479. Does this mean that the Gamma Knife was unsuccessful too?
Your question regarding your father is a very appropriate one. I presume that the numbers you are reporting reflect his 24 hour urine free cortisol.
Gamma Knife surgery does not instantly effectuate an endocrinological remission. Most of the time, normalization of the 24 hour urine free cortisol in Cushing's disease patients occurs 6 to 18 months following Gamma Knife surgery. At the University of Virginia, we recommend a brain MRI and endocrinological testing at 6 month intervals for the first 2 years following Gamma Knife surgery.
While it does not appear that your father is cured of his Cushing's disease at present, such a normalization in the cortisol level does not usually occur that quickly and there is still a reasonable chance that he will show signs of improvement attributable to the Gamma Knife in the coming months. However, even if the cortisol reaches a normal level, it is possible that the Cushing's disease can recur so long-term follow-up is needed.
In the meantime, your father may benefit from ketoconazole which inhibits the body's production of steroids and can lessen the effects of the Cushing's disease. I advise that you speak to his endocrinologist about this.