Dr. Ed Oldfield gave a presentation on a patient’s options after a unsuccessful pituitary surgery. A second surgery is a treatment option, but only after review of the diagnostic testing to make sure that the source of Cushing’s is indeed pituitary and that failure was not due to invasion of the tumor into areas that cannot be reached by surgery.
|Dr. Edward Oldfield, Neurosurgeon, Univ. of Virginia, Charlottesville, VA|
Most pituitary tumors are large and most are removed by a surgeon that does only 4-5 surgeries per year. But, because the tumors causing Cushing’s can be very small and often are not visible on an MRI, Cushing’s is a different circumstance that requires a surgeon experienced with Cushing’s disease. The success rate in repeat surgery is low if the entire gland has been previously examined by an experienced pituitary surgeon and no tumor was found. Inexperienced surgeons may make only small openings in the sella which means only a small portion of the pituitary is visible and sometimes only one side of the pituitary is explored. If that is the case, these patients are candidates for a second surgery by an experienced surgeon. Most pituitary tumors causing Cushing’s are contained within a pseudocapsule. Dr. Oldfield showed a video of what the capsule looks like and how it is removed.
For recurrences, Dr. Oldfield presented data showing that in this series, 100% of recurrences were at the same location as a previous tumor. Thus with recurrences, regardless of whether the tumor can be seen on MRI, repeat surgery may be an option because the tumor is most likely in the same location. The most common cause of failed pituitary surgery is invasion of the dura. Depending on the degree of invasion, it may be possible to removal all of the tumor by removing a small section of the cavernous sinus wall, resulting in a cure.
Dr. Oldfield went on to discuss radiation, both fractionated and radiosurgery. Outcomes are similar, but fractionated radiation requires about 5 weeks of treatment, whereas radiosurgery can be done in one day. Neither takes effect immediately. Bilateral adrenalectomy is another treatment option, however, further growth of the tumor is possible. While different studies show different results, radiation before bilateral adrenalectomy can reduce the risk of tumor growth.