However, neurosurgeons are beginning to question this guideline as many have conducted preliminary studies that demonstrate efficacy in the treatment of more than four lesions. In these cases, the major determining factor in proceeding with Gamma Knife is the neurological function of the patient and the life expectancy. The treatment of choice for pituitary tumors is dependent upon patient presentation. Small tumors without optic nerve pressure can be managed by a combination of medical treatment followed by either surgical resection or Gamma Knife radiosurgery to prevent further growth or treat residual tumor. Transsphenoidal microsurgery is effective for decompressing optical pathways, obtaining tissue diagnosis, reducing tumor bulk and rapidly alleviating hormonal abnormalities.
Residual tumor is often a problem after surgical intervention, especially near the cavernous sinus.
Hormone levels gradually fall over time in most patients treated with the Gamma Knife. Published results for a variety of modalities are illustrated in figures nine and ten. Candidates for the treatment of trigeminal neuralgia with the Gamma Knife include those refractory to medication trials with drugs such as Tegretol or Dilantin, those that have no tumor on brain imaging, and those with continued pain after surgical therapy. Radiosurgery is especially suited for patients of advanced age or with medical problems that place the patient at greater risk for complications with other therapies. Relief of pain is variable and ranges from one day to eight weeks post Gamma Knife treatment.