Abstract
Objective To determine the efficacy and safety of stereotactic radiotherapy (RT) in patients
with Cushing’s disease (CD).
Methods The study included 38 patients [31 patients who
received gamma knife radiosurgery (GKS) and 7 patients who received
cyberknife hypofractionated RT (HFRT)] with CD. Hormonal remission was
considered if the patient had suppressed cortisol levels after low dose
dexamethasone, normal 24-hour urinary free cortisol (UFC), and lack or
regression of clinical features.
Results Biochemical control after RT was observed in
52.6% of the patients with CD and median time to hormonal remission
was 15 months. Tumor size control was obtained in all of the patients. There
was no significant relationship between remission rate and laboratory,
radiological and pathological variables except for preoperative UFC.
Remission rate was higher in patients with lower preoperative UFC. Time to
remission increased in parallel to postoperative cortisol and 1mg DST level.
Although medical therapy before RT did not affect the rate of- and time to
remission, medical therapy after RT prolonged the time to hormonal
remission.
Conclusion In this current single center experience,
postoperative cortisol and 1mg DST levels were found as the determinants of
time to remission. Although medical therapy before RT did not affect the
rate of- and time to remission, medical therapy after RT prolonged the time
to biochemical control . This latter finding might suggest a radioprotective
effect of cortisol lowering medication use on peri-RT period.
Key words
Cushing’s disease - cyberknife hypofractionated radiotherapy - gamma knife radiosurgery
- stereotactic