Stereotactic radiosurgery effective for Nelson’s syndrome

Gamma Knife radiosurgery (GKRS) is effective for controlling tumour growth and may be a viable treatment option for Nelson’s syndrome (NS), a recent meta-analysis has found.

“NS is a rare complication with growth of the corticotroph tumour in patients harbouring Cushing's disease subsequent to receiving bilateral adrenalectomy (BLA),” the researchers explained. “In this patient group, NS has a prevalence of 30 percent to 50 percent.”

The present meta-analysis sought to clarify the efficacy of a stereotactic radiosurgery approach to NS. Endocrine remission (ER), the study outcome, was defined as the normalization of adrenocorticotropic hormone levels after cessation of pituitary inhibitory medications. Another study endpoint was tumour control (TC), which was defined according to the included studies.

Four studies were deemed eligible for the meta-analysis, contributing a total of 100 NS patients, all of whom were treated with GKRS a median of 51 to 139 months after BLA. The median follow-up ranged from 37 to 98 months, during which an ER rate of 21 percent (95 percent confidence interval [CI], 13–29) was achieved.

Three studies reported on the TC rate, yielding a total sample size of 72 patients. In this group, researchers saw a TC rate of 91 percent (95 percent CI, 84–98). Meanwhile, the incidence of new onset hypopituitarism was 20 percent.

“More studies with larger sample sizes and longer follow-up periods are needed to further investigate the efficacy and safety of stereotactic radiosurgery for NS,” the researchers said.