Lack of delayed neurocognitive side effects of Gamma Knife radiosurgery in acromegaly: The Later-Ac study

Abstract

Introduction: Persistent growth hormone hypersecretion can be observed in ro ughly 50% of patients operated for somatotroph adenomas, requiring additional treatments. Despite its proven antisecretory efficacy, the use of Gamma Knife radiosurgery (GK) is limited probably due to the lack of data on long-term side effects, including potential cognitive consequences. Methods: The LATe Effects of Radiosurgery in Acromegaly study was a cros s-sectional exposed/unexposed nonrandomized study. The primary objective was to determine the lo ng-term neurocognitive effects of GK focusing on memory, executive functions, and calculation ability. Exposed p atients had been treated by GK for acromegaly at least 5 years before inclusion. Unexposed patients (paired for age) had to be cured or controlled at last follow-up without any radiation technique. Patients of both groups were cured or controlled at the last follow-up. Results: Sixty-four patients were evaluated (27 exposed and 37 unexpose d). Mean follow-up after GK was 13 ± 6 years (including 24 patients followed for at least 10 years). While u p to 23.8% of the patients of the whole cohort presented at least one abnormal cognitive test, we did not observe any si gnificant difference in neurocognitive function between both groups. During the follow-up, 11 patients presented at lea st one new pituitary deficiency (P = 0.009 for thyroidstimulating hormone deficiency with a higher rate in exposed pat ients), two presented a stroke (1 in each group), and one presented a meningioma (12 years after GK). Conclusions: While GK exposes patients to a well-known risk of pituitary de ficiency, it does not seem to induce longterm cognitive consequences in patients treated for acromegaly.