ESPE Abstracts

Introduction: Brain tumors are the most common solid neoplasm in children, and treatment often includes high-dose irradiation of the central nervous system (CNS). Although not universal, growth hormone deficiency (GHD) is a very common endocrine late effect after CNS irradiation in childhood. The consequences of GHD in adults are many e.g., reduced bone mineral density, fatigue, decreased lean body mass and adiposity, which implies that adults with severe GHD should be offered substitution with growth hormone.

Aims: 1) To determine the frequency of GHD in adult long term survivors after CNS irradiation for a brain tumor in childhood 2) To detect undiagnosed GHD in survivors after CNS irradiation in childhood 3) To assess if proton therapy is associated with less GHD than photon therapy.

Methods: The study group comprised population based five-year survivors from two health regions in Denmark treated for a brain tumor in childhood with CNS irradiation in the period 1997–2015. Medical charts from all survivors were reviewed for endocrinological and other health data. Irradiated survivors, where a GH test at final height had not been performed, were invited to an Insulin Tolerance Test (ITT) or a Growth Hormone-releasing hormone-arginine test if ITT was contraindicated.

Results: Forty-one survivors (22 females) with a median age of 21.7 years at follow up (range 15.1-33.8 years) and 14.8 years since diagnosis (range 5.1-23.4 years) had received CNS irradiation of 12-61 Gy. GHD was detected in 26 (63%) of 41 survivors. In total, 17 %, 15 % and 15 % had two, three and four hormonal deficiencies, respectively. Eighteen of 21 patients had already confirmed GHD after reaching final height. Sixteen of 20 patients with no GH test at final height accepted the invitation to a GH test (Participation rate 80%), and 8 (50%) were found to have GHD. Of the 41 irradiated survivors, 11 had received proton irradiation and 30 photon irradiation. GHD was diagnosed in 73 % of patients treated with proton- and in 60 % of patients treated with photon irradiation, respectively.

Conclusion: In this study, a high frequency of undiagnosed GHD in survivors with no GH test at final height were identified. The results reinforce the importance of screening for GHD at final height in survivors of childhood brain tumors with prior exposure to cranial irradiation. In this small study the frequency of GHD was similar in patients treated with proton and photon irradiation.