Introduction

Children with a Low Grade Glioma (LGG) may be at risk for deprived bone health due to hypothalamic-pituitary dysfunction, exposure to multiple treatment modalities, and/or decreased mobility in combination with vision loss. Currently this has been understudied and its prevalence or severity is unclear. We aimed to identify the prevalence and risk factors for bone problems in children with supratentorial midline LGG.

Methods

A retrospective study was performed in children aged ≤ 18 years at diagnosis of a supratentorial midline (suprasellar or thalamic) LGG between 1-1-2003 and 1-1-2022. Optic pathway gliomas without involvement of the optic chiasm were excluded. Bone problems were defined as presence of vertebral fractures, vertebral collapse, any fractures not related to (the intensity of) trauma, treatment with bisphosphonates, or very low bone mineral density (BMD) as measured by DXA scan or by Bone Health Index using digital X-ray radiogrammetry (Z score below -2 SDS).

Results

In total, 161 children were included. Median age at tumor diagnosis was 4.7 years (range 0.1 – 17.9) with a median follow-up of 6.1 years (0.1 – 19.9). ‘Any’ bone problem occurred in 22.4% (36/161).  In addition to these 22.4%, in 13.7% low BMD was found. Prior diencephalic syndrome (p < 0.001), any pituitary deficiency (p = 0.038 to p = 0.002), hypothalamic syndrome (p = 0.025), delta BMI SDS from diagnosis to follow-up (p = 0.016), any neurosurgical intervention (p = 0.023), and visual problems (p = 0.003), were univariately with bone problems.

Conclusion
Decreased BMD and bone problems are prevalent in 36.1% of children with supratentorial midline LGG. The results from this study may even be an underestimation. The origin of bone problems appears to be multifactorial in these children and is especially related to weight problems due to hypothalamic dysfunction. Given this high prevalence, bone health must be a point of awareness in the care and follow-up of children with supratentorial midline LGG.