gms | German Medical Science

Objective: The optimal therapeutic management of children with WHO grade I and II gliomas not accessible to complete resection is poorly defined. IRS might be an attractive treatment concept for selected patients with small and circumscribed tumours. Precise high dose application, maximal sparing of the surrounding normal tissue, and the absence of long-term complications have been reported to be the hallmarks of IRS. Therefore, the therapeutic impact and the risk of IRS alone or in combination with microsurgery were prospectively tested for pediatric patients with eloquently located gliomas.

Methods: Seven boys and 4 girls were included (mean age: 6.8 years, range: 11 months to 16 years). IRS (after stereotactic biopsy) was considered to be indicated for circumscribed tumours with a diameter in the range of 3.5 cm (4 patients). In the case of larger tumours a combined microsurgical/radiosurgical approach was preferred (7 patients). Exclusively temporary Iodine-125 seeds were used (tumour dose calculated to the boundary: 55 Gy, dose rate: 10 cGy/h). Tumour location was hypothalamic/suprasellar in 4, lobar in 3, deep (thalamus, pineal gland) in 3, and within the brainstem in 2 children. Treatment effects of IRS were estimated according to the Macdonald criteria.

Results: A complete response after IRS was seen in 4 patients and a partial response in 7 patients (median follow-up: 31.5 months). There was no perioperative morbidity after microsurgery and/or IRS and no radiogenic complications occurred during the follow-up period. Five patients experienced an improvement of their deficits and no deterioration of neurological/endocrinological function was seen for any of the patients at the time of last follow-up evaluation.

Conclusions: IRS alone or in combination with microsurgery (in the case of larger tumours) is a safe, effective, and minimal invasive treatment strategy for eloquently located pediatric low-grade gliomas and deserves further prospective evaluation.