Article
Brachytherapy alone or in combination with microsurgery for pediatric low-grade gliomas in eloquent locations
Search Medline for
Authors
Published: | June 4, 2012 |
---|
Outline
Text
Objective: Treatment of pediatric low-grade gliomas in eloquent areas is still challenging. The aim of this ongoing prospective study was to analyze safety and effectiveness of stereotactic Iodine-125 brachytherapy (BT) alone or in combination with microsurgery (in case of larger tumor volumes).
Methods: Thirty-four consecutively treated patients (15 girls/19 boys mean age: 9.4 years) (4/2000–4/2011) were included. The date of the last follow-up was 10/2011. BT (after stereotactic biopsy) was considered to be indicated for circumscribed tumors with a diameter ≤4 cm (21 patients). For larger tumors, a combined approach was preferred (13 patients): After a planned partial resection, BT of the residual tumour was carried out 3 months later. Exclusively low-activity temporary Iodine-125 seeds were used: the median reference dose was 54 Gy, the dose rate was low (median: 10 cGy/h). Tumor location was lobar (N=8), hypothalamic/suprasellar (N=11), diencephalic (N=9), cerebellar (N=3), and within the brainstem (N=3). Treatment response was estimated according to the MacDonald criteria. For survival analyses, the Kaplan-Meier method was used. Functional evaluation focused on the comparison of the ophthalmological, endocrinological, and neurological data pre- and postoperatively.
Results: Median follow-up was 38 months. Twenty-three patients had a WHO grade I glioma, and 11 a WHO grade II glioma. Complete response, partial response and tumor control after BT were seen in 8, 17, and 6 patients, respectively. Tumor progression was seen in 3 patients and two of them died. The 5-year progression free survival (survival) was 89% (92%). One patient received radiation therapy plus chemotherapy after malignant transformation of a Grade II astrocytoma. Transient perioperative morbidity was 15% after microsurgery and 8.8% after BT. There was no permanent morbidity. Two patients presented with a symptomatic radionecrosis 11 months after BT requiring necrosectomy. Last follow-up with functional evaluation of those with preoperative deficits revealed an improvement, stabilization or deterioration in 18/26, 5/26, and 3/26 patients, respectively.
Conclusions: Stereotactic BT alone or in combination with microsurgery (in the case of larger tumors) is safe and effective for pediatric patients with low-grade gliomas located in eloquent locations. It is mostly associated with improvement/stabilization of functional outcome scores. The application of external beam radiation and/or chemotherapy can be withheld.