Brain Metastases in Pediatric Extracranial Solid Tumors: A 20-Year Experience in Challenging a Rare Diagnosis.

Abstract

Aim: To investigate the clinical features, treatments, and outcomes of pediatric patients with brain metastasis from extracranial solid tumors, which has been known as a rare condition.

Material and methods: Over a 20-year period, 520 children treated for extracranial solid tumors in our radiotherapy clinic were reviewed, and 12 cases (2.2%) of brain metastases were identified. The primary tumors included neuroblastoma (n=5), osteosarcoma (n=3), Ewing sarcoma (n=2), rhabdoid tumor of the kidney (n=1), and Wilms tumor (n=1). Retrospective analysis was performed to evaluate tumor and treatment features. Overall survival was measured from the initial diagnosis. Overall survival after brain metastasis, local control, and brain metastasis progression-free survival were calculated from the time of brain metastasis diagnosis to death.

Results: Median follow-up was 31 months (range, 13-72 months). Brain metastasis developed at a median of 13 months after primary diagnosis (range, 3-69 months). Most brain metastases were supratentorial and solitary, with nine of 12 patients (75%) having solitary lesions and eight of 12 (67%) having supratentorial lesions. Surgical excision was performed in 9 patients (75%). Radiotherapy was administered locally (20-30 Gy, n=7) or to the craniospinal axis (21.6 or 23.4 Gy, n=2). Ten patients died during follow-up, 70% of whom did not experience cranial progression. Local control rate for irradiated lesions was 81.5% (median duration: 22 months). The brain metastasis-free survival was 71.4% (95% confidence interval [CI]: 2.59%-55.41%) with a median of 10 (range, 1-41) months. The 2-year survival rate was 58.3% (95% CI: 6.15%-71.84%). The 2-year overall survival rate after brain metastasis was 16.7% (95% CI: 7.13%-21.53%).

Conclusion: Brain metastasis remains rare in pediatric solid tumors. Most patients died from extracranial disease progression rather than cranial relapse. Radiotherapy can effectively relieve symptoms and may delay the progression of brain metastasis. Guidelines may help optimize the treatment of patients with brain metastasis.