Background: To the authors' knowledge, the incidence of brain metastases at the time of diagnosis in children with metastatic rhabdomyosarcoma (RMS) arising outside the head and neck region is unknown, and routine imaging to identify metastatic brain involvement is costly.
Methods: The authors retrospectively reviewed the results of computed tomography (CT) or magnetic resonance imaging (MRI) scans of the head, which was mandated by protocol, in patients with metastatic RMS arising outside the head and neck region who were enrolled on the fourth Intergroup Rhabdomyosarcoma Study (IRS-IV; 1991--1997).
Results: Of 100 eligible patients with metastatic RMS arising outside the head and neck region, 56 (56%) underwent head CT (n = 51) and/or MRI (n = 11) scans. Seven of these 56 patients (12.5%) had abnormal scans. Three patients with physical findings suggesting head or neck pathology underwent imaging that confirmed the presence of metastases in bone (one patient), orbit (one patient), or lymph nodes (one patient). One patient who presented with seizures had imaging findings consistent with cerebral embolic infarctions. Of three asymptomatic patients, one had bone metastases that also were identified on skeletal survey and one had bone metastases in the base of the skull that were not identified on bone scan. The remaining asymptomatic patient had a retroperitoneal paraspinal tumor with spinal canal extension and subsequently developed leptomeningeal disease dissemination.
Conclusions: Brain metastases are uncommon at the time of initial diagnosis of metastatic RMS arising outside the head and neck region, and the majority of abnormalities detected on head CT or MRI scans are evident clinically or on other imaging studies. Patients with clinical findings suggesting intracranial pathology and those with paraspinal tumors may benefit from brain imaging, but cost savings may be realized by foregoing imaging in patients without these features.
Copyright 2001 American Cancer Society.