Stereotactic radiosurgery for pediatric recurrent intracranial ependymomas

Abstract

<jats:sec> <jats:title>Object</jats:title> <jats:p>To evaluate the role of stereotactic radiosurgery (SRS) in patients with recurrent or residual intracranial ependymomas after resection and fractionated radiation therapy (RT), the authors assessed overall survival, distant tumor relapse, progression-free survival (PFS), and complications.</jats:p></jats:sec> <jats:sec> <jats:title>Methods</jats:title> <jats:p>The authors retrospectively reviewed the records of 21 children with ependymomas who underwent SRS for 32 tumors. There were 17 boys and 4 girls with a median age of 6.9 years (range 2.9–17.2 years) in the patient population. All patients underwent resection of an ependymoma followed by cranial or neuraxis (if spinal metastases was confirmed) RT. Eleven patients had adjuvant chemotherapy. Twelve patients had low-grade ependymomas (17 tumors), and 9 patients had anaplastic ependymomas (15 tumors). The median radiosurgical target volume was 2.2 cm<jats:sup>3</jats:sup> (range 0.1–21.4 cm<jats:sup>3</jats:sup>), and the median dose to the tumor margin was 15 Gy (range 9–22 Gy).</jats:p></jats:sec> <jats:sec> <jats:title>Results</jats:title> <jats:p>Follow-up imaging demonstrated therapeutic control in 23 (72%) of 32 tumors at a mean follow-up period of 27.6 months (range 6.1–72.8 months). Progression-free survival after the initial SRS was 78.4%, 55.5%, and 41.6% at 1, 2, and 3 years, respectively. Factors associated with a longer PFS included patients without spinal metastases (p = 0.033) and tumor volumes &lt; 2.2 cm<jats:sup>3</jats:sup> (median tumor volume 2.2 cm<jats:sup>3</jats:sup>, p = 0.029). An interval ≥18 months between RT and SRS was also associated with longer survival (p = 0.035). The distant tumor relapse rate despite RT and SRS was 33.6%, 41.0%, and 80.3% at 1, 2, and 3 years, respectively. Factors associated with a higher rate of distant tumor relapse included patients who had spinal metastases before RT (p = 0.037), a fourth ventricle tumor location (p = 0.002), and an RT to SRS interval &lt; 18 months (p = 0.015). The median survival after SRS was 27.6 months (95% CI 19.33–35.87 months). Overall survival after SRS was 85.2%, 53.2%, and 23.0% at 1, 2, and 3 years, respectively. Adverse radiation effects developed in 2 patients (9.5%).</jats:p></jats:sec> <jats:sec> <jats:title>Conclusions</jats:title> <jats:p>Stereotactic radiosurgery offers an additional option beyond repeat surgery or RT in pediatric patients with residual or recurrent ependymomas after initial management. Patients with smaller-volume tumors and a later recurrence responded best to radiosurgery.</jats:p></jats:sec>

Clinical, Histological, and Genetic Features of Fourth Ventricle Ependymoma in the Elderly

“…The difference in 5-year survival rate between tumor grades of posterior fossa ependymoma was not statistically significant, 21,27) and, in general, the degree of resection correlated with better prognosis. 13,17,27) Nevertheless, gross total resection may be difficult for ependymomas arising from the caudal half or the lateral part of the fourth ventricle, because critical anatomical structures are present around the tumor. 13) Although the tumor origins of the 3 above cases are unknown, subtotal resection may be accepted in the elderly population to avoid postoperative complications.…”

“…7,21,27) Thus, the survival period of geriatric ependymoma may be longer than that for younger patients, so stereotactic radiotherapy for residual tumor in the fourth ventricle may be an option after subtotal resection. 16,17,19) Although there have been several chemotherapy regimens for ependymoma, none has been established. 8,9,15) None of the 4 patients received chemotherapy.…”

Microsurgical management of pediatric ependymomas of the fourth ventricle via the trans-cerebellomedullary fissure approach: A review of 26 cases

“…Postoperative hydrocephalus may be caused by brain tissue swelling, residual tumor or arachnoid adhesion due to incomplete bipolar coagulation hemostasis. Neurosurgeons should also note that ependymomas have a tendency to disseminate through the CSF, with CSF seeding present in 3-15% of the cases (6,11,12,28). Therefore, during surgery, the cisterna magna and aqueduct should be protected using brain cotton, in order to prevent tumor cells from spreading through the ventricular system.…”

“…The extent of surgical resection is a major determinant of the outcome (1,6,8,11,13,17,(38)(39)(40). It is known that the majority of ependymomas arise from ependymal cells present in the floor of the fourth ventricle (1,2,37).…”

“…The occurrence of ependymomas is more common in pediatric patients than in adult patients, accounting for 8-13% of all intracranial tumors in children and up to 4% of brain tumors in adults. Approximately one-half of ependymomas are found in children aged <3 years (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13). In children, ependymomas usually occur in the fourth ventricle and display a series of symptoms and signs, including increased intracranial pressure, ataxia, vertigo, chronic cerebellar tonsillar hernia and brainstem dysfunction (1,14).…”