Correlation of Acute and Late Brainstem Toxicities With Dose-Volume Data for Pediatric Patients With Posterior Fossa Malignancies.
Int J Radiat Oncol Biol Phys
; 98(2): 360-366, 2017 06 01.
Article
em En
| MEDLINE
| ID: mdl-28463155
ABSTRACT
PURPOSE:
Radiation-induced brainstem toxicity after treatment of pediatric posterior fossa malignancies is incompletely understood, especially in the era of intensity modulated radiation therapy (IMRT). The rates of, and predictive factors for, brainstem toxicity after photon RT for posterior fossa tumors were examined. METHODS AND MATERIALS After institutional review board approval, 60 pediatric patients treated at our institution for nonmetastatic infratentorial ependymoma and medulloblastoma with IMRT were included in the present analysis. Dosimetric variables, including the mean and maximum dose to the brainstem, the dose to 10% to 90% of the brainstem (in 10% increments), and the volume of the brainstem receiving 40, 45, 50, and 55 Gy were recorded for each patient. Acute (onset within 3 months) and late (>3 months of RT completion) RT-induced brainstem toxicities with clinical and radiographic correlates were scored using Common Terminology Criteria for Adverse Events, version 4.0.RESULTS:
Patients aged 1.4 to 21.8 years underwent IMRT or volumetric arc therapy postoperatively to the posterior fossa or tumor bed. At a median clinical follow-up period of 2.8 years, 14 patients had developed symptomatic brainstem toxicity (crude incidence 23.3%). No correlation was found between the dosimetric variables examined and brainstem toxicity. Vascular injury or ischemia showed a strong trend toward predicting brainstem toxicity (P=.054). Patients with grade 3 to 5 brainstem toxicity had undergone treatment to significant volumes of the posterior fossa.CONCLUSION:
The results of the present series demonstrate a low, but not negligible, risk of brainstem radiation necrosis for pediatric patients with posterior fossa malignancies treated with IMRT. No specific dose-volume correlations were identified; however, modern treatment volumes might help limit the incidence of severe toxicity. Additional work investigating inherent biologic sensitivity might also provide further insight into this clinical problem.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Lesões por Radiação
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Tronco Encefálico
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Neoplasias Infratentoriais
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Neoplasias Cerebelares
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Ependimoma
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Radioterapia de Intensidade Modulada
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Meduloblastoma
Tipo de estudo:
Etiology_studies
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Observational_studies
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Prognostic_studies
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Risk_factors_studies
Limite:
Adolescent
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Adult
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Child
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Child, preschool
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Female
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Humans
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Infant
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Male
Idioma:
En
Revista:
Int J Radiat Oncol Biol Phys
Ano de publicação:
2017
Tipo de documento:
Article