Late effects of conformal radiation therapy for pediatric patients with low-grade glioma: prospective evaluation of cognitive, endocrine, and hearing deficits.

Abstract

PURPOSE:

We conducted a prospective trial to evaluate late effects in pediatric patients with low-grade glioma (LGG) treated with conformal radiation therapy (CRT).

PATIENTS AND METHODS:

Between August 1997 and August 2006, 78 pediatric patients with LGG (mean age, 9.7 years; standard deviation, +/-4.4 years) received 54 Gy of CRT with a 10-mm clinical target volume margin. Tumor locations were diencephalon (n = 58), cerebral hemisphere (n = 3), and cerebellum (n = 17). Baseline and serial evaluations were performed to identify deficits in cognition, endocrine function, and hearing. Deficits were correlated with clinical factors and radiation dose within specific normal tissue volumes.

RESULTS:

Cognitive effects of CRT through 5 years after CRT correlated with patient age, neurofibromatosis type 1 status, tumor location and volume, extent of resection, and radiation dose. The effect of age exceeded that of radiation dose; patients younger than 5 years experienced the greatest decline in cognition. Before CRT, growth hormone (GH) secretion abnormality was diagnosed in 24% of tested patients, and 12% had precocious puberty. The 10-year cumulative incidence of GH replacement was 48.9%; of thyroid hormone replacement, 64.0%; of glucocorticoid replacement, 19.2%; and of gonadotropin-releasing hormone analog therapy, 34.2%. The mean +/- standard errors of the cumulative incidence of hearing loss at 10 years did not exceed 5.7% +/- 3.3% at any frequency.

CONCLUSION:

To our knowledge, this is the largest series of prospectively followed children with LGG to undergo irradiation. Adverse effects are limited and predictable for most patients; however, this study provides additional evidence that CRT should be delayed for young patients and identifies the potential benefits of reducing radiation dose to normal brain.

• Authors: Thomas E Merchant, Heather M Conklin, Shengjie Wu, Robert H Lustig, Xiaoping Xiong
• Journal: Journal of clinical oncology : official journal of the American Society of Clinical Oncology (J Clin Oncol) Vol. 27 Issue 22 Pg. 3691-7 (Aug 01 2009) ISSN: 1527-7755 [Electronic] United States
• PMID: 19581535 (Publication Type: Clinical Trial, Phase II, Journal Article, Research Support, N.I.H., Extramural, Research Support, Non-U.S. Gov't)

Topics

• Adolescent
• Age Distribution
• Brain Neoplasms (mortality, pathology, radiotherapy, surgery)
• Child
• Child, Preschool
• Cognition Disorders (epidemiology, etiology)
• Disease-Free Survival
• Dose-Response Relationship, Radiation
• Endocrine System Diseases (epidemiology, etiology)
• Female
• Follow-Up Studies
• Glioma (mortality, pathology, radiotherapy, surgery)
• Hearing Loss (epidemiology, etiology)
• Humans
• Incidence
• Male
• Maximum Tolerated Dose
• Neoplasm Invasiveness (pathology)
• Neoplasm Staging
• Prospective Studies
• Radiation Injuries (diagnosis, epidemiology)
• Radiotherapy Dosage
• Radiotherapy, Adjuvant
• Radiotherapy, Conformal (adverse effects, methods)
• Risk Assessment
• Survival Analysis
• Time Factors
• Young Adult