Growth hormone secretion after conformal radiation therapy in pediatric patients with localized brain tumors.

PURPOSE: Growth hormone deficiency (GHD) after radiation therapy negatively affects growth and development and quality of life in children with brain tumors. PATIENTS AND MATERIALS: Between 1997 and 2008, 192 pediatric patients with localized primary brain tumors (ependymoma, n = 88; low-grade glioma, n = 51; craniopharyngioma, n = 28; high-grade glioma, n = 23; and other tumor types, n = 2) underwent provocative testing of GH secretion by using the secretogogues arginine and L-dopa before and after (6, 12, 36, and 60 months) conformal radiation therapy (CRT). A total of 664 arginine/l-dopa test procedures were performed. RESULTS: Baseline testing revealed preirradiation GHD in 22.9% of tested patients. On the basis of data from 118 patients, peak GH was modeled as an exponential function of time after CRT and mean radiation dose to the hypothalamus. The average patient was predicted to develop GHD with the following combinations of the time after CRT and mean dose to the hypothalamus: 12 months and more than 60 Gy; 36 months and 25 to 30 Gy; and 60 months and 15 to 20 Gy. A cumulative dose of 16.1 Gy to the hypothalamus would be considered the mean radiation dose required to achieve a 50% risk of GHD at 5 years (TD(50/5)). CONCLUSION: GH secretion after CRT can be predicted on the basis of dose and time after irradiation in pediatric patients with localized brain tumors. These findings provide an objective radiation dose constraint for the hypothalamus.

A phase III trial comparing an anionic phospholipid-based cream and aloe vera-based gel in the prevention of radiation dermatitis in pediatric patients.

PURPOSE: Radiation dermatitis is a common side effect of radiation therapy (RT). In severe cases, RT must be interrupted until the skin heals, which can compromise treatment. The purpose of the study was to compare an anionic polar phospholipid (APP)-based cream and an aloe vera-based gel to determine their effectiveness in preventing and treating radiation dermatitis. PATIENTS AND METHODS: Forty-five pediatric patients (median age, 11 years) with various diagnoses who received at least 23.4 Gy participated. APP cream and aloe vera gel were symmetrically applied within the irradiated field after each treatment. Three measures were collected before, during and after completion of treatment: subject's skin comfort, dermatologic assessment, and common toxicity criteria (CTC). RESULTS: Significant differences in specific variables favoring APP cream use were noted in some patients including skin comfort variables, dry (p = 0.002), soft (p = 0.057), feels good (p = 0.002), rough (p = 0.065), smooth (p = 0.012) and dermatologic variables, dryness (p = 0.013), erythema (p = 0.002) and peely (p = 0.008). Grouped CTC scores were supportive of APP cream (p = 0.004). In comparing the first and last assessments, two dermatologic variables, dryness (p = 0.035) and peely (p = 0.016), favored APP cream. CONCLUSION: APP cream is more effective than aloe vera-based gel for prevention and treatment of radiation dermatitis.