Masashi Mizumoto1,2, Yoshiko Oshiro1,2, Haitao Pan3, Fang Wang3, Sue C Kaste4, Amar Gajjar5, Wassim Chemaitilly6, Thomas E Merchant1. 1. Department of Radiation Oncology, St Jude Children's Research Hospital, Memphis, Tennessee. 2. Department of Radiation Oncology, University of Tsukuba, Ibaraki, Japan. 3. Department of Biostatistics, St Jude Children's Research Hospital, Memphis, Tennessee. 4. Department of Diagnostic Imaging, St Jude Children's Research Hospital, Memphis, Tennessee. 5. Department of Oncology, St Jude Children's Research Hospital, Memphis, Tennessee. 6. Department of Pediatric Medicine, St Jude Children's Research Hospital, Memphis, Tennessee.
Abstract
BACKGROUND: We modeled height after craniospinal irradiation (CSI) in pediatric patients with central nervous system (CNS) embryonal tumors to identify factors that impair stature. PROCEDURE: During 1996-2012, 212 pediatric patients (131 male) with CNS embryonal tumors received postoperative CSI: 23.4 Gy (n = 147) or ≥36 Gy (n = 65), similar postirradiation chemotherapy, and were followed for at least 5 years without tumor progression or other event. The group was further characterized by age at CSI and hormone-replacement therapy received. Models were developed to identify factors associated with growth impairment and estimate final height. RESULTS: With median follow up of 10.2 years (range 5.0-20.4 years), the mean final height z-scores at 18 years of age, compared to United States standards, were -1.3 for female and -1.5 for male survivors. Younger age at the time of CSI, higher CSI dose, and female sex were associated with height impairment. Factors associated with higher growth rates before 15 years of age were older age at CSI, male sex, CSI dose < 36 Gy, replacement therapy for growth hormone (GH) and central adrenal insufficiency, and white race. Growth after age 15 in male survivors was associated with treatment of gonadotropin deficiency. Linear mixed-effects models were developed using clinical factors to estimate final height, demonstrate the unique growth curve of this cohort, and interactions between clinical variable and radiation dose. CONCLUSIONS: CSI significantly impaired height at current doses used to treat standard- or high-risk CNS embryonal tumors. Measures to reduce the impact of CSI on height should be sought, with our models serving as benchmarks.
BACKGROUND: We modeled height after craniospinal irradiation (CSI) in pediatric patients with central nervous system (CNS) embryonal tumors to identify factors that impair stature. PROCEDURE: During 1996-2012, 212 pediatric patients (131 male) with CNS embryonal tumors received postoperative CSI: 23.4 Gy (n = 147) or ≥36 Gy (n = 65), similar postirradiation chemotherapy, and were followed for at least 5 years without tumor progression or other event. The group was further characterized by age at CSI and hormone-replacement therapy received. Models were developed to identify factors associated with growth impairment and estimate final height. RESULTS: With median follow up of 10.2 years (range 5.0-20.4 years), the mean final height z-scores at 18 years of age, compared to United States standards, were -1.3 for female and -1.5 for male survivors. Younger age at the time of CSI, higher CSI dose, and female sex were associated with height impairment. Factors associated with higher growth rates before 15 years of age were older age at CSI, male sex, CSI dose < 36 Gy, replacement therapy for growth hormone (GH) and central adrenal insufficiency, and white race. Growth after age 15 in male survivors was associated with treatment of gonadotropin deficiency. Linear mixed-effects models were developed using clinical factors to estimate final height, demonstrate the unique growth curve of this cohort, and interactions between clinical variable and radiation dose. CONCLUSIONS: CSI significantly impaired height at current doses used to treat standard- or high-risk CNS embryonal tumors. Measures to reduce the impact of CSI on height should be sought, with our models serving as benchmarks.