Impact of late radiation effects on cancer survivor children: an integrative review

Abstract

We aimed to identify the late effects of radiation exposure in pediatric cancer survivors. An integrated literature review was performed in the databases MEDLINE and LILACS and SciELO. Included were articles in Portuguese and English, published over the past 10 years, using the following keywords: “neoplasias/neoplasms” AND “radioterapia/radiotherapy” AND “radiação/radiation”. After analysis, 14 articles - published in nine well-known journals - met the inclusion criteria. The publications were divided into two categories: “Late endocrine effects” and “Late non-endocrine effects”. Considering the increased survival rates in children who had cancer, the impact of late effects of exposure to radiation during radiological examinations for diagnosis and treatment was analyzed. Childhood cancer survivors were exposed to several late effects and should be early and regularly followed up, even when exposed to low radiation doses.

Long‐term follow‐up of endocrine function among young children with newly diagnosed malignant central nervous system tumors treated with irradiation‐avoiding regimens

“…Although there are many factors accounting for endocrine sequelae of CNS tumor treatment, radiation therapy has been demonstrated to be a primary cause of damage in very young children . Postirradiation endocrinopathies include hypothyroidism most commonly (primary following spinal irradiation and central following cranial irradiation), growth hormone deficiency, and hypogonadotropic hypogonadism . In addition to disorders of the endocrine system, radiation therapy has been associated with increased risk for late mortality, profound developmental delay and cognitive deficits, growth disturbances due to vertebral growth plate arrest (following spinal irradiation), development of secondary neoplasms, and increased overall risk for chronic health conditions .…”

“Oncofertility” procedures in children and adolescents

“…Permanent and irreversible azoospermia (no sperm in the semen) occurs at total doses of 4 Gy or fractionated 1.2 Gy. Testicular irradiation in boys at prepubertal age in doses exceeding 20 Gy leads to permanent damage to interstitial cells responsible for testosterone production (Leydig cells), while the function of these cells in sexually mature men is maintained even up to 30 Gy [43,44]. Leydig cells show higher resistance to radiation than sperm-producing epithelium of seminiferous tubules, therefore, radiation therapy included in the Oncofertility procedures in children is not usually associated with a complete impairment of reproductive functions in adult life [45].…”