Larger doses of radiotherapy have been linked to hormone deficiencies in young patients treated for brain tumors, according to research published Aug. 17 in the Journal of Clinical Oncology.
The work, led by first author Ralph Vatner, MD, PhD, supports minimizing radiation exposure to the hypothalamus and pituitary gland during cancer treatment, because those brain regions regulate hormones that control metabolism, adrenal function and gonadal function.
“There isn’t much data defining the dose response of radiation therapy to the hypothalamus and pituitary gland in pediatric and young adult patients with brain tumors,” Vatner said in a release from the University of Cincinnati Academic Health Center, where he works as an assistant professor in the department of radiation oncology. “We examined the correlation between radiation therapy (RT) dosage to these brain structures and development of endocrine dysfunction in this population.”
And the pediatric population is especially sensitive to the possibility of hormone deficiency during RT, he said.
For their research, Vatner and his colleagues in Ohio collected dosimetric and clinical data for hundreds of children and young adults with brain tumors who’d been treated with proton radiotherapy during three prospective studies at Massachusetts General Hospital. The team collected serum from patients to measure deficiencies in any hormones, including growth, thyroid and adrenocorticotropic hormones, and measured radiation doses for patients based on their prior treatment plans.
“We were able to analyze data from 189 pediatric and young adult patients treated with proton therapy at [Massachusetts General], with an average follow-up of 4.4 years—the largest study of its kind and the first with patients receiving proton therapy for a variety of brain tumors,” Vatner said. “Among these patients, the rate of any hormone deficiency at four years was 48.8 percent, but this was strongly associated with the dose of radiation and the age at time of treatment.”
Vatner said his team’s research backs the reported benefits of advanced radiation technologies like proton therapy for treating brain tumors, especially in children and young adults.
“These data will help physicians predict the risk of deficiencies in growth hormone, thyroid hormone, adrenal corticosteroids and sex steroids in their patients receiving radiotherapy for brain tumors on the basis of patient age and radiation dose to the hypothalamus and pituitary gland,” he said. “Moving forward, physicians can use these models to help navigate their treatment planning and identify patients who will most benefit from advanced technologies like proton therapy that can treat tumors while better sparing healthy, normal tissue.”
After graduating from Indiana University-Bloomington with a bachelor’s in journalism, Anicka joined TriMed’s Chicago team in 2017 covering cardiology. Close to her heart is long-form journalism, Pilot G-2 pens, dark chocolate and her dog Harper Lee.