A group of researchers at Children’s Hospital Los Angeles found that children who were part of a clinical trial to assess the effectiveness of reduced radiotherapy had less successful results when there were deviations from the treatment protocol.
"This study shows that attention to the timing, dose and location of radiation therapy is crucial," Kenneth K. Wong, MD, a radiation oncologist at Children's Hospital Los Angeles, said in a statement.
The study, published in Pediatric Blood & Cancer, is a qualitative assessment of the Head Start III trial. In the Head Start studies, a high dose chemotherapy followed by transfusion of blood stem cells is used to treat malignant brain tumors as a substitute for radiation in younger children. If the disease continues after this of treatment or if the child is older, they will receive radiation therapy.
In Head Start III, with the aim to reduce radiation exposure, only 31 of 220 children received radiation. However, eight of 25 of these children who received radiation had deviations from the treatment plan. These protocol violations all occurred in those ages 6 and under.
"Parents or providers may want to delay the start of radiation or reduce the dose or area of exposure—particularly in very young children," said Wong. "But in a study already limiting radiation exposure—patients with these kinds of protocol violations experienced worse outcomes."
For patients who were eligible for radiation therapy, received treatment following the protocol and began radiation therapy within 11 weeks of recovery from stem cell transfusion, results showed that it had improved their overall survival. Wong and his team suggest that focusing on reducing protocol violations by looking over treatment plans prior to initiating radiation therapy may help to improve patient outcomes.