Two new studies recently presented at the 3rd ESTRO Forum in Barcelona in Spain revealed that an increase in radiotherapy dose received by children with intracranial ependymoma can significantly improve survival rate.
An ependymoma is a tumor in the ependymal cells lining the hollow cavities of the brain. Although rare in adults, ependymomas are the third most common brain tumor in children. Surgical removal of the tumor is usually combined with radiotherapy to treat ependymoma, resulting in an overall five-year survival rate of around 70%. The individual outcomes can, however, differ considerably depending on factors like patient’s age, radiotherapy technique, dose applied, and the extent of surgery.
As of 2004, the recommended radiation dose for paediatric cases worldwide is of 59.4 Gray instead of the previously used 54 Gray. One of the studies presented by Dr. Anne Ducassou from the Institut Claudius Regaud, Toulouse, France revealed that in a cohort of 177 children with localized ependymoma, those treated with the high radiation dose of 59.4 Gray had better clinical outcomes than children who received the lower dose of 54 Gray. The estimated overall survival rate was found to be 90% in children given a higher dose and 79% in children given a lower dose.
“Our work, which involved a large number of children with ependymoma, has confirmed that the treatment we carry out today is better than it was a few years ago, but there is still much work to be done. For example, we found that children younger than three, and those with more aggressive disease had a poorer outcome, and we need to look further at how we can improve their treatment, as well as identifying other children at high risk of relapse,” noted Dr. Ducassou in a news release.
The second study, presented by Dr. Lorenza Gandola from the Fondazione IRCCS, Istituto Nazionale dei Tumori, Milan, Italy revealed a pioneering method for children with measurable intracranial ependymoma after surgery, based on an extra radiotherapy boost of 8 Gray to the tumor in addition to the standard 59.4 Gray. Through highly directed radiotherapy techniques, the research team was able to deliver the radiation dose directly to the tumor with minor impact on the surrounding normal brain tissue and without reports of major toxicity or patients’ death. The method was tested in 24 children (median age of 4.5 years) and of these, 15 are still alive without signs of disease progression (median of 51 months after the diagnosis).
“Our strategy contributed significantly to obtaining durable local control of disease in these children, and this is more striking because they already had a poorer prognosis after surgery,” said Dr. Gandola. “The hypofractionated radiotherapy boost approach represents an effective alternative to surgery in cases where further surgery cannot be performed without the possibility of causing severe and perhaps life-long damage to the child.” This technique will be evaluated in an international clinical trial expected to start later this year.
The President of ESTRO Dr. Philip Poortmans concluded, “Cancer in children is luckily rare but, when diagnosed, has a major effect of the lives of not only the patient but also the parents and other people close to the child, (…) Both studies presented here demonstrate that a clear dose-effect relationship exists for [ependymoma] tumor control and survival. While the increase from 54 to 59.4 Gray that was adopted first improves disease control and survival in a population-based study, a new study is planned to confirm the results of increasing the dose by a further 8 Gray, (…) We hope that this will bring about even better outcomes for these children.”