According to a recent study, for the very first time researchers have been able to show that the use of helium ions in radiation therapy could provide proper treatment to tumors, all the while sparing healthy organs. A treatment planning study presented at the ESTRO 33 congress has been able to demonstrate that helium may have effects that are better to radiotherapy using protons, themselves a significant advance on traditional photon beam radiotherapy.
Mr. Hermann Fuchs, a PhD student at the Medical University of Vienna/AKH Vienna, Austria, in collaboration with Dr. Barbara Knäusl, and Professor Dietmar Georg, set out to develop a method of calculating the best possible dose of helium ions for use in radiation treatment. The dose calculation algorithm was then implemented for treatment plan calculation for ten pediatric patients, five with neuroblastoma (tumors arising in cells of the hormonal and nervous system), and five with Hodgkin's lymphoma.
"Particle beam therapy involving protons or carbon ions has advantages over conventional radiotherapy. Helium ions may represent another kind of particle that can improve radiotherapy treatment. Due to their increased mass, spreading of the beam is reduced by a factor of two as compared with protons. Moreover helium ions have an increased biological effectiveness at the end of their range," explained Fuchs.
“Heavier ions like carbon have the potential to kill cancer cells more effectively due to their underlying biology. But by modeling these biological processes, large uncertainties are introduced, and these can be reduced by using lighter ions like helium. "Helium ions reside in the low Linear Energy Transfer (LET) area. LET is a physical quantity describing how much energy of a particle is deposited at a given range, and this measure is important when looking at the biological effects of therapy,” he added.
Such higher accuracy and sparing of normal tissue is crucial in the case of children, the researchers note. When treating children it is mainly important to ensure that as little dose of radiation as possible is placed outside the area to be treated, since an increased area treated with a low dose can lead to the development of secondary cancers. And since children have a potentially long lifespan ahead of them, this probability must be reduced as much as possible through the functions of therapies that are targeted as accurately as possible to the tumor, while sparing the dose to surrounding areas, and particularly to healthy organs especially sensitive to radiation located nearby (the organs at risk).
"After three years of extensive research and validation efforts, we were able to produce a treatment planning algorithm that enabled us to investigate the possibilities for using helium ion therapy in children treated with low dose radiation. We would now like to investigate its potential in patients being treated with higher doses, for example, those with brain tumors. The good results that have been achieved so far warrant the verification of the model in order to investigate the real clinical potential of helium ions. In the long term, clinical trials of this therapy will be needed to substantiate the effects of our treatment planning model," said Fuchs.
"Particle beam therapy has already advanced care and treatment options for cancer patients. We hope that the use of helium ions may help to bring about further improvements," he concluded.