The study analysed 59 patients aged between three and 21 from 2003 to 2009
Proton beam therapy causes fewer side effects in young cancer patients than conventional radiotherapy, a study has indicated.
The research, published in the Lancet Oncology journal, suggested the treatment reduced the toxic effects to normal tissue.
It also noted similar survival rates to those seen with conventional radiotherapy.
The alternative treatment came to national attention when the parents of Ashya King took him out of the country to undergo proton therapy in Prague, which was not initially offered to them on the NHS.
Brett and Naghmeh King have said their son is now free of cancer.
The study, led by Massachusetts General Hospital, said: "Our findings suggest that proton radiotherapy seems to result in an acceptable degree of toxicity and had similar survival outcomes to those achieved with photon-based radiotherapy.
"Although there remain some effects of treatment on hearing, endocrine, and neurocognitive outcomes - particularly in younger patients - other late effects common in photon-treated patients, such as cardiac, pulmonary, and gastrointestinal toxic effects, were absent.
"Proton radiotherapy resulted in acceptable toxicity and had similar survival outcomes to those noted with conventional radiotherapy, suggesting that the use of the treatment may be an alternative to photon-based treatments."
The study analysed 59 patients aged between three and 21 from 2003 to 2009.
All the patients had the most common kind of malignant brain tumour in children, known as medulloblastoma.
After five years, their survival rate was similar to that of patients treated with conventional X-ray radiotherapy, but there were fewer side effects to the heart and lungs, the researchers found.
Report author Dr Torunn Yock said: "What this study shows is that proton radiotherapy is just as effective as photon radiotherapy for curing medulloblastoma and the promising aspects of it is that its less toxic in certain circumstances."
The proton therapy is a highly targeted treatment often used on hard-to-reach cancers and has a lower risk of damaging other body tissue.
Several new proton beam therapy centres will open in the UK from this year.