"The use of proton radiotherapy to treat the most common malignant brain tumor in children is as effective as standard photon xray radiation therapy while causing fewer longterm side effects such as hearing loss and cognitive disorders according to a study receiving online publication in Lancet Oncology. The paper from a team led by Massachusetts General Hospital MGH investigators describes patient outcomes an average of seven years after proton therapy for medulloblastoma a fastgrowing tumor that develops in the cerebellum at the base of the brain.  Proton radiotherapy is still not widely available in the U.S. or around the world but it is increasingly recognized for its potential to reduce the side effects of treatment particularly in the pediatric population says Torunn Yock MD MCh MGH Department of Radiation Oncology lead and corresponding author of the report. At experienced centers proton therapy has a proven track record of treatment success and safety.  In contrast to photon radiotherapy in which a dose of radiation is delivered all along the xray beam as it passes through a patients body in proton therapy the dose is precisely focused on the target area with little or no dose delivered to normal tissues in front of or behind the tumor. This feature has made proton therapy particularly attractive to treat tumors in or near the brain or eyes areas where the protection of nearby healthy tissues is particularly critical.  While medulloblastoma can often be successfully treated with a combination of surgery chemotherapy and radiotherapy because of its location within the brain longterm side effects are common. These can include hearing loss which can be particularly problematic in young children problems with learning and memory and neuroendocrine disorders caused by irradiation of the pituitary gland and hypothalamus. Also commonly seen are problems affecting the heart lungs thyroid spine and reproductive organs all of which tend to be more serious in children treated at younger ages.  While proton therapy may appear to be ideal for reducing these adverse effects no previous study had prospectively examined the longterm results of children treated for medulloblastoma with proton therapy. To investigate their hypothesis that proton therapy would reduce the incidence and severity of side effects without loss of treatment effectiveness the researchers enrolled children and adolescents ages  to   with an average age of around    who received proton therapy for medulloblastoma at the MGH from  to . All had previous surgery to remove as much of the tumor as possible and all received chemotherapy before during or after proton therapy.  Study participants were tested for hearing a variety of cognitive functions levels of important hormones and height and weight at the outset of the study and at several followup visits for up to eight years. Of  patients who enrolled  died from their tumor during the study period and one from a traumatic brain injury. Significant hearing loss was seen in  percent of patients three years after treatment and in  percent at five years which compares with around  percent reported in studies using photon radiotherapy. The cognitive effects of proton therapy  primarily affecting verbal comprehension and processing speed  were also less serious than what has been reported with photon radiotherapy and those effects were primarily seen in children who were under the age of  when treated.  The neuroendocrine effects of proton therapy  deficits in any hormone level were seen in  percent of participants seven years after treatment  were similar to what has been reported with photon therapy. However no cardiac pulmonary gastrointestinal seizure or secondary tumor effects  all of which have been reported in photon therapy studies  were seen in the current studys participants. Survival rates and the incidence and type of tumor recurrence all were similar to what has been reported for photon radiotherapy.  Our results indicate that proton therapy maintains excellent cure rates in pediatric medulloblastoma while reducing longterm side effects particularly in hearing and neurocognitive function and eliminating cardiac pulmonary gastrointestinal and reproductive effects says Yock who is an associate professor of Radiation Oncology at Harvard Medical School. While we are currently investigating quality of life differences between proton and photon treatment I truly believe that  particularly for the youngest children  the ability to offer them proton therapy can make a big difference in their lives.   Nancy J. Tarbell MD MGH Radiation Oncology is senior author of the Lancet Oncology report. Additional coauthors are Elizabeth Weyman Bree Eaton MD and Shannon M MacDonald MD MGH Radiation Oncology Beow Yeap ScD MGH Department of Medicine David Ebb MD Beverly Lavally RN and Mary Huang MD MGH Pediatric Oncology Nicole Sherry MD MGH Pediatric Endocrinology Robin Jones MD MGH Pediatric Neurology Margaret Pulsifer PhD MGH Psychiatry Annah Abrams MD MGH Child Psychiatary and Karen Marcus MD Brigham and Womens Hospital Radiation Oncology. The study was funded in part by National Cancer Institute grant P CA.  Massachusetts General Hospital http founded in  is the original and largest teaching hospital of Harvard Medical School. The MGH conducts the largest hospitalbased research program in the United States with an annual research budget of more than  million and major research centers in AIDS cardiovascular research cancer computational and integrative biology cutaneous biology human genetics medical imaging neurodegenerative disorders regenerative medicine reproductive biology systems biology transplantation biology and photomedicine. In July  MGH returned into the number one spot on the  U.S. News  World Report list of Americas Best Hospitals."