MedicalResearch.com Interview with: Dr. Torunn Yock, MD Director, Pediatric Radiation Oncology Associate Professor, Harvard Medical School Radiation Oncology Quality Assurance Massachusetts General Hospital, Proton Center Boston, MA Medical Research: What is the background for this study? Dr. Yock: Proton radiotherapy is a highly targeted form of radiation therapy that can spare normal tissues better than standard x-ray/photon based radiotherapy. Because, all side effects from radiotherapy come from radiation dose to normal healthy tissues, it is widely believed that proton radiotherapy has great potential to mitigate the side effects of treatment, both acute and long term side effects. There have been many planning studies that show that proton radiation can achieve a more highly conformal dose distribution and appear to spare 50% or more normal tissue from unnecessary irradiation.  However, there have been only a handful of retrospective studies that report disease control and side effects of treatment. While the technology looked promising, the definitive clinical data has been lacking to date. Because of this lack of clinical outcome data, the role and benefit of proton radiotherapy has been a subject of great debate in the oncology community.  Critics assert that proton radiotherapy is expensive and unproven and therefore a leading culprit in escalating costs of oncologic health care. Proponents assert that when used in the appropriate patient setting, the margin of benefit in terms of improved health outcomes, outweighs the increased cost of treatment. We embarked on this study to answer help answer the call for prospectively collected clinical outcome data to better define the most appropriate role for proton radiotherapy. Importantly, this study addresses both disease control and side effects of treatment in a pediatric medulloblastoma cohort of children. Medical Research: What are the main findings? Dr. Yock: This study shows that disease control in the pediatric medulloblastoma population is very much the same as that which is achieved by photon based radiotherapy treatments. However, more importantly, late side effects commonly attributed to radiotherapy such as neurocognitive decline over time and hearing loss appear to be improved compared with published photon treated cohorts of pediatric medulloblastoma patients.  Additionally, adverse late side effects on the cardiopulmonary, GI, and reproductive systems were essentially eliminated. (more…)