| Research Focus: | Radiotherapy is an essential component of the treatment of many childhood cancers. However, children are particularly vulnerable to the long-term side effects (late effects) associated with treatment because they have high cure rates and a long life expectancy. Like modern photon radiotherapy techniques, proton beam therapy delivers a high dose to the target while sparing surrounding normal tissue. In contrast to photon radiotherapy, in proton radiation therapy there is much less low dose exposure of large volumes of tissue, which may result in a reduction in the risk of late effects associated with radiation therapy for all pediatric cancers treated with radiotherapy. The research consists of four main parts. First, accurate determination of dose in low dose areas in both photon and proton therapy will be determined using computer simulations and phantom measurements. Second, retrospectively re-planning for proton therapy, pediatric and young adult patients previously treated using photon therapies and re-calculating photon and proton treatment plans using Monte Carlo methods to obtain more detailed dose distributions. Third, quantifying and comparing risks of late effects of photon and proton radiation deliveries using different numerical biological models. Biological models will include existing published models for secondary cancers and neurocognitive outcomes as well as new models for other late effects created from retrospective outcome data. Finally, tools for easy evaluation of the benefits of proton therapy will be created for future new patients seen at any radiation oncology department in Quebec. |
