The researchers report that MRI can spot the immediate injury done by radiation therapy to the muscles of children undergoing radiation treatment for certain types of soft-tissue cancer. This also indicates that MRI might one day be able to help doctors predict the amount of long-term damage that radiation may cause. A report on these findings appears in the Oct. 25 online issue of Magnetic Resonance Imaging.
The study's findings are significant because as radiation treatments become more advanced and complex, clinicians must have a way to predict the outcomes--including side effects--on specific patients, according to Matthew Krasin, M.D., associate member of the St. Jude Department of Radiological Sciences.
The St. Jude study showed that changes in images taken of muscles before and after radiation therapy for soft tissue sarcoma and Ewing sarcoma are related not only to the amount of radiation the child received, but also to the child's age and the presence of a nearby tumor.
"We hope that detecting these changes at such an early stage may help clinicians predict which patients need an intervention to prevent late damage," Krasin said. Soft tissue sarcomas are cancers that arise in muscles, fat, blood vessels and other soft tissues. Ewing sarcoma is a cancer that arises in the bone or soft tissue, usually in the arms, legs, pelvis or chest wall.
St. Jude researchers studied the muscles of 13 patients before, during and 12 weeks after they received radiation therapy for soft tissue sarcoma. The team used a technique called quantitative T2 to determine the extent of swelling in tissues before, during and after radiation therapy; and a technique called dynamic enhanced magnetic resonance imaging (DEMRI) to
Source:St. Jude Children's Research Hospital