To study the inflammatory response during and after radiotherapy, especially by measuring the concentration of an enzyme called autotaxin and its product LPA in the blood plasma. Autotaxin and LPA cause fibrosis in other situation, but they have not been tested in radiation-induced fibrosis. We will determine if the duration and magnitude of the autotaxin and LPA responses are prognostic for the 15-28% of patients who will develop fibrosis. This fibrosis will be detected by ultrasound and a novel application of elastography, which should provide much earlier and quantifiable fibrotic changes compared to conventional physical examination.
