Measuring Radiation Toxicity Using Circulating Cell-Free DNA in Prostate Cancer Patients.

Background: After radiation therapy (RT), circulating plasma cell-free DNA (cfDNA) released in response to RT damage to tissue can be measured within hours. We examined for a correlation between cfDNA measured during the first week of therapy and early and late gastrointestinal (GI) and genitourinary (GU) toxicity.

Material And Methods: Patients were eligible for enrollment if they planned to receive proton or photon RT for nonmetastatic prostate cancer in the setting of an intact prostate or after prostatectomy.