Quantification of cell-free DNA in the plasma during radiation therapy

在癌症患者中，无细胞血浆DNA会升高，而在有效治疗后会降低。因此，这些DNA有可能成为新的肿瘤标记物。我们调查了荷瘤小鼠和癌症患者的血浆DNA浓度在放射治疗过程中是否发生了变化。这些小鼠血浆中的无细胞肿瘤特异性DNA水平与放射后肿瘤体积显著相关。癌症患者血浆总无细胞DNA水平随放射治疗进展呈动态变化，治疗结束时下降。还需要进一步的分析来阐明放射治疗过程中无细胞血浆DNA动态变化的潜在临床应用。

Cell-free plasma DNA is elevated in cancer patients and decreases in response to effective treatments. Consequently, these DNA have potential as new tumor markers. We investigated whether the plasma DNA concentrations in tumor-bearing mice and cancer patients are altered during the course of radiation therapy. The cell-free tumor specific DNA levels in the plasma of those mice were significantly associated with the tumor volume after radiation. The total cell-free plasma DNA levels in cancer patients showed dynamic changes associated with the progression of radiation therapy and decreased at end of the treatment. Additional analysis will be required to elucidate the potential clinical utility of dynamic changes in cell-free plasma DNA during radiation therapy.