A Study on Radiation-induced Pulmonary Fibrosis Treated With Clinical Grade Umbilical Cord Mesenchymal Stem Cells

Radiation therapy is one of the main means for treating malignant tumor, during which radioactive lung injury is inevitable. Currently there is nearly no effective clinical treatment for late post-radiotherapy pulmonary fibrosis. This study intends to carry out an open, single-center, non-randomized phase I clinical trial. During the treatment, the local lesions will be fully lavaged, and then clinical grade umbilical cord mesenchymal stem cells (MSCs) will be injected directly into the lesion by fiberoptic bronchoscopy. After six-month observation, the investigators will initially evaluate the safety and effectiveness of the treatment by measuring two key indicators-the CT density histogram and the patients' self-evaluation, and one secondary indicator-the changes of TGF-β1 contents, both before and after the treatment. Meanwhile, the investigators will make a preliminary discuss about the possible immunomodulatory effects of the umbilical cord MSCs.