A thermosensitive hydrogel for coating radioisotopes and chemotherapeutic agents to treat cancer and a method for preparing the same are revealed. The anticancer drugs such as radiopharmaceuticals or chemotherapeutic agents are coated with the hydrogel formed by PCL-PEG-PCL. By the feature of the hydrogel body that changes from liquid phase at low storage temperature to gel form at body temperature, not only the anticancer drugs can be injected into the human body and reaching the treatment site smoothly but the treatment time of brachytherapy is also extended. Thus the side effects of cancer therapy are significantly reduced.
