In treatment of cervical cancer, unless the tumor has been surgically removed and the radiation is given postoperatively, internal radiation is always a crucial part of the treatment. The reason for that is that with external radiation alone we would not be able to deliver the required doses of radiation to the tumor at the cervix without exceeding the safe tolerated doses of normal tissues within the pelvis. On the other hand by using internal radiation, we can deliver relatively high doses of radiation to the tumor while sparing most of organs within the pelvis. So the standard radiation for cervical cancer always consists of a combination of five weeks of external beam followed by internal radiation.
