The doctor asks questions, the patient reports how they are doing, a physical exam is performed and medical tests may be ordered. Taken together this information determines if the tumor has responded to treatment.
Some tumors shrink slowly after radiation treatment.
Sometimes radiation therapy is given to relieve a cancer patient's symptoms. These symptoms may end while the radiation therapy is being delivered. Even if the symptoms end, the radiation therapy continues to help prevent the symptoms from returning. Sometimes symptoms don't go away until after all the radiation treatments are completed.