Radiation therapy is a common and effective treatment for bladder cancer. It involves the use of high-energy rays or particles to target and destroy cancer cells. Here's how radiation therapy helps in treating bladder cancer:

1. **Localized Treatment:** Radiation therapy is a local treatment, meaning it targets a specific area of the body. In the case of bladder cancer, the radiation is focused on the tumor or the area where cancer cells are present.

2. **Destroying Cancer Cells:** The high-energy radiation damages the DNA inside the targeted cancer cells. This damage prevents the cancer cells from dividing and growing, ultimately leading to their death. Radiation therapy is designed to specifically target cancer cells while minimizing damage to surrounding healthy tissues.

3. **Shrinking Tumors:** Radiation therapy can help shrink tumors before surgery. This is known as neoadjuvant therapy. By reducing the size of the tumor, it may become easier to remove surgically, and the chances of a successful outcome may be improved.

4. **Adjuvant Treatment:** After surgery to remove the bladder or part of it, radiation therapy may be used to kill any remaining cancer cells and reduce the risk of the cancer returning. This is known as adjuvant therapy.

5. **Palliative Care:** In some cases, radiation therapy is used to relieve symptoms and improve the quality of life for individuals with advanced bladder cancer. This is called palliative radiation therapy, and it may help control pain, bleeding, or other symptoms associated with the disease.

6. **Combined Approaches:** Radiation therapy is often used in combination with other treatments such as surgery, chemotherapy, or immunotherapy to enhance the overall effectiveness of bladder cancer treatment. The combination of therapies is tailored to the specific characteristics of the cancer and the individual patient.

It's important to note that the decision to use radiation therapy, the type of radiation, and the specific treatment plan depend on various factors, including the stage of the cancer, the overall health of the patient, and the goals of treatment. The treatment plan is typically determined by a multidisciplinary team of healthcare professionals, including oncologists, radiation oncologists, and surgeons, who collaborate to provide the most effective and personalized care for each patient.