Radiotherapy for prostate cancer

Radiotherapy uses concentrated radiation to destroy cancer cells in the prostate. It is a relatively common treatment method and is suitable for cases where the prostate is difficult to remove locally and no distant metastasis has been found.

Currently, radiotherapy for prostate cancer can be divided into external radiotherapy and internal tissue radiotherapy. Radionuclides can be used to relieve pain in patients with advanced bone metastases.

1. External radiotherapy

External radiotherapy uses radiation from a radiation source or linear accelerator to aim at the prostate and use multiple different incident angles to reduce damage to the skin and surrounding tissues. The 5-year survival rate of prostate cancer after treatment is 75% for stage B and 55% for stage C. After the total radiation dose is calculated, it can be divided into 30 to 40 courses, and the radiation is given in the treatment room for a period of time every day.

2. Intra-tissue radiotherapy

Intra-tissue radiotherapy currently uses radionuclides such as 125I, 198AU or 222Ra, which are placed into the prostate through the pubic bone, perineum or rectum, and are placed directly at the tumor site for irradiation treatment, and remain in the body permanently. Compared with traditional radioactive sources (such as radium), the half-life of new radioactive sources is about 60 days, and they release gamma rays (γ-rays), which have low penetration and less radiation damage.

3. Radionuclide therapy for bone metastasis

For patients with bone metastasis from prostate cancer, whole-body radiotherapy with radionuclides 32P and 89Sr can relieve local pain from bone metastasis and slow the progression of lesions to a certain extent.