Approximately 1 out of every 6 men in the United States will develop prostate cancer, according to the American Cancer Society. Radiation treatment remains a common form of therapy for men with prostate cancer. Different types of radiation treatment for prostate cancer vary by the method of radiation delivery. Prostate cancer radiation treatment may be combined with other forms of therapy, such as surgery, chemotherapy and hormonal treatment.
External Radiation Delivery
External beam radiation therapy involves delivery of the treatment from outside the body. Preparation for treatment begins with imaging studies, such as CT or MRI scans, which enable precise mapping of the prostate and internal organ positions within the body. This process, termed the simulation, concludes with a member of the treatment team marking the skin of the lower abdomen with semi-permanent ink. The ink marks help technicians align the radiation beams at each treatment session.
During a treatment session, the patient lies on the treatment table in the same position as was assumed during the simulation. A machine called a linear accelerator generates high-energy radiation beams, which the technician focuses on the prostate. Patients usually receive one treatment each day, five days per week for seven to nine weeks, reports the American Cancer Society. The treatments do not cause pain and typically last a few minutes each.
Conformal External Radiation Delivery
Three-dimensional conformal radiation therapy, abbreviated 3D-CRT, is another form of external beam radiotherapy commonly used to treat prostate cancer. With this technique, a computer program helps the treatment team map the prostate with a high level of precision, explains the medical information website Cancer Help UK. The precise mapping helps reduce the risk for side effects caused by radiation reaching healthy tissues near the prostate.
The procedures for 3D-CRT of the prostate are similar to those used for standard external beam radiation therapy, with the exception of the creation of molds to help position the body accurately. A mold is a plastic device made for the patient, based on his body shape, to help ensure that he reliably assumes the same position at each treatment session.
Internal Radiation Delivery
Radiation can be delivered to the prostate from within the body, a treatment technique known as brachytherapy. With low-dose brachytherapy, the patient goes to a treatment suite where the doctor implants hundreds of tiny radioactive beads into the prostate. The beads emit a low level of radiation for approximately 30 days before gradually becoming inactive, notes the medical information website RadiologyInfo.org, developed by the Radiology Society of North America and the American College of Radiology. The beads remain in the prostate permanently.
With high-dose brachytherapy, the doctor inserts several small tubes into the prostate while the patient is under anesthesia. A radioactive pellet placed into each tube delivers a high dose of local radiation to the prostate for several minutes. The doctor then removes the radioactive pellet and the delivery tubes. Patients may receive one to three separate high-dose brachytherapy treatments, reports RadiologyInfo.org. Doctors typically use high-dose prostate brachytherapy in combination with external beam radiation treatment.
References
- American Cancer Society: Cancer Facts and Figures 2010
- American Cancer Society: Prostate Cancer Radiation Therapy
- CancerHelp UK: Conformal Radiotherapy, 3D Conformal Radiotherapy (3DCRT)
- RadiologyInfo.org: Prostate Cancer
- National Cancer Institute: Prostate Cancer Treatment Overview, Radiation Therapy
