Radiation Therapy for Prostate Cancer

Prostate cancer develops in a walnut-sized male reproductive gland located below the bladder in front of the rectum. Comprised of both glandular and muscular tissue, the prostate has two main functions: to produce seminal fluid, which nourishes and transports sperm, and to force semen out of the urethra during ejaculation.

The most common type of cancer in men, prostate cancer tends to grow slowly and often remains confined to the prostate, making it highly treatable. In some cases, however, the tumor is aggressive and spreads to other parts of the body. Common symptoms include difficulty urinating, bloody urine and erectile dysfunction.

The optimal treatment approach for prostate cancer can vary based on the stage and aggressiveness of the tumor. Common options include active surveillance, surgery, chemotherapy and radiation therapy.

What types of radiation therapy are used for prostate cancer?

Radiation therapy for prostate cancer can be delivered externally or internally. External beam radiation therapy (EBRT) involves the use of a machine (linear accelerator) located outside the patient’s body. The linear accelerator generates powerful energy beams and directs them precisely at the tumor site.

Internal radiation therapy (brachytherapy) involves the surgical placement of a tiny radioactive implant—such as seeds, pellets or wires—inside or near a tumor. The implant slowly delivers a high dose of radiation directly to the tumor while sparing the surrounding healthy tissues. The radiation gradually depletes over approximately one year. The inactive implant can remain safely in place for the rest of the patient’s life.

Common radiation delivery methods for prostate cancer include:

Intensity-modulated radiation therapy (IMRT)

The most common type of EBRT for prostate cancer, IMRT involves the use of a computer-controlled linear accelerator to deliver precise radiation doses to a tumor. While delivering the radiation beams, the linear accelerator moves around the patient’s body, targeting the cancer from many different angles. Additionally, by modulating the intensity of the energy beams and conforming them to the three-dimensional shape of the tumor, IMRT maximizes the dose to the cancer cells while minimizing exposure to the surrounding healthy tissues. This targeted radiation delivery approach can reduce the risk of side effects and damage to nearby organs, such as the bladder and rectum.

IMRT is typically administered over several weeks, with daily treatment sessions lasting only a few minutes each. It can be an effective treatment option for various stages of prostate cancer, aiming to control or eradicate the tumor while preserving the patient’s quality of life.

High dose-rate (HDR) brachytherapy

HDR brachytherapy involves the temporary surgical placement of a radioactive source in the prostate gland. Guided by real-time ultrasound imaging, the surgeon will insert several thin catheters through the perineum and into the prostate. The surgeon will then place a radioactive source into the catheters for a short period to deliver a computer-controlled dose of radiation directly to the tumor. The highly precise placement of the catheters allows for the delivery of a high radiation dose to the prostate while minimizing exposure to the surrounding healthy tissues.

Typically performed in several short sessions, HDR brachytherapy can be effective in treating localized prostate cancer with reduced side effects and a shorter treatment time compared to traditional radiation therapy. It may be used as a standalone treatment or in addition to IMRT.

Image-guided radiation therapy (IGRT)

IGRT for prostate cancer is an advanced radiation therapy technique that involves the use of a linear accelerator with built-in imaging technology to enhance the precision and accuracy of the radiation delivery. Before each treatment session, the physician will use images such as computed tomography (CT) scans, magnetic resonance imaging (MRI) scans or X-rays to visualize the prostate and surrounding tissues. The images will help the physician adjust both the patient’s body position and the radiation beams to ensure precise delivery to the tumor while minimizing exposure to nearby healthy tissues.

IGRT enhances the effectiveness of radiation therapy by allowing for more accurate dose delivery, which can improve the treatment outcome and reduce side effects. This approach can be particularly useful for managing prostate cancer because the prostate gland can move slightly during treatment due to bladder and rectal filling.

Stereotactic ablative radiotherapy (SABR)

Also known as stereotactic body radiation therapy (SBRT), SABR is a highly precise form of radiation therapy that delivers very high doses of radiation to a prostate tumor in a few treatment sessions, typically five or fewer. SABR uses advanced imaging and computer-guided techniques to target the tumor with pinpoint accuracy while minimizing damage to the surrounding healthy tissues. This precision is achieved through careful planning and the use of immobilization devices to keep the patient still during treatment.

SABR is known for its effectiveness in treating localized prostate cancer, offering a shorter treatment duration compared to conventional radiation therapy, with the potential for fewer side effects and a quicker return to normal activities.

What are the risks and possible complications of radiation therapy for prostate cancer?

Radiation therapy for prostate cancer, while effective, carries several risks and potential complications, including:

• Persistent fatigue and lack of energy
• Skin irritation, redness and dryness at the treatment site
• Urinary frequency, urgency or incontinence
• Bowel irritation, bloody stool and diarrhea
• Erectile dysfunction

These side effects can vary in severity and may develop during or after radiation therapy. To help the patient make fully informed treatment decisions, the physician will discuss the potential side effects of radiation therapy for prostate cancer and how they can be managed.

What to expect during recovery from radiation therapy for prostate cancer

Any side effects of radiation therapy for prostate cancer, such as skin irritation and urinary issues, should gradually improve and eventually resolve after the treatment is completed. Persistent fatigue is common, but energy levels typically return to normal within a few months. Regular follow-up visits with the oncologist will be scheduled to monitor the patient’s recovery, assess the effectiveness of the treatment and manage any lingering side effects.

How effective is radiation therapy for prostate cancer?

Radiation therapy can be highly effective for treating prostate cancer, especially in its early stages. Advances in radiation delivery techniques, such as IGRT and SABR, have enhanced the precision of treatment, increasing its effectiveness while minimizing any side effects.

Benefit from world-class care at Moffitt Cancer Center

Moffitt is an American College of Radiology-accredited center, a designation that recognizes the expertise of our team as well as the high quality of our equipment and facilities. We are also the only cancer center in the United States that can provide internal radiation treatment for prostate cancer using an absorbable Duraseal gel that reduces radiation exposure to the rectum.

If you would like to learn more about radiation therapy for prostate cancer, you can request an appointment with a specialist in our Urologic Oncology Program by calling 1-888-663-3488 or submitting a new patient registration form online. We do not require referrals.