Radiation for Prostate Cancer

Treatments for prostate cancer range from watchful waiting (closely monitoring the condition without giving treatment) to surgery. Radiation therapy (radiotherapy) is often used as a first-line treatment for this disease. It’s also used to treat recurrences (times when cancer returns) and help relieve advanced-stage prostate cancer symptoms.

The primary forms of radiation therapy for prostate cancer are administered either externally or internally. Multiple factors, such as the stage of your cancer and overall health, will determine the type of radiation treatment you receive.

This article will explore the various types of radiation therapy used to treat prostate cancer. It will explain how each type works and the side effects each may cause. It will also provide tips for coping with treatment.

Man receiving radiation therapy for prostate cancer

Mark Kostich / Getty Images

Overview of Radiation for Prostate Cancer

Radiation therapy has the same cure rate as surgery for prostate cancer that's localized (cancer that's only in the prostate) and locally advanced (cancer that's in the prostate and nearby tissues). This treatment uses high-intensity ionizing radiation, such as X-rays and gamma rays, to strategically pinpoint and destroy cancer cells.

Ionizing radiation is a kind of energy that can pass through living tissue. Low levels of ionizing radiation are used in medical tests such as X-rays and computed tomography (CT) scans. Radiation therapy for cancer differs from these common tests in intensity and frequency of use.

Radiation can be used to target cancer cells from outside the body. This technique is called external beam radiation.

Radiation can also be deposited internally in the form of “seeds” that are placed strategically in the prostate gland. This technique is called brachytherapy (internal radiation). You may be given one or both types of radiation during treatment.

Radiation therapy of either type may be used alone or in conjunction with other treatments. These treatments include surgery and hormone therapy called androgen deprivation therapy, in which levels of hormones that can stimulate the tumor are reduced.

In some instances, the Gleason score may be used as a tool to determine which treatments will be most effective for you. The Gleason score is a diagnostic tool that can help predict the aggressiveness of prostate cancer.

The Gleason score is determined by how much cancer looks like normal prostate tissue. It ranges from 2 to 10, with 2 being the least aggressive and 10 being the most aggressive. Prostate cancer may also be graded through a system called grade groups. Grade groups range from 1 to 5, with 1 being the least aggressive and 5 the most aggressive.  

Your doctor may recommend radiation therapy at various stages of treatment, such as:

  • As first-line therapy for low-grade prostate cancer that has a Gleason score of 6 or less (grade group 1)
  • As a first-line therapy in conjunction with hormone therapy for cancer that has spread outside the prostate gland, and into nearby tissues
  • As a first-line therapy in intermediate grade disease with favorable features (grade group 2)
  • To treat localized prostate cancer that comes back (recurs) after surgery
  • To target cancer cells that are not removed during surgery
  • To shrink tumors and alleviate the symptoms of advanced prostate cancer

Radiation therapy can cause short-term and long-term side effects. The type of radiation you have may impact the risks and side effects you experience. In general, these may include:

  • Radiation cystitis (inflammation of the bladder)
  • Problems with urination, including incontinence (loss of control of the release of urine)
  • Radiation proctitis (inflammation of the rectum)
  • Problems with bowel movements, including diarrhea
  • Erectile dysfunction (inability to achieve or maintain an erection sufficient for penetration)
  • Fatigue
  • Lymphedema (fluid retention in the legs and groin)

Coping With Side Effects of Radiation for Prostate Cancer

The side effects you experience from radiation and other prostate cancer treatments can be upsetting and challenging to live with.

Erectile dysfunction and urinary problems may be worse in people who have these issues prior to treatment. Your age and underlying conditions such as high blood pressure and diabetes may also be factors.

Urinary dysfunction often lessens or resolves on its own, over time. It can also be treated successfully with oral medication. In some instances, surgical solutions may produce long-term, satisfactory results.

Radiation therapy can damage nerves located near the prostate gland that help you have an erection. Challenges with getting and keeping an erection hard enough for penetration is common after radiation therapy.

The amount of ejaculate you produce will also diminish significantly, altering fertility potential and your ability to genetically parent a child.

If no nerve damage occurred, your doctor may prescribe medications, such as Cialis (tadalafil), that can help you have and keep an erection. Other treatments, such as penile injections, vacuum pumps, and penile implants can also help.

Keep in mind that you don’t need to have an erection to have an orgasm. As long as you maintain normal skin sensation, orgasm is possible.

In some instances, you and your partner may benefit from speaking to a sex therapist. This type of professional can help guide you through new areas of sexual exploration which can provide satisfaction for both of you. The American Association of Sexuality Educators, Counselors and Therapists has a directory you can use to find a therapist in your state.

Types of Radiation for Prostate Cancer

Your doctor may recommend one or several types of radiation therapy for you:

  • External beam radiation therapy is applied from outside of the body.
  • Brachytherapy involves applying radiation inside the body.
  • Radium-223 is applied intravenously (through infusion into a vein) when prostate cancer has spread to the bones.

External Beam Radiation Therapy (EBRT)

EBRT delivers radiation to the prostate from a machine that directs a penetrative beam into the body. This procedure is similar to getting an X-ray and is painless. Each treatment is short in duration, but you may need to have it done up to five times a week for several weeks. There are several types of EBRT.

Three-Dimensional Conformal Radiotherapy (3D-CRT)

3D-CRT utilizes specialized computers to map out the size, shape, and location of the tumor being targeted. This form of EBRT shapes radiation beams to conform to the contours of the tumor being targeted. This technique is beneficial for reducing the effects of radiation on healthy tissue.

Intensity-Modulated Radiation Therapy (IMRT)

IMRT is an advanced form of 3D-CRT. It’s also the most common type of EBRT used for treating prostate cancer. This treatment relies on a computer-controlled machine to shape and aim radiation beams directly at cancerous tissue from multiple angles.

The machine moves around you while you lie still during treatment. This machine also raises and lowers the amount of radiation being delivered to limit damage to normal, healthy tissue.

Image Guided Radiation Therapy (IGRT)

This treatment uses radiation machines that contain scanners. These machines produce photos of the prostate gland prior to administering each dose of radiation. This allows for constant adjustments that provide precise delivery and dosing.

Volumetric modulated arc therapy (VMAT) is a variation of IGRT that provides faster treatments. It utilizes a radiation machine that circles the body once while delivering radiation.

Stereotactic Body Radiation Therapy (SBRT)

This form of treatment is also referred to as stereotactic ablative radiotherapy (SABR). This technique targets pinpointed beams of very intense, strong radiation directly at a tumor. Because it is so targeted, SBRT is effective at reducing the amount of radiation that reaches surrounding tissue.

Because the radiation dosage is high, the number of visits required is reduced. Unlike IMRT, SBRT can be completed in days, rather than weeks.

Proton Beam Radiation Therapy (PBRT)

PBRT uses subatomic particles called protons instead of ionizing radiation to kill cancer cells. Like 3D-CRT and IMRT, this machine reduces the amount of radiation that reaches healthy tissue.

Side Effects of External Beam Radiation Therapy

Each type of external beam radiation therapy causes similar side effects. Some are temporary or self-resolving, but others may be long-lasting or permanent. In some instances, erectile dysfunction may start to occur several months after your treatment is complete.

Short-term side effects may include:

  • Urinary symptoms such as urgency, needing to urinate often at night, and a weaker urine stream
  • Loose bowel movements
  • Redness or bruising at the radiation site
  • Fatigue
  • Lymphedema (fluid retention in the legs and groin)

Long-term side effects may include:

  • Erectile dysfunction, including difficulty getting and maintaining an erection hard enough for penetration
  • Urinary dysfunction, including incontinence
  • Rectal inflammation (proctitis)

You may be able to reduce your risk of some long-term side effects before beginning therapy. Before starting radiation, talk to your doctor about using a hydrogel spacer during treatments. This technique reduces exposure of healthy rectal tissue to radiation.

Your surgeon will insert hydrogel in the space between the prostate and rectum, increasing the distance between the rectum and the radiation beam. This technique may help you to avoid proctitis.

Erectile dysfunction affects most prostate cancer patients who have radiation, at least temporarily. When the nerves are left intact, this side effect usually improves.

Talk to your doctor about vessel-sparing radiation, which may preserve erectile function more effectively than some other forms, including standard external beam radiation.   

Brachytherapy (Internal Radiation Therapy)

Brachytherapy is also referred to as seed implantation therapy. It may be used as a first-line, sole treatment for low-grade prostate cancer caught early. It may also be combined with external radiation if there is a risk of cancer spreading outside of the prostate.

Brachytherapy is a surgical procedure done under spinal anesthesia or general anesthesia. During brachytherapy, your surgeon will place radioactive “seeds” that are about the size of a grain of rice directly into the prostate gland.

This type of treatment is not appropriate for everyone. If you have had a prior surgery, such as a transurethral resection of the prostate (a surgery in which the prostate is removed), your doctor may not recommend brachytherapy for you. This type of treatment may also worsen already-existing urinary problems.

If your prostate gland is large, it may be challenging to place the seeds in the most effective locations. You and your doctor can discuss the efficacy of this procedure, to determine if it is appropriate for you. There are two types of brachytherapy:

Low Dose Rate (Permanent)

This procedure uses needles to place radioactive seeds into the prostate. The needles are removed but the seeds remain inside the body. Each seed emits low-dose radiation for weeks or months at a time.

Up to 100 seeds may be inserted. They remain inside the body permanently, even after their radiation dosage has been used up.

High Dose Rate (Temporary)

This procedure uses hollow needles to place catheters (delivery lines) into the prostate. Radioactive seeds containing high-dose radiation are placed into the catheters for five to 15 minutes at a time.

The catheters remain in place so that this procedure can be repeated up to four times over the course of two days. They will be removed after your last treatment.

Side Effects of Brachytherapy

Brachytherapy causes the same types of side effects that external beam radiation therapy does, such as erectile dysfunction.

In some instances, side effects to the bowels may be less severe than those caused by EBRT. Side effects that impact the bladder, however, may be more severe.

High-dose brachytherapy may cause temporary pain and swelling. It may also cause your urine to look red or brown for a short period of time.

Brachytherapy presents with some risks that external beam radiation therapy does not. If you have permanent brachytherapy, you may emit radiation to others for several weeks or months. Your doctor may advise you to stay away from pregnant people and small children during this time.

Occasionally, the seeds may migrate away from their original placement. For this reason, you may also be instructed to wear condoms during sexual activity, to protect your partner.


This treatment is used in advanced-stage prostate cancer that has metastasized (spread) to the bones. Radium-223 dichloride (trade name Xofigo) is a radioactive isotope that emits low levels of radiation directly in bone. It is administered intravenously every four weeks, up to six times.

A phase 3 trial found that this treatment increased life expectancy and improved quality of life for people with advanced-stage prostate cancer that had spread to the bones.

Side effects from radium-223 are usually mild and temporary. They include:

  • Diarrhea
  • Nausea
  • Anemia
  • Bruising
  • Bone pain

Pluvicto (lutetium Lu 177 vipivotide tetraxetan)

This treatment is used in adults with prostate-specific membrane antigen (PSMA)-positive metastatic castration-resistant prostate cancer (mCRPC) who have been treated with androgen receptor (AR) pathway inhibition and taxane-based chemotherapy. Pluvicto is a radioligand that emits radiation to PSMA-expressing cells. It is administered intravenously every six weeks, up to six times.

Side effects from Pluvicto include:

  • Vomiting
  • Nausea
  • Anemia
  • Dry mouth
  • Fatigue


Prostate cancer is often treated with radiation therapy. The methods include externally applied radiation and internally applied radiation (brachytherapy). Side effects can include inflammation of the bladder and rectum, erectile dysfunction, urinary dysfunction, and digestive symptoms such as diarrhea.

A Word From Verywell

Some people dread the treatments for prostate cancer more than they do the disease itself. This is understandable, given the scope of side effects that may occur.

Keep in mind that radiation is usually administered to prolong life. When prostate cancer is found and treated early, the five-year relative survival rate is nearly 100%.

Even so, side effects can and do occur. Advances in radiation treatment help decrease the risk of side effects. Medical treatments also can reduce side effects, such as erectile dysfunction, that can be challenging to live with.

You may have a learning curve after radiation. With perseverance and patience, you may find that your new normal is full of joy, and life is not so different from before.

Frequently Asked Questions

  • What is the success rate of radiation therapy for prostate cancer?

    The stage of cancer you're in will determine in part how successful your treatment will be. This includes the amount of spread that has occurred outside of the prostate.

    When caught early, radiation therapy is very successful for the treatment of prostate cancer. The five-year relative survival rate for localized and regional prostate cancer that is treated with radiation and other treatments is nearly 100%.

  • How many radiation treatments are needed for prostate cancer?

    It varies, based on the type of radiation treatment you receive. External beam radiation therapy may be done five days a week for several weeks. Stereotactic body radiation therapy only takes days, not weeks, to complete.

  • How long does it take to recover from radiation treatment for prostate cancer?

    Radiation treatments can be taxing on the body. Your age and overall health will play a role in how long recovery takes. Some side effects, such as fatigue, diarrhea, and pain with urination, should start to diminish in about two weeks.

    You may continue to have side effects from radiation, even after you've recovered from treatment.

  • What are the long-term effects of radiation treatment for prostate cancer?

    The long-term effects you experience may include problems with erectile dysfunction and, in some instances, urinary symptoms such as leakage. Most long-term side effects can be treated with medication or surgery.

18 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. American Cancer Society. Radiation therapy for prostate cancer.

  2. Prostate Cancer Foundation. Radiation for prostate cancer.

  3. American Cancer Society. Tests to diagnose and stage prostate cancer.

  4. UCLA Health. Dealing with erectile dysfunction.

  5. Johns Hopkins Medicine. Urinary dysfunction after prostate cancer treatment.

  6. UAB Medicine. 3D conformal radiation therapy (CRT).

  7. Stanford Health Care. What is stereotactic ablative radiotherapy(SABR/SBRT)? https://stanfordhealthcare.org/medical-treatments/s/stereotactic-body-radiation-therapy.html

  8. Prostate cancer free foundation. Prostate cancer side effects. https://www.prostatecancerfree.org/prostate-cancer-treatment-side-effects/?gclid=Cj0KCQiA2sqOBhCGARIsAPuPK0jrtQmOFE7BZV2QJ3zVrxGlRy8KARNXj7lTDI01Ab9VrFYa-JXFv00aAmaGEALw_wcB

  9. Prostate Cancer Free Foundation. Prostate cancer treatment side effects.

  10. Chao M, Ho H, Chan Y, et al. Prospective analysis of hydrogel spacer for patients with prostate cancer undergoing radiotherapy. BJU Int. 2018;122(3):427-433. doi:10.1111/bju.14192

  11. Johns Hopkins Medicine. Erectile dysfunction after prostate cancer.

  12. Spratt DE, Lee JY, Dess RT, et al. Vessel-sparing radiotherapy for localized prostate cancer to preserve erectile function: a single-arm phase 2 trial. European Urology. 2017;72(4):617-624. doi:10.1016/j.eururo.2017.02.007

  13. Macmillan Cancer Support. Brachytherapy for prostate cancer.

  14. Cancer Research UK. Radium 223 (Xofigo).

  15. Parker C, Nilsson S, Heinrich D, et al. Alpha emitter radium-223 and survival in metastatic prostate cancer. N Engl J Med. 2013;369(3):213-223. doi:10.1056/NEJMoa1213755

  16. U.S. Food and Drug Administration. Pluvicto label.

  17. American Cancer Society. Survival rates for prostate cancer.

  18. Cancer Research UK. Side effects of external radiotherapy.

By Corey Whelan
Corey Whelan is a freelance writer specializing in health and wellness conntent.