What is External-Beam Radiation for Prostate Cancer? Purpose, Procedure & Results

External-beam radiation therapy is a precise, non-invasive treatment that uses high-energy X-rays to target and destroy prostate cancer cells from outside your body. Think of it as a focused beam of energy that aims directly at the tumor while protecting the healthy tissue around it.

This treatment has helped thousands of men successfully fight prostate cancer, and it's considered one of the most effective options available today. The radiation works by damaging the DNA inside cancer cells, which stops them from growing and dividing.

What is external-beam radiation therapy?

External-beam radiation therapy (EBRT) delivers targeted radiation to your prostate from a machine positioned outside your body. The radiation beams are carefully planned and shaped to match the exact size and location of your prostate cancer.

During treatment, you'll lie on a table while a large machine called a linear accelerator moves around you, delivering radiation from different angles. The entire process is painless and typically takes about 15-30 minutes per session.

There are several types of external-beam radiation, including intensity-modulated radiation therapy (IMRT) and stereotactic body radiation therapy (SBRT). Your radiation oncologist will choose the best approach based on your specific situation and cancer characteristics.

Why is external-beam radiation therapy done?

External-beam radiation therapy treats prostate cancer by destroying cancer cells while preserving as much healthy tissue as possible. Your doctor might recommend this treatment if your cancer is contained within the prostate or has spread only to nearby areas.

This treatment works particularly well for early-stage prostate cancer, where it can be just as effective as surgery. It's also an excellent option if you're not a good candidate for surgery due to age, other health conditions, or personal preference.

Sometimes, radiation therapy is used after surgery if cancer cells remain or return. It can also be combined with hormone therapy to make the treatment more effective, especially for more aggressive cancers.

For men with advanced prostate cancer, radiation therapy can help control symptoms and improve quality of life by shrinking tumors that cause pain or other problems.

What is the procedure for external-beam radiation therapy?

The external-beam radiation process begins with a detailed planning session called simulation. During this appointment, your medical team will create a precise treatment plan tailored specifically to your prostate cancer.

First, you'll lie on a treatment table in the exact position you'll be in during each treatment session. The radiation team will use CT scans and sometimes MRI images to map the exact location of your prostate and surrounding organs.

Small, permanent tattoos about the size of a freckle will be placed on your skin to help position you correctly for each treatment. Don't worry - these marks are tiny and barely noticeable.

Your radiation oncologist and medical physicist will spend several days creating your personalized treatment plan. This plan determines exactly where the radiation beams will be aimed and how much radiation you'll receive.

Once planning is complete, you'll begin your daily treatments. Here's what happens during each session:

1. You'll change into a hospital gown and lie on the treatment table
2. The radiation therapists will position you using the tattoo marks as guides
3. The linear accelerator will move around you, delivering radiation from multiple angles
4. You'll need to lie very still during the actual radiation delivery, which takes just a few minutes
5. The therapists will monitor you from a nearby room through cameras and speakers

Most men receive treatments five days a week (Monday through Friday) for about 7-9 weeks. However, newer techniques like SBRT may require only 4-5 treatments over 1-2 weeks.

How to prepare for your external-beam radiation therapy?

Preparing for external-beam radiation therapy involves both physical and emotional preparation. Your healthcare team will give you specific instructions, but here are the most important steps to follow.

For your bladder and bowel preparation, you'll need to maintain consistent habits throughout treatment. Your doctor may ask you to drink a specific amount of water before each session to ensure your bladder is comfortably full, which helps protect nearby organs.

You might also need to follow bowel preparation guidelines, such as having a bowel movement or using an enema before treatment. These steps help ensure your internal organs are in the same position for each session.

Take care of your skin in the treatment area by using only mild, unscented soap and avoiding lotions, deodorants, or powders unless approved by your team. Don't apply anything to your skin on treatment days until after your session.

Continue taking your regular medications unless your doctor tells you otherwise. If you're on blood thinners or other medications, discuss timing with your healthcare team.

Emotionally, it's completely normal to feel anxious about starting treatment. Consider bringing a support person to your first few appointments, and don't hesitate to ask questions about anything that concerns you.

How to read your external-beam radiation therapy results?

External-beam radiation therapy results are measured through follow-up appointments and tests rather than immediate readings. Your success will be tracked over months and years through PSA blood tests and physical exams.

Your PSA levels will be checked regularly after treatment, typically every 3-6 months for the first few years. A successful treatment usually shows a steady decline in PSA levels, though this drop happens gradually over 18-24 months.

The definition of treatment success varies, but generally, your PSA should reach its lowest point (called the nadir) within two years. Some men achieve undetectable PSA levels, while others maintain very low but measurable levels.

Your doctor will also monitor you for any signs of cancer recurrence through physical exams and imaging tests if needed. Rising PSA levels after reaching the nadir might indicate that cancer cells have survived or returned.

It's important to understand that radiation effects continue for months after treatment ends. Your body needs time to eliminate the damaged cancer cells, so improvements in PSA levels happen gradually.

How to manage side effects from external-beam radiation therapy?

Managing side effects from external-beam radiation therapy focuses on supporting your body's healing process while maintaining your quality of life. Most side effects are temporary and manageable with proper care.

For urinary symptoms like frequent urination, burning, or urgency, drink plenty of water and avoid caffeine, alcohol, and spicy foods. Your doctor might prescribe medications to help control these symptoms if they become bothersome.

Bowel symptoms such as diarrhea, gas, or rectal discomfort can be managed with dietary changes. Eat smaller, more frequent meals and avoid high-fiber foods during treatment. Probiotics and anti-diarrheal medications may help if recommended by your doctor.

Fatigue is common during radiation therapy, so plan for extra rest and avoid overexertion. Light exercise like walking can actually help maintain your energy levels, but listen to your body and rest when needed.

Skin changes in the treatment area should be cared for gently. Use mild soap, pat dry instead of rubbing, and apply moisturizer if recommended by your team. Avoid sun exposure to the treated area.

Sexual function changes may occur during or after treatment. Talk openly with your healthcare team about these concerns - there are treatments and strategies that can help maintain or restore sexual health.

What are the best outcomes for external-beam radiation therapy?

The best outcomes from external-beam radiation therapy occur when the cancer is caught early and the treatment is delivered with precision. Success rates are excellent for localized prostate cancer, with cure rates similar to surgical removal.

For low-risk prostate cancer, external-beam radiation therapy achieves cancer control in about 95% of men at 10 years. Intermediate-risk cancers have success rates of 85-90%, while high-risk cancers benefit from combination treatments.

The most favorable outcomes happen when your PSA drops to very low levels and stays there. Men who achieve PSA levels below 0.5 ng/mL after treatment have the best long-term prognosis.

Quality of life outcomes are generally excellent, with most men maintaining good urinary and bowel function. Sexual function may be affected, but this often improves over time, especially with appropriate treatment and support.

Long-term survival rates are very encouraging. Most men treated with external-beam radiation therapy for localized prostate cancer live normal lifespans without cancer recurrence.

What are the risk factors for complications from external-beam radiation therapy?

Several factors can increase your risk of complications from external-beam radiation therapy. Understanding these risk factors helps you and your medical team plan the safest, most effective treatment approach.

Age plays a role in how well you tolerate treatment, though external-beam radiation is generally well-tolerated by men of all ages. Older men may experience more fatigue and take longer to recover from side effects.

Previous abdominal or pelvic surgery can increase the risk of bowel complications because scar tissue may be more sensitive to radiation. Your radiation oncologist will carefully plan around any surgical areas.

Pre-existing urinary problems, such as an enlarged prostate or urinary retention, may worsen during treatment. Your doctor might recommend treating these conditions before starting radiation therapy.

Inflammatory bowel conditions like Crohn's disease or ulcerative colitis increase the risk of severe bowel side effects. Your medical team will weigh these risks carefully when planning your treatment.

Diabetes can affect healing and increase the risk of complications, though radiation therapy is still often an excellent treatment option. Good blood sugar control before and during treatment is important.

The size and location of your prostate cancer also influence complication risks. Larger tumors or those close to sensitive structures may require more complex treatment planning.

Is it better to have external-beam radiation therapy or surgery?

The choice between external-beam radiation therapy and surgery depends on your individual situation, cancer characteristics, and personal preferences. Both treatments are highly effective for localized prostate cancer.

External-beam radiation therapy offers several advantages, including no surgical risks, shorter recovery time, and the ability to treat cancer that has spread just beyond the prostate. You can maintain your normal activities throughout most of the treatment period.

Surgery might be preferred if you're younger, have a longer life expectancy, or have certain cancer characteristics. Surgical removal provides immediate cancer removal and eliminates the small risk of radiation-induced secondary cancers decades later.

Recovery differs significantly between the two approaches. Radiation therapy allows you to continue most normal activities during treatment, while surgery requires several weeks of recovery and activity restrictions.

Long-term side effects vary between treatments. Radiation therapy may cause gradual changes in urinary and bowel function, while surgery has immediate effects on continence and sexual function that may improve over time.

Your age, overall health, cancer stage, and personal values all factor into this decision. Many men find it helpful to get second opinions and thoroughly discuss both options with their healthcare team.

What are the possible complications of external-beam radiation therapy?

External-beam radiation therapy can cause both short-term and long-term complications, though most are manageable and many improve over time. Understanding these potential complications helps you make informed decisions and prepare for treatment.

Short-term complications typically develop during treatment and in the weeks following completion. These acute effects are usually temporary and resolve within a few months.

Common short-term complications include:

• Urinary frequency, urgency, or burning during urination
• Bowel changes like diarrhea, gas, or rectal discomfort
• Fatigue that may persist for several weeks after treatment
• Skin irritation or redness in the treatment area
• Temporary worsening of urinary flow if you have an enlarged prostate

Long-term complications are less common but can develop months or years after treatment. These chronic effects require ongoing management and monitoring.

Potential long-term complications include:

• Chronic urinary problems like incontinence or difficulty emptying the bladder
• Bowel dysfunction including chronic diarrhea or rectal bleeding
• Sexual dysfunction due to damage to nerves and blood vessels
• Urethral stricture (narrowing of the urethra) requiring surgical correction
• Secondary cancers in the treatment area, though this is extremely rare

Rare but serious complications can occur, particularly with higher radiation doses or in men with pre-existing conditions. These might include severe bowel obstruction, fistulas (abnormal connections between organs), or significant urinary retention requiring catheterization.

The risk of complications depends on factors like your overall health, the radiation dose and technique used, and how well you follow post-treatment care instructions. Modern radiation techniques have significantly reduced complication rates compared to older methods.

When should I see a doctor during external-beam radiation therapy?

You should contact your healthcare team immediately if you experience severe or concerning symptoms during or after external-beam radiation therapy. While many side effects are expected and manageable, some require prompt medical attention.

Contact your doctor right away if you develop severe urinary symptoms such as complete inability to urinate, severe burning that doesn't improve with medication, or blood in your urine that's more than just a few drops.

Serious bowel symptoms that warrant immediate attention include severe abdominal pain, significant rectal bleeding, persistent vomiting, or signs of bowel obstruction like severe constipation with bloating.

Call your healthcare team if you experience fever over 101°F (38.3°C), severe fatigue that prevents you from performing daily activities, or any symptoms that seem to be getting worse rather than better.

Skin changes that require attention include severe redness, blistering, open sores, or signs of infection in the treatment area. While mild skin irritation is normal, severe changes need professional evaluation.

You should also contact your doctor if you're having trouble managing your symptoms with the prescribed treatments, if you're concerned about any new symptoms, or if you're feeling overwhelmed by the side effects.

Regular follow-up appointments are crucial for monitoring your progress and catching any complications early. Don't skip these appointments, even if you're feeling well.