What is Radiation Therapy? Purpose, Procedure & Results

Radiation therapy is a medical treatment that uses high-energy beams to destroy cancer cells and shrink tumors. Think of it as a precisely targeted beam of energy that works at the cellular level to stop cancer from growing and spreading. This treatment has helped millions of people fight cancer and can be used alone or alongside other treatments like surgery or chemotherapy.

What is radiation therapy?

Radiation therapy delivers controlled doses of high-energy radiation directly to cancer cells. The radiation damages the DNA inside these cells, which prevents them from dividing and growing. Your healthy cells can usually repair themselves from this damage, but cancer cells cannot recover as easily.

There are two main types of radiation therapy. External beam radiation comes from a machine outside your body that directs beams toward the cancer. Internal radiation, also called brachytherapy, involves placing radioactive material directly inside or near the tumor.

Modern radiation therapy is incredibly precise. Advanced imaging and computer planning help doctors target cancer cells while protecting as much healthy tissue as possible. This precision has made treatment much more effective and comfortable than in the past.

Why is radiation therapy done?

Radiation therapy serves several important purposes in cancer treatment. It can cure cancer when used as the main treatment, especially for certain types like early-stage prostate or breast cancer. It also works well to shrink tumors before surgery, making them easier to remove completely.

After surgery, radiation can eliminate any remaining cancer cells that might be too small to see. This approach, called adjuvant therapy, helps prevent cancer from coming back. Your doctor might also recommend radiation to slow cancer growth when a complete cure isn't possible.

Sometimes radiation therapy focuses on comfort rather than cure. It can shrink tumors that press on nerves or organs, reducing pain and improving your quality of life. This palliative approach helps many people feel better and stay active during their cancer journey.

What is the procedure for radiation therapy?

Your radiation therapy journey begins with careful planning and preparation. First, you'll meet with a radiation oncologist who specializes in this treatment. They'll review your medical history, examine you, and explain how radiation fits into your overall cancer treatment plan.

The planning process, called simulation, involves creating a detailed map of your treatment area. You'll lie on a table while technicians use CT scans or other imaging to pinpoint exactly where the radiation should go. They might place small tattoos or stickers on your skin to mark the treatment area.

During actual treatment sessions, you'll lie still on a treatment table while the radiation machine moves around you. The machine makes some noise, but the radiation itself is completely painless. Each session typically lasts 15 to 30 minutes, though the actual radiation only takes a few minutes.

Most people receive radiation therapy five days a week for several weeks. This schedule allows healthy cells time to recover between treatments while keeping constant pressure on cancer cells. Your radiation team will monitor you closely throughout the entire process.

How to prepare for your radiation therapy?

Preparing for radiation therapy involves both practical and emotional steps. Your healthcare team will give you specific instructions, but some general preparation helps most people feel more confident and comfortable.

Before your first treatment, you'll likely need blood tests and imaging scans to make sure your body is ready. Your doctor might adjust other medications you're taking, especially if they could interfere with radiation effectiveness or increase side effects.

Here are some steps that can help you prepare physically and emotionally:

• Eat nutritious foods and stay hydrated to support your body's healing
• Get plenty of rest to maintain your energy and immune system
• Arrange transportation since you might feel tired after treatments
• Prepare your skin by using gentle, fragrance-free moisturizers
• Plan comfortable clothing that's easy to remove for treatment access
• Consider bringing music or audiobooks to help you relax during sessions
• Ask about support groups or counseling services if you're feeling anxious

Don't hesitate to ask your radiation team questions about what to expect. Understanding the process often helps reduce anxiety and makes you feel more in control of your treatment experience.

How to read your radiation therapy results?

Unlike blood tests with specific numbers, radiation therapy results are measured through imaging scans and physical examinations over time. Your doctor will use CT scans, MRIs, or PET scans to see how tumors respond to treatment and whether cancer has spread.

A complete response means imaging shows no visible cancer after treatment. This is the best possible outcome, though it doesn't guarantee that microscopic cancer cells aren't still present. A partial response indicates the tumor has shrunk significantly, usually by at least 30 percent.

Sometimes scans show stable disease, meaning the cancer hasn't grown or shrunk much. This can actually be a positive result, especially when the goal is controlling cancer growth rather than eliminating it completely. Progressive disease means cancer has continued growing despite treatment.

Your doctor will explain what these results mean for your specific situation. They'll also monitor you for months or years after treatment ends, since radiation effects can continue working long after your last session.

How to manage radiation therapy side effects?

Managing radiation side effects focuses on supporting your body's natural healing while staying comfortable during treatment. Most side effects are temporary and manageable with the right care and attention.

Fatigue is one of the most common side effects, often building gradually over several weeks of treatment. This tiredness differs from normal exhaustion because rest doesn't always help. Getting light exercise, eating regular meals, and maintaining a consistent sleep schedule can help maintain your energy levels.

Skin changes in the treatment area are also very common. Your skin might become red, dry, or sensitive, similar to a sunburn. Here's how to care for radiation-treated skin:

• Use gentle, fragrance-free soaps and moisturizers
• Avoid hot water and take lukewarm showers instead
• Don't use lotions with alcohol, perfumes, or harsh chemicals
• Protect treated skin from sun exposure with loose clothing
• Ask your team before using any new skin products
• Report any severe redness, blistering, or open sores immediately

Other side effects depend on which part of your body receives radiation. Treatment to the head and neck might cause mouth sores or changes in taste. Radiation to the chest could lead to throat irritation or difficulty swallowing. Your radiation team will prepare you for area-specific side effects and provide management strategies.

What are the risk factors for radiation therapy complications?

Several factors can influence how well you tolerate radiation therapy and whether complications develop. Understanding these risk factors helps your medical team plan the safest, most effective treatment for your specific situation.

Age and overall health status play important roles in radiation tolerance. Older adults or people with chronic health conditions like diabetes or heart disease may experience more side effects. However, age alone doesn't prevent successful radiation treatment.

Previous cancer treatments can affect radiation therapy outcomes. If you've had radiation before, especially to the same area, your risk of complications increases. Certain chemotherapy drugs can also make tissues more sensitive to radiation effects.

Here are additional factors that might increase complication risks:

• Smoking, which impairs healing and increases infection risk
• Poor nutrition status that weakens your immune system
• Autoimmune disorders that affect tissue healing
• Genetic conditions that make you more sensitive to radiation
• Large treatment areas that expose more healthy tissue
• High radiation doses needed for certain cancer types
• Concurrent chemotherapy that amplifies radiation effects

Your radiation oncologist will carefully evaluate these factors when planning your treatment. They might adjust radiation doses, change treatment schedules, or recommend additional supportive care to minimize your risk of complications.

Is it better to have high or low radiation doses?

The "best" radiation dose isn't about high or low numbers, but about finding the optimal balance for your specific cancer and situation. Your radiation oncologist calculates the precise dose needed to destroy cancer cells while protecting healthy tissues as much as possible.

Higher doses can be more effective at killing cancer cells, but they also increase the risk of side effects and complications. Lower doses might be gentler on your body but may not control cancer growth as effectively. The goal is finding the sweet spot that maximizes cancer control while minimizing harm to healthy tissues.

Modern radiation therapy uses sophisticated techniques to deliver optimal doses with incredible precision. Intensity-modulated radiation therapy (IMRT) can vary radiation intensity within the same treatment area. Stereotactic radiosurgery delivers very high doses to small, precise areas in fewer sessions.

Your doctor considers many factors when determining your radiation dose, including cancer type, location, size, and your overall health. They also factor in whether you're receiving other treatments and your personal treatment goals.

What are the possible complications of radiation therapy?

Most people complete radiation therapy with manageable side effects, but understanding potential complications helps you know what to watch for and when to seek help. Complications can occur during treatment, shortly after, or sometimes years later.

Early complications usually develop within the first few weeks of treatment. These acute effects are often temporary and resolve within weeks to months after treatment ends. Your skin might become severely irritated, or you might develop mouth sores if receiving head and neck radiation.

Here are some early complications that require medical attention:

• Severe skin breakdown or infected wounds in the treatment area
• Difficulty swallowing or breathing from throat swelling
• Persistent nausea and vomiting that prevents eating or drinking
• Signs of infection like fever, chills, or unusual discharge
• Severe fatigue that prevents basic daily activities
• Pain that isn't controlled with prescribed medications

Late complications can develop months or years after treatment ends. These might include tissue scarring, organ dysfunction, or secondary cancers. While late complications are less common with modern radiation techniques, they're important to monitor for during follow-up care.

The risk of complications varies greatly depending on the radiation dose, treatment area, and your individual health factors. Your radiation team will discuss specific risks for your situation and create a monitoring plan to catch any problems early.

When should I see a doctor during radiation therapy?

You should contact your radiation oncology team immediately if you experience any severe or concerning symptoms during treatment. Don't wait for your next scheduled appointment if something feels wrong or different from what your team prepared you to expect.

Seek immediate medical attention if you develop a fever over 100.4°F (38°C), especially if you're also receiving chemotherapy. Fever can indicate infection, which requires prompt treatment when your immune system might be compromised.

Here are specific warning signs that require urgent medical evaluation:

• Difficulty breathing or chest pain
• Severe skin breakdown with open wounds or pus
• Inability to eat or drink due to mouth sores or throat pain
• Persistent vomiting that prevents keeping food or fluids down
• Signs of dehydration like dizziness, dark urine, or extreme thirst
• Unusual bleeding or bruising
• Severe pain that doesn't respond to prescribed medications
• Any symptom that significantly worsens or doesn't improve as expected

Even if symptoms seem minor, don't hesitate to call your radiation team with questions or concerns. They're experienced in managing radiation side effects and can often provide helpful guidance over the phone. Early intervention often prevents minor issues from becoming serious complications.