What is Image-Guided Radiation Therapy (IGRT)? Purpose, Procedure & Results

Image-guided radiation therapy (IGRT) is a precise cancer treatment that uses real-time medical imaging to guide radiation beams directly to tumors. Think of it as having a GPS system that helps doctors deliver radiation with pinpoint accuracy while protecting your healthy tissues. This advanced approach has transformed how we treat cancer, making radiation therapy safer and more effective than ever before.

What is Image-Guided Radiation Therapy?

IGRT combines traditional radiation therapy with sophisticated imaging technology to create a highly targeted treatment approach. Your medical team uses CT scans, MRI, or X-rays taken right before or during each treatment session to see exactly where your tumor is located.

This real-time imaging is crucial because tumors and organs can shift slightly between treatments due to breathing, digestion, or other natural body functions. With IGRT, your radiation oncologist can adjust the treatment in real-time to account for these small movements, ensuring the radiation hits the cancer cells precisely.

The technology allows for incredibly accurate delivery of high-dose radiation to cancerous tissue while minimizing exposure to surrounding healthy organs. This precision is especially valuable when treating tumors near critical structures like the spinal cord, brain, or heart.

Why is Image-Guided Radiation Therapy done?

IGRT is recommended when your doctor needs to deliver radiation with exceptional precision to improve treatment outcomes and reduce side effects. This approach is particularly beneficial for tumors that are close to vital organs or structures that could be damaged by radiation.

Your oncologist might suggest IGRT if you have cancers in areas where organs naturally move or shift, such as lung tumors that move with breathing or prostate cancers affected by bladder and bowel filling. The imaging guidance helps ensure consistent, accurate treatment despite these natural body movements.

This treatment approach is also valuable for treating irregularly shaped tumors or cancers that have returned after previous treatment. IGRT allows your medical team to deliver higher, more effective radiation doses while maintaining safety standards for surrounding healthy tissue.

What is the procedure for Image-Guided Radiation Therapy?

Your IGRT treatment begins with a detailed planning session called simulation, where your medical team creates a personalized treatment map. During this appointment, you'll lie on a treatment table while technologists take precise measurements and imaging scans to plan your therapy.

Your radiation therapy team will create custom positioning devices or molds to help you maintain the exact same position during each treatment session. These devices, which might include masks for head and neck treatments or body cradles, ensure consistent positioning throughout your treatment course.

Here's what happens during each IGRT treatment session:

1. You'll be positioned on the treatment table using your custom positioning devices
2. The radiation therapist will take imaging scans (CT, X-ray, or MRI) to see your tumor's current location
3. Your medical team compares these images to your original treatment plan
4. If needed, they'll make small adjustments to the treatment table or radiation beam angles
5. The linear accelerator delivers the prescribed radiation dose with real-time monitoring
6. Additional imaging may be taken during treatment to ensure continued accuracy

Each treatment session typically takes 15 to 45 minutes, though the actual radiation delivery usually lasts only a few minutes. Most of the time is spent on careful positioning and imaging to ensure optimal accuracy.

How to prepare for your Image-Guided Radiation Therapy?

Preparation for IGRT varies depending on the area being treated, but your medical team will provide specific instructions tailored to your situation. Generally, you'll want to wear comfortable, loose-fitting clothing without metal zippers, buttons, or jewelry near the treatment area.

For certain types of IGRT, your doctor might ask you to follow specific guidelines before each session. These could include drinking a certain amount of water to fill your bladder for prostate treatments, or fasting for a few hours before abdominal treatments to ensure consistent organ positioning.

Your radiation therapy team will discuss any medications you should continue or temporarily stop before treatment. It's important to maintain your regular routine as much as possible, including taking prescribed medications unless specifically instructed otherwise.

Mental preparation is equally important, and it's completely normal to feel anxious about your treatment. Consider bringing relaxing music, practicing deep breathing exercises, or asking your team about relaxation techniques that might help you feel more comfortable during sessions.

How to read your Image-Guided Radiation Therapy results?

IGRT results are measured through ongoing monitoring rather than immediate test results like blood work or scans. Your radiation oncologist tracks your progress through regular check-ups, imaging studies, and assessments of how well your body is tolerating treatment.

During treatment, your medical team monitors the accuracy of each session through the real-time imaging data. They'll document any adjustments made and ensure that the radiation is being delivered according to your treatment plan specifications.

Your doctor will schedule follow-up appointments to assess treatment effectiveness, typically starting a few weeks after completing IGRT. These appointments may include physical exams, blood tests, or imaging scans to evaluate how your tumor is responding to treatment.

Long-term results are evaluated over months and years through regular monitoring appointments. Your oncologist will track tumor response, monitor for any recurrence, and assess your overall health and quality of life following treatment.

What are the benefits of Image-Guided Radiation Therapy?

IGRT offers significant advantages over traditional radiation therapy approaches, primarily through its enhanced precision and safety profile. The real-time imaging guidance allows for more accurate tumor targeting, which often translates to better treatment outcomes and fewer side effects.

The precision of IGRT enables your radiation oncologist to deliver higher radiation doses to the tumor while better protecting surrounding healthy tissues. This improved accuracy is particularly valuable when treating tumors near critical organs like the brainstem, spinal cord, or heart.

Here are the key benefits you might experience with IGRT:

• Reduced side effects due to better protection of healthy tissues
• Potentially shorter treatment courses in some cases
• Improved tumor control rates
• Better quality of life during and after treatment
• Ability to treat previously inoperable tumors
• More consistent treatment delivery despite natural body movements

Many patients find that IGRT allows them to maintain more of their normal activities during treatment compared to conventional radiation therapy. The enhanced precision often means fewer restrictions on daily activities and better preservation of organ function.

What are the possible side effects of Image-Guided Radiation Therapy?

While IGRT is designed to minimize side effects through its precision, you may still experience some effects from radiation treatment. Most side effects are temporary and manageable with proper medical support and self-care strategies.

Common side effects typically develop gradually and are related to the specific area being treated. These effects usually appear within the first few weeks of treatment and often improve within weeks to months after completing therapy.

Here are the most frequently experienced side effects:

• Fatigue that may increase gradually during treatment
• Skin irritation or redness in the treatment area
• Temporary hair loss if the head or neck area is treated
• Digestive changes if abdominal or pelvic areas are treated
• Urinary symptoms for pelvic treatments
• Throat irritation or difficulty swallowing for chest or neck treatments

Rare but more serious side effects can occasionally occur, particularly with treatments near critical organs. These might include nerve damage, organ dysfunction, or secondary cancers developing years later, though the precision of IGRT significantly reduces these risks compared to older radiation techniques.

Your medical team will monitor you closely throughout treatment and provide strategies to manage any side effects that develop. Most patients find that the side effects are quite manageable with proper support and care.

What types of cancer are treated with Image-Guided Radiation Therapy?

IGRT is particularly effective for treating cancers where precision is crucial due to tumor location or the need to protect nearby healthy tissues. Your oncologist might recommend this approach for various types of cancer, depending on your specific situation.

Brain and spinal tumors are excellent candidates for IGRT because of the critical nature of surrounding tissues. The precision imaging helps protect vital neurological structures while delivering effective radiation doses to the tumor.

Here are the types of cancer commonly treated with IGRT:

• Prostate cancer, where bladder and bowel proximity requires precision
• Lung cancer, especially tumors that move with breathing
• Head and neck cancers near critical structures
• Brain tumors and metastases
• Liver cancer and liver metastases
• Pancreatic cancer
• Spinal tumors and bone metastases
• Breast cancer, particularly for partial breast irradiation

IGRT is also valuable for treating recurrent cancers where previous radiation limits the dose that can safely be delivered to surrounding tissues. The enhanced precision allows for retreatment in many cases where conventional radiation might not be feasible.

How long does Image-Guided Radiation Therapy treatment take?

The duration of your IGRT treatment depends on your specific cancer type, tumor size, and treatment goals. Most patients receive treatment five days a week for several weeks, though some conditions may require different scheduling approaches.

A typical course of IGRT ranges from one to eight weeks, with each daily session lasting 15 to 45 minutes. The actual radiation delivery usually takes only a few minutes, while most of the time is spent on precise positioning and imaging verification.

Some cancers may be treated with hypofractionated schedules, where higher doses are delivered over fewer sessions. This approach can sometimes complete treatment in just one to five sessions, depending on the tumor type and location.

Your radiation oncologist will discuss the optimal treatment schedule for your specific situation, balancing treatment effectiveness with your convenience and quality of life considerations. The treatment plan is carefully calculated to provide the best possible outcome while minimizing side effects.

When should I contact my doctor during Image-Guided Radiation Therapy?

Your medical team will provide specific guidelines about when to contact them during your treatment course. Generally, you should reach out if you experience any concerning symptoms or if existing side effects worsen significantly.

It's important to maintain open communication with your radiation therapy team throughout your treatment. They're experienced in managing treatment-related concerns and can often provide simple solutions to help you feel more comfortable.

Contact your doctor or radiation therapy team if you experience:

• Severe or worsening fatigue that interferes with daily activities
• Significant skin irritation, blistering, or open wounds in the treatment area
• Persistent nausea or vomiting
• Difficulty swallowing or severe throat pain
• Urinary problems or blood in urine
• Severe diarrhea or abdominal pain
• Signs of infection like fever or unusual discharge
• Any new or unexpected symptoms

Remember that your medical team expects to hear from you and wants to help manage any concerns that arise. Most treatment-related symptoms can be effectively managed with appropriate medical support and adjustments to your care plan.