Stereotactic Body Radiation Therapy (SBRT)

Overview

Stereotactic body radiation therapy (SBRT) is a cutting-edge cancer treatment that delivers highly concentrated doses of radiation directly to small tumors. Think of it as a super-precise, non-invasive alternative to surgery for certain cancers. Unlike traditional radiation, which often involves many smaller doses over weeks, SBRT gets the job done in fewer sessions, often just one to five, making it a quicker and highly effective option. This technique aims to destroy cancer cells while keeping damage to nearby healthy tissues at an absolute minimum.

What Is Stereotactic Body Radiation Therapy (SBRT)?

Stereotactic body radiation therapy is a specialized type of radiation therapy that uses advanced imaging to pinpoint the exact location, size, and shape of a tumor. This allows for the delivery of powerful, focused radiation beams that conform precisely to the tumor’s outline. It’s often used for small, isolated tumors and can be a great option for people who can’t undergo surgery due to other health issues. SBRT works by damaging the DNA within cancer cells, stopping them from growing and causing the tumor to shrink.

Advantages of Stereotactic Body Radiation Therapy (SBRT)

SBRT offers several significant benefits for patients. It’s a powerful tool in cancer treatment because it can deliver a highly effective dose of radiation directly to the tumor while largely sparing surrounding healthy tissues. This precision can lead to better outcomes and fewer side effects compared to conventional radiation therapy.

• Non-invasive: SBRT doesn’t require incisions or anesthesia, making it a less taxing option than surgery.
• Fewer Treatment Sessions: Instead of many weeks of daily treatments, SBRT typically involves only one to five sessions, saving patients time and reducing disruption to their lives.
• High Precision: Advanced imaging and targeting allow for extremely accurate radiation delivery, minimizing damage to healthy organs and tissues.
• Effective for Certain Cancers: It has shown to be very effective for small, early-stage tumors in areas like the lung, prostate, liver, and pancreas.
• Quicker Recovery: Most people can return to their normal activities within a day or two after treatment.

Stereotactic Body Radiation Therapy Procedures

Getting ready for stereotactic body radiation therapy involves a few key steps to ensure the treatment is as accurate and effective as possible. Your healthcare team will guide you through each stage, making sure you understand what to expect and that you’re comfortable throughout the process.

Before the procedure 

Before your SBRT sessions begin, your healthcare provider will meticulously plan your treatment. This involves understanding your medical history and performing detailed scans to map out the tumor.

• Consultation and Medical History Review: Your provider will discuss your health and determine if SBRT is the right choice for you, explaining the benefits and potential risks. You’ll sign a consent form if you decide to proceed.
• Imaging Tests (Treatment Simulation): You’ll undergo scans like CT, MRI, or X-rays. These aren’t for diagnosis but to create a detailed 3D map of your tumor and surrounding structures. This helps the team precisely plan the radiation beams.
• Positioning and Immobilization:  To help you stay comfortably and perfectly still during treatment, your care team may create a custom mold or cushion for the part of your body being treated. This ensures the radiation is delivered with pinpoint accuracy or they may also make small marks on your skin to guide the radiation delivery.
• They may also make small marks on your skin to guide the radiation delivery.
• Pre-treatment Instructions: You’ll receive specific instructions, such as whether you need to fast, take certain medications (like anti-nausea or anti-anxiety medicine), or what to wear to your appointments.

During the procedure 

The SBRT treatment itself is generally painless and doesn’t require you to be hospitalized. You’ll be alone in the treatment room, but under constant supervision.

• Positioning on the Treatment Table: You’ll lie on a special table, similar to the one used during your simulation. The radiation technician will carefully position you using the marks and immobilization devices to ensure accurate alignment.
• Radiation Delivery: The machine, called a linear accelerator, will deliver the radiation. It has a wide arm that moves around you at different angles, sending multiple small beams of high-dose radiation that precisely conform to the shape of your tumor.
• Monitoring and Communication: Technicians will operate the machine from a separate room, observing you through a screen. You’ll be able to communicate with them via an intercom, and you can stop the treatment at any time if you feel anxious or uneasy.
• No Pain, Some Noise: You won’t feel the radiation during treatment, but you might hear some noise as the machine moves around you.

After the procedure 

Once your SBRT session is complete, the immediate recovery is usually quick, allowing you to return to your daily routine fairly soon.

• Assistance from the Treatment Table: Technicians will help you off the table once the session is finished.
• Number of Sessions: Depending on your specific treatment plan, this might be your only session, or you may have a few more over one to two weeks.
• Immediate Activities: Most people can immediately resume eating and drinking as usual.
• Recovery Time: Generally, you can return to work or other normal activities within one or two days after your treatment.
• Tumor Response: Tumors that respond well to SBRT typically begin to shrink over the next few months.

Risks and Side Effects of SBRT

While stereotactic body radiation therapy is known for its precision and ability to minimize damage to healthy tissues, like any medical treatment, it does carry some potential risks and side effects. These usually depend on the specific area of the body being treated and your overall health. Your healthcare team will discuss these with you in detail before your treatment begins.

• Fatigue: Feeling unusually tired is a common side effect for many people in the days following treatment.
• Localized Swelling or Pain: You might experience temporary swelling or an increase in pain at or near the treatment site. This is often managed with medication.
• Nausea or Diarrhea: If the treatment is near your stomach, liver, or bowel, you might experience nausea or diarrhea for a short period. Dietary changes and medication can help manage these.
• Skin Changes: The skin in the treated area might become irritated, itchy, or dry.
• Cough or Phlegm (for Lung SBRT): After lung SBRT, some people experience a mild cough or bring up phlegm in the first few weeks. Any sudden breathing changes should be reported immediately.
• Urinary or Bowel Changes (for Prostate SBRT): For prostate cancer treatment, you might have an urgent or more frequent need to urinate, or notice changes in your bowel habits.
• Rare Long-Term Side Effects: In very rare cases, radiation can damage healthy tissue, leading to long-term side effects like weakened bones, changes in lung or spinal cord function, or lymphedema. Your care team meticulously plans treatment to minimize these risks.
• Very Small Risk of New Cancer: All radiation therapies carry a minimal, theoretical risk of developing a new cancer years later. However, SBRT’s precision significantly limits radiation exposure to healthy areas, making this risk exceptionally low.

Stereotactic Body Radiation Therapy Results

The positive effects of stereotactic body radiation therapy unfold over time. While you won’t see immediate changes, the radiation works to damage the tumor cells, leading to their shrinkage. For non-cancerous (benign) tumors, the primary goal of SBRT is to halt their growth, with shrinkage sometimes taking up to 18 months or even two years. For cancerous tumors, shrinkage can often be observed within a few months after treatment. Your healthcare provider will schedule follow-up appointments and tests to monitor your progress and assess how well the SBRT has worked. These regular check-ups are crucial to track the tumor’s response and ensure your ongoing well-being.