Would you trust a cancer treatment that continuously checks your position during radiation therapy?
This is one of the questions I often discuss when explaining modern radiation oncology to my patients. Radiation therapy has evolved significantly over the years. Today, our focus is not only on delivering the prescribed radiation dose, but also on delivering it with greater precision, consistency, and attention to the surrounding healthy tissues.
One of the technologies contributing to this evolution is Surface Guided Radiation Therapy (SGRT).
For patients undergoing breast cancer radiotherapy, SGRT can provide an additional layer of precision by monitoring the patient’s external surface and position during treatment. It represents an important step toward making radiation therapy more accurate, comfortable, and technology-driven.
What Is SGRT?
Surface Guided Radiation Therapy, or SGRT, is a modern, non-invasive technology used to assist with patient positioning and motion monitoring during radiation treatment.
Unlike conventional positioning methods that may rely on marks placed on the patient’s skin and imaging performed at specific points during treatment, SGRT uses optical surface imaging to create and monitor a three-dimensional representation of the patient’s external surface.
The treatment team can use this information to determine whether the patient is positioned appropriately before radiation begins and to monitor movement during treatment.
In simple terms, SGRT allows the radiation therapy team to continuously observe changes in the patient’s surface position rather than relying only on a single positioning check.
This becomes particularly valuable when we are delivering highly precise radiation treatments where even small changes in positioning can matter.
Why Does Positioning Matter During Radiation Therapy?
Radiation therapy is carefully planned before the first treatment session.
Using CT scans and other clinical information, we identify the area that needs treatment and carefully define nearby organs and tissues that we want to protect. A treatment plan is then created to deliver the prescribed radiation dose as accurately as possible.
However, a treatment plan exists in three-dimensional space, while the patient has to reproduce a similar position every day.
Patients naturally breathe, move, swallow, adjust their shoulders, or make small involuntary movements. These are normal human movements, but radiation treatment requires us to account for them carefully.
This is where image guidance and surface monitoring can become valuable.
SGRT provides the treatment team with additional information about the patient’s position and movement, helping us maintain treatment accuracy throughout the session.
SGRT and Breast Cancer Treatment
Breast cancer is one of the situations where precision in radiation therapy is particularly important.
After breast-conserving surgery, radiation therapy may be recommended to reduce the risk of cancer returning in the treated breast. Depending on the individual patient’s disease characteristics and treatment plan, radiation may also be required after mastectomy.
The breast and chest wall are located close to several important structures, including the heart and lungs. Therefore, our treatment planning focuses not only on treating the appropriate target but also on minimizing unnecessary radiation exposure to surrounding organs.
Modern techniques such as IMRT, VMAT and IGRT have already transformed radiation treatment planning and delivery. SGRT adds another useful layer of information by helping us monitor the patient’s external surface and positioning.
What Happens During an SGRT Session?
The process is designed to be non-invasive.
Before treatment, the patient is positioned on the treatment couch according to the planned setup. The SGRT system then captures the patient’s surface and compares it with the reference position established during treatment planning.
If the patient’s position is appropriate, treatment can proceed according to the clinical protocol.
During treatment, the system can continue to monitor the patient’s surface and detect movement. Depending on the technology and treatment setup, significant movement can trigger an alert or treatment interruption so that the radiation team can assess the situation and make appropriate adjustments.
This does not replace the expertise of the radiation oncology team or other imaging and verification procedures. Rather, SGRT works as an additional tool within a carefully designed radiation treatment workflow.
Why Is This Particularly Relevant to Breast Cancer Patients?
One of the major considerations in breast cancer radiotherapy is the relationship between the treatment area and nearby organs.
For example, in patients with left-sided breast cancer, protecting the heart is an important consideration during radiation planning. Techniques such as Deep Inspiration Breath Hold (DIBH) may be used in selected patients to help increase the distance between the heart and the treatment area.
SGRT can support such workflows by monitoring the patient’s external surface and respiratory-related movement.
This can be particularly useful when a treatment technique requires the patient to maintain a specific breathing position.
The objective is straightforward: deliver the planned radiation accurately while keeping treatment as safe and precise as possible.
SGRT and Patient Movement
A common question patients ask is:
“What happens if I move during radiation?”
It is important to understand that patients are not expected to remain completely motionless like a machine.
Breathing itself causes movement. Small movements can also occur naturally during treatment.
The purpose of modern radiation technology is not to expect patients to behave like perfectly stationary objects. Instead, we use technology and appropriate treatment margins to account for normal movement and help identify changes that may require attention.
SGRT can provide real-time information about changes in the patient’s external surface.
This gives the treatment team another way to monitor positioning and respond when necessary.
A More Comfortable Approach
Another advantage of SGRT is that it is a non-contact technology.
Traditional radiation treatment setups may involve permanent or temporary skin markings. Although these marks can be useful, surface-guided systems can provide additional positioning information without requiring physical contact with the patient.
For many patients, particularly those already undergoing an emotionally and physically demanding cancer journey, every effort to make treatment more comfortable and reassuring matters.
Technology should not make cancer care feel more complicated. It should make the treatment process more precise while keeping the patient’s experience in mind.
SGRT Does Not Replace the Radiation Oncologist
It is equally important to understand what SGRT does—and what it does not do.
SGRT is a technology that supports radiation treatment. It does not independently decide whether a patient requires radiation, determine the appropriate radiation dose, or replace clinical judgment.
Every patient’s treatment begins with a detailed assessment.
We consider:
- The type and stage of cancer
- Pathology findings
- Surgical history
- CT, MRI or PET imaging when relevant
- Previous treatments
- Overall health
- Treatment intent
- Target volumes
- Organs at risk
- Individual patient considerations
Only after this assessment can we determine the most appropriate treatment approach.
Technology becomes meaningful when it is integrated into sound clinical decision-making.
From Treatment Planning to Treatment Delivery
Modern radiation oncology is a chain of carefully connected steps.
First, we identify the disease and determine the treatment objective.
Then, using appropriate imaging, we define the target and surrounding organs at risk. Treatment planning software helps us develop a radiation plan that provides appropriate tumor coverage while limiting dose to healthy structures.
During treatment, image guidance and technologies such as SGRT can help ensure that the patient’s position corresponds appropriately with the planned treatment setup.
This integration of clinical expertise, imaging, planning and treatment delivery is what makes modern radiation oncology increasingly precise.
Precision Is More Than Technology
As a Radiation Oncologist, I believe that precision in cancer care goes beyond machines and software.
Precision begins with the diagnosis.
It continues with accurate staging, appropriate target delineation, thoughtful treatment planning and careful selection of the radiation technique.
It also includes monitoring the patient throughout treatment, identifying side effects early, addressing concerns and adapting care when clinically necessary.
The most advanced technology cannot replace a good treatment plan or a strong doctor-patient relationship.
Technology should serve the patient—not the other way around.
What Should Patients Know About SGRT?
If you have been advised radiation therapy for breast cancer, it is reasonable to ask your radiation oncology team about the technology being used during your treatment.
You may ask:
- How will my treatment position be verified?
- Will image guidance be used?
- Is SGRT appropriate for my treatment?
- Will my breathing need to be monitored?
- Is DIBH recommended in my case?
- How will my heart and lungs be protected?
- What radiation technique is being planned?
- How will treatment-related side effects be monitored?
These are important questions, and patients should feel comfortable discussing them with their radiation oncologist.
The Future of Precision Radiation Therapy
Radiation oncology continues to evolve rapidly.
Technologies such as IMRT, IGRT, VMAT, SBRT, SRS, SGRT and adaptive radiotherapy are helping us approach cancer treatment with increasing precision.
At the same time, our understanding of cancer biology, imaging, treatment response and individual patient characteristics continues to improve.
The future of radiation oncology is not simply about delivering higher doses or using more sophisticated machines. It is about delivering the right treatment, to the right patient, at the right time, with the greatest possible precision and safety.
SGRT is one part of this larger evolution.
My Message to Breast Cancer Patients
If you or someone you love has been diagnosed with breast cancer, please remember that a cancer diagnosis does not mean that you have to navigate the journey alone.
Modern cancer care is multidisciplinary. Radiation oncologists work alongside surgeons, medical oncologists, radiologists, pathologists, nurses, physiotherapists and other healthcare professionals to develop an individualized treatment pathway.
Do not hesitate to ask questions about your treatment.
Understand why radiation has been recommended.
Ask about the technique being used.
Discuss potential side effects.
And most importantly, make your treatment decisions based on a clear understanding of your individual diagnosis rather than fear or information found without context.
SGRT is an excellent example of how technology can add another layer of precision to radiation therapy. But behind every advanced system is a clinical team making thoughtful decisions for an individual patient.
For me, that is the real goal of modern radiation oncology: precision in treatment, compassion in care, and a constant commitment to improving outcomes for every patient.
Frequently Asked Questions
Is SGRT painful?
No. SGRT is a non-invasive, non-contact technology used to monitor the patient’s external surface and positioning during radiation treatment.
Does SGRT replace regular imaging?
Not necessarily. SGRT is an additional positioning and motion-monitoring technology. The imaging and verification methods used depend on the patient’s treatment plan and clinical requirements.
Is SGRT useful for every breast cancer patient?
SGRT may be useful in selected patients and treatment workflows. The appropriate technology depends on the individual treatment plan, equipment available and clinical requirements.
Can SGRT monitor breathing?
Surface-guided systems can provide information about external respiratory motion and may support certain breathing-management techniques. Whether this is used depends on the patient’s treatment plan.
Does SGRT mean that radiation treatment is completely risk-free?
No radiation treatment is completely free of potential side effects. SGRT is intended to improve positioning and monitoring as part of a comprehensive treatment process; it does not eliminate all treatment-related risks.
Precision is not just about how radiation is delivered. It is about every decision made before, during and after treatment.
