Helping Patients and Clinics Save Time by Keeping Breath-Holds Consistent with SDX®
For Most Patients, There’s a Better Way to Manage Motion
In Stereotactic Body Radiation Therapy (SBRT), every second matters. Patients often need to hold their breath three or four times in a single treatment, and each breath-hold is traditionally followed by confirmatory imaging such as Cone Beam Computed Tomography (CBCT), kilovoltage (kV/kV) image pairs, or fluoroscopy. These checks confirm the tumor has not shifted, but they also add time and increase radiation exposure.
The SDX® system changes this process. As a spirometry-based respiratory guidance tool, it makes breath-holds consistent and reproducible. With SDX®, clinicians can be confident the tumor returns to the same position every time, reducing the need for repeated CBCT, kV/kV, or fluoroscopy scans. The result is faster treatments, lower imaging dose, and the same high level of precision.
Clinical experience shows that nearly 80% of patients are able to use SDX® successfully with the support of visual coaching and real-time monitoring. For these patients, the benefits are clear: smaller target volumes, better protection of healthy tissue, greater accuracy, and improved outcomes.
Breath-Hold Is A Clinical Advantage
For many patients, holding their breath for 20 to 25 seconds allows clinicians to deliver high-dose SBRT safely and precisely. It minimizes tumor motion, allows clinicians to stabilize internal anatomy, and leads to tighter margins and less dose to surrounding organs. Since SBRT often requires fractional doses of 10 Gy or higher, most patients will need to hold their breath multiple times during a single treatment session.
For these patients, the benefits are significant:
- Smaller margins and more precise targeting
- Less radiation exposure to healthy tissue
- A more repeatable, confident treatment experience
What Happens In Between Breath-Holds?
Surface Guided Radiation Therapy (SGRT) is helpful for monitoring a patient’s external position, but it does not confirm the internal location of the tumor after each breath-hold. When multiple holds are required during a session, this limitation becomes more significant.
According to AAPM Task Group 302:
“For SBRT treatment that includes advanced motion management techniques, such as breath hold… SGRT may not track the internal target with sufficient accuracy, and internal imaging may be more appropriate.
Because of this, many clinics use internal imaging such as CBCT, kV/kV image pairs, or fluoroscopy after the first breath-hold to verify internal alignment. While this is an important safety measure, repeating this process for every breath-hold increases treatment time and exposes patients to additional imaging dose.
SDX® Provides Confidence Without Repeating Imaging
With SDX®, patients can perform breath-holds that are consistent and measurable. This reproducibility gives clinicians greater confidence in the internal alignment of the tumor without the need for repeated internal imaging throughout treatment.
By using spirometry-based breath-hold, SDX® helps ensure that the tumor consistently returns to the same location with each breath-hold. When combined with SGRT, this provides strong reassurance that the internal anatomy is unchanged across the entire session.
In some cases, internal imaging may only be needed once at the beginning of treatment. If the breath-holds are reproducible, there may be no need to repeat imaging between each segment of the dose delivery. This can result in:
- Faster treatment sessions
- Less imaging dose for the patient
- Greater efficiency and comfort for both patients and clinical staff
This could be a valuable subject for further clinical study. If your team is interested in evaluating this further, DYN’R is available for consultation.
A Smarter, Simpler Workflow for SBRT
There are cases where patients have irregular breathing or are physically unable to hold their breath. In those situations, 4DCT and Internal Target Volume (ITV) techniques remain necessary. These protocols play a vital role in motion management.
However, for the large majority of patients who can tolerate breath-hold with spirometry guidance, SDX® offers a better option. It supports precise, repeatable breath-hold treatments while reducing reliance on confirmatory imaging throughout the session. This has the potential to improve efficiency, reduce imaging dose, and streamline SBRT delivery for most patients.
As radiation oncology continues to evolve, tools like SDX® demonstrate how technology can elevate both precision and efficiency. For the majority of patients who can perform breath-hold, it represents a better standard of care—one that reduces imaging, streamlines treatment, and supports better outcomes.
