Augmented SBRT (ASBRT)

Enhanced Method for Accuracy 
in Prostate Cancer Treatment

What is Augmented SBRT?

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What is Augmented SBRT?

Augmented SBRT (ASBRT) is an enhanced approach to prostate cancer radiotherapy. ASBRT refers to a category of different high-precision SBRT techniques and methods that utilize real-time motion monitoring and delivery accuracy to minimize side effects, reduce the number of treatment sessions, and improve patient outcomes.

Common ASBRT delivery include:

  • CyberKnife® system, delivering robotic, adaptive SBRT
  • MR-Linac, allowing real-time imaging and online adaptive planning
  • Standard LINAC equipped with organ motion system as Raypilot System, Clarity from Elekta, Calypso from Varian enabling real-time prostate tracking

Each setup under the ASBRT umbrella shares the same clinical vision: 
zero toxicity.

This includes;

  • Real time organ motion control
  • Margin reduction (PTV<2 mm)
  • Urethra-sparing
  • Focal boost to the dominant intraprostatic lesion (DIL)
  • Consecutive treatment days (in 1–5 sessions)

ASBRT reflects a shift from conventional SBRT to image-guided, motion-informed, accurate treatment.

Standard SBRT vs Augmented SBRT

ConfigurationTraditional SBRTAugmented SBRT (ASBRT)
Number of sessions5-71-5
Total treatment time10–14 days1–5 days
Consecutive daysNot standardYes
Delivery platformConventional LINACLINAC + Organ Motion System, CyberKnife®, or MR-Linac
Prostate motion trackingIndirect (fiducials + margins)Real-time (tracking or imaging)
Treatment margins5–7 mm< 2 mm
Urethra sparingNot StandardProactively optimized
Focal boost capabilityNot standardEnabled
Workflow impactLimited increased resources Increased resources
Evidence baseStrongStrong in early phase

Standard SBRT vs Augmented SBRT

Number of sessionsTraditional SBRT
5-7

Augmented SBRT (ASBRT)
1-5
Total treatment timeTraditional SBRT
10–14 days

Augmented SBRT (ASBRT)
1–5 days
Consecutive daysTraditional SBRT
Not standard

Augmented SBRT (ASBRT)
Yes
Delivery platformTraditional SBRT
Conventional LINAC

Augmented SBRT (ASBRT)
LINAC + Organ Motion System, CyberKnife®, or MR-Linac
Prostate motion trackingTraditional SBRT
Indirect (fiducials + margins)

Augmented SBRT (ASBRT)
Real-time (tracking or imaging)
Treatment marginsTraditional SBRT
5–7 mm

Augmented SBRT (ASBRT)
< 2 mm
Urethral sparingTraditional SBRT
Not standard

Augmented SBRT (ASBRT)
Proactively optimized
Focal boost capabilityTraditional SBRT
Not standard

Augmented SBRT (ASBRT)
Enabled
Workflow impactTraditional SBRT
Limited increased resources

Augmented SBRT (ASBRT)
Increased resources
Evidence baseTraditional SBRT
Strong

Augmented SBRT (ASBRT)
Strong in early phase

News & Events

Latest updates on ASBRT adoption, presentations, and clinical collaborations.

Want to share your experience, event or news about ASBRT and SBRT?

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Want to share your experience, event or news about ASBRT and SBRT?

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Clinical Benefits 
of
Augmented SBRT

ASBRT is designed to address limitations of traditional SBRT for prostate cancer:

  • Lower toxicity through reduced margins and adaptive delivery
  • Improved accuracy with real-time tracking or imaging
  • Significantly shorter treatment time — often completed in 
1–5 sessions over consecutive days

Traditional SBRT often involves 5–7 non-consecutive sessions over multiple weeks. ASBRT enables a more efficient and patient-centered workflow, with no compromise on clinical outcomes.

Technology & Clinical Evidence Behind ASBRT

Each technology can be used independently as part of an ASBRT workflow, depending on your clinic’s infrastructure and treatment planning strategies.

Robotic Linear Accelerator

A robotic linear accelerator delivers radiation with submillimeter accuracy. The system integrates real-time image guidance with a robotic arm capable of delivering beams from hundreds of non-coplanar angles. By continuously tracking and correcting for intrafractional motion such as breathing, it ensures precise dose delivery to the tumor while minimizing irradiation of surrounding healthy tissue. The high level of precision enables hypofractionated stereotactic treatments, where high doses are delivered in a limited number of sessions compared to conventional fractionation.

Electromagnetic Position System

An electromagnetic positioning system, such as the Raypilot System, Varian Calypso (or Elekta Clarity), continuously localizes the prostate during radiation therapy. The system includes a transmitter which tracks the prostate tumour movements and outlines the urethra in real-time 3D, thus enhancing treatment precision and enabling a significant reduction of the risk of damaging surrounding healthy tissue. The precision makes it possible to use higher radiation dose and treatment may be given in a week or less, compared to conventional therapy over an 8-week period.

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MRI Linear Accelerator

MRI-guided linear accelerator technology integrates real-time soft tissue imaging with radiation delivery. Continuous visualization of the target and surrounding organs enables automatic beam gating based on tumor motion. With the capability to adapt treatment plans directly at the console, the system supports online adaptive radiotherapy, accounting for daily anatomical changes. This combination of imaging and precision dose delivery facilitates hypofractionated schedules while maintaining protection of adjacent healthy tissue.

Further Reading 
& Resources

Want to explore the foundations of ASBRT? The term itself is new — yet the concept is built on well-established, evidence-based components and systems. Here are links to studies related to increased precision and accuracy in SBRT.

Note: There are currently no published studies specifically using or focusing on the term “ASBRT” as a defined concept — it refers to a best-practice combination of tools used today by clinics aiming for maximal targeting precision and minimal toxicity.

  • Interim Toxicity Analysis From the Randomized HERMESTrial of 2- and 5-Fraction Magnetic Resonance Imaging−Guided Adaptive Prostate Radiation Therapy

    Westley et al, Red Journal, 2023

    Go to articleopen_in_new

  • Ablative Radiation Therapy for Unfavorable Prostate Tumors (ABRUPT): Preliminary Analysis of Toxicity and Quality of Life from a Prospective Study

    Arcangeli et al, Int J Radiat Oncol Biol Phys . 2024 Dec 1

    Go to articleopen_in_new

  • Magnetic Resonance Imaging Versus Computed Tomography Guidance for Stereotactic Body Radiotherapy in Prostate Cancer: 2-year Outcomes from the MIRAGE Randomized Clinical Trial

    Kishan et al, European Association of Urology, 2024

    Go to articleopen_in_new

FAQ

Looking for more information?

We’re happy to discuss configurations, technologies or implementation strategies for different clinical environments.

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Is Augmented SBRT a specific device or product?

No. ASBRT is a treatment framework — not a commercial product. It describes a category of SBRT workflows that use real-time tracking or imaging to enhance precision.

Do all ASBRT configurations use the same technology?

No, there is different techniques and methods.

Can ASBRT be implemented with our existing LINAC?

It depends on the technology being used to conduct SBRT and ASBRT. For example, Raypilot® System can be added to a standard LINAC with minimal changes to infrastructure.

Is ASBRT supported by clinical evidence?

Yes, each technology used in ASBRT has a strong evidence base. While ASBRT as a concept is not yet covered by combined trials, it reflects real-world best practice based on validated systems.

Does ASBRT increase treatment complexity?

It depends on the configuration. Some setups can be integrated with minimal workflow change while other require new protocols and training.

What makes ASBRT different from traditional SBRT?

Traditional SBRT typically uses pre-treatment imaging, fixed margins, and multiple non-consecutive fractions. ASBRT adds real-time control and adaptive capabilities, enabling margin reduction, focal boosting, and a compressed treatment schedule.

Looking for more information?

We’re happy to discuss configurations, technologies or implementation strategies for different clinical environments.

Contact Us

Want to present this to your team?

Download our summary “Augmented SBRT – Summary for Clinical Teams”.

descriptionDownload summary (PDF)