Skip to content

Lung SBRT with the CyberKnife® System

AI-driven, real-time respiratory motion synchronization for unmatched precision

Revolutionary Synchrony® Motion Synchronization technology powers radically precise, highly effective non-surgical treatments for lung cancer regardless of tumor complexity and location.

CyberKnife central lung

Precise robotic treatment as individual as every patient

The CyberKnife® System combines advanced robotic treatment and the world’s only real-time, AI-driven motion synchronization technology to dynamically synchronize treatment delivery with natural respiration, enabling the clinical team to deliver high doses of radiation with extreme precision while providing the patient with a personalized treatment.

Real-Time Motion Synchronization and Delivery Adaptation

The CyberKnife fully integrated image-guidance system continually acquires stereoscopic kV images during treatment, tracks motion and leverages advanced AI to automatically synchronize the treatment beam alignment in real-time. The 6-axis robotic arm aims each treatment beam taking into account tumor motion throughout treatment delivery. All measured displacements are automatically corrected, regardless of how small, maintaining sub-millimeter accuracy1.

Synchronized with natural breathing

A lung tumor will continuously move throughout the course of treatment delivery. Unlike any other radiation therapy device, the CyberKnife System uses the world’s only real-time motion synchronization technology to continuously track that motion and adapt treatment delivery to maintain sub-millimeter precision. This potentially helps to ensure the radiation dose is delivered to the target — maximizing treatment effectiveness while minimizing dose to surrounding tissues to help reduce the incidence of certain side effects. And unlike other radiotherapy options, the CyberKnife System does not require uncomfortable patient restraints or breath-hold techniques; you can relax and breathe normally, with full confidence in the CyberKnife’s synchronization capabilities.

CyberKnife chest wall

Sharp dose gradient

The robotic design of the CyberKnife System seamlessly delivers non-coplanar, non-isocentric and isocentric beams from a wide range of angles. These unique delivery capabilities sculpt conformal dose distributions and enable precise and effective treatments regardless of the target complexity and location. Sharp dose gradients provided by the system for lung treatments minimize dose to critical structures and reduce the total dose of radiation to the lung as measured by V20 and V5 calculations in comparison to standard motion management techniques. Dose-volume histogram (DVH) parameters, such as lung V20 and V5, play an important role in radiation treatment planning for thoracic malignancies including pulmonary toxicity risk prediction.

Validated accuracy

The CyberKnife System uses proprietary anatomy-specific algorithms to track tumor motion. Synchrony Respiratory Modeling is used for lung treatments and allows the patient to lie on the treatment couch and breathe naturally without the need for restraints, breath holding techniques, or gating. Academic institutions have independently validated the total accuracy of this modality to be even better than Accuray’s industry leading sub-millimeter specification of performance.

Synchrony Respiratory Modeling, total system error:

  • 0.95 mm (Accuray specification)
  • < 0.6 mm7

Versatility in collimator options

The CyberKnife System offers a collection of available collimators, providing the versatility needed to treat a wide range of lung tumors.

  • Fixed Circular Collimators
  • Iris Variable Aperture Collimator
  • InCise Multileaf Collimator

Demonstrated clinical benefits

The CyberKnife System enables effective SBRT for central lung tumors surrounded by sensitive structures2 and lung tumors near the chest wall3. It also provides excellent clinical outcomes for patients with inoperable peripheral lung tumors4-6. Furthermore, a pooled analysis of two randomized trials indicates that lung SBRT is better tolerated and might lead to better overall survival compared to surgery for operable early-state lung cancer7.

CyberKnife central lung

Lung SBRT Clinical Examples

CyberKnife System Accuracy:

1) Muacevic A. et. al. “Technical Description, Phantom Accuracy, and Clinical Feasibility for Single-session Lung Radiosurgery Using Robotic Image-guided Real-time Respiratory Tumor Tracking” TCRT. 2007; 6(4): 321-328 –


2) Nuyttens J.J. et al. “Outcome of four-dimensional stereotactic radiotherapy for centrally located long tumors” Radiotherapy and Oncology. 2012; 102: 383-387

3) Podder T. et al. “Chest wall and rib irradiation and toxicities of early-stage lung cancer patients treated with CyberKnife stereotactic body radiotherapy.” Future oncology. 2014; 10(15): 2311-2317

4) Brown W.T. et al. “Application of robotic stereotactic radiotherapy to peripheral state I non-small cell lung cancer with curative intent.” Clin Oncol (R Coll Radiol). 2009; 21: 623-631

5) Snider J.W. et al. “CyberKnife with tumor tracking: an effective treatment for high-risk surgical patients with single peripheral lung metastases” Front Oncol. 2012; 2: 63 –

6) Lischalk J.W. et al. “Long-term outcomes of stereotactic body radiation therapy (sbrt) with fiducial tracking for inoperable stage I non-small cell lung cancer (nsclc).” J Radiat Oncol. 2016; 5: 379-387 –

7) Chang S. et al. “Stereotactic ablative radiotherapy versus lobectomy for opereable stage I non-small-cell lung cancer: a pooled analysis of two rancomised trials.” Lancet Oncol. 2015; 16(6) 630-637 –

Technology naming information:

In April 2020 Accuray expanded the use of the Synchrony® brand name. As such, please be advised that the names for motion tracking and correction algorithms referenced in clinical publications may be different that current naming. Below you will find information on those name changes so that you may find the appropriate reference in existing clinical literature:

Synchrony Respiratory Modeling was called the Synchrony System prior to April 2020.
Synchrony Fiducial Tracking with Respiratory Modeling was called Fiducial Tracking with the Synchrony System
Synchrony Lung Tracking with Respiratory Modeling was call Xsight Lung with Synchrony System

Lung – Central

  • Treatment mode: CyberKnife SBRT
  • Rx: 50 Gy / 5 Fx
CyberKnife central lung

Lung – Central

  • Treatment mode: CyberKnife SBRT
  • Rx: 50 Gy / 5 Fx
CyberKnife central lung

Lung – Central

  • Treatment mode: CyberKnife SBRT
  • Rx: 50 Gy / 5 Fx
CyberKnife central lung
CyberKnife lung chest wall

Lung – Peripheral

  • Treatment mode: CyberKnife SBRT
  • Rx: 60 Gy / 3Fx (RTOG0618)

Connect with an SBRT expert.

See additional plan examples and get the answers you need.

Unmatched service to protect uptime and maximize ROI

Industry-leading service to support your ongoing success, from speedy install and optimization, to proactive monitoring and unrivalled on-site service, to smart upgrade paths to keep your system at the leading edge.

Redefining the future of cancer care

Learn how Accuray radiation technologies enable clinicians to get patients back to living their lives, faster. Explore coming innovations that unlock entirely new possibilities.

Accuray treatment options

The following pages explore some of the many ways clinicians around the globe use Accuray technologies to deliver unique and effective treatments for a wide range of clinical indications.

Treatment Centers

About Accuray

Accuray is expanding radiation therapy: our products can deliver it accurately, precisely and effectively, from oncology to neuro-radiosurgery and beyond.