Data for SGRT

 We Take Extra Measures When Treating Patients for Left-Breast Cancer: SGRT


The hidden danger in treating left-breast cancer — Data for SGRT.  Radiation therapy is a highly effective treatment for breast cancer.  

But the proximity of the left breast to the heart leaves the heart vulnerable to radiation exposure. This leads to serious long-term cardiac complications[1].

In fact, one study of patients shows risk when treated for left-breast cancer.  A full 27% of patients had cardiac perfusion defects within only six months[2].

Patients breathe in different ways at different times. We achieve optimal breath hold during planning.  But during treatment, patients may not exactly repeat the same movements [3]. Precise breathing separates the heart from the breast.

That’s why we use Surface Guided Radiation Therapy (SGRT).  SGRT accurately reproduces the breath hold achieved during planning.  This minimizes risk of radiation-induced cardiac perfusion defects.


Study Results in 0% Perfusion Defects

Data for SGRT comes from a recent study at the NCI-Accredited Lineberger Cancer Center, University of North Carolina.  Patients were treated using SGRT for DIBH. 0% exhibited cardiac perfusion defects six months after treatment.[4]

The cancer is treated.  The heart is spared. 


Cardiac perfusion defects at 6 months using SPECT imaging

How SGRT Works to Protect the Heart

During treatment, patient motion is tracked using SGRT.

SGRT (Surface Guided Radiation Therapy) monitors the patient’s external surface.  It does this in real time with incredible accuracy.  This level of monitoring ensures radiation is applied exactly as intended.

SGRT technology uses three camera units to monitor thousands of points on the patient’s skin. SGRT can sense movements in six degrees of freedom.  This means up to down, forward to back, and side to side.  Additionally, it senses all rotations.  

SGRT activates radiation only once the patient is correctly positioned.  The radiation is immediately held if the patient moves during treatment.

protect your heart

SGRT uses patterned light and proprietary imaging technology to monitor patient movement with sub-millimeter accuracy.

What the patient experiences

Prior to treatment, the patient comes to our clinic for radiation treatment planning.
During planning, we coach the breath-hold technique.  We complete a planning scan while holding the breath (this usually takes 15-25 seconds).

At treatment, SGRT technology tracks the patient set-up and position. Patient takes a deep breath and SGRT monitors accuracy of positioning.  SGRT compares treatment position to planning position.  This comparison makes sure patient  positioning is exact from day-to-day,

Also, SGRT enables the radiation beam. If the patient moves out of position, the beam is turned off.

Advanced technology used by advanced institutions

Data for SGRT continues to show benefits.  SGRT technology is now in 37 of the top 50 US News “Best Hospitals for Cancer” as reported in 2019. We use SGRT in the treatment of left breast cancer.  However, we also now use SGRT when treating other cancers as well.  These include prostate, lung, head and neck, sarcoma in addition to others.

Read more about the advanced treatment techniques we provide our patients.

Read more about heart sparing with SGRT.

Beam Off:

SGRT senses the patient is out of alignment

Beam On:

SGRT confirms the patient is aligned for treatment

Treatment Screen out of tolerance.

Treatment Screen in tolerance.

[1] Darby et al. Risk of Ischemic Heart Disease in Women after Radiotherapy for Breast Cancer. N Engl J Med 2013; 368:987-998
[2] Marks, L. B. et al. The incidence and functional consequences of RT‑associated cardiac perfusion defects. Int. J. Radiat. Oncol. Biol. Phys. 63, 214–223 (2005)
[3] Gierga et al. A Voluntary Breath-Hold Treatment Technique for the Left Breast With Unfavorable Cardiac Anatomy Using Surface Imaging. Int J Radiat Oncol Biol Phys. 2012 Dec 1;84(5):e663-8

[4] Zagar et al. Prospective Assessment of Deep Inspiration Breath Hold to Prevent Radiation Associated Cardiac Perfusion Defects in Patients With Left-Sided Breast Cancer J Appl Clin Med Phys. ;93:3S 2027, plus recent personal communication

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