An Algorithm for Optimized Patient-Specific Phase Selection During Stereotactic Body Radiation Therapy (SBRT)


An algorithm for optimizing SBRT tumor targeting.

Key Benefits

  • Reduction in motion errors
  • Faster treatment planning
  • Applicable on different treatment modalities such as IMRT and VMAT
  • Minimize dose delivery to surrounding organs-at-risk
  • Does not rely on a physician’s subjective judgment

Market Summary

SBRT is a radiation therapy for cancer that involves delivering high dose radiation to a limited, but highly precise treatment field containing a tumor. Compared to conventional radiation therapy, which has a two-year success rate of 30-40%, SBRT has shown dramatically better outcomes with a two-year success rate of 80-90%. However, precise targeting of the radiation and patient positioning verification are essential for SBRT, as missing the tumor due to respiratory-induced motion can have devastating consequences for the surrounding normal tissue. The existing (“non-optimized”) method to achieve this targeting and positioning (phase selection) is not reproducible, can be inconsistent, and relies on a physician’s subjective judgment about all organ motion uncertainties that may occur during SBRT execution.

Technology Summary

The goal of Emory inventors was to develop a fast algorithm for accurate dose calculation on deformed anatomies, design a strategy for phase optimization in gated SBRT based on the dose calculation, and demonstrate its clinical impact on improvements to sparing organs-at-risk, in addition to planning target volume conformality. This algorithm was tested in a pilot study on 8 cases of pancreatic cancer for its ability to spare the neighboring duodenum relative to a conventional treatment plan. Using the optimized approach, there was a reduction in the dose (exposure) to 1 cm3 of the duodenum by 16.15%, 40% reduction to 3 cm3 of the duodenum, and 62.1% to 5 cm3 of the duodenum. The relative volume of duodenum getting >5 Gy (SI unit of radiation dose) was reduced by 35% with optimization. These results suggest that optimization using this algorithm spares organs-at-risk during SBRT.

Development Stage

A proof of concept study on 8 cases has been conducted.

Patent Information

App Type Country Serial No. Patent No. File Date Issued Date Patent Status
Utility (parent) United States 14/623,999 9,919,163 2/17/2015 3/20/2018 Issued
Tech ID: 15044
Published: 8/25/2021