SGRT Europe 2023: Improving efficiencies with MapRT

David Parsons, PhD
Associate Director of Medical Physics Residency Program
University of Texas Southwestern, Dallas, Texas, USA

1. Improving efficiencies with MapRT
David Parsons
12/1/2023
SGRT Europe 2023

2. SGRT Europe 2023 • London, UK
Outline
▪Why non-coplanar treatments and increased safety risk
▪MapRT: what is it and workflow
▪Accuracy and historical comparison
▪Dosimetric advantages for lung SAbR
2

3. SGRT Europe 2023 • London, UK
SAbRPlanning: Priorities
Respect tumor coverage and “DoseCompactness”
constraints
▪These characterize (define) SAbR
▪High doseconformality, d2cm, low gradient index (GI)
▪Designed to require many beams, many angles,spread out
entrance dose,etc​…
▪Effectively, isotropic dose falloff
3
Robert Timmerman, M.D.
Department Chair

4. SGRT Europe 2023 • London, UK
SAbRPlanning: Lung Beam Orientation
4
Mu-Han Lin, Ph.D.
Medical Physicist

5. SGRT Europe 2023 • London, UK
SAbRPlanning: Lung Beam Orientation
5
Mu-Han Lin, Ph.D.
Medical Physicist

6. SGRT Europe 2023 • London, UK
SAbRPlanning: Lung Beam Orientation
6
Mu-Han Lin, Ph.D.
Medical Physicist

7. SGRT Europe 2023 • London, UK7
Currently this is mostly a manual process
X
10

8. SGRT Europe 2023 • London, UK8
Not every risk can be evaluated

9. SGRT Europe 2023 • London, UK9
Manual clearance checks adds to planning time
Mean additional
time is 6.2 hours
(n=60)

10. SGRT Europe 2023 • London, UK
MapRT
10
▪MapRT is a SGRT virtual
clearance mapping
software

11. SGRT Europe 2023 • London, UK
MapRT
11
▪MapRT is a SGRT virtual
clearance mapping
software
▪Consists of 2 Horizon
cameras in the CT vault
MapRT
SimRT
MapRT
MapRTSimRT

12. SGRT Europe 2023 • London, UK12
MapRT
Imported Dicom
parameters

13. SGRT Europe 2023 • London, UK13
MapRT
Imported Dicom
parameters
Clearance
Map
with arc
locations

14. SGRT Europe 2023 • London, UK14
MapRT
Imported Dicom
parameters
Clearance
Map
with arc
locations
Collision
Zones

15. SGRT Europe 2023 • London, UK15
MapRT
Imported Dicom
parameters
Clearance
Map
with arc
locations
Collision
Zones
Interactive
Window

16. SGRT Europe 2023 • London, UK16
MapRT

17. SGRT Europe 2023 • London, UK17
What is the accuracy?
SiqiuWang, Ph.D.
Physics Resident

18. SGRT Europe 2023 • London, UK18
Clearance accuracy is within ±1°
SiqiuWang, Ph.D.
Physics Resident

19. SGRT Europe 2023 • London, UK19
How does it compare to manual checks?
Method Clearance AgreedClearance DisagreedSuccess Ratio
Physical Angle Check 55 5 91.7%
MapRT 60 0 100%
60 SAbRand non-coplanar brain patients at UTSW
SiqiuWang, Ph.D.
Physics Resident

20. SGRT Europe 2023 • London, UK20
How does it compare to manual checks?
Method Clearance AgreedClearance DisagreedSuccess Ratio
Physical Angle Check 55 5 91.7%
MapRT 60 0 100%
60 SBRT and non-coplanar brain patients at UTSW
SiqiuWang, Ph.D.
Physics Resident

21. SGRT Europe 2023 • London, UK21
How this is done in practice
▪74-year-old female
▪17.6 cm
3
right lung legion
▪SAbRcandidate with 60Gy in 5Fx
▪2 partial arc treatment was
chosen

22. SGRT Europe 2023 • London, UK22
How this is done in practice
▪74-year-old female
▪17.6 cm
3
right lung legion
▪SAbRcandidate with 60Gy in 5Fx
▪2 partial arc treatment was
chosen

23. SGRT Europe 2023 • London, UK23
Enter MapRT

24. SGRT Europe 2023 • London, UK24
Identify the trouble spots

25. SGRT Europe 2023 • London, UK25
Adjust the areas of interest​

26. SGRT Europe 2023 • London, UK26
Check the revise the field arrangement

27. SGRT Europe 2023 • London, UK27
Resulting comparison
Coplanar
CI
Paddick= 0.89
GI
50%= 4.54
GI
25%= 28.5
5688 MU
Non-coplanar
CI
Paddick= 0.91
GI
50%= 4.30
GI
25%= 15.1
4061 MU

28. SGRT Europe 2023 • London, UK28
Over 20 lung SAbRpatients
SiqiuWang, Ph.D.
Physics Resident
p = 0.001 p = n.s. p = n.s.p < 0.001

29. SGRT Europe 2023 • London, UK29
Over 20 lung SAbRpatients
SiqiuWang, Ph.D.
Physics Resident

30. SGRT Europe 2023 • London, UK30
Going Live with MapRT –Historical Trend
n = 51 n = 61 n = 67 n = 68

31. SGRT Europe 2023 • London, UK 31
Going Live with MapRT –Rapid Decrease
n = 51 n = 61 n = 67 n = 68 n = 78 n = 40
MapRT go-live

32. SGRT Europe 2023 • London, UK
Estimated in-vault time savings
▪We estimate that in
▪October we should have had ~125
angle checks
▪November we should have had ~75
angle checks
▪This equals to an estimated in-
vault time savings of
▪8.0hours in October
▪5.7hours in November
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33. SGRT Europe 2023 • London, UK
Summary
▪MapRT is a novel SGRT clearance mapping software
▪More accurate than manual clearance checks
▪Greatly reduces the planning time
▪Saves in-vault time
▪Improved dosimetry
▪In short, MapRT enables confidence in non-coplanar
treatments
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34. SGRT Europe 2023 • London, UK
Acknowledgments
34
▪Andrew Godley
▪David Sher
▪Eric Chambers
▪Siqiu Wang
▪Yesenia Gonzalez
▪Xinran Zhong
▪Liyuan Chen
▪Kara James
▪Jennifer Cleaton
▪Lindsi Seaux
▪Phu Ho
▪Rashad Campbell
▪Gannon Arnold
▪Jordan Getchell
▪Weihan Lee
▪Jeff Dubas
▪Romona Frame
▪Hung Ho