3D Printed Bolus in SGRT - SGRT USA 2024

Jae Lee, RT(T)
Manager, Radiation Oncology – South Bay, Stanford University Healthcare
Joseph B. Schulz, BS
Medical Physics Assistant, Stanford University Healthcare
SGRT US 2024

1. 1Confidential

2. 3D Printed Bolus in SGRT
Joseph B Schulz, BS
Jae Lee, RT(T)

3. 3
Agenda
q 3D Printing
q 3D Printed Bolus
q SGRT
q Pros and Cons

4. Agenda
Ø 3D Printing
q 3D Printed Bolus
q SGRT
q Pros and Cons

5. 5
3D Printing – AM vs SM
Subtractive ManufacturingAdditive Manufacturing
[1] Human Head Time Lapse: Machining at Form Factory.
https://www.youtube.com/watch?v=hErWGgRRCKg

6. 6
3D Printing – FDM, Filament
[2] Al-Mobarak et al. Material properties of sponge-gourd fiber–reinforced polylactic acid
biocomposites (2023). Journal of Thermoplastic Composite Materials, 32(7), 967–994.
[3] https://www.amazon.com/Colors-PLA-Filament-Refill-MIKA3D/dp/B0B7FT135F
§PLA

7. 7
Agenda
ü 3D Printing
Ø 3D Printed Bolus
q SGRT
q Pros and Cons

8. 8
3D Printed Bolus – Rigid (PLA)
§General
ü Pink, White, etc.
§AlignRT
ü Light Colors
Quick and easy
Rigid feel compared to flexible bolus

9. 9
3D Printed Bolus – Flexible (Silicone)
§General
ü Clear Silicone
§AlignRT
ü Opaque Silicone
Increase patient comfort
Longer fabrication time then rigid

10. 10
Agenda
ü 3D Printing
ü 3D Printed Bolus
Ø SGRT
q Pros and Cons

11. 11
SGRT – AlignRT
Treatment
Planning
Fabrication
& QATreatment

12. 12
SGRT – Bolus Planning
§Accurate body contour
ü Expand by ~1 mm for good fit
ü Create bolus on “Body + 1 mm” structure
§Choosing a bolus material

[4] Bolus figures by Dr. Lawrie Skinner, PhD, DABR

13. 13
SGRT – Bolus Color
§Rigid
ü Light Colors
§Flexible
ü Opaque Silicone

14. 14
SGRT – Bolus Fabrication and QA
§FDM 3D Print with PLA
ü Tune infill for rigid to match water
ü 1-2 walls for Silicone shell
§QA
ü Compare shape against plan
ü Measure thickness
ü Compare density to plan

15. 15
SGRT – Planning
§Before treatment
ü Dosi makes custom light field
ü Dosi pushes bolus structure to Tx
ü Used after imaging and shifts
ü Verifies placement

Light Field
Bolus

16. 16
SGRT – On Treatment
§Setup patient
ü Place bolus guided by light field
ü Ensure bolus covers light field
ü Ensure bolus won't move!
ü Capture reference

17. 17
SGRT – In Progress
§Setup patient
ü Capture reference on 1st day
ü Next day confirm placement

18. 18
Agenda
ü 3D Printing
ü 3D Printed Bolus
ü SGRT
Ø Pros and Cons

19. 19
Pros and Cons
ØEasy to sterilize
ØCost efficient in the long run
ØPatient comfort
ØMore conformal, reduced airgaps
ØEasy placement, reliable
ØStaff training
Ø3D Printer upkeep
ØSilicone is messy
ØColor is important

20. 20
Summary
§PLA filament is the gold standard
§Bolus color is important, lighter the better!
§An accurate body contour is crucial (~1mm margin)
§3D printed bolus is easier & more reliable for the
RTTs and patient
§3D printing is cost effective in the long run

[5] JB Schulz et al. Shaping Success: Clinical implementation of a 3D-printed electron cutout program in EBRT (2023). Frontiers in Oncology.
[6] DPI Capaldi et al. Tungsten Filled 3-Dimensional Printed Lung Blocks for Total Body Irradiation (2023). Practical Radiation Oncology.
[7] JB Schulz et al. A clinical solution for non-toxic 3D-printed photon blocks in external beam radiation therapy (2024). JACMP.

21. Thank you!
Jae Lee [email protected]
Joey Schulz [email protected]