Can sgrt be used to eliminate tattoos and reduce setup time for sbrt lung treatments

1. Can SGRT be used to eliminate
tattoos and reduce setup time for
SBRT lung treatments?
Jonathan Day, RT(T.)
University Hospital Zurich

2. Where is Switzerland?

4. Zürich

5. Current Situation
• 3 LINACs - 2 SGRT devices
• Edge – July 2014
• Trilogy – May 2016
Jonathan Day, Atlanta 2018

6. //
Lung SBRT at our Clinic
Current Standard
Jonathan Day, Atlanta 2018
3x12.5Gy 3x13.5Gy 5x8Gy 5x10Gy
-4D planning CT
-Varian Truebeam or Edge
-Leveled with tattoos
-Manually calculated shift to Isocentre
-CBCT
-Treat with 2 -4 arcs
-Isocentre drawn with marker

7. Workflow
 Patient in Vac-Lok
 Table driven based on SGRT reference surface
• 4DCT DICOM Average Surface
 Translational Tolerance: 2mm
 Rotation/Roll/Pitch: 2°
• CBCT and PTV match in 6 axes
SBRT lung Radiation with SGRT
Jonathan Day, Atlanta 2018

8. Workflow continued
• Match CBCT in 6 axes
 Shift table
 Capture a new reference
• Beam Gating
«ON»
SBRT lung Radiation with SGRT
Jonathan Day, Atlanta 2018

9. Methods
Jonathan Day, Atlanta 2018
Tattoos + skin marks SGRT
10 patients 10 patients
37 fractions 41 fractions

10. Methods
• Compared setup accuracy with CBCT images
• Compared time from opening the patient‘s plan in
treatment mode unti the start of CBCT
Jonathan Day, Atlanta 2018

11. Typical Montoring Data
Jonathan Day, Atlanta 2018
-2
-1.5
-1
-0.5
0
0.5
1
1.5
2
2.5
3
1
18
35
52
69
86
103
120
137
154
171
188
205
222
239
256
273
290
307
324
341
358
375
392
409
426
443
460
477
494
511
528
545
562
579
596
613
630
647
664
681
698
715
732
749
766
783
800
817
834
851
868
885
902
919
936
shiftincm
elapsed time in seconds
Set up and CBCT
Vertical longitudinal Lateral

12. Typical Montoring Data
Jonathan Day, Atlanta 2018
-15
-10
-5
0
5
10
15
1
26
51
76
101
126
151
176
201
226
251
276
301
326
351
376
401
426
451
476
501
526
551
576
601
626
651
676
701
726
751
776
801
826
851
876
901
926
951
976
1001
1026
1051
1076
1101
1126
1151
1176
1201
shiftincm
elapsed time in seconds
Set up and CBCT with Centre Couch
Vertical Longitudinal Lateral

13. Results
Jonathan Day, Atlanta 2018
Mean post-match shift, based on
imaging
vertical longitudinal lateral
SGRT 0.25 ± 0.24 cm 0.34 ± 0.24 cm 0.14 ± 0.13 cm
Tattoos 0.50 ± 0.60 cm 0.60 ± 1.1 cm 0.60 ± 1.7 cm

14. Results
Jonathan Day, Atlanta 2018

15. Results
Jonathan Day, Atlanta 2018
9.5cm
0.97cm
>1cm SGRT = 0
>1cm Tattoo = 12

16. Results: Time/Efficiency
Jonathan Day, Atlanta 2018
Time from plan opening to CBCT
Tattoos + skin marks SGRT
Average 10 ± 3 minutes 7 ± 2 minutes
Max 17 minutes 14 minutes

17. Discussion
• Miscalculated shifts
• Loss of marks
• Movement of marks
• Longer setup with marks
Jonathan Day, Atlanta 2018

18. Conclusion
Jonathan Day, Atlanta 2018
SGRT can be used to eliminate tattoos and reduce setup
time for SBRT lung treatments

19. Thanks!
• Therapist Team
• Amanda Moreira
• Alessandra Tini
• Josh Sharpe
• Frederique Cavelaars
• Physicians
• Prof. Dr. med. Matthias Guckenberger
• Dr. med. Claudia Linsenmeier
• Medical Physics Team
• M.Sc. Izabela Pytko
• Dr. Mariangela Zamburlini
• Dr. Stephanie Tanadini-Lang
Jonathan Day, Atlanta 2018

20. Thank you for your
attention 
Jonathan Day, Atlanta 2018