SGRT London 2021 Nicki McGrath, Principal Radiotherapy Physicist, The Christie NHS Foundation Trust, UK

1. The Christie NHS Foundation Trust
Safe implementation of
AlignRT® across a multi-site
centre:
Commissioning and clinical
validation work
Nicki McGrath
Principal Physicist, The Christie NHS Foundation Trust
nichola.mcgrath1@nhs.net

2. The Christie NHS Foundation Trust
Overview
• Background
• Project timeline
• Commissioning
• Calibration robustness
• Clinical validation
• Challenges faced
• Where we are now

3. The Christie NHS Foundation Trust

4. The Christie NHS Foundation Trust
Background
• DIBH at The Christie
• DIBH with the Elekta ABC system in 2016
• Limited numbers due to lack of resources and capacity
• Falling short of NICE guidelines (2018)
• Initial business case put together for SGRT, then COVID
hit…but ultimately assisted…..
• Spirometry technique has infection control risk
• Cumbersome to set up and increased time with patient
• SGRT could offer a more efficient workflow reducing time in
the department

5. The Christie NHS Foundation Trust
Timeline of Project
• Business case approved August 2020
• AlignRT® at The Christie
• 2 systems at Withington
• 2 systems at Oldham
• 1 system at Salford
• GateCT® at The Christie
• 1 system at each satellite

6. The Christie NHS Foundation Trust
Timeline of Project
• Install and accept systems across all three sites by end
of 2020
• A lot of scheduling/organisation
• Site survey, preparatory work by Engineering, Estates and IT
COMPLETED BY END NOVEMBER 2020 !!
• ………Treat DIBH “as soon as possible”
Oldham
Mid Oct 2020
Withington
Early Nov 2020
Salford
End Nov 2020

7. The Christie NHS Foundation Trust
Commissioning Work
• Surface detection - translations and rotations
• Establishing QC Program
• Integrity of surface from TPS (including SSD checks)
• Effect of mis-calibration
• Effect of light settings
• System stability prior to clinical use
• Importance of ROI definition
• End to end testing

8. The Christie NHS Foundation Trust
Commissioning Work
• Surface detection - translations and rotations
• Establishing QC Program
• Integrity of surface from TPS (including SSD checks)
• Effect of mis-calibration
• Effect of light settings
• System stability prior to clinical use
• Importance of ROI definition
• End to end testing

9. The Christie NHS Foundation Trust
Commissioning Work – Quality Control
• Calibration procedure
• Automated
• Easy but “too easy”
• Lots of clicks (v5.1)
• Daily QA
• Automated
• Will the system do what its supposed to following on
from this?

10. The Christie NHS Foundation Trust
Commissioning Work – Quality Control
• Surface detection and couch moves
• Additional test using the Penta-Guide phantom
• Checks real time surface against reference capture
• Ensures couch moves based on translational deltas are correct
• Rotational deltas can also be checked

11. The Christie NHS Foundation Trust
Commissioning Work – Quality Control
• Ensures phantom moves back to isocentre
• Additional confidence in system calibration
• Currently check monthly and following recalibration

12. The Christie NHS Foundation Trust
Mis-calibration
• Can the system be mis-calibrated and what is the
effect on the resultant surface?
• Calibrate with plate at 100cm FSD
• What if set the wrong FSD? (e.g. 102cm)
• System won’t allow you to recalibrate
• Inbuilt safety reassuring

13. The Christie NHS Foundation Trust
Mis-calibration
• If FSD is 3mm/4mm off then will allow a recalibration
• Daily QA afterwards wouldn’t detect error
• Unlikely …..but possible scenario?
• Resultant surface is displaced by a similar magnitude
• Hence Penta-Guide QC check is always done following
a recalibration

14. The Christie NHS Foundation Trust
Machine S5 Oldham 1 Oldham 1
Calibration FSD (cm) 100.3 100.4 100.0
Plate alignment to lasers centre centre 0.3cm to B
VRT (cm) -0.30 -0.48 -0.10
LNG (cm) 0.06 -0.01 0.01
LAT (cm) -0.01 0.00 -0.30
Mis-calibration

15. The Christie NHS Foundation Trust
Clinical Implementation
• Start with standard TP breast
• AlignRT® used for set up
• Phased approach…..
• Allowed additional validation of the system
• Radiographers gain experience of AlignRT®
• Felt like a safe approach

16. The Christie NHS Foundation Trust
Clinical Implementation
Phase 1:
• 10 patients
• Use the current clinical set up workflow:
• Align to tattoos
• CMA moves from Pinnacle TPS
• AlignRT® monitoring switched on
• Deltas recorded
• “Couch moves” function used
• Image and continue as standard practice
• Monitoring turned off during treatment

17. The Christie NHS Foundation Trust
Clinical Implementation
• Phase 1 results:
• Mean translations are close to zero (within 0.2cm)
• No systematic offset of the system P
• Correcting for these translations resulted in good set up
• All MV imaging in tolerance and therefore no
corrections were necessary to the set up P
VRT
(cm)
LNG
(cm)
LAT
(cm)
YAW
(deg)
Roll
(deg)
Pitch
(deg)
Mean delta 0.0 -0.2 -0.1 -0.4 -0.3 0.4

18. The Christie NHS Foundation Trust
Clinical Implementation
• Comparison between 10 Phase 1 patients and 10 breast
patients (TP) prior to this
• Compared FSDs and Lung depth from MV portal image
• Again nothing to suggest any issues using AlignRT®
FSD:
Lung depth:
Difference from Pinnacle FSD (cm)
SGRT patients Pre-SGRT patients
Isocentre FSD Med FSD Lat FSD Isocentre FSD Med FSD Lat FSD
Mean -0.1 -0.2 -0.3 0.1 -0.1 -0.2
Max 0.5 0.5 0.5 0.7 0.5 0.7
Min -1.0 -1.2 -1.0 -0.6 -1.1 -1.0
Difference in lung depth compared to Pinnacle DRR (cm)
SGRT patients Pre-SGRT patients
Mean 0.1 -0.1
Max 0.5 0.6
Min -0.1 0.8

19. The Christie NHS Foundation Trust
Clinical Implementation
Phase 2:
• As for Phase 1 but with monitoring turned on during
beam delivery
• Record the number of times the AlignRT® deltas fell
outside tolerance
• ±5mm translations
• ±3o rotations
• Allowed assessment of tolerances set
• Gating turned off

20. The Christie NHS Foundation Trust
Clinical Implementation
Phase 3:
• Align to tattoos, but then use AlignRT for set up
• Eliminates shifts from TPS
• Image and continue as standard practice
• Gating turned on during beam delivery
• Not DIBH yet

21. The Christie NHS Foundation Trust
Clinical Implementation – DIBH
• Move on to DIBH left breast
• Patient assessed for DIBH suitability at pre-treatment
• Ideally should be able to hold their breath for 20s
• Two patients identified and scanned at Oldham
• Treated 2 weeks later
• Training of Radiographers and planning staff
• Identify any issues
• Achieve at all 3 sites
• Slowly ramp up from here

22. The Christie NHS Foundation Trust
Timeline of Implementation
18th Jan 2021 - used for set up only @Oldham
15th Mar 2021 - 1st DIBH @Oldham
17th Mar 2021 - used for set up only
@Withington and Salford
14th Apr 2021 - 1st DIBH @Withington
21st Apr 2021 - 1st DIBH @Salford

23. The Christie NHS Foundation Trust
Challenges faced
• Timeframe
• Large centre across multiple sites
• Implementing anything challenging
• Coordinating training – VisionRT very accommodating which helped!
• Ensuring enough people trained within Physics/Engineering across all sites
• COVID
• Limited (zero) opportunities to visit/see system in use elsewhere
• Staff shortages
• Project success
• Thanks to dedicated team
• Good idea to start “simple”

24. The Christie NHS Foundation Trust
Where we are now
• Treated 366 breast patients with DIBH SGRT
• Compare with approx. 60-80 DIBH ABC in same time period
pre-SGRT
• Accepted 2 AlignRT®systems in Macclesfield (Nov 21)
0
10
20
30
40
50
60
70
Mar Apr May Jun Jul Aug Sept Oct
Patient
numbers
DIBH SGRT numbers by month

25. The Christie NHS Foundation Trust
Heart Dose Audit
• Audit of different groups (50 patients each) in July
2021
• Note: ABC patients are chosen due to higher heart dose
0.0
50.0
100.0
150.0
200.0
250.0
m
e
a
n
m
i
n
m
a
x
m
e
d
i
a
n
Dose
(cGy)
TPS Mean Heart Dose
FB
SGRT_DIBH
ABC_DIBH

26. The Christie NHS Foundation Trust
Acknowledgements
• Huge team effort across The Christie…..
• Engineers, Physics, Radiographers, IT
• VisionRT, in particular…..
• Lorna Wood
• Rob Cowdrey & Mos Khalfallah
• Birmingham and Guys and St Thomas
• Thanks for sharing information/experience