This study evaluated the feasibility of using deep inspiration breath-hold (DIBH) technique with AlignRT InBore for lung stereotactic body radiotherapy (SBRT) treatments on the Halcyon system. Thirteen patients underwent lung SBRT in DIBH, which reduced intrafraction tumor motion to less than 2 mm/° compared to free breathing. DIBH with AlignRT InBore also decreased planning target volumes by an average of 33% and mean lung doses by 35% on average compared to free breathing. Real-time position monitoring with AlignRT InBore showed high correlation and reproducibility between CBCT and breath hold position. This study demonstrates the effectiveness and reproducibility of DIBH using AlignRT

1. Daniel Nguyen, Rebeca Reinoso, Mustapha Khodri, Nicolas Barbet
ORLAM Mâcon - Villeurbanne – France
Feasibility study of deep inspiration breath-hold
technique with AlignRT InBore™ for lung
stereotactic body radiotherapy treatments on
Halcyon™

2. D. NGUYEN, R. REINOSO et al. - European SGRT Community Meeting, 2022
q Orlam Group worked with Vision RT to develop a SGRT solution
for Halcyon
q The views expressed in this presentation are my own and do not
reflect Vision RT’s and ORLAM’s official position
Conflicts and Disclosure

3. Introduction
• SBRT is a standard treatment for inoperable NSCLC lung
cancer and oligometastatic disease
• High dose per fraction over few fractions (1-8#) with
heterogenous dose distributions in the PTV
• Sharp dose gradient with rapid dose fall-off outside the
PTV and precise dose delivery are required
• IGRT mandatory with CBCT before each fraction
D. NGUYEN, R. REINOSO et al. - European SGRT Community Meeting, 2022

4. Lung SBRT issues
• Lung tumor are mobile / very mobile depending on the
topography (lower / middle lobe) *
• Lack of intra fraction motion monitoring in many LINACs
• Located close to the organs at risk
• Limit the irradiated lung volume
* Seppenwoolde et al 2002

5. 1. ITV defined with 4D-CT 2. Abdominal compression
(ITV if 4D-CT)
3. Breath-hold
Courtesy
B.
J.
Cooper
et
al.
5
Lung SBRT solutions
D. NGUYEN, R. REINOSO et al. - European SGRT Community Meeting, 2022
Courtesy J. Heitmann and M. Guckenberger
Courtesy
B.
J.
Cooper
et
al.
… and more

6. Patient Setup – Lung SBRT in DIBH Treatment at Orlam’s
D. NGUYEN, R. REINOSO et al. - European SGRT Community Meeting, 2022
• arm and foot rest only
• do not use abdominal compression systems and vacuum bag
è hide the cameras views and the therapists cannot correct rotational errors

7. Objectives
q Study the advantages of lung SBRT in DIBH implementation:
● Doses
● Target volumes
Respiratory motion information in VRT extracted from AlignRT
Screen capture of AlignRT during treatment
q Confirms the reproducibility and stability of
SBRT in DIBH using AlignRT Inbore
D. NGUYEN, R. REINOSO et al. - European SGRT Community Meeting, 2022

8. Methodology
Thirteen patients treated with lung SBRT in DIBH :
● 03/ 2021 - 10/2022
● Dose: 44 - 60 Gy / 4 - 8 fractions / 4 - 6 full or partial VMAT arcs
● Age: 73 yo [44 - 86] yo
● 3 women & 10 men
● DIBH eligibility criteria (coaching session prior to CT acquisition):
○ BH time at least 20s
○ Repeatability (on 10 consecutive BH)
Patient population
D. NGUYEN, R. REINOSO et al. - European SGRT Community Meeting, 2022

9. The secret to successful coaching:
Øuse the same equipment as in the treatment
D. NGUYEN, R. REINOSO et al. - European SGRT Community Meeting, 2022
Courtesy to Darina Hickey et al.
Courtesy to Julie Kilkenny et al
Rodrigo Hepp et al. 2015
https://www.sdx-gating.com/voluntary-breath-hold-method/
SDX® VARIAN - RPM ™ C-RAD - Sentinel™ Vision RT - SimRT
Waste of time
- Only 1 DoF (vertical)
- Not the same equipment used during the treatment.
- The patient does not understand the goals

10. The secret to successful coaching:
ØUse alignRT with the RTC for coaching, DIBH CT, and treatment sessions
è AlignRT: 6 degrees of freedoms monitoring
RTC (Real Time
Coaching): Visual
Use the same tool during treatment for
effective coaching and smooth treatment
D. NGUYEN, R. REINOSO et al. - European SGRT Community Meeting, 2022

11. Methodology
Treatment planning
Free
breathing
DIBH
Prescription Isodose Surface Coverage:
● 95% of the target volume (PTV) is conformally covered
by the prescription isodose surface
● 99% of the target volume (PTV) receives a minimum of
90% of the prescription dose.
UK SABR and French RECORAD guidelines
Raystation V11B – CCC (Raysearch) (grid 1mm) - 4/6 full or
partials VMAT arcs
è Treatment plans
D. NGUYEN, R. REINOSO et al. - European SGRT Community Meeting, 2022

12. Lung SBRT in DIBH delivery on Halcyon V2.0
SGRT : AlignRT® InBore™
q 3 ceiling mounted cameras pods
Ø Patient Setup
q 2 Inbore ring mouted cameras pods
Ø Intra-fraction monitoring
Both isocentres are co-calibrated with the MV
isocentre by using the SRS module of AlignRT*
*D. NGUYEN et al., SFPM 2022, Avignon, France

13. Methodology
Treatment workflow
AlignRT in DIBH Threshold :
● VRT = ±1 mm
● 5DoF = ±2 mm / °
SBRT in DIBH workflow:
● 4 kv-CBCT in DIBH per treatment fraction:
○ Positioning
○ Intra-fractional control
Time-lapse time of one treatment session
D. NGUYEN, R. REINOSO et al. - European SGRT Community Meeting, 2022
Positioning Intra-fractional control
Couch shifts

14. Methodology
Materials ● RTD reports
● Treatment time-lapse of Aria – Varian
● CBCT shift Eclipse (6DoF) - Varian
VRT = -0.07 mm
LNG = 0.757 mm
LAT = -0.487 mm
ROLL = -0.245°
YAW = -0.484°
PITCH = 0.17°
VRT = 0.4 mm
LNG = 0.7 mm
LAT = 0.7 mm
ROLL = 0.1°
YAW = -0.2°
PITCH = -0.2°
Python script
Respiratory motion information in VRT for one session
CBCT of the first control BH
D. NGUYEN, R. REINOSO et al. - European SGRT Community Meeting, 2022

15. Methodology
Data analysis: Intra fraction motion Tumour motion
Amplitude = |max(3CBCTshifts) − min(3CBCTshifts)|
SGRT versus CBCT
Correlation between RTD data and tumour
position
D. NGUYEN, R. REINOSO et al. - European SGRT Community Meeting, 2022

16. Results
Differences in DIBH and FB targets
Free breathing
DIBH
● ITV: 11.05 (6.78 – 18.88) cc
● GTV: 5.14 (3.9 – 12.87) cc
èRatio DIBH-FB ITV: 57%
● PTV FB: 33.91 (22.8 – 54.81) cc
● PTV DIBH: 21.66 (17.51 – 45.73) cc
èRatio DIBH-FB PTV: 67%
D. NGUYEN, R. REINOSO et al. - European SGRT Community Meeting, 2022

17. Results 17
Differences in DIBH and FB lung doses
● The ratio DIBH-FB:
○ Mean lung dose: 65.2%
(min = 40.89%, max= 98.74%)
○ Maximal dose (D1%): 73.45%
(min = 38.34%, max= 95.41%)
● Lung volumes increased on average by 61%
● RTOG (Critical Volume Dose Max (Gy))
12.5 Gy and 13.5 Gy: reduction in volumes
of 55% and 54% with DIBH
D. NGUYEN, R. REINOSO et al. - European SGRT Community Meeting, 2022
● Mean Anterior SSD: 85.17cm
○ (min = 80.1cm, max= 91.7cm)

18. Results 18
For all patients, the median amplitude of tumour movement in DIBH ranged between
● 0.2 mm – 1.9 mm in 3 translational DoF
● 0.2º to 2º in the 3 rotational DoF.
Tumour remains in the PTV (CTV + 5 mm) during all DIBH kv CBCTs
Reproducibility of target position: 175 control kV-CBCTs in DIBH analysed
D. NGUYEN, R. REINOSO et al. - European SGRT Community Meeting, 2022
Reproducibility of surface positioning during the control kv-CBCTs in DIBH
For each patient showing the surface position in DIBH to remain within
● 0.2 – 1.3 mm in the vertical direction
● 0.3 – 3 mm in the longitudinal direction
● 0.1 – 2.1 mm in lateral direction
● 0° to 1.7° in the 3 rotational DoF.

19. Results 19
Correlation between RTD data and tumour position
D. NGUYEN, R. REINOSO et al. - European SGRT Community Meeting, 2022
Scatter plots of 6 DoF RTD values against CBCT
shifts with their respective regression lines
calculated using the Linear Mixed Model
The correlation was found between RTD values
and CBCT for the LNG (p < 0.001), LAT (p =
0.001) and ROLL (p = 0.05) directions
No relationship was obtained for the VRT, YAW
and PITCH directions
è more than 90% of CBCT and RTD values are
in an interval [- 1, 1] mm

20. q AlingRT InBore enables reproducible lung SBRT in DIBH treatments
q DIBH with AlignRT InBore reduces intrafraction tumour motion to <2 mm/°
q AlignRT InBore reduces SBRT in DIBH treatment time and increases patient
comfort
q High correlation and reproducibility between CBCT and breath hold
q SGRT facilitates the implementation of the DIBH technique even for lung
cancer patients
Conclusion
D. NGUYEN, R. REINOSO et al. - European SGRT Community Meeting, 2022

21. Thank you for your attention
D. NGUYEN, R. REINOSO et al. - European SGRT Community Meeting, 2022