innovations conference 2014 dr john kipritidis can we use ventilation imaging to measure predict...
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Dr John Kipritidis - Can We Use Ventilation Imaging to Measure, Predict and Reduce Pulmonary Function Loss in Lung Cancer RadiotherapyTRANSCRIPT
SYDNEY MEDICAL SCHOOL
John Kipritidis, CINSW Early Career Fellow
Radiation Physics Laboratory
UNIVERSITY OF SYDNEY
Innovations in Cancer Treatment and Care Conference
October 17th 2014
Can we use Ventilation Imaging to measure, predict and reduce
pulmonary function loss in lung cancer radiotherapy?
Acknowledgements
Peter MacCallum Cancer Centre
Prof. Michael Hofman.
Dr Shankar Siva
Jason Callahan
Prof. Rodney Hicks
DisclosureSupported by a Cancer Institute NSW Early Career Fellowship, NHMRC Australia Fellowship,
NHMRC project grant 1034060 and NIH/NCI P01CA116602.
University of Sydney
Prof Paul Keall
Dr John Kipritidis
Dr Enid Eslick
Andy Shieh
Virginia Commonwealth Univ.
Jeffrey Williamson, Ph.D.
Geoffrey Hugo, Ph.D.
Elisabeth Weiss, Ph.D.
Contributing authors:
Special thanks:
Nepean Cancer Care Centre
Dr Fiona Hegi-Johnson
Dr Roland Yeghiaian-Alvandi
Jeffrey Barber
Dr Chuong Bui
Katrina West
Kylie Unicomb
University of Sydney
Dr Ricky O’Brien
Benjamin Cooper
Royal North Shore Hospital
Dr Dale Bailey
Dr Jeremy Booth
› 10-30% of lung cancer radiotherapy patients experience radiation-induced lung toxicity (RILT)
› Functionally weighted dose-volume metrics can outperform standard dose-volume metrics as
a predictor of RILT;
c.f. Hoover et al. 2014. J Med Imaging Radiat Oncol 58 (2)
› Functional image-guided treatment planning requires functional imaging! `Gold standard' is
SPECT ventilation / perfusion.
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(i) Why is ventilation imaging important in lung
cancer radiotherapy?
Peter MacCallum Cancer Centre
Technegas SPECT Galligas PET
Nepean Cancer Care Centre
› “CT-ventilation imaging” models regional air volume change in terms of regional lung volume
(or intensity) changes during the breathing cycle.
c.f. Guerrero et al. (IJROBP 2005)
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(ii) Innovative ventilation imaging using 4D-CT
4DCT data courtesy of
Nepean Cancer Care Centre
(i) Acquire 4D-CT (ii) Deformable image registration (iii) Quantify volume/intensity
change
high
low
Ventilation
Main advantages:
High accessibility
High resolution (same as CT)
No-extra cost in scan time / imaging dose (just image processing!)
› CT-ventilation will allow greater access to functional image guided radiotherapy treatment planning, with
the potential to reduce functionally-weighted mean lung dose by 2-5 Gy.
(iii) How could CT-ventilation be practice-changing?
Yamamoto et al. 2011
IJROBP 79 (1)
› In-room 4D cone beam CT could maximise sparing of functional
lung by enabling adaptive functional image guidance:
Modalities 4D-CT 4D-CBCT SPECT V/Q 4D-PET V/Q PFTs
4D-CT VCU VCU NCCCPMCC
RNSH
RNSH
NCCC
BH-CT RNSH RNSH RNSH
4D-CBCT VCU VCU NCCC NCCC
• NCCC = Nepean Cancer Care Centre (Ongoing QA study)
• RNSH = Royal North Shore Hospital (Ongoing prospective trial)
• PMCC = Peter MacCallum Cancer Centre (Ongoing prospective trial)
• VCU = Virginia Commonwealth University (Existing database from earlier study)
We are aiming to validate CT-ventilation imaging across multiple modalities:
LEGEND Under-wayHappening
soon
Not
yet
(iv) How is CT-ventilation being validated?
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high
low
Ventilation
Patient 7 (Best case)
4D-CT ventilation:
PET ventilation: VPET
Std
rVHU
MC
(iv) How is CT-ventilation being validated?
› 12-patient comparison* using baseline Galligas 4D-PET/CT scans.
› Strongest voxel-wise correlation with nuclear medicine ventilation imaging (so far!)
*Kipritidis et al. Med Phys 2014 41(1)
Data courtesy of Peter MacCallum Cancer Centre
(Melbourne, VIC Australia)
12 patients:
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Data courtesy of Nepean Cancer Care Centre
(Penrith, NSW Australia)
(iv) How is CT-ventilation being validated?
high
low
Ventilation
4D-CBCT ventilation:
SPECT perfusion:
› Comparing daily 4D-CBCT ventilation images to baseline Q-SPECT in lung SBRT patients:
› Ongoing QA study; comparison of functional changes underway.
5 patients:
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• Comparing CT ventilation to Technegas V-SPECT:
Technegas V-SPECTCT ventilation
(HU based)
Data courtesy of Nepean Cancer Care Centre
(Penrith, NSW Australia)
(iv) How is CT-ventilation being validated?
Author Reference
modality
Subjects Dice similarity Voxel-wise
correlation
Fuld et al.
(J Apply Physiol 2008)
Xe-CT 4 sheep ~ 0.81
(Small ROIs)
Reinhardt / Ding et al.
(Med. Image Anal.
2008)
Xe-CT 5 sheep ~ 0.85
(Small ROIs)
Yamamoto et al.
(IWPIA 2010)
SPECT V/Q 1 patient ~ 0.18/0.48
(Whole lung)
Castillo et al.
(PMB 2010)
SPECT V 7 patients 0.30-0.35
(low function)
~
Castillo et al.
(PMB 2012)
SPECT Q 10 patients 0.78
(low function)
~
Mathew et al.
(Med. Phys. 2012)
3He-MRI 11 patients 0.86-0.88
(good function)
~
Kipritidis, Siva et al. Ga 4D PET/CT 12 patients 0.38-0.68
(low function)
0.22-0.76
(Whole lung)
Hegi-Johnson et al. SPECT V/Q 30 patients
(goal)
TBA TBA
Eslick et al. Ga PET/CT 30 patients
(goal)
TBA TBA
(iv) How is CT-ventilation being validated?
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4D-CBCT patient study:
o 19 locally advanced NSCLC patients received daily 4D-CBCTs over 4-6 weeks
o We generated 56 interfraction pairs (Week 1 vs. Weeks 2, 4 and 6).
o Main question: How does ventilation change during radiotherapy treatment?
(v) New technologies, new questions
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First day
Week 2
Week 4
Week 6
First day
Week 2
Week 4
Week 6
Sca
n
Ventilation increase
Transient change
Stable
Ventilation decrease
Highly variable
• 4D-CBCT ventilation images can exhibit a wide range of changes
(both positive and negative!) during treatment.
• Adaptive functional image guidance is important as poor-functioning
lung can re-ventilate.
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• Patients breathe differently from day-to-day (and breath-to-breath!)
4D-CBCTs courtesy Virginia Commonwealth Univ.
(Richmond, VA USA)
(v) New technologies, new questions
• Intrafraction changes can sometimes exceed interfraction changes.
• Careful normalisation of serial images is required.
› CT-ventilation imaging: a potentially practice-changing technology enabling (adaptive)
functional image guidance in radiotherapy treatment planning.
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Take home messages
› In-room ventilation imaging: innovative technology driving new questions.
› Australian researchers are driving world-first validation studies across multiple imaging
modalities.
SYDNEY MEDICAL SCHOOL
Thanks for listening!
Radiation Physics Laboratory
UNIVERSITY OF SYDNEY
John Kipritidis, CINSW Early Career Fellow