1. Lung SBRT Implementation at the Regional Cancer Centre
On Behalf of the Radiation Therapy Lung & Thoracic Group:
Tracey Hill
Bans Arjune
Kevin Ramchandar

2. Why Are We Giving this Talk??
Share knowledge from Lung IGRT Course
Improve outcomes for our inoperable early stage lung cancer patients (and potentially others)
Advance capabilities of centres
Bring on-par with other centres which treat lung cancer and enable collaborative trials

3. Outline Overview of Lung Cancer Treatment in General
Define SBRT and IGRT and explain why they are “hot topics”
Discuss where we are at now
Discuss how we move to SBRT Lung
Needs to involve all of us!
Future Step! – a gradual process but are starting already
Once we get started, where else can we go?

4. Lung Cancer (in 5 minutes...)
One of top 2 cancer diagnoses in Canada
By far the largest cancer killer in Canada
The Cancer with the greatest probability of death for men or women
Twice as many deaths from lung cancer as next most deadly cancer (colorectal)
85-90% are associated with smoking
Broadly divided into Small Cell Lung Cancer (15-20%) and Non-Small Cell Lung Cancer (80-85%)

5. NSCLC at Presentation 30% are amenable to resection (Stage I or II)
Generally like to resect these!!!
40% are unresectable but eligible for aggressive chemo-RT
Outcomes not ideal, but combined modality maximizes long-term survivals
30% are eligible for palliative treatments only

6. However...
Technically resectable and eligible for surgery are different...
Some patients have small tumours that are “easily” resectable, but medically can not tolerate anaesthesia and/or major surgery
The best solution:
Radiation Therapy!

7. What do we do now for T1/2N0 medically inoperable patients?
Conformal radiation – similar techniques, planning and dose/fraction to conformal radiation for Stage III or more advanced medically inoperable patients
52-60Gy in 4Gy fractions
Tumour control BED (α/β = 10) of
Note that standard fractionation 60Gy/30, BED = 72
Important: Typically cover with 95% isodose line

8. SBRT Stereotactic Body Radiation Therapy Radiotherapy Involving
Significantly higher dose per fraction
Few fractions – or only one!
(Typically) more beams
(Typically) more involved imobilization
 (typically) requires more precision

9. SBRT v. Conventional RT Conventional RT SBRT 2-4 beams Many beams/arcs
“Swaths of radiation”
Small beam apertures
(?) weekly image guidance
Daily image guidance
Variable
Strict motion control
Small “forgiving” daily dose
Large “ablative daily dose
30-35 treatments over 6-8 weeks
1-5 treatments over 1-2 weeks

10. Can be used for medically inoperable node-negative patients!
SBRT for Lung??
Can be used for medically inoperable node-negative patients!

11. Let’s Compare BED for tumour control:
Conventional
Dose: 60Gy/30 fractions
α/β = 10
BED (10) = 72
Dose: 60/15
BED (10) = 84
SBRT
Dose: 50Gy/10 fractions
α/β = 10
BED (10) = 100!
Dose: 48Gy/3 fractions
BED (10) = 124.8!
Also: 54/3 and 60/8

12. Also Note...
PMH prescribes to 75% isodose line! (other sites prescribe to 67%, and 95%)

14. Why SBRT for Lung??
Onishi, H. et al. Cancer 101, (2004).

15. Why SBRT for Lung??
Grills, Mangona et al, JCO 2010.

16. Why SBRT for Lung??
Grills, Mangona et al, JCO 2010

17. IGRT Image Guided Radiation Therapy
The technical definition – any imaging used to guide therapy!
Practically: Referred almost exclusively now to (kV) cone beam CT
Also potentially MRI-guided therapy or other 3-D imaging

18. IGRT Rx: The Prescription
Imaging Technique
– kVp, mA, ms
FOV, half vs. full Scan
Imaging Dose
Targeting
ROI (clip-box)
Manual vs. Automatic
Bone vs. Soft-tissue
Action Levels
Online vs. Offline
Shifts/Rotations
Verification/Monitoring
Residual Error
Intra-Fraction Motion
Evidence based margins
Thanks to Doug Moseley

19. Why IGRT?? Goals of Radiotherapy planning:
Maximize dose to tumour volumes
Minimize dose to organs at risk/normal tissues
Set-up Error/Uncertainty accounts for either:
Underdosing of tumour (margins too small for uncertainty)
Overdosing of normal structures (have to expand PTV expansion

20. Why IGRT?? For SBRT minimizing uncertainty is even more important:
Large ablative dose given daily
Minimal benefit from fractionation
Small recovery and repair of normal tissues
Normal tissues in volume are irreversibly damaged
Improved IGRT is required for SBRT!
Soft tissue and/or tumour matching

21. Why haven’t we done SBRT Lung already??
Need IGRT/kV Cone Beam CT capabilities
NEW MACHINES COMING!
Need to develop skills and confidence and expertise of all team members

22. Why haven’t we done SBRT Lung already??
Will take significant time investment to develop IGRT:
will lead to improved targeting for multiple tumour sites!
Becoming standard of care for many sites. i.e. Prostate, lung

23. The new machines are still a while coming and commisioning...

24. But the process can be started right now!

25. Current/Future Steps to SBRT Lung
Account for breathing motion – doing already (2010)!!
Move to daily imaging of all lungs – in process!
Moving to heterogeneous calcs
 In process! Rita’s project will determine prescription adjustments to be made
Set-up equipment for lung RT and SBRT – in process.
NEW MACHINES!
Develop IGRT
 likely start with prostate? v. Lung to develop expertise
Develop local planning/treatment protocols for SBRT

26. Why daily imaging in lung RT?

28. Start with IGRT for prostate??
Most Centres started with IGRT for prostate
Technically less risky: could be done and compared with fiducial markers already be used.
Learning curve in a safe environment
With experience fiducial markers were phased out!
Clinically less risky
Especially for low risk prostate cancer

29. Other Benefits to Developing IGRT/SBRT Capabilities
Lung Cancer
IMRT lung (IGRT and heterogeneous calcs)
Trials (JCC proposal to NCIC)
Image Guidance
*Prostate
Bladder
*Head and Neck
Other SBRT sites
SBRT
Liver
Spine
Prostate?

30. Questions?