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

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

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?

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%)

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

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!

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 72.8-84 Note that standard fractionation 60Gy/30, BED = 72 Important: Typically cover with 95% isodose line

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

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

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

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

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

Why SBRT for Lung?? Onishi, H. et al. Cancer 101, 1623-1631(2004).

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

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

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

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

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

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

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

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

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

But the process can be started right now!

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

Why daily imaging in lung RT?

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

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?

Questions?