1. Colorectal SSG: SABR and Oligometastatic Disease
Charlie Comins
28/11/2016

2. SABR – what is it? Stereotactic Ablative Body Radiotherapy A misnomer?
Extremely high dose
Body
As opposed to intracranial
Radiotherapy

3. SABR - History Stereotactic radiotherapy is an old technique
Developed at Karolinska Institute in 1960s for treatment of intracranial lesions
Use of multiple radiotherapy fields (7 or more) delivering a high dose to the target but low dose to surrounding structures
Taken up by Japanese to treat peripheral lung tumours

4. Why now? 2 main technical advances Compensation for tumour motion
4DCT
ABC
Respiratory gating
Image guided radiotherapy
Daily CT imaging of target to ensure accuracy

5. SABR platforms
Tomotherapy
Cyberknife

6. Linear Accelerator

7. SABR plan

9. Indications for SABR Medically-inoperable lung cancer
Good evidence base; standard of care
Oligo-metastatic disease
Synchronous
Metachronous
Oligo-progressive disease
Progression in a small number of sites while patient on maintenance treatment
Stage IV disease
Combining SABR with systemic treatment - immunotherapy

10. Oligometastatic disease
What is this?
The clinical state of oligometastatic disease was proposed in 1995 by Hellman and Weichselbaum. 
They hypothesized that, in some patients with a limited number of clinically detectable metastatic tumors, the extent of disease exists in a transitional state between localized and widespread systemic disease.
Is this a real entity?
Even if it isn’t, could ablative treatment be worthwhile?
Can we determine in which patients it might be beneficial?

11. Oligometastatic disease
NHS England CtE
Commissioning through Evaluation
Bristol one of 17 centres to be selected to deliver SABR for oligometastatic disease
Only funding treatment of metachronous lesions

12. CtE - Eligibility for treatment
Metastatic carcinoma with histologically proven primary
1-3 sites of metastatic disease
Maximum size 6cm
Disease free interval > 6 months
Life expectancy > 6 months
PS 0-2
Includes any cancer type other than breast, lung and prostate that can only be offered entry into CORE trial

13. CORE Trial
Assessing the impact of SABR in patients 1-3 metachronous mets from breast, lung and prostate cancer primaries
Maximum 3 metastases and two different organs
Randomised trial: standard of care +/- SABR
Patients eligible for the CORE will not be able to receive SABR through CtE scheme

14. Background & Rationale
Emerging concept
Hellman and Weichselbaum 1995
No Level 1 evidence
Current PRTs on-going
SABR-COMET (CA & NL)
Randomised ph II (N=99) for any tumour type
Oligomets ≤ 5 including brain mets
SBRT vs Pall RT or systemic Rx
OS endpoint
STEREO-SEIN (IGR)
Randomised Ph III (N=280), Breast ca
SBRT + systemic Rx vs Pall RT or systemic Rx
PFS endpoint
Oligomets ≤ 5 & ≤ 10 cm
PULMICC trial for colorectal lung metastases – option to include SABR

15. Liver metastases and SABR
Unresectable disease
RFA recommended where possible
Maximum size 6cm
Adequate liver function
Bili < 3 x ULN, INR < 1.3, ALT < 5 x ULN
MRI liver required for planning
?PET scan

16. Practicalities Patient attends for coaching session Motion management
4DCT scan or ABC
Voluming by clinician
Planning by physicists
Day 1: first treatment, last minutes depending on patient compliance

17. Practicalities
Lung, lymph node, bone/spine, liver and adrenal mets treatable
Range of prescriptions: 3 to 8 fractions
Toxicities minimal; dependent on area treated
Fatigue, skin reaction, cough, dysphagia
Chest wall pain, fracture, pneumonitis
Nausea, ulceration, RILD
Diarrhoea, perforation

18. No Fly Zone

19. Or this can happen…..

20. Development of SABR in Bristol
VMAT
Flattening –filter free
Active Breathing Co-ordination
?Abdominal compression
Participation in trials

21. Conclusions Thank you for your support
Techniques and service continue to be improved
Will need continued support to recruit to current and future SABR trials
Other ablative techniques available but no randomised evidence of superiority of one over another