Stereotactic body radiotherapy (SBRT) delivers high doses of radiation to liver lesions while sparing surrounding tissues. For hepatocellular carcinoma (HCC), SBRT results in local control rates of 87% at 1 year and median overall survival of 17 months. For liver metastases, SBRT achieves complete and partial response rates of 60-80% and median progression-free survival of 15.1 months. Response is evaluated using multiparametric MRI and RECIST/mRECIST criteria. Persistent enhancement after SBRT may indicate fibrosis rather than tumor in some cases. SBRT is a feasible, low toxicity treatment option for selected liver lesions.

1. Imaging following
Stereotactic Radiotherapy
in the Liver
Luigi Grazioli MD
Department of Radiology - Civic and University Hospital
Brescia -Italy
March 23-24 2018

2. What is SBRT ?
Stereotactic body radiotherapy: is a high dose radiation treatment
delivery to the target volume and a rapid fall off outside the target, thus
sparing surrounding normal tissues.
Appropriate target coverage and organ at risk sparing

3. SBRT Liver: Clinical Volumes >> PTV
GTV (Gross Target Volume) on CT in each breathing phases (otherwise on a
single phase followed by automatic propagation on Velocity software)
ITV ( Interior Target Volume) (volume resulting from the sum of every GTV) =
CTV( Clinical Target Volume)
CTV + adeguate margin = PTV ( Planning Target Volume)
Target Definition
What is SBRT ?

4. Jonathan Klein and Laura A. Dawson, Int J Rad Onc Biol Ph. 2012
Is there any role in BCLC staging system for RT?

5. HCC and RT

6. HCC and EBRT

7. SBRT and HCC
2015
Ø The role of radiation therapy for hepatocellular carcinoma has evolved over the
years.
Ø The technological advances that provided the means to deliver a tumor radical
dose to liver lesions while sparing the surrounding normal parenchyma have
given new insight to the treatment options for HCC.
Ø Radiation therapies alone or in combination with other local therapies such as
radiochemoembolization give encouraging results on local control and survival.

8. SBRT and HCC
Kalogeridi et al, World J Hepatol 2015

9. SBRT and HCC
2013
Ø 50 patients in phase I trial and 52 patients in phase II
trial
Ø The SBRT dose ranged from 24 to 54 Gy in six
fractions.
Ø Globally 1y-Local Control was 87%.
SBRT dose was significant on LC at univariate
analysis.
Ø Median OS was 17.0 months. The presence of Tumor
Vascular Thrombosis was significant on multivariate
analysis. Grade 3 toxicity was observed in 30% of
patients.
Ø Conclusion: these results provide strong rationale for
studying SBRT for HCC in a randomized trial.

10. E. Van Cutsem et al, Annals of Oncology 0: 1–38, 2016
2016
SBRT and Mets

11. SBRT & oligometastatic disease & prospectives trials
Oligometastatic patients may be characterized by the existence of up to 5 metastases at 1 to 3 sites.
Treatment strategies for patients with OMD should be based on the possibility of achieving complete
ablation of all tumour masses, using surgery and/or local ablative therapies
Nair et al. World J Radiol 2014 February 28; 6(2): 18-25

12. SBRT and Mts local control
2009
Patients with liver metastases from solid tumors, for whom a critical volume dose
constraint could be met, were treated with single-fraction SBRT. The treated
tumors were located outside of the central liver zone.
Seven patients were enrolled to the first group, with a prescription dose of 35 Gy
in a single fraction.
Dose was then escalated to 40 Gy in a single fraction, and seven more patients
were treated at this dose level.

13. SBRT and Mets local control
Correlation between local control and diameter > 3cm
2009

14. Imaging and SBRT response evaluation
What imaging for SBRT response evaluation?
What criteria?

15. SBRT and HCC: patients and treatment characteristics
Pts HCC characteristics Value
No. of patients 10
Age (y) 73a (63–81)
Sex (male:female) 9:1
Baseline KPS > 90
CPT class All Child A
Lesions charateristics Value
No. of lesions 16
No. of lesions per patients
1 for 6 pts.
2 for 3 pts.
4 for 1 pts.
Size 3.1 cm (1.5 - 4.5 cm)
Histology Grading G1 9
G2 4
G3 3
February 2013 - September 2017
by Multhidisciplinary Team
Dose prescription Lesions
20-60 Gy / 3fr 8 (50 %)
16-48 Gy / 3fr 8 (50 %)
Dose prescription and fractionation were
according to lesions size and liver function.
Follow up Value
No. of patients 10
Mediam months
1-3-6-9-12-24-30-36
12 m(3-36)

16. SBRT and HCC: response criteria
Response criteria Imaging criteria
mRECIST
Signal intensity on T1w
and T2w and DWI images
Dynamic evaluation
(enhancement / washout)
Signal intensity on T1w
on HBF images
Response Value
Complete response 6/16
Partial response 8/16
Non response 2/16*
Progression Free Survival median 11.5 months (6-18 m)

17. SBRT and HCC: response criteria
MDCT pre RF ablation
Pts with cirrhosis HCV+.
During survegliance US discovevered one nodule sospected for HCC

18. SBRT and HCC: response criteria
Pre SBRT 5.2016
b=50 b=400 ADC map
T1W in T1W opp T2 W FS
Dynamic evaluation HBF
b=0 b=800
3 months later

19. SBRT and HCC: response criteria
b=400 b=800 ADC map
T1 W in T1 W opp TSE T2 W
Dynamic evaluation HBF
b=50
Follow up 1 months
after SBRT

20. SBRT and HCC: response criteria
Follow up 3 months
after SBRT
b=50 b=400 ADC map
T1W in T1 W opp TSE T2 W
Dynamic evaluation HBF
b=0 b=800

21. SBRT and HCC: response criteria
Follow up 14 months
after SBRT 7.2017
Dynamic evaluation HBF
TSE T2 W fs

22. SBRT and HCC: response criteria
NC Art PVP Eq
81Y M HBV+ with multiple comorbidity

23. SBRT and HCC: response criteria
b=50 b=400 ADC map
T1W in T1W opp T2 W FS
Dynamic evaluation HBF
b=0 b=800
Follow up 1 months
after SRBT

24. SBRT and HCC: response criteria
Follow up 3 months
after SRBT
b=400 b=800 ADC map
T1W in T1W opp T2 W FS
Dynamic evaluation HBF
b=50

25. SBRT and HCC: response criteria
Follow up 6 months
after SRBT
b=50 b=400 ADC map
T1W in T1W opp T2 W FS
Dynamic evaluation HBF
b=0 b=800

26. SBRT and HCC
2017
Ø To correlate the imaging finding of SBRT treated HCC with explanted pathology
Ø Reference standards for successfull response were >90% necrosis on explant pathology
Ø All had successfully treated Hcc. 4/10 had persistent central arterial hyperenhancement.
Ø Persistent arterial hyperenhancement after SBRT may be secondary to a giant cell reaction
induced by radiation therapy. The loss of arterial phase hyperenhancement over time may
be secondary to progressive cell death from coagulation necrosis and fibrosis
Ø Conclusion: in the absence of increasing size ,arterial hyperenhancement can occour
within the first 12 mounths after SBRT and may not represent residual viable tumor.

27. SBRT and Mets: patients and treatment characteristics
Pts Mets characteristics Value
No. of patients 14
Age (y) 68a (55–85)
Sex (male:female) 9:5
Baseline KPS > 85
February 2013 - September 2017
by Multhidisciplinary Team
Dose prescription Lesions
20-60 Gy/3fr 10 (65 %)
16-48 Gy/3fr 6 (35 %)
Dose prescription and fractionation were
according to lesions size and liver function.
Follow up Value
No. of patients 12
Medium months
1-3-6-9-12-24-30
19 m (6-31)
No follow up* > 6m 2
Lesions charateristics Value
No. of lesions 16
No. of lesions per patients
1 for 6 pts.
2 for 3 pts.
4 for 1 pts.
Size 3.1 cm ( 2 - 5.5 cm)
Tumour origin Colon 9, Chest 2
Kidney 1, NET 2
Pancreas 1, ovary 1

28. SBRT and Mets: response criteria
Response criteria Imaging criteria
Signal intensity on T1w and
T2w and DWI images
Dynamic evaluation
(enhancement / washout)
Signal intensity on T1w
on HBF images
Response Value
Complete response 6/16
Partial response 8/16
Non response 2/16*
Progression Free Survival median 15.1 months (2-30 m)
RECIST 1.1
mRECIST

29. SBRT and Mets: response criteria
Pre SBRT 3.2015
b=50 b=400 b=800 ADC map
T1 W in T1 W opp TSE T2 W
Dynamic evaluation HBF3’
53 y M pts with previos colon cancer
treated by surgery (2 times)
and CHT ( 2 lines)

30. SBRT and Mets: response criteria
Follow up > 2 year
Partial response (RECIST 1.1)
Complete response ( mRECIST)
b=50 b=400 b=800 ADC map
T1W in T1W opp T2 W
Dynamic evaluation HBF
b=0

31. SBRT and Mets: response criteria
Pre SBRT
11. 2015
b=400 b=800 ADC map
T1W in T1W opp T2 W
Dynamic evaluation HBF
b=50
85 y M pts with previous Ca colon

32. SBRT and Mets: response criteria
Follow up after 3 months
b=400 b=800 ADC mapb=50
Dynamic evaluation HBF

33. SBRT and Mets: response criteria
Folow up after 18 months
Dynamic evaluation HBF
TSE T2 W

34. SBRT and Mets: response criteria
1.6.2017
29.11.2015 pre SBRT treatment
1.12.2016 10.6.2016 11.3.2016
Follow up after SBRT treatment

35. Conclusions
SBRT & Liver lesions
Current evidences and our experience confirm in selected cases:
Feasibility: Non invasive and low toxicity approach
Efficacy: Optimal/ sub optimal local control rates
Response evaluation: Multi parametric MR approach

38. SBRT and HCC: response criteria

40. SBRT and Mets: response criteria
ESEMPI - COMPLETE RESPONSE,PARTIAL RESPONSE AND NON RESPONSE

41. SBRT and Mets: response criteria
ESEMPI - COMPLETE RESPONSE,PARTIAL RESPONSE AND NON RESPONSE

42. SBRT and Mets: response criteria
ESEMPI - COMPLETE RESPONSE,PARTIAL RESPONSE AND NON RESPONSE

43. SBRT and Mets: response criteria
ESEMPI - COMPLETE RESPONSE,PARTIAL RESPONSE AND NON RESPONSE

45. SBRT and Liver lesions