ROSE CASE CARDIAC ARRHYTHMIA SBRT

1. 1
ROSE CASE- Radiation Oncology Simulation to Execution
SBRT IN CARDIAC ARRYTHMIA
Dr KanhuCharanPatro
MD,DNB(Radiation Oncology),MBA,FICRO,FAROI(USA),PDCR,CEPC
HOD, Radiation Oncology
ISRo- Institute of Stereotatctic Radiation Oncology
Mahatma Gandhi Cancer Hospital & Research Institute, Visakhapatnam
drkcpatro@gmail.com /M- +91-9160470564/ www.drkanhupatro.com

2. SRS
Cranial
Strict immobilization
High dose

3. SBRT
Extracranial
Strict immobilization
Extreme high dose
Motion management

4. The wide spectrum
Cranial
1. Metastasis
1. De novo
2. After WBRT
2. Arteriovenous malformation
3. Vestibular schwannoma
4. Reirradiation glioma
5. Glomus jugular
6. Hamartoma
7. Cavernoma
8. Meningioma
9. Trigeminal neuralgia
10. Tremor
11. Epilepsy
Extracranial
1. Bone metastasis
2. Prostate
3. Lung primary
4. Lung metastasis
5. Pancreas
6. Adrenal metastasis
7. Liver metastasis
8. HCC
9. PVTT- Portal Vein Tumor
Thrombosis
10. Spine metastasis
11. Nodal recurrence
12. Head and neck reirradiation
13. Renal tumors
14. Cardiac SBRT
4

5. Normal ECG
Ventricular arrythmia
QRS duration more than 120miliseconds and heart
rate more than 100 beats per minute

6. Pathophysiology

7. Scar types

8. The substrate
• VT originates from myocardial scar tissue
which is termed as “substrate”. When scar
tissue is interspersed with some normal
myocardial fibres, it is called a border zone.
• Slow and circuitous electrical conduction
through the border zone, results in a re-
entrant circuit causing a VT.

9. What is arrythmia?
Ventricular tachycardia is characterized as a
wide complex (QRS duration greater than 120
milliseconds) tachyarrhythmia at a heart rate
greater than 100 beats per minute

11. Causes
• Ischemic heart disease (Acute, Chronic
infarct)
• Valvular heart disease
• Cardiomyopathy
• Myocarditis
• Systemic diseases- e.g Sarcoidosis
• Dyselectrolytemia
• Drugs
• Congenital

12. Clinical
symptoms
Palpitation
Syncopal attack
Arrest
Death

13. Treatment
options
Antiarrhythmic drugs
RFA
ICD- Defibrillator
STAR- SBRT

14. Catheter ablation

15. Rationale
Hard to reach with Catheters
- Mid-myocardial
- Epicardial
RT
Rationale: RT can induce fibrosis in the
border zones , cause a full thickness
ablation block the re-entry circuit

16. Defibrillator

18. Indication STAR
• Patients considered for SBRT were required to
have received at least 2 of the following
characteristics:
• Failed at least 2 antiarrhythmic drugs
• Failed at least 1 RF ablation defined as 1
inducible VTs after ablation
• Failed 1 adjunctive therapy such as
mechanical support or sympathetic
blockade defined as recurrent VT after
intervention

19. How?
• Initially though to be due to fibrosis
• Average time to reduction of VT post RT – 6 weeks
• Not sufficient to induce fibrosis
• Causes electrical reprogramming – Increases Conduction velocity
(shortens QRS)
• Increase levels of the cardiac sodium channel and improve
conduction
Zhang DM. Cardiac radiotherapy induces electrical conduction reprogramming in the absence of transmural fibrosis. Nat Commun. 2021 Sep 24;12(1):5558.

21. Who is the legend?

24. First publication?

25. THE FIRST CASE REPORT
Circ Arrhythm Electrophysiol June 2015

26. The first case
1. The first use of stereotactic arrhythmia radioablation for VT in humans was performed by Loo et al.
in 2015.
2. VT scar substrate was localized to the left ventricular (LV) myocardium in a 71-year-old man with a
history of ischemic heart disease.
3. A dose of 33 Gy of radiation was targeted to the center of this scar. A significant decrease in the
burden of VT was seen after the procedure, but recurrence was seen after 9 months; this was
thought to be because of underdosing of radiation.
4. There were no acute or long-term complications from the procedure

27. Stereotactic arrhythmia radio ablation (STAR) treatment plan

29. What is the preclinical data?

30. Preclinical data

31. What was the inference?

34. Workflow involved?

36. Radiation procedure Steps

38. Steps

39. Steps
CARDIOLOGIST
RADIATION
ONCOLOGIST

41. What are the evidence?

42. Studies

43. Maintaining motion Mx?

46. Gating -The artefact

47. Varian RPM gating

49. Elekta ABC

50. CARDIAC ITV IN BREATHHOLD

51. Imaging
1. Pre-treatment
2. ECG gated cardiac CT
3. MRI
4. Nuclear medicine imaging (SPECT/PET CT)
5. Electrophysiological mapping

53. How it looks?
Presence of hypo-attenuation and delayed
contrast enhancement are characteristic of scar

54. ECG guided CT

55. Non-invasive Electro-cardiographic Imaging (ECGI):

56. INVASIVE ELECTRO-ANATOMIC MAPPING

57. Electrophysiological mapping

58. Delayed MRI contrast Scan

59. Cardiac SPECT
Technetium99 Sestamibi or F18-FDG PET

62. CT-MRI
• 62-year-old male with ischemic cardiomyopathy (ICM)
• Late Iodine Enhanced –CT (LIE-CT)
• Late Gadolinium Enhanced MRI (LGE-MRI)
Reduced wall thickness (<5 mm)
Presence of hypo-attenuation
Delayed contrast enhancement

63. Cardiac cycle CT with contrast

65. Machinery
HARDWARE SOFTWARE IMAGE
FUSION
ECG GUIDED
CT
Image registration

66. Software and
hardware CARDIAC IMAGING INTEGRATION PLATFORMS
ARE A VERY USEFUL TOOL TO MERGE
ELECTROPHYSIOLOGICAL AND ANATOMICAL
DATA TO ENABLE ACCURATE TARGET
DELINEATION.
MUSIC (MULTIMODALITY PLATFORM FOR
SPECIFIC IMAGING IN CARDIOLOGY) AND
MIMICS ARE COMMERCIALLY AVAILABLE
PLATFORMS THAT ALLOW ANALYSIS OF MULTI-
PARAMETRIC DATASETS AND TO INTERFACE
SUCH DATA WITH SIMULATION PLATFORMS.
THEY GENERATE A THREE-DIMENSIONAL TARGET,
THAT IS DEFINED DIRECTLY ON THE MYOCARDIAL
SURFACE AND A TARGET VOLUME IS GENERATED
THAT IS EXPORTED TO CREATE A DICOM

67. Defining the target?

70. 17-segment AHA heart model

74. • Target -GTV
• ITV – Generated
• PTV: 5MM margin over the ITV

76. DOSE
25Gy/ single fraction

78. OAR Plan evaluation-ENCORE-VT trial

79. Delivery- day 0
Dummy
• Dummy run, CBCTs
Familiarize
• Familiarize yourself with
matching
Assess
• Assess the extent of motion

80. Day 1 - Treatment
2hrs fasting if target close
to Stomach. Oral contrast
before treatment to
visualize the stomach.
CBCT before each arc
Matching performed on
bony structures, device
leads and left ventricle
outline
The cardiologist and cardiac
physiologist will interrogate
the ICD functioning pre and
post treatment.
Crash trolley close by

81. CBCT matching
Treatment is delivered in a single session
Bony structures, ICD leads and left ventricular outline
serve as landmarks to ascertain positional accuracy.
CBCT is done before each arc.

82. Toxicity
Pneumonitis
Hypotension.
Pericarditis,
Fatigue
Gastric fistula have been reported
as occasional toxicities.

83. Follow up
6 weeks , 3 Months, 6 months
(clinical ex, Echo)
ICD data
(Number of VT episodes/shocks)
(Echo/ other investigations at cardiologist
discretion)

84. Control rate
Results are promising with >85% reduction in VT
after a 6–12-week blanking-out period.
The ENCORE-VT study showed that 94% of
patients had reduction in VT, 6months post STAR
with a 12-month overall survival (OS) of 72%.[

85. Post treatment imaging

87. Can we implement in our clinic?

88. POP STAR
RANIT
ELSTAR VT
NRI -VT
STAR VT NIRA VT
SMART VT
ENCORE VT
STARMI VT
STARNL-1
PROSTAR
RAVENTA

92. Summary
• SBRT is proving to be a promising alternative for refractory VT with what has so far
been shown to be a low side effect profile.
• However, continued improvement in strategies to compensate for cardiac and
respiratory cycle motion in SBRT is needed, as are more long-term efficacy and
long-term recurrence data.
• Furthermore, the toxic effects of radiation to both cardiac structures and adjacent
organs need to be assessed, and more multicenter studies are needed with
randomized controlled trials comparing radioablation to repeated catheter
ablation

93. Stereotaxy
class

94. Target delineation class

95. Radiology
class

96. Neuro-Oncology Class

97. SRS/SBRT

98. Dr Kanhu’s Oncoeducation

99. Kanhu
11/20/2023 99
DR Nandhitha