Ultrasound molecular imaging: oncology & cardiology applications - - PowerPoint PPT Presentation

23rd floor

Therapeutic UCA Group,

• Dept. Biomedical Engineering,

Thoraxcenter Kirby Lattwein

Ultrasound molecular imaging:

• ncology & cardiology applications

Medical ultrasound

P_ P_ = peak negative pressure f = frequency MI = mechanical index = P_ (in MPa) f (in MHz)

λ f = c / λ

c = speed of sound (m/s)

Ultrasound: some parameters

Bats use frequencies as high as 210,000 Hz Dolphins use frequencies as high as 150,000 Hz Cats can detect frequencies as high as 60,000 Hz Humans can hear up to 20,000 Hz Diagnostic Ultrasound: 1-50 MHz

Sound frequencies

How is an echo made?

Micro Ultrasound

10-6 10-2 10-4 10-3 10-5

Scale (m)

Optical Microscopy Micro MRI Micro PET In vivo Optical Micro CT

Resolution

• Harmless to patients
• Real-time images
• Mobile
• Versatile
• No contra indications
• Cost effective
• Functional imaging

(flow, motion, …)

Why ultrasound in medicine?

Ultrasound molecular imaging

How?

• Ultrasound Contrast Agent
• Used in hospitals worldwide for more than decade

+ contrast agent B-mode

Courtesy of Dr. O.I.I. Soliman, Dr. F.J. ten Cate, Erasmus MC

Ultrasound Molecular Imaging

Ultrasound Contrast Agents

Microbubbles

• gas: air / N2 / SF6 / perfluorocarbon (CnF2n+2)
• shell: protein, lipids, polymers, sugars
• 1 - < 8 µm diameter: blood pool markers

Ultrasound Contrast Agents

New direction: therapy

• Molecular imaging
• Drug delivery
• since 1990s
• Perfusion imaging cardiology + radiology

Clinical use (non-targeted):

Ultrasound time bubble size Changes in

Microbubble in ultrasound field

Ultrasound time bubble size Changes in

Microbubble in ultrasound field

13.3 Mfps 1 MHz, 80 kPa

C4 F10

phospholipid

PEG

non-targeted biotinylated bubble biotin

Ultrasound Contrast Agent: molecular imaging

biotinylated bubble + avidin

~105 per bubble

a) antibody c) peptide

RGD RGD

b) polymer a) b) c)

Molecular imaging

Blood vessel pathology

αVβ3 and similar molecules

• Selectins (P-selectin, E-selectin)
• ICAM-1
• VCAM-1
• Phosphatidylserine
• VEGF receptor; VEGF+receptor

=> are all endothelial markers because: injected UCA do not extravasate cancer atherosclerosis inflammation ischaemia

Markers for ultrasound molecular imaging

Two options for using targeted microbubbles:

• Target biomarkers to detect diseased tissue
• Target and treat disease,

i.e. therapy: local drug delivery

Courtesy of Prof. J.R. Lindner, Oregon Health & Science University, USA

P-selectin targeted microbubbles

Molecular imaging with ultrasound and microbubbles

Using targeted microbubbles in vivo in oncology

Assessment of tumor vasculature markers (1)

Baseline Just after injection 10 min after BR55 SonoVue MI = 0.25 f = 7 MHz

Reference: Pochon et al., Invest Radiol 2010; 45: 89-95

Target: VEGFR2 (BR55) or non-targeted (SonoVue) UCA: lipid shell bubble (Bracco) Disease: patient-derived xenograft breast cancer

VEGFR2

Courtesy of Prof. H. Wijkstra, AMC BR55

Assessment of tumor vasculature markers (2)

by Bracco

Phase 0 trial

MI = 0.1 f = 7 MHz

Smeenge et al., Invest Radiol 2017; 52: 419

Assessment of early response to therapy

4 weeks: volume measurements Drug: Aurora-A kinase inhibitor 2 weeks: non-targeted bubble MI = 0.2 f = 15 MHz

Reference: Streeter et al., Technol Cancer Res Treat 2013; 12: 311-321

Target:

αvβ3

UCA: lipid shell bubble Disease: patient-derived xenograft pancreatic cancer

MI = 0.18 f = 15 MHz

Using targeted microbubbles in vivo in cardiology

Disease: LAD coronary artery occlusion (10 min)

Reference: Davidson et al., J Am Soc Echocardiogr 2014; 27: 786-793.e2

Target: P-selectin UCA: lipid shell bubble

30 min after reperfusion

Ischaemia-reperfusion heart

30 min 30 min MI = ? f = 1.3 MHz

Carotid Maximal Intensity Projection

Disease: atherosclerosis (ApoE-/-)

Reference: Daeichin, Kooiman et al., Ultrasound Med Biol 2016; 42: 2283- 2293

Target: αvβ3 on endothelial cells UCA: lipid shell bubble (MicroMarker)

Atherosclerosis (1)

MI = 0.1 f = 18 MHz

Bmode plaque ROI salivary gland ROI no plaque ROI Contrast mode

αvβ3 control

Atherosclerosis (2)

* p < 0.01

αvβ3 control

Atherosclerosis (3)

Using targeted microbubbles for cellular drug delivery

Microbubble-mediated drug delivery

I: cell membrane pores (sonoporation) II: endocytosis

Kooiman et al., Adv Drug Del Rev 2014; 72: 28

III: opening cell-cell junctions

1 MHz 6x10 cycles 37 °C

videocamera high-speed camera (Brandaris-128)

lens

PI uptake + PI

Experiments: + + +

Kooiman et al, J Contr Rel 2011; 154: 35

CD31 PI = propidium iodide (1 nm) endothelial

Brandaris-128 (frame rate 13.4 Mfps) 5 µm : 1 MHz, 80 kPa PI

Experiments: + + +

Kooiman et al, J Contr Rel 2011; 154: 35

CD31 endothelial

MI = 0.08

Experiments: + + +

before ultrasound

5 µm

after ultrasound

PI uptake

: 1 MHz, 80 kPa (MI = 0.08) PI

Kooiman et al, J Contr Rel 2011; 154: 35

CD31 endothelial

Experiments: + +

: 1 MHz, 850 kPa,

Hu et al., Ultrasound Med Biol 2013; 39: 2393-2405 fibroblast CellMask Orange

10 cycles MI = 0.85

Skachkov, Luan, van der Steen, de Jong, Kooiman, IEEE TUFFC 2014; 61: 1661-1667

%

αVβ3

Experiment: + + +

αvβ3

: 1 MHz, 150 kPa, 10,000 cycles MI = 0.15

Experiment: + +

P-selectin

Xie et al., Jacc-Cardiovasc Imag 2013; 5: 1253-1262

: 1.6 MHz, 600 kPa, 25,000 cycles (MI = 0.6) for 9 min Hind limb ischemia skeletal muscle (20 min iliac ligation)

Luciferase cDNA

Bioluminescence (3 days) Immunohistochemistry

5x

• Easy
• Fast
• Imaging is non-invasive and real-time
• Excellent spatial and temporal resolution
• Suitable for small animals (access during imaging +

longitudinal)

• Combination with drug delivery

Advantages of molecular imaging with UCA

• Target on endothelial cells

Limitations of molecular imaging (of experimental animals) with UCA

• Only in sonographically accessible tissue:

* Not possible in lung (air) * Getting possible in intact brain (skull)

MI = 0.4 f = 15 MHz

Errico et al., Nature 2015; 527: 499-502

Acknowledgements

• Dept. of Biomedical Engineering:

www.erasmusmc.nl/thoraxcenterbme

Collaborators:

• Dr. Klazina Kooiman
• Prof. Nico de Jong
• Prof. Ton van der Steen
• Dr. Hans Bosch
• Dr. Ilya Skachkov
• Dr. Ying Luan
• Dr. Tom Kokhuis
• Dr. Verya Daeichin
• Dr. Tom van Rooij
• Prof. Alexander Klibanov (University of Virginia)

Questions  k.lattwein@erasmusmc.nl