Radiation-force technique to monitor lesions during ultrasonic therapy

Lizzi, Frederic L.; Muratore, Robert; Deng, Cheri X.; Ketterling, Jeffrey A.; Alam, S. Kaisar; Mikaelian, S; Kalisz, Andrew

doi:10.1016/s0301-5629(03)01052-4

Cited by 155 publications

(112 citation statements)

References 23 publications

Supporting

Mentioning

111

Contrasting

Order By: Relevance

“…In one study, for example, RAP was used to validate the formation of thermal ablative lesions produce by continuous FUS exposures. Displacement after the lesions were formed were found to be significantly lower compared to those prior to the treatments; apparently due to the denaturing of the proteins that made the tissue noticeably stiffer (Lizzi et al, 2003).…”

Section: Figmentioning

confidence: 98%

Pulsed focused ultrasound exposures enhance locally administered gene therapy in a murine solid tumor model

Ziadloo

Xie

Frenkel

2013

The Journal of the Acoustical Society of America

View full text Add to dashboard Cite

Gene therapy by intratumoral injection is a promising approach for treating solid tumors. However, this approach has limited success due to insufficient distribution of gene vectors used for gene delivery. Previous studies have shown that pulsed-focused ultrasound (pFUS) can enhance both systemic and local delivery of therapeutic agents in solid tumors and other disease models. Here, murine squamous cell carcinoma flank tumors were treated with single intratumoral injection of naked tumor necrosis factor-alpha (TNF-a) plasmid, either with or without a preceding pFUS exposure. The exposures were given at 1 MHz, at a spatial average, temporal peak intensity of 2660 W cm -2 , using 50 ms pulses, given at a pulse repetition frequency of 1 Hz. One hundred pulses were given at individual raster points, spaced evenly over the projected surface of the tumor at a distance of 2 mm. Exposures alone had no effect on tumor growth. Significant growth inhibition was observed with injection of TNF-a plasmid, and tumor growth was further inhibited with pFUS. Improved results with pFUS correlated with larger necrotic regions in histological sections and improved distribution and penetration of fluorescent surrogate nanoparticles. Electron microscopy demonstrated enlarged gaps between cells in exposed tissue, and remote acoustic palpation showed decreases in tissue stiffness after pFUS. Combined, these results suggest pFUS effects may be reducing barriers for tissue transport and additionally lowering interstitial fluid pressure to further improve delivery and distribution of injected plasmid for greater therapeutic effects. This suggests that pFUS could potentially be beneficial for improving local gene therapy treatment of human malignancies.

show abstract

Section: Figmentioning

confidence: 98%

Pulsed focused ultrasound exposures enhance locally administered gene therapy in a murine solid tumor model

Ziadloo

Xie

Frenkel

2013

The Journal of the Acoustical Society of America

View full text Add to dashboard Cite

show abstract

“…Other non-thermal mechanisms, such as radiation forces, have been proposed for both augmenting tPA mediated thrombolysis [1,17], as well as drug delivery in other tissue models [13]. Locally induced displacements by these forces, occurring non-destructively and with minimal generation of heat [11,12], are thought to create structural alterations on a macroscopic scale, rendering the tissue more permeable to therapeutic agents [13]. For example, in one study, Frenkel et al [17] found that increased rates of tPA mediated thrombolysis correlated well with higher radiation forces and consequent displacements.…”

Section: Discussionmentioning

confidence: 99%

“…The effects of pulsed-HIFU are more mechanical in nature, such as the creation of acoustic radiation forces. These forces, if high enough, can produce local displacements on the order of cellular dimensions [11,12]. It has been suggested that repetitive displacements are capable of inducing structural alterations in the tissue, through the creation of locally induced strain.…”

mentioning

confidence: 99%

Pulsed-high intensity focused ultrasound enhanced tPA mediated thrombolysis in a novel in vivo clot model, a pilot study

Frenkel

Dromi

et al. 2007

Thrombosis Research

View full text Add to dashboard Cite

Introduction-Thrombotic disease continues to account for significant morbidity and mortality. Ultrasound energy has been investigated as a potential primary and adjunctive treatment for thrombotic disease. We have previously shown that pulsed-high intensity focused ultrasound (HIFU) enhances thrombolysis induced by tissue plasminogen activator (tPA) in vitro, including describing the non-destructive mechanism by which tPA availability and consequent activity is increased. In this study we aimed to determined if the same effects could be achieved in vivo.

show abstract

“…In these areas, motion estimation is typically called speckle tracking or time-delay estimation. Work based on exploiting thermal effects that induce tissue strain has primarily been aimed at guiding focused ultrasound therapies rather than at accurate estimation of temperatures [35][36][37][38]. Measurement of echo shifts and tracking of apparent motion has been based on correlation techniques.…”

Section: Apparent Image Motion and Tracking Echo Shiftsmentioning

confidence: 99%

Non-invasive estimation of hyperthermia temperatures with ultrasound

Arthur

Straube

Trobaugh

et al. 2005

International Journal of Hyperthermia

205

134

View full text Add to dashboard Cite

Ultrasound is an attractive modality for temperature monitoring because it is non-ionizing, convenient, inexpensive and has relatively simple signal processing requirements. This modality may be useful for temperature estimation if a temperature-dependent ultrasonic parameter can be identified, measured and calibrated. The most prominent methods for using ultrasound as a non-invasive thermometer exploit either (1) echo shifts due to changes in tissue thermal expansion and speed of sound (SOS), (2) variation in the attenuation coefficient or (3) change in backscattered energy from tissue inhomogeneities. The use of echo shifts has received the most attention in the last decade. By tracking scattering volumes and measuring the time shift of received echoes, investigators have been able to predict the temperature from a region of interest both theoretically and experimentally in phantoms, in isolated tissue regions in vitro and preliminary in vivo studies. A limitation of this method for general temperature monitoring is that prior knowledge of both SOS and thermalexpansion coefficients is necessary. Acoustic attenuation is dependent on temperature, but with significant changes occurring only at temperatures above 50 C, which may lead to its use in thermal ablation therapies. Minimal change in attenuation, however, below this temperature range reduces its attractiveness for use in clinical hyperthermia. Models and measurements of the change in backscattered energy suggest that, over the clinical hyperthermia temperature range, changes in backscattered energy are dependent on the properties of individual scatterers or scattering regions. Calibration of the backscattered energy from different tissue regions is an important goal of this approach. All methods must be able to cope with motion of the image features on which temperature estimates are based. A crucial step in identifying a viable ultrasonic approach to temperature estimation is its performance during in vivo tests.

show abstract

Radiation-force technique to monitor lesions during ultrasonic therapy

Cited by 155 publications

References 23 publications

Pulsed focused ultrasound exposures enhance locally administered gene therapy in a murine solid tumor model

Pulsed focused ultrasound exposures enhance locally administered gene therapy in a murine solid tumor model

Pulsed-high intensity focused ultrasound enhanced tPA mediated thrombolysis in a novel in vivo clot model, a pilot study

Non-invasive estimation of hyperthermia temperatures with ultrasound

Contact Info

Product

Resources

About