Ultrasonic tissue characterization and histopathology in tumor xenografts following ultrasonically induced hyperthermia

Silverman, Ronald H.; Coleman, D. Jackson; Lizzi, Frederic L.; Torpey, J H; Driller, J.; Iwamoto, Takeo; Burgess, S. E. P.; Rosado, A.

doi:10.1016/0301-5629(86)90185-7

Cited by 30 publications

(8 citation statements)

References 8 publications

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“…QUS methods have been used to diagnose prostate cancer, ocular tumors, liver and cardiac abnormalities (15 -18); differentiate benign fibroadenomas from mammary carcinomas and sarcomas (19); and have provided good diagnostic accuracy in prostate cancer detection and lesion localization (20). QUS methods, specifically spectral parameters, can be used to detect structural alterations induced by ultrasonically induced hyperthermia in tumor xenografts (21), discern between different types of ocular tumors (22,23), and classify these depending on their lethality potential (16,24).…”

Section: Discussionmentioning

confidence: 99%

Quantitative Ultrasound Characterization of Responses to Radiotherapy in Cancer Mouse Models

Vlad

Brand²,

Giles

et al. 2009

Clinical Cancer Research

100

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Purpose: Currently, no imaging modality is used routinely to assess tumor responses to radiotherapy within hours to days after the delivery of treatment. In this study, we show the application of quantitative ultrasound methods to characterize tumor responses to cancer radiotherapy in vivo, as early as 24 hours after treatment administration. Experimental Design:Three mouse models of head and neck cancer were exposed to radiation doses of 0, 2, 4, and 8 Gray. Data were collected with an ultrasound scanner using frequencies of 10 to 30 MHz. Ultrasound estimates calculated from normalized power spectra and parametric images (spatial maps of local estimates of ultrasound parameters) were used as indicators of response. Results: Two of the mouse models (FaDu and C666-1) exhibited large hyperechoic regions at 24 hours after radiotherapy. The ultrasound integrated backscatter increased by 6.5 to 8.2 dB (P < 0.001) and the spectral slopes increased from 0.77 to 0.90 dB/MHz for the C666-1tumors and from 0.54 to 0.78 dB/MHz for the FaDu tumors (P < 0.05), in these regions compared with preirradiated tumors.The hyperechoic regions in the ultrasound images corresponded in histology to areas of cell death. Parametric images could discern the tumor regions that responded to treatment. The other cancer mouse model (Hep-2) was resistant to radiotherapy. Conclusions:The results indicate that cell structural changes after radiotherapy have a significant influence on ultrasound spectral parameters. This provides a foundation for future investigations regarding the use of ultrasound in cancer patients to individualize treatments noninvasively based on their responses to specific interventions.

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Section: Discussionmentioning

confidence: 99%

Quantitative Ultrasound Characterization of Responses to Radiotherapy in Cancer Mouse Models

Vlad

Brand²,

Giles

et al. 2009

Clinical Cancer Research

100

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“…2 The search for new treatments or methods of improving the results of existing therapy has included studies of chemosensitisation by temperature3 and radiotherapy. 4 In 1985, Russo et al first showed that high energy shock waves (HESW) suppressed tumour growth both in vitro and in vivo. Since then, several other groups have shown that HESW cause delayed cell growth and cell death in both normal and malignant cells in vitro.…”

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confidence: 99%

Effect of electrohydraulic and extracorporeal shock waves on gastrointestinal cancer cells and their response to cytotoxic agents.

Warlters

Cameron-Strange

et al. 1992

Gut

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This spark results in the dielectric breakdown of water in the area of the probe, which generates an initial shock wave and a gas bubble. When the initiation bubble collapses, a second pressure wave is produced."Cells were placed in a polyurethane tube and allowed to form a pellet. A 5 Fr probe was placed just below the surface of the culture fluid (this was found to contain sufficient electrolytes for shock wave generation) and cells received either 0, 1, 10, or 20 shocks at 150 V.

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“…Changes can also occur in tissue properties at the high temperatures achieved in ablation, and addir tional phenomena such as degassing, cavitation, and vaporization can occur. These latter phenomena may be responsible for the conical, rather than elliptical, shapes observed in some of our experimental ablation studies (Lizzi et al 1986). …”

Section: But Usinggeometricmentioning

confidence: 88%

Computer simulations of ultrasonic heating for ocular therapy

Lizzi

Driller

Kalisz

et al. 1992

Acta Ophthalmologica

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Computer simulations are being performed to model the temperature patterns produced during ultrasonically induced hyperthermia of ocular tumours. The software package for these simulations incorporates operator interaction and uses tissue geometry obtained from B-mode data. Previous studies used geometric approximations for the incident beams used for hyperthermia. In the current study, these beams were computed using diffraction analysis to obtain more realistic simulations of clinical exposures.Ultrasonically induced heating of ocular tissues has been studied because of its importance in evaluating ultrasonic safety and its potential role in therapeutic ultrasound systems. At sufficiently high intensities, ultrasound can produce thermally mediated ocular damage such as cataracts and chorioretinal lesions, as described in early reports by Purnell, Sokullu, and their coworkers (1964, 67) and by our laboratories (Lizzi et al. 1978 a,b).Ultrasonically induced heating can also produce lesions that are potentially useful in therapeutic applications. As an example, to treat refractory glaucoma, we have employed a highly focused beam that produces trans-scleral lesions of the ciliary body (1985). A recent report (Silverman et al. 1991) on over 1000 clinical cases of refractory glaucoma demonstrated that this approach can provide high efficacy rates while maintaining side effects at low rates of incidence. We have also been evaluating ultrasonically induced hyperthermia, applied conjointly with radiotherapy, for treating choroidal malignant melanomas (Coleman et al. 1988).In order to delineate the various physical factors that influence desired tissue heating, we have developed computer simulations of ultrasonically induced heating in various types of ocular tissue.For studies of glaucoma therapy and chorioretinal lesions, we developed a thin-layer model and examined relatively short ultrasonic exposures (up to several seconds) (Lizzi et al. 1984, 87). Computed results demonstrated excellent agreement with experimental data; for example, the computed sizes of scleral lesions, as determined from damage-integral analysis, were within 15% of measured lesion sizes.To examine tumour therapy, we are expanding our computer model to include thick tissue segments, intervening acoustic attenuation, and blood-flow cooling. The model has been used in initial studies of heating produced by two therapeutic exposure modes. The first mode involves hyperthermia in which the distal, defocused segment of a beam is used to encompass a large tumour volume: low spatial-average (SA) intensities (e.g., 1 W/cm2) are used to produce sustained temperature elevations (e.g. to 45" C ) for relatively long periods (e.g., 30 min). The intensities within the focal zone, which is located in the vitreous, have not been found to produce deleterious changes. The second mode involves ablation, in which the focused segment of the beam is placed within the tumour to achieve immediate focal destruction of exposed tissue volumes. In this mode, high SA intensiti...

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Ultrasonic tissue characterization and histopathology in tumor xenografts following ultrasonically induced hyperthermia

Cited by 30 publications

References 8 publications

Quantitative Ultrasound Characterization of Responses to Radiotherapy in Cancer Mouse Models

Quantitative Ultrasound Characterization of Responses to Radiotherapy in Cancer Mouse Models

Effect of electrohydraulic and extracorporeal shock waves on gastrointestinal cancer cells and their response to cytotoxic agents.

Computer simulations of ultrasonic heating for ocular therapy

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