Document Detail


Focused ultrasound treatment of VX2 tumors controlled by local harmonic motion.
MedLine Citation:
PMID:  19436103     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
The purpose of this study was to evaluate the feasibility of using localized harmonic motion (LHM) to monitor and control focused ultrasound surgery (FUS) in VX2 tumors in vivo. FUS exposures were performed on 13 VX2 tumors implanted in nine rabbits. The same transducer induced coagulation and generated a localized oscillatory motion by periodically varying the radiation force. A separate diagnostic ultrasound transducer tracked motion by cross-correlating echo signals at different instances. A threshold in motion amplitude was instituted to cease exposure. Coagulation was confirmed by T2-weighted MR images, thermal dose obtained through MR thermometry and histological examinations. For tumor locations achieving coagulation, the LHM amplitude was 9% (p = 0.04) to 57% (p < 0.0001) lower than that before exposure. Control was successful for 74 (69%) out of 108 cases, with 52 (48%) reaching the threshold and achieving coagulation and 22 (21%) never reaching threshold nor coagulating. For the 34 (31%) unsuccessful exposures, 16 (15%) never reached the threshold but coagulation occurred, and 18 (16%) reached threshold without coagulation confirmed. Noise or radio-frequency signal changes explained motion over- or underestimation in 24 (22%) cases; the remaining 10 (9%) had other causes of error. The control was generally successful, but sudden change or noise in the acquired echo signal caused failure. Coagulation after exposure could be validated by comparing amplitudes before and after exposure.
Authors:
Laura Curiel; Yuexi Huang; Natalia Vykhodtseva; Kullervo Hynynen
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Publication Detail:
Type:  Journal Article; Research Support, N.I.H., Extramural; Research Support, Non-U.S. Gov't; Research Support, U.S. Gov't, P.H.S.     Date:  2009-05-13
Journal Detail:
Title:  Physics in medicine and biology     Volume:  54     ISSN:  0031-9155     ISO Abbreviation:  Phys Med Biol     Publication Date:  2009 Jun 
Date Detail:
Created Date:  2009-05-20     Completed Date:  2009-08-31     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  0401220     Medline TA:  Phys Med Biol     Country:  England    
Other Details:
Languages:  eng     Pagination:  3405-19     Citation Subset:  IM    
Affiliation:
Imaging Res., Sunnybrook Health Sciences Centre, 2075 Bayview Av., Toronto, ON, M4N 3M5, Canada. High Intensity Focused Ultrasound (HIFU) Lab., Thunder Bay Regional Research Institute, 980 Oliver Rd, Thunder Bay, ON, P7C 1M5, Canada. curiell@tbh.net
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MeSH Terms
Descriptor/Qualifier:
Animals
Male
Motion
Neoplasms, Experimental / pathology,  therapy*,  ultrasonography
Rabbits
Temperature
Treatment Outcome
Ultrasonic Therapy / methods*
Grant Support
ID/Acronym/Agency:
R21/R33 CA102884/CA/NCI NIH HHS

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