Scholarly Works, Institute for Critical Technology and Applied Science (ICTAS)
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Browsing Scholarly Works, Institute for Critical Technology and Applied Science (ICTAS) by Subject "Ablation"
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- Bubble cloud behavior and ablation capacity for histotripsy generated from intrinsic or artificial cavitation nucleiEdsall, Connor; Khan, Zerin Mahzabin; Mancia, Lauren; Hall, Sarah; Mustafa, Waleed; Johnsen, Eric; Klibanov, Alexander L.; Durmaz, Yasemin Yuksel; Vlaisavljevich, Eli (2021-03)The study described here examined the effects of cavitation nuclei characteristics on histotripsy. High-speed optical imaging was used to compare bubble cloud behavior and ablation capacity for histotripsy generated from intrinsic and artificial cavitation nuclei (gas-filled microbubbles, fluid-filled nanocones). Results showed a significant decrease in the cavitation threshold for microbubbles and nanocones compared with intrinsic-nuclei controls, with predictable and well-defined bubble clouds generated in all cases. Red blood cell experiments showed complete ablations for intrinsic and nanocone phantoms, but only partial ablation in microbubble phantoms. Results also revealed a lower rate of ablation in artificial-nuclei phantoms because of reduced bubble expansion (and corresponding decreases in stress and strain). Overall, this study demonstrates the potential of using artificial nuclei to reduce the histotripsy cavitation threshold while highlighting differences in the bubble cloud behavior and ablation capacity that need to be considered in the future development of these approaches. (E-mail: cwedsall@vt.edu) (C) 2020 The Author(s). Published by Elsevier Inc. on behalf of World Federation for Ultrasound in Medicine & Biology.
- Histotripsy Ablation of Bone Tumors: Feasibility Study in Excised Canine Osteosarcoma TumorsArnold, Lauren; Hendricks-Wenger, Alissa; Coutermarsh-Ott, Sheryl; Gannon, Jessica; Hay, Alayna N.; Dervisis, Nikolaos G.; Klahn, Shawna L.; Allen, Irving C.; Tuohy, Joanne L.; Vlaisavljevich, Eli (Elsevier, 2021-12)Osteosarcoma (OS) is a primary bone tumor affecting both dogs and humans. Histotripsy is a non-thermal, non-invasive focused ultrasound method using controlled acoustic cavitation to mechanically disintegrate tissue. In this study, we investigated the feasibility of treating primary OS tumors with histotripsy using a 500-kHz transducer on excised canine OS samples harvested after surgery at the Veterinary Teaching Hospital at Virginia Tech. Samples were embedded in gelatin tissue phantoms and treated with the 500-kHz histotripsy system using one- or two-cycle pulses at a pulse repetition frequency of 250 Hz and a dosage of 4000 pulses/point. Separate experiments also assessed histotripsy effects on normal canine bone and nerve using the same pulsing parameters. After treatment, histopathological evaluation of the samples was completed. To determine the feasibility of treating OS through intact skin/soft tissue, additional histotripsy experiments assessed OS with overlying tissues. Generation of bubble clouds was achieved at the focus in all tumor samples at peak negative pressures of 26.2 ± 4.5 MPa. Histopathology revealed effective cell ablation in treated areas for OS tumors, with no evidence of cell death or tissue damage in normal tissues. Treatment through tissue/skin resulted in generation of well-confined bubble clouds and ablation zones inside OS tumors. Results illustrate the feasibility of treating OS tumors with histotripsy. CORRIGENDUM: The authors regret that errors were present in the above article. The legend for Figure 5 on page 3441 should read “Fig. 5. Normal, healthy, non-neoplastic bone was excised from amputated canine limbs and subjected to histology. No histological differences were noted between untreated (a: magnification 4 x, b: magnification 40 x) and treated samples (c: magnification 4 x, d: magnification 40 x).” Also, the final section heading on page 3439 should read “Histotripsy ablation of ex vivo bone and nerve specimens.” Finally, the reference after the last complete sentence on page 3437 is incomplete and should read “Focal pressure waveforms for the 500-kHz transducer were measured using a custom-built fiberoptic hydrophone (FOPH) in degassed water at the focal point of each transducer (Parsons et al. 2006).” The authors would like to apologise for any inconvenience caused.