Publication Details
Transurethral ultrasound therapy of the prostate in the presence of calcifications: a simulation study
Treeby Bradley
Jaroš Jiří, doc. Ing., Ph.D. (DCSY)
MAKELA, P.
ANTTINEN, M.
SAUNAVAARA, J.
SAINIO, T.
KIVINIEMI, A.
BLANCO, R.
therapeutic ultrasound, prostate cancer, calcification, heating, efficacy
Transurethral ultrasound therapy is an investigational treatment modality which could potentially be used for the localised treatment of prostate cancer. One of the limiting factors of this application are the prostatic calcifications which attenuate and reflect ultrasound, and thus, reduce the efficacy of the heating. The aim of this study is find out how prostatic calcifications affect the therapeutic efficacy and what is the best sonication strategy to overcome these limitations. The presence of calcifications in front of the ultrasound field was found to increase the peak pressure by 100% on average while the maximum temperature only rose by 9% during a 20-second sonication. Losses in ultrasound energy were caused due to relative large acoustic impedance mismatch between the prostate tissue and the calcifications (1.63 vs. 3.20 MRayl) and high attenuation coefficient (0.78 vs. 2.64 dB/MHz^1.1/cm), which together left untreated tissue regions behind the calcifications. In addition, elevated temperatures were seen in the region between the transducer and the calcifications. Lower sonication frequencies (1-4 MHz) were not able to penetrate through the calcifications effectively, but longer sonication durations (20-60 s) with selected transducer elements were effective in treating the tissue regions behind the calcifications.
@article{BUT155052,
author="SUOMI, V. and TREEBY, B. and JAROŠ, J. and MAKELA, P. and ANTTINEN, M. and SAUNAVAARA, J. and SAINIO, T. and KIVINIEMI, A. and BLANCO, R.",
title="Transurethral ultrasound therapy of the prostate in the presence of calcifications: a simulation study",
journal="MEDICAL PHYSICS",
year="2018",
volume="45",
number="11",
pages="4793--4805",
doi="10.1002/mp.13183",
issn="0094-2405",
url="https://aapm.onlinelibrary.wiley.com/doi/abs/10.1002/mp.13183"
}