Treatment Planning Strategies for Interstitial Ultrasound Ablation of Prostate Cancer.

Autor:	Gupta P; Department of Radiation OncologyUniversity of California San Francisco San Francisco CA 94115 USA., Heffter T; Acoustic MedSystems Savoy IL 61874 USA., Zubair M; Department of Neurology and Neurological SciencesStanford University Stanford CA 94305 USA., Hsu IC; Department of Radiation OncologyUniversity of California San Francisco San Francisco CA 94115 USA., Burdette EC; Acoustic MedSystems Savoy IL 61874 USA., Diederich CJ; Department of Radiation OncologyUniversity of California San Francisco San Francisco CA 94115 USA.
Jazyk:	angličtina
Zdroj:	IEEE open journal of engineering in medicine and biology [IEEE Open J Eng Med Biol] 2024 May 08; Vol. 5, pp. 362-375. Date of Electronic Publication: 2024 May 08 (Print Publication: 2024).
DOI:	10.1109/OJEMB.2024.3397965
Abstrakt:	Purpose: To develop patient-specific 3D models using Finite-Difference Time-Domain (FDTD) simulations and pre-treatment planning tools for the selective thermal ablation of prostate cancer with interstitial ultrasound. This involves the integration with a FDA 510(k) cleared catheter-based ultrasound interstitial applicators and delivery system. Methods: A 3D generalized "prostate" model was developed to generate temperature and thermal dose profiles for different applicator operating parameters and anticipated perfusion ranges. A priori planning, based upon these pre-calculated lethal thermal dose and iso-temperature clouds, was devised for iterative device selection and positioning. Full 3D patient-specific anatomic modeling of actual placement of single or multiple applicators to conformally ablate target regions can be applied, with optional integrated pilot-point temperature-based feedback control and urethral/rectum cooling. These numerical models were verified against previously reported ex-vivo experimental results obtained in soft tissues. Results: For generic prostate tissue, 360 treatment schemes were simulated based on the number of transducers (1-4), applied power (8-20 W/cm2), heating time (5, 7.5, 10 min), and blood perfusion (0, 2.5, 5 kg/m3/s) using forward treatment modelling. Selectable ablation zones ranged from 0.8-3.0 cm and 0.8-5.3 cm in radial and axial directions, respectively. 3D patient-specific thermal treatment modeling for 12 Cases of T2/T3 prostate disease demonstrate applicability of workflow and technique for focal, quadrant and hemi-gland ablation. A temperature threshold (e.g., Tthres = 52 °C) at the treatment margin, emulating placement of invasive temperature sensing, can be applied for pilot-point feedback control to improve conformality of thermal ablation. Also, binary power control (e.g., Treg = 45 °C) can be applied which will regulate the applied power level to maintain the surrounding temperature to a safe limit or maximum threshold until the set heating time. Conclusions: Prostate-specific simulations of interstitial ultrasound applicators were used to generate a library of thermal-dose distributions to visually optimize and set applicator positioning and directivity during a priori treatment planning pre-procedure. Anatomic 3D forward treatment planning in patient-specific models, along with optional temperature-based feedback control, demonstrated single and multi-applicator implant strategies to effectively ablate focal disease while affording protection of normal tissues. (© 2024 The Authors.)
Databáze:	MEDLINE
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