Optimized Hyperthermia Treatment of Prostate Cancer Using a Novel Intracavitary Ultrasound Array
Abstract
Ultrasound induced hyperthermia is a useful adjuvant to radiation therapy in the treatment of prostate cancer. This requires specific ultrasound phased array design and appropriate thermometry method. Inhomogeneous, acoustical, three-dimensional (3D) prostate models and economical computational methods provide necessary tools to predict the appropriate shape of hyperthermia phased arrays for better focusing and steering. A 3D acoustical prostate model was created depending on photographical data from the Visible Human Project(trade name). The k-space computational method was used on this coarse grid and inhomogeneous tissue model to simulate the steady state pressure wavefield of the designed phased array using the linear acoustic wave equation. To insure the uniformity and spread of the pressure in the length of the array, and the steering and focusing capability in the width of the array, the equally-sized elements of the 80 elements phased array were 1 x 14 mm. Noninvasive MRI thermometry and a feedback controller were used to accomplish ex vivo and in vivo hyperthermia evaluations of the fabricated probe. Both exposimetry and k-space simulation results demonstrated good agreement within 9%. With a desired temperature plateau of 43.0 deg C, ex vivo and in vivo controlled hyperthermia experiments showed that the MRI temperature at the steady state was 42.9 +- 0.38 deg C and 43.1 +- 0.80 deg C, respectively. Noninvasive MRI thermometry validated this optimized hyperthermia transducer design and the feedback controller with in vivo hyperthermia treatment of canine prostate.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 2006
- Accession Number
- ADA449060
Entities
People
- Nadine Smith
Organizations
- Pennsylvania State University