Share Email Print
cover

Proceedings Paper

Three-dimensional finite element simulations of vertebral body thermal treatment
Author(s): Thomas P. Ryan; Samit J. Patel; Ronit Morris; P. Jack Hoopes; Jeffrey A. Bergeron; Roop Mahajan
Format Member Price Non-Member Price
PDF $17.00 $21.00
cover GOOD NEWS! Your organization subscribes to the SPIE Digital Library. You may be able to download this paper for free. Check Access

Paper Abstract

Lower back pain affects a large group of people worldwide and when in its early stages, has no viable interventional treatment. In order to avoid the eventuality of an invasive surgical procedure, which is further down the Care Pathway, an interventional treatment that is minimally invasive and arrests the patient's pain would be of tremendous clinical benefit. There is a hypothesis that if the basivertebral nerve in the vertebral body is defunctionalized, lower back pain may be lessened. To further investigate creating a means to provide localized thermal therapy, bench and animal studies were planned, but to help select the applicator configuration and placement, numerical modeling studies were undertaken. A 3D finite element model was utilized to predict the electric field pattern and power deposition pattern of radiofrequency (RF) based electrodes. Three types of tissues were modeled: 1) porcine (ex-vivo), ovine (in-vivo preclinical), and 3) human (ex-vivo, in-vivo). Two types of RF devices were simulated: 1) a pair of converging, hollow electrodes, and 2) an in-line pair of spaced-apart electrodes. Temperature distributions over time were plotted using the electric field results and the bioheat equation. Since the thermal and electrical properties of the vertebral bodies of porcine, ovine, and human tissue were not available, measurements were undertaken to capture these data to input into the model. The measurements of electrical and thermal properties of cancellous and cortical vertebral body were made over a range of temperatures. The simulation temperature results agreed with live animal and human cadaver studies. In addition, the lesion shapes predicted in the simulations matched CT and MRI studies done during the chronic ovine study, as well as histology results. In conclusion, the simulations aided in shaping and sizing the RF electrodes, as well as positioning them in the vertebral body structures to assure that the basivertebral nerve was ablated, but other neighboring structures such as the spinal cord and nerve roots were spared.

Paper Details

Date Published: 14 April 2005
PDF: 19 pages
Proc. SPIE 5698, Thermal Treatment of Tissue: Energy Delivery and Assessment III, (14 April 2005); doi: 10.1117/12.592496
Show Author Affiliations
Thomas P. Ryan, Microsulis Americas Inc. (United States)
Samit J. Patel, Johnson & Johnson Co. (United States)
Ronit Morris, Johnson & Johnson Co. (United States)
P. Jack Hoopes, Dartmouth Medical School (United States)
Jeffrey A. Bergeron, Dartmouth Medical School (United States)
Roop Mahajan, Univ. of Colorado (United States)


Published in SPIE Proceedings Vol. 5698:
Thermal Treatment of Tissue: Energy Delivery and Assessment III
Thomas P. Ryan, Editor(s)

© SPIE. Terms of Use
Back to Top