Thermal therapy of canine cerebral tumors using a 980 nm diode laser with MR temperature-sensitive imaging feedback
Article first published online: 20 JUL 2004
Copyright © 2004 Wiley-Liss, Inc.
Lasers in Surgery and Medicine
Volume 35, Issue 1, pages 41–50, July 2004
How to Cite
Kangasniemi, M., McNichols, R. J., Bankson, J. A., Gowda, A., Price, R. E. and Hazle, J. D. (2004), Thermal therapy of canine cerebral tumors using a 980 nm diode laser with MR temperature-sensitive imaging feedback. Lasers Surg. Med., 35: 41–50. doi: 10.1002/lsm.20069
- Issue published online: 20 JUL 2004
- Article first published online: 20 JUL 2004
- Manuscript Accepted: 7 APR 2004
- National Institutes of Health (to J.D.H.). Grant Number: CA16672
- National Institutes of Health (to R.J.M.). Grant Numbers: CA79282, AG19276
- The Wilson Hospital Foundation (to J.D.H.)
- interstitial thermal therapy;
- MR thermal imagining;
- brain tumors
Background and Purpose
The laser-induced thermal therapy (LITT) of cerebral tumors has conventionally been performed using Nd:YAG lasers and is associated with a risk of high focal temperatures potentially followed by cavitation that could result in boiling and/or explosive char. We have developed small diffusing laser fiber tips to better distribute the energy deposition and a computer controlled feedback system to monitor therapy and prevent excess temperature buildup. In this study, we evaluated the feasibility of using magnetic resonance temperature imaging (MRTI)-based feedback system for the thermal treatment of experimental intracerebral tumors using 980 nm laser irradiation delivered through these diffusing tips.
Study Design/Materials and Methods
Transmissible venereal tumors (TVTs) were grown via inoculation in the right cerebral hemisphere of seven canines. The laser fiber tips were inserted into a total of 10 independent TVT-suspected regions in the seven animals. Margins for the target area in each animal were prescribed on the basis of pretreatment MR images. MRTI-based feedback software was used to measure and regulate both temperature and the delivered thermal dose to achieve the desired thermal ablation and prevent excess heating. The effects of treatment were verified by results of histologic analyses.
Treatments resulted in contiguous areas of thermal necrosis in tumors and adjacent brain margin. The feedback software successfully cut off the laser power once the desired treatment volume was achieved, and prevented focal temperatures from exceeding predefined thresholds. Follow-up MRI studies showed 1.4- to 2.9-fold LITT-induced lesion expansion within 1–6 days after treatment.
Targeted thermal coagulation of small intracerebral tumors is feasible using MRTI-based feedback and diffused 980 nm diode laser light. Lasers Surg. Med. 35:41–50, 2004. © 2004 Wiley-Liss, Inc.