Translator Disclaimer
7 July 1993 Imaging of interstitial laser photocoagulation of liver tumors
Author Affiliations +
Proceedings Volume 1882, Laser-Tissue Interaction IV; (1993)
Event: OE/LASE'93: Optics, Electro-Optics, and Laser Applications in Scienceand Engineering, 1993, Los Angeles, CA, United States
Imaging plays a crucial role in the treatment of liver tumors by interstitial laser photocoagulation (ILP). Ultrasound allows location of the tumors and enables guided placement of thin hollow needles (through which the optical fibers are passed) into the appropriate part of the tumor. Heating of the tumor during ILP is seen as an enlarging echogenic zone around the fiber tips. However, the margins of the echogenic zone are often ill-defined and irregular and ultrasound cannot clearly differentiate treated from untreated tumor on follow-up scans. CT (pre-contrast, dynamic, and delayed) is used to define the number and sizes of metastases prior to ILP. 24 hrs after ILP dynamic enhanced CT clearly shows the laser-induced necrosis as a well-defined non-enhancing area, although real-time CT monitoring of ILP shows very little change around the fiber tip. MRI (standard spin-echo sequences) has been used to evaluate lesions post-ILP. On T1-weighted images the lesions appear heterogenous with areas of high and low signal intensity. With these current sequences the lesion-to-liver contrast is not as good as with dynamic enhanced CT. Conclusion: Ultrasound plays a useful role in treatment delivery. At present the post-ILP evaluation is best performed using CT. MRI has the potential for real-time monitoring of ILP using temperature sensitive sequences.
© (1993) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Zahir Amin, J. J. Donald, Margret A. Hall-Craggs, Martyn Paley, William R. Lees M.D., and Stephen G. Bown "Imaging of interstitial laser photocoagulation of liver tumors", Proc. SPIE 1882, Laser-Tissue Interaction IV, (7 July 1993);

Back to Top