17 May 1996 Model development of laser fiber optic endoablative treatment for primary breast cancer
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A mammographic stereotactic core biopsy instrument can be adapted for laser hyperthermic ablation of breast cancer. The object of this study is to characterize laser endohyperthermia ex-vivo and in-vivo to develop a reliable approach leading to human trials. Light of a Nd:YAG laser passed through a fiberoptic cable to a diffusing quartz tip upon entering surrounding tissues can bring about very high temperatures. This approach concentrating on the heat distribution to fat and fibrofatty tissue, first analyzed a physical model into which both the quartz tip and thermocouple needles were placed. Temperature recordings in volume through a time course demonstrated a progressive thermal increase around the tip. Additional light distribution studies in several media demonstrated the tip's output. The technique transferred to ex-vivo human breast and porcine fibrofatty tissue showed similar findings leading to an in-vivo analysis of subcutaneous porcine fibrofatty tissue. A step-down energy program beginning at 20 watts and decreasing to 15 watts, 10 watts, and to 7 watts, at 30 second intervals was held at the latter power for the remainder of 6 minutes. Three such cycles appear to be the optimal treatment program to develop temperatures between 60 degrees Celsius and 80 degrees Celsius (approximately equals 9700 joules). In-vivo experiments conducted on 5 occasions revealed no skin change. At necropsy the treated tissues demonstrated a circular sharply defined 3 cm volume of necrosis with no change in adjacent tissue. Time-temperature correlations between ex-vivo and in-vivo tissues showed great similarity. Nd:YAG laser energy distributed to a quartz tip through a fiberoptic cable is capable of uniform, complete tissue destruction to a 1 1/2 cm radius with no change beyond that field. This technique with further refinement will be appropriate to the treatment of small breast cancers that have been stereotactically biopsied.
© (1996) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
David S. Robinson, Jean-Marie A. Parel, David B. Denham, Fabrice Manns, Xochitl Gonzalez, Robert D. Schachner, Alan J. Herron, and Everette C. Burdette "Model development of laser fiber optic endoablative treatment for primary breast cancer", Proc. SPIE 2671, Lasers in Surgery: Advanced Characterization, Therapeutics, and Systems VI, (17 May 1996); doi: 10.1117/12.240000; https://doi.org/10.1117/12.240000

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