Pulsed neodymium laser radiation —capable of producing high temperatures in malignant tissues for an extremely short duration—results in tissue and cellular fluid vaporization, protein coagulation, and cellular death, John P. Minton, MD, National Cancer Institute, Bethesda, Md, reported to the American College of Surgeons in Chicago.
"Laser radiation is attenuated when passing through tissues and possibly attenuated to a greater extent in pigmented tissues than in nonpigmented tissues," Minton said.
He described experiments to document thermal variations inside three different tumor systems at the moment of impact from a high energy pulse of neodymium laser radiation.
Immediately prior to laser radiation, the tumors were positioned sothe focal point of the laser beam was 3 mm beneath the surface of the tumor and directly over the thermocouples. The laser pulse duration was 1.6 millisecond. Thermal recordings were taken for a period of 1 to 20 seconds. Each laser pulse was measured