The word laser is an acronym for "light amplification by stimulated emission of radiation." The light is produced by devices that can "excite" substances such as carbon dioxide, argon and neodymium:yttrium-aluminum-garnet (Nd:YAG) to a higher energy state. As these substances return to their "resting" state, they release their extra energy in the form of a powerful light with a special "energy" that is capable of vaporizing human tissue , including tumor cells .
What makes this type of energy so useful in cancer treatment is that it can be aimed so precisely. Lasers focus on very small areas with extreme accuracy.
Endoscopic Laser Therapy Laser therapy is usually given by activating the special light beam through a flexible tube called an endoscope , the same instrument used to diagnose many cancers. The scope can be passed through any opening in the body—the mouth, nose, anus or vagina.
A laser operator looking through the scope can see the tumor directly and aim the light beam precisely into
the target tissue. The operator then activates the device and the energy is produced. On contact with the tissue, the laser beam produces an intense heat. At 60°C (140°F), this heat can coagulate protein. At 100°C (212°F),
it can vaporize tissue. The tissue usually burns for just a few seconds, giving off a bit of smoke and
