Targeting Tumors with Technology
Several noninvasive or minimally invasive techniques are used to combat cancer. They have the same outcomes as surgery but without scalpels or large scars. Stereotactic radiosurgery isn’t actually surgery. No cuts are made into the body and no incisions need to heal afterward. It is, instead, a form of radiation therapy. Radiation sources aimed at a tumor from different angles deliver a forceful, precisely targeted dose to a tumor. Two technologies used in many hospitals to deliver stereotactic radiation therapy are brand-named Gamma Knife and CyberKnife, although neither does any cutting. These instruments are most often employed against cancers in the brain.
Ionizing radiation isn’t the only tool doctors have for removing tumors without cutting the body open. Cryosurgery uses liquid nitrogen or a very cold probe to freeze and kill abnormal cells. Electrosurgery is the destruction of cancerous cells with a high-frequency electrical current. In radiofrequency ablation, a small antenna is placed in a tumor. Then radio waves transmitted to the antenna kill cancer cells with heat.
Laser surgery uses a strong, focused beam of light energy to excise or vaporize a tumor. In 2009, for example, the US Food and Drug Administration approved a new MRI-guided laser surgery method for otherwise inoperable brain tumors. The system uses an MRI-guided laser probe, passed through a small hole in the skull, to deliver laser interstitial thermal therapy (LITT). The laser heats and coagulates the tumor from the inside without damaging normal tissue. The MRI measures temperature inside the brain, showing thermal damage as it happens and facilitating precise control. Once coagulated by the laser’s heat, the treated tumor mass is dead.
Last updated on 31 May 2011