New Radiation Treatment Targets Tumors more Precisely
A new radiation technique is allowing doctors to target tumors with greater
accuracy, at higher doses, with fewer side effects. It’s called “intensity
modulated radiation therapy,” or IMRT. Using computers, technicians generate
images of a tumor. Then clinicians are able to treat the tumor with a precise
radiation beam that corresponds to the tumor’s shape and depth. This type of
treatment allows physicians to treat tumors that might not have been treatable
Higher level of accuracy, fewer complications and side effects
Because the radiation is beamed so precisely at the location of the tumor,
doctors can give higher dosages and patients generally experience fewer, less
severe side effects. Not only are physicians able to target tumors they
previously could not, they are also able to do so without damaging surrounding
tissue. For example, for prostate cancer, patients can receive higher dosages of
the radiation and have decreased chances of damaging the bladder or rectum. And
studies have shown that increased doses of radiation for prostate cancer yield
increased chances of eliminating the cancer itself.
IMRT is useful for cancers of the prostate, head and neck, spinal cord,
abdomen and pelvis. All of these are areas with delicate tissue that, if
damaged, can produce serious lifelong consequences.
Preparing patients for IMRT requires a great deal of precision. It can take
five to 10 hours of preparation, which includes data transfer from computer to
radiation equipment. The actual treatment takes about 15 minutes. It’s important
that patients remain completely still, but even when they do, the tumors can
move internally. So ultrasound equipment locates the tumor and makes sure to
target the exact middle of it.
IMRT offers new hope for patients who may not have had any treatment options
previously. It also offers improved quality of life for those undergoing
The National Cancer Institute, Cartilage (Bovine and Shark) PDQ; K. Pelletier, The Best Alternative Medicine, Simon & Schuster, New York, New York, 2000.