Organs in our body constantly move, which previously meant that a large treatment field needed to be used because from day to day or minute to minute the tumor shifted as well. IGRT helps pin down precisely where the tumor is during each treatment. This precision, in turn, lets us make the treatment fields much smaller, thus limiting exposure of normal tissues nearby. 

The methods employed in IGRT depend on the type of tumor and the location. But in all applications of this technology, we use daily imaging to precisely pinpoint the coordinates of the tumor. This increased precision allows for higher doses of radiation – ultimately leading to higher cure rates.

In some situations, image-guided localization is significantly aided by surgically implanted markers that reliably show up on images. Implanted markers are broken into two main categories – bone and soft tissue. Bone markers are used in cranial and spinal applications primarily. The markers are typically placed in a small hole in the bone, and bone wax is used to ensure that they stay in place. In thousands of cases, these gold markers have never moved from their seated position in the bone. Soft tissue markers can be easily inserted using a needle. They are an alternative way to localize the prostate (and many other tumor types) just prior to treatment.

 Respiratory gating is another IGRT technique used to pinpoint tumors that move with breathing, especially those within the lung and abdomen. Using IGRT techniques and the latest accelerator technology we can track the position of the tumor throughout the breathing cycle, turning on the beam only when the tumor is centered within the treatment area. Gating often lengthens the overall time you spend on the treatment bed by about 5-10 minutes. But the extra time can be worthwhile in selected situations.

Like standard external-beam therapy, the IGRT-based treatment is typically given for only a few minutes a day, five days a week. The radiation treatment is completely painless and non-invasive.