Radiation Oncology
Radiation Therapy Daily Treatment

Daily Treatment

Treatments are normally administered on a daily basis, Monday through Friday. The average course lasts from five to six weeks, although some patients are treated for as little as two weeks and others as long as nine. The number of treatments required will be based upon the total dose of radiation necessary to treat the particular cancer, which will be determined by the radiation oncologist.

Each treatment is by appointment and normally requires only a few minutes. The total time from arrival to departure is usually less than 30 minutes.

Patients will lie flat on a special table to receive their daily treatment. The X-rays from the linear accelerator pass through the body; treatment is invisible and painless. There are no injections or discomfort associated with the treatment. Verification "port" films are taken during the treatment on a regular basis to confirm that the appropriate area is being covered. These X-rays, however, do not allow us to accurately assess the status of the cancer.

Diagnostic X-rays differ from those used in treating cancer and are required to gauge your response to treatment. Since tumors may continue to shrink for several months after a radiation treatment course, diagnostic X-rays are not usually obtained until well after your therapy is complete.

Radiation Machines

The selection of a particular machine depends upon the individual patient, as well as the site and location of the tumor. In some cases, more than one machine may be used.

Several linear accelerators are available with X-ray beam energies ranging from four to 20 million electron volts (MV). These machines produce high-energy X-rays as well as electron beams for treatment. All of these machines are very complex and can be moved in an up-and-down, as well as side-to-side, direction. They tend to be noisy, but they are very safe. The treatments with linear accelerators are often performed based upon 3-D planning or Intensity Modulated Radiotherapy (IMRT). The 3-D planning treats highly specific and localized target volumes based upon information gleaned from CT, MRI and/or PET scans. IMRT is similar to 3-D, but allows us to change the intensity of different parts of a particular beam, similar to making some parts of a flashlight beam brighter than others.

This specialized therapy allows us to shape our doses to very unusual contours, thus preserving nearby normal tissues.

The sophisticated Gamma Knife machine uses 201 pencil-thin gamma ray beams of Cobalt-60 radiation to pinpoint small targets in the brain. In contrast to the linear accelerators, this machine is very quiet.

Because of their sophistication, as well as the presence of many microcomputers, these machines sometimes require either routine maintenance or, at times, unscheduled servicing that may disrupt the treatment schedule. We will attempt to minimize your inconvenience during those times by rescheduling your appointment.