Radiation Treatment

Penn radiation oncologists use special techniques to maximize the impact of radiation on the tumor and minimize the effect on normal surrounding body tissue. The sophisticated equipment used at Penn works to direct just the right amount of radiation at the precise location of a tumor. Full-time Penn physicians direct treatment programs at Penn Medicine and various satellite facilities, which have the latest equipment and technology. Our radiation oncologists utilize the latest technology available including many that combine radiation therapy with chemotherapy and/or surgery.

About Radiation Treatment

Radiation treatment uses X-rays or other high energy rays to kill cancer cells and shrink tumors. Radiation treatment is an effective treatment for many types of cancers in almost any part of the body.

The two main goals of radiation treatment are to cure cancer and relieve symptoms. For many patients, radiation is the only treatment needed. However, radiation treatment may also be given in combination with chemotherapy and/or surgery. Radiation can be used before surgery to shrink a tumor, and during or after surgery to kill any cancer cells that may still be present. Sometimes radiation is used along with anticancer drugs to destroy the cancer, instead of performing surgery.

Radiation can be used as a palliative therapy, meaning that its primary intent is not to cure the cancer, but to relieve pressure, bleeding, or pain by shrinking tumors.

Types of Radiation Treatment

External radiation (or external beam radiation) comes from a machine outside the body. The machine directs high-energy rays at the cancer and some normal surrounding tissue. It is the most often used radiation treatment. The machine used to deliver the high-energy rays is called a linear accelerator.

Three-dimensional (3-D) conformal radiation treatment is a type of external beam radiation. It uses computers to allow doctors to more precisely target a tumor with radiation beams (using width, height, and depth).

Intensity-modulated radiation treatment (IMRT) is a type of 3-D conformal radiation treatment that uses radiation beams (usually x-rays) of various intensities to give different doses of radiation, at the same time, to small areas of tissue. This allows the delivery of higher doses of radiation to the tumor and lower doses to nearby healthy tissue.

Proton therapy is an advanced form of radiation therapy that is currently in use at the Roberts Proton Therapy Center at Penn. The Roberts Proton Therapy Center, is the world's most comprehensive proton therapy center and one of only six such centers in the country.

Protons are different from conventional radiation because the beam can deposit the bulk of the radiation in the target and significantly reduce normal tissue exposure to excess radiation. There is significant potential to reduce side effects and improve overall outcomes. For some tumors, higher doses of radiation may be delivered with protons and there is also the potential to improve combination treatment with other therapies, such as chemotherapy, which can be difficulty with conventional radiation therapy. As with all cancer therapies, protons should not be used for everything. They are a tool that may be of benefit for particular tumors and particular situations. The following sections will help explain both the promise and limitations of this technology.

Learn more about Proton Therapy at OncoLink.

Photodynamic therapy (PDT) combines a drug called a photosensitizer or photosensitizing agent with a specific type of light to kill cancer cells. Photosensitizers are drugs that when exposed to a specific wavelength of light, produce a form of oxygen that kills nearby cells. PDT can also work by shrinking or destroy tumors by damaging blood vessels in the tumor. This prevents the cancer from receiving nutrients. Also, PDT may activate the immune system to attack the tumor cells.

Stereotactic radiosurgery uses a large dose of radiation to destroy tumor tissue in the brain. The procedure does not involve actual surgery. The patient's head is placed in a special frame, which is attached to the patient' skull. The frame is used to aim high-dose radiation beams directly at the tumor inside the patient's head. The dose and area receiving the radiation are coordinated very precisely.

Radiation Oncology Patient Guide: What to Expect