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Radiation Oncology / Radiation Therapy

What Is a Radiation Oncologist?

A board-certified physician who specializes in using radiation to treat cancer. People are referred to as a radiation oncologist after a diagnosis of cancer is made, and when treated with radiation is considered.

What Is Radiation Therapy?

Radiation Therapy is the use of high-energy penetrating rays or subatomic particles to destroy cells. There are several types of radiation including x-ray, electron beam, alpha and beta particles, and gamma rays. Today, more than 99% of patients worldwide requiring radiation interventions are treated with photons or x-rays generated by means of linear accelerators.

How Does Radiation Work?

Both cancer cells and healthy cells are affected by radiation. Because radiation has its greatest effects on tissue that divides rapidly such as cancer; cancer cells are more susceptible to injury than normal cells. This cell injury stops the cancer cells from reproducing or it can actually destroy the cancer cell outright. Either way, the tumor mass will begin to shrink as the viable cancer cells are reduced in number. With each treatment, more of the cells die and the tumor shrinks. The dead cells are broken down, carried away by the blood and excreted by the body. Most of the healthy cells are able to recover. However, the damage to the healthy cells may cause long and short-term side effects related to the body area irradiated.

The dose of radiation is determined by the size, extent, type, and grade of tumor and its known response to radiation. Complex calculations and computer-generated planning are performed to determine the dose distribution and timing of radiation. Often, the treatment is delivered from many different angles or a rotating beam in order to deliver the maximum amount of radiation to the tumor and the minimum amount to normal surrounding tissues. Treatments are generally given daily over a period of days or weeks to adequately destroy the cancer cells.

Questions? Click Here to get your questions answered from the American Society for Radiation Oncology new patient website!

Some things to remember about external beam radiation therapy:

  • External beam radiation passes through your body and does not remain in you. You are not radioactive.
  • Only the body area in the field of radiation is affected.
  • Normal cells exposed to radiation have the ability to repair themselves.
  • The side effects that occur during radiation therapy are manageable.

Our board-certified physicians provide consultation; treatment and follow-up care for those who need radiation treatment for the management of their cancer. Once a patient consents to a treatment course, we begin the planning process. This can take up from a few days to a couple of weeks depending on the complexity of the case but is usually completed within 4 days.

Treatment planning is accomplished by employing highly sophisticated computer systems using cross-sectional body images, which we acquire on our dedicated CT scanner. These CT images are fussed with other imaging studies the patient may have had done such as MRI, PET and diagnostic CT studies. This allows for the most accurate, focused radiation treatment to the tumor or tumor bed without damaging the surrounding normal tissue.

The Center’s technically advanced linear accelerators, Varian Trilogy with RapidArc and TomoTherapy HD are not only the best radiation technology available but both are capable of IMRT (Intensity Modulated Radiation Therapy). Additionally, they are both equipped with various IGRT (Image Guided Radiation Therapy) technologies, CT, KV-KV matching and infraction external contour tracking. These imaging technologies support the delivery of precise customized and reproducible radiation treatments day after day.

Some patients may require a radiation treatment using radioactive materials injected or inserted temporarily or permanently into the body, which is known as brachytherapy. Brachytherapy is used alone or in conjunction with external beam radiation treatments to offer patients the best achievable outcomes such as HDR (High Dose Rate) gynecological insertions, HDR APBI (accelerated partial breast irradiation) via a balloon catheter and prostate cancer to list a few.

For more information on Pomona Valley Hospital Medical Center's Cancer Care Center, please call 909.865.9555.