Radiation Therapy | What is it? | MedStar Health
Health professionals of radiation therapy

What is radiation therapy?

Radiation therapy is one of the primary treatments for many cancers and is prescribed for more than one-half of cancer patients. It uses high-energy radiation beams (including X-rays, gamma rays, electrons, and protons) to attack cancer cells. Following your treatment, you will have periodic scans to determine how your cancer responded to the radiation therapy. Sometimes, the results from the therapy are immediate. Other times, it takes weeks or months for the cancer to respond.

Your therapy will be managed by a radiation oncologist, a doctor who specializes in the use of radiation to treat cancer.

How it is used

MedStar Health cancer specialists use this type of therapy in the following ways:

  • Primary treatment: The only treatment needed to destroy the cancer cells (Certain cancers do not respond to or need surgery, so radiation is an option)
  • In conjunction with chemotherapy: When radiation and chemotherapy are given together, it’s called chemoradiation or chemoradiotherapy
  • Neoadjuvant radiation: To shrink a tumor as much as possible before surgery, often in conjunction with chemotherapy
  • Adjuvant radiation therapy: Radiation after surgery to keep cancer from returning
  • Intraoperative radiation therapy: Radiation during surgery
  • Symptom relief: To relieve certain symptoms of the cancer

The type of therapy prescribed depends on many factors, including:

  • The type and size of cancer
  • Where the tumor is located in your body
  • How close it is to other organs
  • What other kinds of cancer treatment you will need or have received
  • Your general health and medical history

Side effects

High doses of radiation attack and destroy cancer cells but may also affect some healthy cells in the process. This may cause side effects. Radiation side effects vary for different people and depend on the kind of cancer you have and the part of your body the radiation is targeting.

The two most common side effects of this type of therapy are fatigue and changes in the color of the skin in the radiated area. Your skin may become dry, pink, or itchy. Other possible side effects include:

  • Hair loss
  • Mouth discomfort, when treating the area around the mouth
  • Throat discomfort, when treating the head and neck area
  • Nausea and vomiting, when treating around the stomach
  • Diarrhea, when treating around the abdomen and pelvis
  • Sexual changes and fertility problems, when treating around the pelvis


MedStar Health provides several radiation techniques and technologies:

  • Accelerated partial breast irradiation (APBI) is an advanced method of high-dose radiation used for select breast cancer patients after a partial mastectomy/lumpectomy. It delivers radiation to the area where the tumor was removed and eliminates the need for whole breast radiation.

  • Brachytherapy destroys cancer cells from inside your body. You may have a small radioisotope container or wire temporarily inserted into the tumor.

    • Internal radiation, or low-dose rate (LDR) brachytherapy, delivers radiation to your tumor from inside your body. Your doctor places small radioactive pellets or seeds into the tumor area. The pellets, or seeds, release targeted doses of radiation at precise locations.

    • For high-dose rate (HDR) brachytherapy robotic delivery, a radioactive source attached to a wire is controlled by a robotic machine. The robotic machine strategically guides the delivery of the radiation into the tumor and then removes it after the treatment session.

  • Edge Radiation Technology: Using advanced cancer treatment technology, this system offers patients a fast, effective, non-invasive option for treating tumors without incisions or the need for overnight hospital stays.

  • Electron beam therapy uses energy from electrons instead of photons to limit high-dose radiation to the skin surface.

  • External beam therapy uses a linear accelerator to aim high-energy radiation beams at your cancer from outside your body. Our specialists focus these beams directly on your cancer, avoiding unnecessary damage to your healthy tissue. External beam therapy is the most frequently used treatment for breast cancers.

    • 3D conformal radiotherapy sculpts radiation beams to the shape of a tumor. This is ideal for tumors that have irregular shapes or for those that are close to healthy tissues and organs. We view a tumor in three dimensions with the help of advanced imaging. Based on the dosimetry or treatment plan, we then deliver radiation beams from several directions to the tumor.

    • Image-Guided Radiation Therapy (IGRT) uses high-quality imaging technology to create pictures of a tumor during the radiation procedure. Using these images, your radiation oncology team carefully adjusts radiation beams and doses during the procedure to best fit the size, shape, and location of the tumor, while sparing normal tissues. IGRT can integrate respiratory motion technology to track the exact position of a tumor while a patient is breathing. IGRT is primarily used for patients whose tumors are directly adjacent to critical structures when an immediately adjacent area has been previously irradiated or when dose escalation is planned and where conventional means of targeting are deemed to be inadequate.

    • Intensity-modulated radiation therapy (IMRT) uses devices that allow the radiation beamlets to move and change intensity depending on what kind of tissue they are targeting. This flexibility allows different areas of a tumor to receive different amounts of radiation and helps protect surrounding healthy tissue from unnecessary radiation exposure.

  • Intraoperative radiation therapy (IORT) is a single-dose radiation alternative for women with early stage breast cancer. IORT is directed at the tumor bed and delivered in the operating room immediately following a partial mastectomy/lumpectomy. In contrast, standard radiation treatment can involve 5 to 6 weeks of treatment.

    IORT can also be used for pancreatic cancer and other related tumors. The treatment is given during surgery and applied directly to the targeted area or tumor, ensuring that normal surrounding tissue is spared.

  • Proton beam therapy uses energy from protons instead of photons, allowing high-dose radiation with no exit dose, which may be optimal in certain situations or for certain tumor locations. MedStar Health offers the latest type of proton therapy available with HYPERSCAN™ technology.

  • Systemic radiation therapy addresses your entire body, not just a targeted area. The substance is chemically targeted to address cancer cells. This is often utilized when the cancer is in multiple locations in the body.

  • Stereotactic Radiosurgery (SRS) and Stereotactic Body Radiation Therapy (SBRT) deliver large doses of highly focused radiation to the tumor site, sparing as much surrounding healthy tissue as possible.

    • CyberKnife® is an advanced technology that uses robotic technology to administer this radiation therapy anywhere in the body, even in places previously considered unreachable.

    • ZAP-X® is modern radiosurgery designed to treat brain tumors. MedStar Health is just one of a few health systems in the world to offer this technology.

The specific type of treatment you need often depends on where the cancer is located. Your radiation therapy team will evaluate your case and develop a treatment plan that is most effective for you. We will also help you manage the possible side effects of radiation treatment.


During your initial visit to the radiation oncology department, you’ll meet your doctor, a radiation oncologist, who will review your pathology, diagnostic images, medical history, and pertinent laboratory data and will also examine you. Based on this information, the radiation oncologist works together with your other oncology specialists and doctors and with you to develop your treatment plan. 

If radiation therapy is recommended, we’ll schedule a special planning session with you. A radiation oncology nurse will provide you with general information about radiation therapy, as well as disease-specific information. Prior to beginning your treatments, the nurse will discuss and provide information in writing about site-specific side effects and recommendations for managing those side effects.

During your treatments, you will meet with the nurse and doctor weekly to review your response to treatment and assess side effects that you may have developed. During these weekly visits, you will have an opportunity to ask the nurse and doctor questions.

We understand that patients who are managing cancer need support beyond the clinic. We have a variety of patient and family support services, including nutritionists, social service counselors, financial counselors, psychosocial counselors, support groups, and more.

Frequently asked questions

  • Will I be able to work during radiation treatments?

    Your ability to work while receiving therapy will be dependent upon the area being treated. Your doctor can explain any restrictions you will have during treatment.

  • Will I be able to drive or should someone come with me to my treatments?

    In most cases, you’ll be able to drive yourself to and from treatment, but you’ll want to discuss this with your doctor first to be sure.

  • Will I be able to choose my treatment time?

    We will make every effort to offer you a time slot that fits your schedule.

  • Can I drink alcoholic beverages while under treatment?

    Social drinking (one to two drinks) may be allowed for some patients, but you should discuss this with your doctor.

Our providers

Radiologist and medical technician at the computer tomography getting a scan

Expert radiation therapy care

Getting the care you need starts with seeing one of our radiation therapy specialists.