Dr. David Perry, Radiation Oncologist

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

MedStar Health cancer specialists use radiation therapy in the following ways:

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

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

  • The type and size of cancer
  • Where it is located in your body
  • How close it is to normal tissue
  • How far into the body the radiation needs to travel
  • 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 kill 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. Possible side effects include

  • Mild fatigue
  • Skin discomfort within the margins of the area treated
  • 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
  • Sexual changes and fertility problems, when treating around the pelvis


At the MedStar Health Baltimore Cancer Network, we provide several forms of radiation therapy, including:

  • Brachytherapy destroys cancer cells from inside your body. You may have a small radioisotope container or wire temporarily inserted in 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.
  • 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.
    • 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.
    • 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. Standard treatment can involve five to six weeks of treatment; with IORT, a single dose is delivered in the operating room immediately following a partial mastectomy/lumpectomy.
  • 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. 

The specific type of radiation treatment you need often depends on where the cancer is located. Your team of radiation oncology experts 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. Read more about the types of radiation treatment available at MedStar Health.

MedStar Health Radiation Treatment Support

During your initial visit to the radiation oncology department, a nurse will provide you with general information about radiation therapy, as well as disease-specific information. Prior to beginning your radiation treatments, the nurse will discuss and provide information in writing about site-specific side effects and recommendations for managing those side effects.

During your radiation treatments, you will meet with the nurse and physician 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 physician 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, wigs, support groups, and more.

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