What is radiation therapy?

Radiation therapy uses high-energy radiation from x-rays, protons, gamma rays, or other energy sources to target and eliminate cancer cells or benign tumors. It works by damaging the DNA inside abnormal cells, preventing them from dividing, growing, and spreading. Radiation for cancer treatment may be used on its own or in combination with chemotherapy or other treatments, such as immunotherapy.

Virtually any type of cancer can be treated with radiation therapy. Your doctor will decide how and when to use it in your treatment plan:

  • Before surgery to shrink a cancerous tumor
  • After surgery to destroy any remaining cancer cells
  • In advanced stages of cancer to relieve symptoms

During your treatment journey, you’ll work with a team of highly skilled doctors, therapists, nurses, and providers with experience in radiation therapy. A radiation oncologist, who is a doctor with specialized training in using radiation to treat disease, will oversee your treatment. They’ll coordinate your care with other radiation therapy experts, including a medical physicist who makes sure the radiation equipment is working properly and the right dose is given, and a dosimetrist, who helps design and deliver exact dosage requirements. Each member of the team is trained to deliver treatment with precision and compassion to produce the best possible outcome while keeping you comfortable and informed.

Types of radiation therapy

There are two basic categories of radiation therapy: external radiation therapy and internal radiation therapy.

  • External radiation therapy is delivered by machines outside the body that send radiation beams into the body. This type of therapy is also known as external-beam radiation therapy. It includes a subgroup called stereotactic radiosurgery (SRS), a form of radiation therapy that uses specialized machines to deliver highly precise doses of radiation to treat certain cancers.
  • Internal radiation therapy is delivered by implanting small pieces of radioactive material directly inside the body, in or near a tumor. This type of therapy is also known as brachytherapy. Internal radiation therapy delivers intense radiation to a very small area of the body and limits the dose to healthy tissue.

Penn Medicine offers multiple radiation treatments within each of these categories.

Who receives radiation therapy?

Radiation therapy is an effective means of treating many types of cancers in almost any part of the body. Nearly two-thirds of cancer patients receive radiation during their treatment. It’s also used to treat some benign tumors.

For many patients, radiation is the only treatment needed. Though sometimes it’s combined with other types of treatment. There are several benefits of using radiation therapy:

  • It’s a localized treatment, meaning it targets a specific area of the body.
  • It can be used in the management of cancers that cannot be treated successfully by surgery or chemotherapy alone.
  • It can be used following surgery to eradicate existing cancer cells that couldn’t be removed.
  • It can reduce the size of a tumor so that it can be more safely removed or treated with chemotherapy during surgery.
  • It can be combined with chemotherapy to enhance the effectiveness of both treatments.
  • It can help control symptoms of a tumor by reducing pressure, bleeding, pain, and other distressing symptoms to enhance your quality of life.

Whether you need radiation therapy—and the type of radiation you need—depends on your general health and the type of cancer or tumor you have. Your doctor will determine when and how to include radiation therapy in your treatment plan and discuss treatment options with you.

What to expect during radiation treatment

Each type of radiation treatment has its own unique process. The overall process generally includes phases for planning, treatment, and follow-up care. Your radiation therapy team will prepare you for each phase and answer any questions, so you are comfortable with each step of your treatment plan and understand the process.

During the planning phase, you often have imaging tests to identify the size and shape of the tumor. This informs your exact radiation plan. You may also take part in a simulation test in a treatment room to be sure that the machine setup is accurate, and you are properly positioned to receive treatment.

The radiation treatments themselves are typically given in small daily doses on a schedule that your doctor specifies. This gives normal cells time to heal and reduces possible side effects. During the treatment period, you’ll meet with a doctor regularly to assess side effects you may be experiencing. Your doctor may adjust the radiation treatment plan or treat your side effects if needed. If side effects become severe, treatment may be put on hold to allow the tissue time to heal before continuing. Be sure to discuss questions and concerns with your team throughout treatment.

You’ll also have follow-up care after treatment is complete. Your doctor will evaluate your post-treatment health and suggest any further treatment or screening that can help address any lingering symptoms and keep you healthy.

Radiation therapy side effects and recovery

Radiation therapy does not hurt when it’s being administered, though you may experience pain or discomfort during your recovery period. This is because radiation that damages or destroys cancer cells may also hurt healthy cells, producing side effects. These side effects vary and depend upon your health history and the treatment site.

Many side effects of radiation therapy are considered acute or short term because they occur during treatment and tend to resolve within a few months after therapy is completed. Occasionally, patients develop chronic side effects. Your care team will monitor you for extended periods of time after treatment to evaluate you for long-term side effects and provide additional support and treatment if needed.

Experts in radiation oncology

When you need cancer care, you want the latest treatment options delivered by top cancer specialists with proven expertise. At Penn Medicine, you’ll find radiation oncologists who are leaders in research-backed patient care. We offer virtually every treatment option available in radiation therapy, with sophisticated technology and years of experience in treatment planning. Using specialized techniques, our cancer experts maximize the effects of radiation to eliminate abnormal cells while reducing exposure to healthy tissues.

When you come to Penn Medicine for radiation therapy, you can expect:

  • Up-to-date treatment options for virtually any type of cancer that can be treated with radiation
  • Conventional and emerging therapies, so you have access to the radiation treatment options that are best for you
  • Nationally accredited facilities with a commitment to exceptional safety and care standards
  • A multidisciplinary team of radiation oncologists, radiation physicists, dosimetrists, radiation therapists, and radiation oncology nurses, who deliver exceptional patient care

The latest cancer radiation technologies for enhanced care

We continually update our facilities to include the latest radiation technologies. This includes the addition of a Varian Ethos linear accelerator machine at Chester County Hospital. This adaptive radiotherapy technology uses artificial intelligence to create a personalized treatment plan for each patient. As treatment is delivered, the Variant Ethos machine adapts the radiation treatment to changes in a tumor’s size and shape in real time, helping to track even tiny movements in a tumor as they happen. This enables our care team to target radiation beams more precisely to cancerous tumors, which leads to fewer complications, better outcomes, and speedier treatments.

National Cancer Institute Designated Comprehensive Cancer Center badge on top of shot of hospital

Rated “exceptional” by The National Cancer Institute

Penn Medicine’s Abramson Cancer Center is a world leader in cancer research, patient care, and education. Our status as a national leader in cancer care is reflected in our continuous designation as a Comprehensive Cancer Center by the National Cancer Institute (NCI) since 1973, one of 7 such centers in the United States. The ACC is also a member of the National Comprehensive Cancer Network, one of a select few cancer centers in the U.S., that are working to promote equitable access to high-quality, advanced cancer care.

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