Radiation Oncology

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Radiation oncology is a cancer treatment which employs high-energy x-rays or other particles to destroy cancer cells. Radiation oncologists are medical professionals who specialize in applying radiation therapy as a cancer treatment. Typically, a radiation therapy plan or program includes a set number of sessions spread out over a specified amount of time.

Many different forms of cancer can be treated with radiation treatment. Additionally, it can be used along with additional treatments for cancer including chemotherapy and/or surgery. Cancer patients might receive radiation therapy alone or in combination with other treatments including surgery, chemotherapy, or immunotherapy.

Sometimes the doctor may give radiation therapy before surgery to shrink the tumor. This treatment can also be utilized after surgery to prevent the cancer from coming back. Sometimes radiation therapy takes place before chemotherapy. Other times it is combined with chemotherapy. Depending on the type of cancer, the doctor may combine radiation and cancer treatment to improve the effectiveness of both.  (1,2)

Radiation Oncology Residency

Definition and Overview

Radiation oncology therapy is used to kill cancer cells using carefully targeted and regulated doses of high-energy radiation. Radiation causes some cancer cells to die soon after treatment. In some cases, however, most cancer cells die or become inactive as a result of radiation damage to their chromosomes and DNA. The radiation oncology team usually consists of a radiation therapy nurse, radiation therapist, dosimetrist, and medical physicist.

Radiation therapy often targets a localized area of the body, as opposed to other cancer treatments like chemotherapy that include the entire body. This indicates that it typically just affects the part of the body where the cancer is located. While treatment may cause some healthy tissue close to the cancer cells to suffer harm, this tissue normally recovers once treatment is over. (3,4)


Many types of cancer can be treated with radiation treatment. Radiation therapy will be given to more than half of cancer patients. Radiation therapy alone can be a successful treatment for some cancers. Combination therapies work better for other cancer types. Recurrent cancer and metastatic cancer (cancer that has spread to other places of the body) can both be treated with radiation therapy. Radiation oncology therapies include;

  •  External-beam radiation therapy

External beam radiation therapy is the most used kind of radiation treatment. Radiation is given from a machine outside the patient's body. When necessary, it can be applied to treat large areas of the body.

For x-ray or photon radiation therapy, a device known as a linear accelerator, or linac, produces a radiation beam. The size and form of the beam are modified by specialized computer software. Bypassing neighboring healthy tissue, this makes it easier to target the tumor.

For several weeks, most radiation therapy treatments are administered every working day. For radiation therapy to the head, neck, or brain, a plastic net mask or form-fitting braces are used to keep patients immobile and guarantee that the beam hits the same spot each session.

There are different types of external beam radiation therapy available, including

  • Three-dimensional conformal radiation therapy (3D-CRT)
  • Intensity-modulated radiation therapy (IMRT)
  • Proton beam therapy
  • Image-guided radiation therapy (IGRT) 
  • Stereotactic radiation therapy (SRT)

The type of external-beam radiation therapy is selected based on the patient's cancer status, location, and health status.

  •  Internal radiation therapy

Internal radiation therapy is additionally referred to as brachytherapy. When radioactive material is applied to the cancer or surrounding tissue, radiation therapy of this type is used. In this type of treatment, radiation-containing seeds, ribbons, or capsules are injected into or close to the tumor in the body. Implants can be either temporary or permanent. The procedure may necessitate a hospital stay. The types of internal radiation therapy include 

  • Permanent implants
  • Temporary internal radiation therapy (5)


Radiation therapy can be used to treat many cancer conditions. Radiation therapy types, usually administered to cancer patients for

  • curing or shrink early-stage cancer,
  • preventing cancer from coming back (recurring) somewhere else,
  • treating symptoms caused by advanced cancer,
  • recurring cancer that has returned. (6)

Risks and Side Effects

Radiotherapy may damage some healthy cells in the area being treated in addition to eliminating cancer cells. This therapy may cause some risks and side effects, including;

  • a sore mouth
  • diarrhea
  • painful skin that may turn the color red, lighter, or darker than normal skin tone
  • hair loss in the treated area
  • feeling sick
  • feeling tired
  • lose of appetite

Most of these side effects and risks can be prevented or treated, and the majority disappear once therapy is over. As the radiation passes through the patient's body, receiving external radiotherapy does not render the patient radioactive. It may be required to stay in the hospital for a few days as a precaution and avoid close contact with others because radiation from implants or injections can persist in the body for several days. (7)

Post-Procedure and Follow-up

There will be follow-up appointments with the radiation oncologist after the course of treatment is finished. Maintaining follow-up care is crucial. The medical staff will want to assess the patient's progress and keep an eye out for any treatment-related adverse effects, which might not manifest right away.

Less frequent follow-up visits can be required as the body heals. When managing long-term health care, asking the doctor for a written record of the treatments the patient received might be helpful.


Radiation therapy has a diverse effect on various people. These effects can differ from person to person, even with the same type of treatment. Before starting therapy, the patient should inquire with the medical staff about any potential and important physical adverse effects. It's possible to encounter emotional side effects as well, and getting mental health care can help with anxiety and stress. 

To fully recover, the patient should speak with the medical staff about how to take care of themselves throughout treatment, including getting enough rest, eating well, and staying hydrated. Regular physical activity or workouts should be performed under management. In the recovery process, when adverse symptoms initially occur, get worse, or continue despite therapy, see a doctor.


After radiation therapy finishes healthy cells that have been damaged typically make a full recovery within a few months. However, sometimes people can have side effects that do not improve. After radiation therapy has finished, more side effects could appear months or years later. They are referred to as late effects. The part of the body being treated, other cancer treatments taken, genetics, and other factors like smoking all affect whether and what late effects will happen. The patient should carefully follow the doctor's directions to get the greatest results.