External Beam Radiation Therapy

External beam radiation therapy is mainly used to treat different types of cancer. The beam is applied to the affected area only, and radiation is used to kill the cancer cells.

Alternate name

External beam radiation therapy is also known as:

• 3D-CRT (conformational radiation therapy)
• IMRT ( intensity-modulated radiation therapy)
• IGRT (intensity-guided radiation therapy)

Body location:

The radiation beam is guided to the tumour site externally on the affected area, e.g., in the case of lung cancer, radiation therapy is given only to the chest region.

Procedure Type:

External beam radiation therapy is a non-invasive procedure.

How External Beam Radiation Therapy is Performed:

External beam radiation therapy is usually carried out in the daycare department, and a night stay is not required. Prior to the procedure, the doctor will explain in detail the procedure and suggest some tests. This involves blood tests, imaging tests, ECG, X-rays, etc. The doctor will explain the risks, side effects, recovery time, and process and ask the patient to fill up a consent form if they agree to the radiation therapy. The radiation oncologist will mark the treatment area and take a few X-rays and scans of the area. This will help the oncologist gauge the condition of the tumour, its size, and surrounding organs. Based on these reports, the oncologist will then decide the dosage, frequency, and duration of radiation therapy. Usually, the area identified for radiation is marked permanently so that in the following doses, the exact area is identified easily, and any other area is not involved.

Preparation for External Beam Radiation Therapy:

Before commencement of treatment

• The patient has to change his dress and put on the hospital gown.
• The patient is then taken to the radiation room, which has a very low temperature.
• The patient may be asked to lie down or sit depending on the cancer location.
• The external area surrounding the tumour will be marked. In case radiation is to be given to the head/neck region, a face mask is to be used.
• Before the radiation, the area will be lit up using an external colored light source.
• The patient must be calm and be still throughout the procedure.
• Each radiation varies typically between 1-5 minutes.
• The entire procedure takes about 1-2 hours in the hospital.
• The technician, after placing the patient in a proper position, will go to the adjacent control room to switch on the machine. During the entire duration, the technician will observe the patient on a TV screen and talk to him if needed through a microphone.
• The patient will be informed once the process is over, and the technician will take them to the recovery room.

Follow-up

After completing the procedure, the patient is taken to the recovery room and is advised to rest. Normally, there might be signs of nausea, fatigue, dizziness, and headache after the therapy, but these symptoms usually disappear after 2-3 hours. The patient is advised to have lots of fluids. Thereafter, the patient is kept on medication as prescribed by the oncologist. Follow-up visits are to be taken as scheduled by the doctor.

Risks of External Beam Radiation Therapy:

• Brain- fatigue, nausea, vision loss, memory loss, hair loss
• Breast fatigue, hair loss, skin irritation, nausea, oedema
• Chest- loss of Breath, fatigue, nausea, cough
• Head and neck- Fatigue, nausea, headache, dizziness
• Pelvis- fatigue, nausea, diarrhoea, fertility problem, urination problem

Recovery

The recovery process after completion of the procedure varies from a few months to years. This depends on the tumour size, malignancy, organs involved, etc. The schedule typically involves five days a week, with weekly breaks. This time also helps the normal cells to grow and recover. This goes on for 1-2 months, depending on the tumour condition and the doctor's treatment method. In cases where there is no malignancy and cancer has not spread to other organs, good results have been observed. The doctor decides, based on the scan reports, whether the tumour is present or has ceased to exist. However, radiation therapy is a very effective method of fighting cancer and increasing life expectancy.