Radiation Treatment

What is radiotherapy?

Radiotherapy is a treatment that kills cancer cells using ionizing radiation. Radiation is capable of inflicting damage at the DNA level of a cell and can stop cells from reproducing.


How does radiotherapy work?

Radiotherapy works by killing breast cancer cells directly on exposure to the radiation beam. Normal human cells are able to recover from radiation damage to a much more efficient degree than cancer cells. Therefore, radiation treatment is able to kill cancer cells selectively while allowing normal cells to recover.

In most cases, radiotherapy treatment can be given after surgery or chemotherapy. It is a procedure to destroy any cancer cells that may remain and it helps reduce the risk of recurring.


Who needs radiotherapy? 

For breast cancer patients, radiotherapy treatment to the breast is needed when the tumour is treated by breast conserving surgery (local excision of the tumour and axillary lymph node surgery preserving the breast). This applies to all patients with invasive breast cancer and most patients with in-situ cancer. Radiotherapy is also needed by some patients who have mastectomy, if the tumour is locally advanced, for example large tumour size or with multiple lymph nodes showing cancer, or where cancer cells are formed in the lymphatic or blood vessels. These indications are irrespective of whether the patient to receive chemotherapy or hormonal therapy as well.


How is it carried out?
Before starting radiotherapy treatment, the patient needs to visit the radiotherapy centre, where “planning” (i.e. preparation of treatment) is carried out. The planning is an initial simulation procedure which usually takes 45 - 60 minutes. The oncologist will use a special X-ray machine called the simulator to "sketch out" the target of treatment (the breast, and in some cases, the regional lymphatics as well). A CT scan planning procedure is currently used in many patients. Marks are put on the skin to direct the radiation beams. These marks are small and patient is advised to be careful not to wash them off for the duration of the treatment period. In some cases, the marks may be permanent (tattoo). Radiotherapy treatment is delivered daily and usually involves around 25 to 30 treatments over a period of 5 to 6 weeks.


What are the likely side effects?
Radiotherapy does not make patients radioactive. Receiving radiotherapy is painless and side effects of radiotherapy are site-related only. Loss of hair, mouth ulcers, dry mouth, vomiting or diarrhea will not occur in breast cancer patients receiving radiotherapy to the breast, chest wall or axilla. The likely side effects of radiotherapy are:


During radiotherapy:
Erythema: The skin on the breast will become red and dry, much like sunburn. This can begin from the second week of treatment, and usually improves a few weeks after completing treatment. 

Nursing tips:

  • Protect the skin of the radiated area from physical or chemical damage.
  • Do not rub the radiated area but gently pat the skin dry after washing.
  • Bathing is not recommended.
  • Avoid using deodorants, perfumes, oil or talcum powder (baby powder).
  • Avoid products that contain alcohol or menthol as they remove natural lipids and worsen skin’s reaction to the treatment.
  • Avoid adhesives.
  • Avoid extremes of temperatures around the radiated areas, such as hot water packs or ice packs.
  • Do not expose the radiated area to direct sunlight.
  • Protect the radiated area from injury. Avoid wearing tight clothing, bra and jewelry.

Desquamation: The radiated skin may start to peel or blister towards the middle or end of the treatment as the skin’s epithelial barrier becomes loosened by the radiation. This usually settles within weeks of completing treatment.

Nursing tips:

  • Follow the above nursing tips and inform the oncologist if you are showing symptoms of desquamation.
  • Apply topical hydrogel or cream if prescribed. Dressing may be needed for moist desquamation.

Tiredness: The patient may feel tired for about a week or so after starting radiotherapy. This may last for a few weeks after completion of the treatment. Observe your body’s reaction and take rest if necessary.


Darker skin: The radiated area looks darker than usual. This may last for a few months after completion of treatment, but the colour will fade with time.


After radiotherapy

  • The breast will become firmer in the first year after radiotherapy treatment, and will usually soften again.
  • In patients who require radiotherapy to the axilla--where surgery has been performed, a certain degree of swelling (lymphoedema) of the arm may occur. Patients are advised to consult the oncologist or nurse for lymphoedema prevention information.
  • In very rare cases patients may develop pneumonitis (inflammations of the lungs) after completion of radiotherapy.
  • Patients who have radiotherapy to the left side of their chest may encounter side effects on their heart many years later. However, with the advancement of planning and treatment techniques the risk of this may be much reduced or avoided altogether.


Special thanks to Dr. Peter Choi for editing.