Radiation Oncology Victoria

Why is radiotherapy given for breast cancer?

Breast radiation therapy is a local treatment targeted at the breast and sometimes the surrounding lymph node area to destroy any stray cells (pink dots in diagram to left) that may have been left behind to reduce the chance of a recurrence. It is sometimes also given after a mastectomy, but only if there is a high risk of a local recurrence.

Patients who need systemic therapy, such as chemotherapy, may receive their radiation after chemotherapy is completed. The oncologist, breast surgeon, radiation therapist, and plastic surgeon (if reconstruction after mastectomy is planned) will work together to decide the best sequence of treatments.

What does radiotherapy for breast cancer involve?

Prior to commencement of radiation therapy in a process called simulation, the radiation oncologist designs a specific and individualised treatment for the patient, using a special CT scanner to image her in the same position that will be used for the course of treatment. This type of simulation was pioneered as a routine part of breast radiation therapy planning in Australia by Radiation Oncology Victoria (ROV) since 1999.

The ability to acquire imaging data digitally allowed the radiation oncologist together with his team of radiation therapists and physicists to choose the best beam directions that target the area at risk without exposing nearby healthy organs such as the lungs and heart to significant radiation. In addition, it also allowed for more technically advanced forms of radiotherapy for breast cancer treatment.

Highly conformal radiotherapy for breast cancer

Highly conformal radiotherapy, available at all ROV centres, is used to deliver a uniform or homogenous dose to the breast, and in special circumstances, can be used to limit the radiation dose to critical normal organs such as the heart. The ability to provide a uniform or homogenous dose to the breast will eliminate radiation "hot spots" within the breast that can sometimes exceed 10-15% of our prescribed radiation dose. If uncorrected this will lead to higher skin side effects during (such as skin burning) and after (such as thickening of the breast) the radiation. The use of more conformal radiotherapy will minimise the potential of these side effects. There is also a well-established relationship between radiation dose to the heart from collateral radiation exposure and the risk of future heart attacks. As such the ability of radiation oncologist to minimise and in the majority of patients exclude radiation exposure to the heart will reduce or indeed eliminate this side effect.

Standard radiotherapy versus highly conformal radiotherapy

Above is a comparison of planning scan for breast cancer of the right breast. "A" represents a standard radiotherapy plan, while "B" is a highly conformal plan for breast cancer.

The colors represent the dose levels: blue and red presents the ideal dose distribution, whereas orange and green represent undersirable higher doses, called "hot-spots". With standard plan A, there is a wider range of dose including "hot-spots". Compared to the more desirable conformal Plan B, there are minimal to no "hot-spots" and a more even, homogenous distribution of ideal dose in blue and red.

Individualised treatment

At ROV, we have taken pride in the provision of individualised radiation treatment planning for our patients for 10 years. Once this plan has been finalised, the patient starts her course of therapy, coming five days each week for up to six and a half weeks. Each sessions requires the patient to lie on her back, and it approximately takes 10 minutes.

Is breast radiotherapy safe?

Radiation treatments today are very precise, and there is little harm to surrounding skin or tissues. The treatments are generally very well tolerated, but after the third week or so there may be some side effects, such as a sunburn-like effect on the skin, fatigue, discoloration of the skin, or swelling and heaviness in the breast. In some women the breast becomes smaller and firmer. Some of these effects wear off, while others may last a few months. The patient's skin may be marked with tiny tattoos so each treatment can be aimed at precisely the same region.

Where is breast radiotherapy available?

All of our centres in Melbourne and Albury-Wodonga offer state-of-the-art radiotherapy for breast cancer.