What Is Radiation Therapy?
About half of Australians and New Zealanders diagnosed with cancer each year may benefit from radiation therapy.
Radiation therapy, also called radiotherapy, uses radiation, such as high-energy x-rays, gamma rays, electron beams or protons, to kill or damage cancer cells and stop them from growing, in a way which spares the normal tissue around the cancer.
Professor Julia White is a tenured Professor of Radiation Oncology and Koltz Sisters Chair for Cancer Research at The Ohio State University.
She explained that radiation is an important part of breast cancer treatment for most patients.
“In breast cancer treatment, it’s used for every stage of breast cancer,” she said.
“In early stage breast cancer, the main focus of radiation is to help women keep their breasts.”
“We know the addition of radiation following a breast conserving surgery or a lumpectomy is really what makes the treatment equivalent of removing the breast.”
“In more locally advanced breast cancer, when the cancer has spread to the lymph nodes, it’s a barometer or a sign, that the cancer is at risk of spreading to the blood stream and causing distant metastases.”
“So, in node positive, armpit node positive breast cancer, we’re able to use radiation to treat the lymph nodes and reduce the chance of that cancer spreading through distant metastases.”
“And then the last way we use radiation, is when breast cancer is incurable, it’s metastatic, and patients and women are having pain or disrupting their lives with function problem because of pain, radiation can be used to help reduce the symptoms and improve quality of life in women with metastatic breast cancer.”
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Professor Julia White explains why it is an important part of breast cancer treatment.
How Much Radiation Is Given?
Professor White explained patient safety is the priority when deciding what dose of radiation should be given.
“To make radiation safe we have to divide the dose of radiation we want to give into many doses that are delivered Monday through Friday – five days a week and that allows the normal tissue surrounding the cancer to heal appropriately.”
“So, most radiation gets delivered for breast conserving therapy to help women keep their breasts. If they have early stage breast cancer it’s done in about three to four weeks, Monday through Friday. So, typically somewhere between 15 and 21 treatments is what’s used regularly.”
“When we treat the lymph nodes, that’s typically between 15 to 25 treatments Monday through Friday, five days per week.”
Professor White’s experience is in predominately in the United States and she said these doses can differ worldwide.
She said women will typically receive between three to five weeks of radiation. However, she said, it’s not as daunting as it sounds.
“That sounds miserable right. Five weeks of radiation.”
“You’re in the radiation centre for about an hour a day at most, and you’re on the radiation treatment table on average for about 20 minutes, the on time for the actual radiation machine is only between 8 and 12 minutes typically and you won’t feel anything, you won’t see anything, you hear the machine kind of click on and click off during the treatment.”
Side Effects Of Radiation Therapy
Professor White said most patients will suffer side effects from this treatment.
“Nearly every patient who goes through radiation therapy, either for breast conservation or because her lymph nodes have cancer cells in them, have symptoms from the radiation.”
Professor White said the skin is what takes the brunt of the radiation.
“By the end of radiation nearly 100% of patients will have some skin discoloration; usually redness of the skin or tanning the skin, the skin darkens and that can be really managed regularly early intervention with moisturisers, emollients and anti-itch creams to help keep patients safe.”
She said most women can manage these side effects through topical agents and over the counter medicines. However, there are treatments that can be prescribed from your treating physician if symptoms persist.
Research Into Radiation Therapy
Although radiation therapy is an established treatment in breast cancer, there is continuing research into how best to personalise the treatment.
“I think the goal of radiation oncology clinical trials in breast cancer is to figure out what radiation therapy strategy best fits the cancer and the patients individually.”
Now that we understand so much more about the biology of breast cancer, we think we can identify women who can have successful breast conservation with just having surgery.”
“Now that won’t be everyone, but there is a subset of patients out there.”
“For example, luminal breast cancers which are characterised by being hormone sensitive and particularly women who are dedicated to taking their endocrine treatment, we can identify biologically some that can be done with breast conservation after surgery.”
Another area of research is into how best to reduce the number of treatments for suitable patients.
“There is partial breast irradiation, which can be done somewhere between five and eight days of radiation and that reduces the burden of treatment.”
“What characterises all our clinical trials are trying to fit whatever the stage of cancer is and the needs of the patient, trying to make sure we have a strategy for radiation, that either means back off a little bit or enhances or intensifying a little bit, figuring that out is, I think, is where the goal of our radiation is right now.”
Breast Cancer Trials currently has one clinical trial investigating if some women with early breast cancer can avoid radiation therapy.
The EXPERT trial uses a genomic test of breast cancer tissue to identify which patients are suitable.
You can learn more about our open clinical trials here.
Professor Julia White
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