From The Straits Times    |

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What’s the difference between radiotherapy versus chemotherapy? If your knowledge of medical jargon is (like us) rudimentary at most, then it’s a question that may stump you. In fact, a quick survey of our Her World team revealed that we were equally – for the lack of a better word – clueless about these treatments. 

“Radiation therapy uses high energy x-rays to safely treat and manage cancer by destroying cancer cells, thus reducing the growth and spread of cancer,” explains Dr Choo Bok Ai, a senior radiation oncologist in private practice in Singapore.

On the other hand, chemotherapy uses powerful, anti-cancer chemicals/drugs to kill the fast-growing cancer cells in your body. 

He adds: “Radiation therapy attacks cancer cells while limiting damage to healthy cells, as cancer cells are more sensitive to radiation.”

But what about the efficacy of radiotherapy vs chemotherapy? Are there instances where one treatment is better than the other? According to Dr Choo, these treatments are not mutually exclusive. For example, “radiation can be given alone or in combination with chemotherapy.”

“Depending on the cancer profile, chemotherapy can enhance the effect and impact of radiation therapy by 9% to 26% when given together, for example, in the treatment of lung, oesophagus, head and neck and cervix cancer. Chemotherapy on its own is used in Stage 4 cancers when the cancer has spread widely or as an additional treatment after surgery to prevent a recurrence in the body. 

“In comparison, radiation is used to prevent local recurrence after surgery. For example, radiation is given after a lumpectomy, which is partial removal of breast tissue, in order for the patient to avoid a mastectomy, which is removal of the whole breast. Using radiation after a lumpectomy helps to preserve the breast from unnecessary removal with the same control rate for the cancer,” he says.

Below, he elaborates on the latest advancements, as well as the common concerns and misconceptions about the treatment.

Dr Choo Bok Ai, a senior radiation oncologist in private practice in Singapore.

Tell us more about the latest advancements in radiotherapy.

Radiotherapy has evolved to become much more precise than one to two decades ago. New technologies such as machine learning and AI allow us to tailor treatment plans to the individual. We can even update radiologists in the treatment room if there are changes to the patient’s physiology.

Stereotactic radiosurgery for brain tumours such as HyperArc has advanced significantly. These solutions allow doctors to treat up to 20 tumours within a few minutes, with each cancer being targeted individually This not only provides a quicker treatment for the patient but also less side effects. 

Previously, these many tumours would have required whole brain radiation which comes with significant cognitive side effects. 

It is said that radiation therapy has fewer side effects than chemotherapy. Is this true?

The side effects from radiation therapy differ slightly from chemotherapy. 

As radiation therapy is targeted to a specific area of the body, patients often experience side effects at that particular area. For example, for head and neck cancers, the side effects will be limited only to the head and neck area.

Inflammation on skin: Common early side effects experienced during radiation therapy occur due to inflammation. For example, the skin can become red and dry and occasionally peel. These skin reactions will usually resolve a few weeks after treatment has finished. 

Feeling tired: Fatigue is another common side effect and a patient will also experience this side effect from chemotherapy. The amount of fatigue will vary for each individual and does not usually affect the patient’s daily activities greatly. 

Hair loss: This is a common side effect from chemotherapy. However for radiation therapy, hair loss may occur if the targeted area is the head area. The hair can grow back in time.

Most of the side effects from radiation therapy occur while the treatment is in progress and will resolve quite quickly after the treatment ends.

What is the treatment cycle like for radiation therapy patients?

Treatment is usually provided each day (Monday to Friday) over a number of weeks, which allows the radiation to target cancer cells and provides healthy cells with enough time to recover over the weekend. The course of radiation therapy is unique and tailored for each individual, depending on the location and stage of disease, type of cancer, age and general health.

The usual radiation treatment schedule for breast cancer after surgery is two weeks for early breast cancer and three to four weeks for more advanced stages. 

When no surgery is performed and the stage of cancer is more advanced, for example, in head and neck cancers, lung or prostate, the length of a course of radiation can be over six to seven weeks. 

What are the common concerns about radiation therapy?

For head and neck cancer, common side effects of radiation are skin burn, mouth ulcers or a sore throat affecting the ability to eat. All patients do get a certain degree of these side effects but severe effects leading to hospital admission for hydration or insertion of a feeding tube is rare. 

This is certainly different compared to radiation done 20 years ago, when most patients would have required a feeding tube. With advancement in the hardware and software used to deliver radiation, the radiation dose can be adjusted to avoid high doses to the oral cavity, throat and salivary glands. Most patients’ symptoms improve within one to two weeks upon completion of treatment and are well managed with a soft diet, oral mouthwash and pain killers. 

In breast cancer, the side effects are much less with only skin redness as the most common concern. Nowadays, the radiation dose can be adjusted so that painful skin peeling can be avoided. Regular moisturisers will be given to apply during the radiation treatment to minimise the side effect. 

Dr Choo is a senior radiation oncologist in private practice with 20 years of experience in cancer treatment. He is the current chairman of the Chapter of Radiation Oncology, Academy of Medicine.