Side Effects of Radiotherapy

There are numerous types of cancer treatment. Your doctor may recommend chemotherapy, radiotherapy, surgery, or a combination of these treatments if you have been diagnosed with cancer.

The choice of treatment depends on the type and stage of cancer. Fortunately, you will be able to make this decision with your doctor who would guide you through every step of the process.

This article discusses the side effects of radiotherapy so that you can make an informed decision about the treatment options available.

What is radiotherapy?

Radiotherapy or radiation therapy uses high-energy beams such as X-rays to kill cancer cells.

A radiotherapy regimen typically consists of a certain number of treatments administered over a predetermined time frame.

Radiotherapy is effective against numerous types of cancer. Additionally, it can be administered in conjunction with surgery and/or chemotherapy.

How does radiotherapy treat cancer?

Radiotherapy destroys the DNA of cancer cells with high energy or ionising radiation. In contrast to other cancer treatments, radiotherapy is a localised cancer treatment and often only affects the area where the cancer is located.

During the treatment, some healthy tissue close to the cancer cells may be affected but usually recovers when treatment ends.

Radiotherapy can be used:

• Before surgery to shrink tumour size
• After surgery to destroy the remaining cancer cells
• In combination with radiotherapy for more effective treatment
• Symptomatic relief if no cure is possible (palliative radiotherapy)

What are the types of radiotherapy?

Radiotherapy may be administered as:

1. External radiotherapy

External radiotherapy utilises a machine outside the body to aim radiation beams at the cancer cells to destroy them.

Types of external beam radiotherapy include:

• Conformal radiotherapy - Also known as 3D conformal radiotherapy (3D-CRT), this treatment fits the radiation beams to the cancerous area while avoiding the healthy surrounding tissue.
• Intensity-modulated radiotherapy (IMRT) - This is a more complex type of radiation treatment. It delivers varying levels of radiation that target the cancerous area better than 3D-CRT.
• Image-guided radiotherapy (IGRT) - X-rays and scans are used to ensure that the radiotherapy beams are delivered accurately. The radiation is positioned precisely based on the images taken prior to and during therapy.
• Stereotactic radiotherapy (SRT) - This treatment delivers radiotherapy from different angles to shrink or destroy a tumour while minimising damage to healthy cells.
• Proton beam therapy - In this treatment, low or high-energy proton beams are used to destroy cancerous cells.
• Superficial radiotherapy - This treatment is usually used for cancer close to or on the skin surface. This type of radiotherapy does not penetrate deeply into the body.

2. Internal radiotherapy

Internal radiotherapy delivers radiation from inside one’s body. Types of internal radiotherapy include:

• Brachytherapy - A radioactive implant or source is placed in your body close to or into the cancer. The radioactive material can be left for a few minutes, days, or even permanently.
• Radioactive liquid treatment - This will include radionuclides or radioisotopes. It can be taken as an injection, drink, or capsules.

What are the side effects of radiotherapy?

The side effects of radiotherapy can be short-term or long-term. However, most symptoms can be prevented or treated. The severity of side effects varies for different individuals. Discuss with your doctor the side effects and the management before starting the treatment.

Common side effects of radiotherapy

You might feel fatigued and lack energy during the course of treatment, and this may continue for a few weeks after the treatment ends. This can be due to:

• Decreased levels of red blood cells, resulting in anaemia.
• Journeying to the hospital or clinic for treatment daily.

Do get sufficient rest and engage in light exercises such as taking short walks to help you increase your energy level. Ask your family and friends for assistance with daily tasks.

Reach out to your doctor immediately if you are breathless or feeling extremely tired.

You might experience skin changes in the treatment area, including:

• Dry and itchy skin
• Blisters
• Sensitive skin
• Red or darker skin

Your doctor may recommend using a non-fragranced moisturiser if your skin is dry or itchy. Additionally, you should use sunscreen with a minimum of SPF 50 for at least one year after completing your treatment.

A typical side effect of radiotherapy is hair loss. Radiotherapy may result in hair loss only in the treatment area, unlike chemotherapy.

A few weeks after treatment ends, it should begin to grow back, although it may have a little different colour or texture than what it was previously.

Occasionally, a high dose of radiotherapy may result in permanent hair loss. Before beginning therapy, ask your physician if this is a risk.

Nausea and vomiting during radiotherapy can reduce your appetite resulting in weight loss. However, it is vital to maintain a healthy diet and weight. Inform your doctor if you are not eating enough. They may be able to give you tips to consume frequent small meals or recommend a dietitian.

Radiotherapy can be a tiring and stressful affair. It is normal to experience anxiety and question your treatment's efficacy. Communicate with your healthcare team if you are struggling emotionally, and they will be able to provide support and discuss treatment options.

Common side effects of radiotherapy

Long-term side effects of radiotherapy depend on the part of the body that was treated.

Long-term side effects include:

• Change of skin colour in the treated area – darker skin
• Sensitive skin
• Telangiectasia, or spidery red marks due to broken blood vessels
• Dry mouth
• Breathing difficulties
• Low libido
• Impotence
• Infertility
• Pain and soreness
• Bowel and bladder changes
• Swelling due to blocked drainage channels in the arms and legs (lymphoedema)

Site-specific side effects of radiotherapy

Site-specific side effects of radiotherapy include:

Radiotherapy directed to the head and neck area may result in the following side effects:

• Dry mouth
• Sore mouth
• Tooth decay
• Difficulty swallowing (dysphagia)
• Hoarseness of voice
• Nausea
• Vomiting
• Hair loss
• Loss of weight
• Lymphedema

Radiotherapy to the chest area may result in the following side effects:

• Difficulty breathing
• Difficulty swallowing
• Sore breast or nipples
• Stiffness in the shoulders
• Fluid accumulation around the heart (pericardial effusion)
• Nausea
• Vomiting

Radiotherapy to the pelvic and abdomen may result in the following side effects:

• Nausea
• Vomiting
• Loss of appetite
• Loss of weight
• Bladder inflammation (cystitis)
• Incontinence
• Weakened pelvic bones
• Pelvic pain
• Infertility
• Menopausal symptoms such as dry skin, hot flushes, mood changes
• Erection problems
• Bowel cramps
• Diarrhoea

Radiotherapy vs chemotherapy

Radiotherapy and chemotherapy differ in the delivery mechanism used to kill cancer cells. Radiotherapy provides localised treatment either externally or internally, whereas chemotherapy requires the usage of medications that travel throughout the entire body to kill cancer cells.

There are also some differences in side effects. However, there is no better or worse between these two types of cancer treatment. The most effective treatment depends on several factors, including cancer type, stage, and location.

For more on the differences between these two cancer treatments, read ‘Radiotherapy vs Chemotherapy'.

Book an appointment at Pantai Hospitals

Early cancer detection makes treating the disease easier with effective and appropriate treatment. A dedicated and expert team of oncologists at Pantai Hospitals is available for consultation to provide the best care and assistance to patients through cancer screening, diagnosis, and treatment.

Get in touch with us to book an appointment today if you have any concerns or questions about radiotherapy and other cancer treatment options.

Pantai Hospitals have been accredited by the Malaysian Society for Quality in Health (MSQH) for its commitment to patient safety and service quality.

References

1. American Cancer Society (10 December 2020) Radiation therapy side effects. Available at https://www.cancer.org/treatment/treatments-and-side-effects/treatment-types/radiation/effects-on-different-parts-of-body.html [Accessed 4 March 2022]
2. Cancer Research UK (6 November 2020) What is radiotherapy? Available at https://www.cancerresearchuk.org/about-cancer/cancer-in-general/treatment/radiotherapy/about [Accessed 4 March 2022]
3. Mayo Clinic (1 July 2020) Radiation Therapy. Available at https://www.mayoclinic.org/tests-procedures/radiation-therapy/about/pac-20385162 [Accessed 4 March 2022]
4. National Institutes of Health (8 January 2019) Radiation Therapy to Treat Cancer. Available at https://www.cancer.gov/about-cancer/treatment/types/radiation-therapy [Accessed 4 March 2022]
5. National Health Services (4 July 2022) Radiotherapy. Available at https://www.nhs.uk/conditions/radiotherapy/side-effects/