Radiotherapy Side Effects: What you need to Know

Written By Lotte May
Founder of Comfort Crate & Cancer Advocate

What Does Radiation Do to Your Body?

During radiotherapy, high-energy beams are used to destroy the genetic material (DNA) that controls how cells grow and divide. While the primary goal is to kill cancer cells, the radiation also impacts healthy tissue in the treatment path. Most healthy cells are resilient and can repair themselves over time, but this cellular stress is what leads to various side effects.

The Science of Fractionation

Radiotherapy is rarely given in one large dose. Instead, doctors use a process called fractionation, breaking the total dose into small daily sessions. This technique gives your healthy cells a recovery window to repair DNA damage between treatments, significantly reducing the severity of long-term side effects and allowing your body to tolerate the therapy more effectively.

Side Effects of Radiotherapy

Side effects are generally categorised into two phases. Understanding this timeline helps you manage expectations during recovery:

• 1. Early Side Effects: These typically occur during or shortly after treatment and are usually short-term and treatable. Common issues include fatigue, skin changes, and hair loss in the localised treatment area. Most early effects disappear within a few weeks of your final session.
• 2. Late Side Effects: These can take months or even years to develop as they affect the deeper tissues. The risk depends on the radiation dose and the specific area treated. It is vital to discuss long-term monitoring with your radiation oncologist.

The Truth About Individual Reactions

Everyone reacts differently to radiation. Some individuals experience very few side effects, while others face a more challenging recovery. Factors like your general health, the specific location of the cancer, and the precise dose of radiation play a major role. Educating yourself on how to prepare for cancer treatment is the most effective way to stay in control.

Side Effects by Treatment Area

Unlike chemotherapy, which is systemic (affects the whole body), radiation side effects are usually localised to where the beams are aimed:

• Brain: May cause cognitive changes (chemo brain), nausea, headaches, and blurry vision.
• Chest: Often leads to throat soreness, coughing, shortness of breath, and localised skin sensitivity.
• Stomach & Abdomen: Can result in nausea, vomiting, diarrhoea, and bladder irritation.
• Breast: Common symptoms include tenderness, skin redness (radiation dermatitis), and swelling known as lymphoedema.
• Head & Neck: May cause taste changes, dry mouth (mucositis), and thyroid gland changes.
• Rectum & Pelvis: Can lead to bowel changes, bladder urgency, and potential fertility or sexual health concerns.

Master Your Recovery: Radiotherapy is a marathon, not a sprint. For a complete, survivor-led roadmap on managing localised side effects and protecting your skin, discover The Chemo Side Effect Guide Book. This resource provides the expert-peer guidance you need to maintain comfort throughout your journey.

Further Reading and Support:

For more in-depth clinical information regarding treatment in the UK, these two resources are highly recommended:

• NHS: What Happens During Radiotherapy
  This is the gold standard for understanding the patient journey. It covers everything from the initial planning sessions (CT scans) to the daily routine of external radiotherapy and internal options like radioactive implants.
• Macmillan Cancer Support: Radiotherapy Fact Sheet
  Macmillan provides excellent easy read and detailed technical guides. This resource is particularly helpful for understanding the emotional and practical side of treatment, including how to talk to your radiography team and what to expect from follow-up care.

About the Author: Lotte May is a Stage 4B Hodgkin Lymphoma survivor and founder of Comfort Crate. She provides cancer patients with research-backed tools and practical peer-to-peer knowledge to make the treatment journey more manageable. Read more about her mission.

Medical Disclaimer: This information is for support and guidance only. It does not replace the advice of your medical team.