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Radiotherapy Step by Stepุงู„ุนุฑุจูŠุฉ

Under physician review

Handout: Side Effects and How to Manage Them

Radiotherapy Step by Step โ€” Designed for radiation oncologists to use in clinic

Every effective treatment has possible side effects, and most in radiotherapy are local, temporary, and manageable. This page helps you know what to expect, how to ease it, and most importantly: when to call us immediately.

A key rule: effects occur where the treatment is

  • Radiotherapy side effects usually appear only in the treated area, not throughout the body. Pelvic treatment may affect the bladder and bowel, head-and-neck treatment may affect the mouth and swallowing, and so on.
  • Most effects appear gradually a week or more after starting, peak near the end of treatment or a few days after, then improve over weeks.

Common general effects

  • Fatigue: the most common effect, building up gradually over the weeks. Balance rest with light activity, and do not hesitate to ask for help at home.
  • Skin changes in the treated area: redness, dryness, or itching like mild sunburn. Use a gentle moisturizer your team recommends, and avoid perfumes, very hot water, and rubbing the area.
  • Hair loss: only in the treated area โ€” chest or pelvic treatment does not cause head-hair loss.

How to ease the effects

  • Skin care: cleanse gently with lukewarm water and mild soap, pat dry (do not rub), and wear loose cotton clothing.
  • Nutrition and fluids: keep drinking water and eat small, frequent meals. If treatment affects your mouth or swallowing, ask a dietitian for advice early.
  • Do not apply any cream or medication to the treated area without asking your team first โ€” some products increase skin irritation during radiation.

When to contact us immediately

  • Fever or chills during treatment โ€” may indicate an infection needing urgent assessment
  • New severe pain that does not settle, or a severe headache with vomiting
  • New weakness or numbness in the limbs, or difficulty controlling urination or bowels (may indicate spinal cord compression โ€” an emergency)
  • Severe shortness of breath or chest pain
  • Bleeding that will not stop, or severe vomiting/diarrhea preventing you from drinking fluids
  • Severe ulceration in the treated area with unbearable pain

If any of these appear, contact your treatment team immediately or go to the emergency department.