Iris Oncology
Diagnosis and Treatment

Radiation Therapy: What to Expect

An estimated 50% of cancer patients will receive some form of radiation during their treatment process — and many report having anxiety around what to expect. If you’re preparing for radiation therapy, a good first step is to better understand the treatment and how it may affect you. 

What is Radiation?

Radiation is a form of focused treatment used to treat many types of cancer. Radiation works by damaging the portion of DNA in cancer cells that causes them to continue growing. Along with damaging cancer cells, normal tissue cells surrounding the radiation site can also be affected. Radiation can be used to treat some cancers on its own but is often used in combination with other types of treatment such as surgery and chemotherapy.  

Are There Different Types of Radiations Treatments?

Your specific radiation treatment can take several different forms depending on the location and type of cancer. Types of radiation treatment include: 

External Beam Radiation  

  • External Beam Radiation is given using an X-ray or proton beam of energy. 

  • This type of radiation can be used to treat many different types of primary cancers, as well as areas where cancer may have spread.  

  • Treatments are given once or twice a day, as often as five days a week. The duration and frequency of your treatments will depend on the total dosage of radiation that you need.

    • Good to know: If you are receiving external radiation, you are not radioactive or dangerous to those around you.   

 Internal Radiation(Brachytherapy) 

  • This type of radiation is delivered via implantable seeds near the tumor site.   

  • Internal radiation can be in place short-term or permanently. However, the radioactive effects wear off over time.

    • Good to know: Internal radiation may require you to take special precautions to protect those around you from exposure (your radiation oncologist should provide these instructions if applicable).  

 Therapeutic Radiopharmaceuticals 

  • Can be given as a pill or intravenously. 

  • This type of treatment consists of three key parts: a radioactive component, a targeting component, and a component that binds or links the two together. This allows the radiation to be delivered directly to the targeted area. 

    • Good to know: This kind of treatment may make body fluids radioactive, so your doctor may recommend that you take precautions at home to protect those around you. 


What Side Effects Should I Expect?

Side effects are generally related to the area where the radiation is being delivered, how much radiation is delivered per dose – or single radiation treatment — and the number of doses. Some side effects are usually temporary and oftentimes, will improve over the few months following your course of treatment. Occasionally, people may have side effects that do not ever improve, that last for a long time, or that get worse before they get better. Though it’s not common, side effects can also develop months after treatment.  

 General Side Effects  

  • Skin changes: This can include redness or tanning and/or irritation. Skin changes can vary in severity and can occur in the area that was radiated, along with surrounding tissue. It is important to be diligent about skincare and follow your radiation oncologists’ recommendations regarding any use of creams. Report any skin changes to your radiation oncologist. 

  • Fatigue: You may feel “wiped out” or less energized than normal. Intensity can vary from person to person. Radiation fatigue is generally progressive as treatment goes on and improves in the months that follow. 

  • Hair thinning or loss: Your hair may grow back thinner or in some cases not at all in areas that were radiated.

  • Lymphedema: Damage to the lymphatic system in radiated field can sometimes cause short or long-term swelling due to fluid accumulation in tissues. 

 Radiation Site-Specific Side Effects 

  • Brain: Your memory and concentration changes. You may suffer headaches and blurred vision. 

  • Head and Neck: You may suffer from dry mouth, have trouble swallowing, and experience sore throat, taste changes, and tooth decay. Head hair loss only occurs if radiation is directed at the brain/skull area. 

  • Breast: You may experience skin changes, fatigue, and swelling. 

  • Chest: You may have difficulty swallowing, have a cough, or experience shortness of breath. 

  • Stomach: You may experience nausea, cramping, vomiting, and diarrhea. 

  • Pelvis: You may suffer from diarrhea, abdominal cramping, urinary changes or irritation, sexual problems, menopausal symptoms, and fertility concerns.  


What Questions Should I Ask My Radiation Oncologist?

As you begin radiation, here are some specific questions we recommend asking your doctor, so you have more insight into what to expect: 

  • What is the length, frequency, and duration of my radiation course? 

  • What are the potential side effects of this radiation and when should I expect to see those side effects? 

  • Can I eat before my treatments? 

  • Are there any special instructions on what I should do before each treatment? 

  • Are there any precautions I need to take to keep those around me safe? 

  • What type of products/skincare should I use or avoid during treatment? 

  • What is the best way to contact you if I have concerns? 

  • Are there any possible late side effects I should watch for after treatment is complete? 

We know that starting radiation can be anxiety-provoking. We’re here to help you understand what to expect from your radiation therapy so that you can put your energy towards getting through it and feeling better. Message an Iris nurse 24 hours a day, 7 days a week for additional support for radiation and its side effects. 

This article meets Iris standards for medical accuracy. It has been fact-checked by the Iris Clinical Editorial Board, our team of oncology experts who ensure that the content is evidence based and up to date. The Iris Clinical Editorial Board includes board-certified oncologists and pharmacists, psychologists, advanced practice providers, licensed clinical social workers, oncology-certified nurses, and dietitians.