Radiation Therapy for Cancer: An Introduction with Dr. Karen Winkfield

Last Updated: April 11, 2018

Dr. Karen Winkfield explains what radiation therapy is, the types used in cancer treatment, and how it may affect the body during treatment and after treatment is complete.

More Information

If you are having trouble watching videos, you may need to download and install the latest version of Adobe Flash Player. To see additional videos, visit and subscribe to Cancer.Net's YouTube channel.


Cancer.Net®: Doctor-Approved Patient Information from ASCO®

Radiation Therapy for Cancer: An Introduction

What is Radiation Therapy?

Karen Winkfield, MD; Member, American Society of Clinical Oncology: Radiation therapy is actually just one of several tools that we have to treat cancer.  Many people know about chemotherapy, which is a systemic therapy that goes all over the body, but there are some local treatments; surgery being one of them, but radiation being the other.  And radiation therapy is simply the use of energy to actually treat and kill tumor cells.  And we oftentimes use it in combination with either surgery or chemotherapy and sometimes even both. 

A radiation oncologist is a medical doctor and instead of learning how to use chemotherapy or surgery, we actually learn how to use energy, radiation, to treat patients.

Types of Radiation Therapy in Cancer Treatment

Dr. Winkfield: There are several different types of radiation therapy.  The most common one that’s used is called external beam radiation, and that’s just an x-ray that comes from outside of the body. 

It doesn’t hurt.  It doesn’t sting.  It doesn’t burn as it goes in.  And we oftentimes think of x-rays for diagnostic purposes, a broken arm or maybe looking at a chest x-ray.  But, that same energy can be used to actually treat and kill tumors.

There are other types of radiation, particle therapy, such as protons or electrons, and those also come from external to the body as well, but they don’t have the same properties as x-rays.  And so, we can actually focus protons just a little bit differently.

There’s also internal radiation therapy.  That can be given using a device that simply puts the radiation source close to the tumor.

Side Effects of Radiation Therapy

Dr. Winkfield: One person may have a different treatment regimen from another, even if they have the same type of cancer. 

A radiation-specific regimen is simply a prescription: how the radiation therapy is going to be delivered, what site is going to be treated.

Just as each different type of cancer may require a different regimen, every single tissue in the body has a different tolerance to radiation therapy.  And often times, that is what dictates what the side effects of radiation are. 

Some of the common side effects though, are fatigue.  People oftentimes will feel tired during the course of radiation.  It is an everyday treatment; so very different from other treatment modalities, and sometimes the treatment courses can be several weeks. 

Side effects of radiation therapy are gradual side effects.  Most people do not feel anything the first couple of times they have radiation.  And so, the side effects of radiation therapy develop over time; again, fatigue being the most common.

Oftentimes, patients will experience some skin irritation, maybe some redness in the treatment field, almost like having a sunburn.  It’s usually not peeling unless it’s very high doses, and that can sometime happen with people who have cancers in the head and neck region, or some very sensitive tumors in areas that might be in the private areas of patients, and sometimes that can be uncomfortable. 

Depending on the regimen, it’s going to be very important for the patient to really chat with their doctor, to have a good frank conversation about what side effects they can expect during the course of radiation therapy, and what might be some long-term side effects that they might get from the treatment.

Preventing and Relieving Side Effects

Dr. Winkfield: People oftentimes will ask me is there anything that they can do to prevent any of those side effects from developing.  I oftentimes encourage them to make sure that they’re drinking enough water.  It seems like something very simple, but staying hydrated during the course of therapy is important, but also just to have a regular well-balanced meal. 

The doctor will also talk with patients about things that they may be able to take.  There may be some medicines.  For instance, if they’re getting really dry mouth, mouth rinses that they can use that can help prevent those side effects.  I oftentimes will encourage my patients too to make sure they’re moisturizing their skin every day to avoid some of that skin redness and irritation.

So, there are certain things that can be done.  But again, I think it’s always best to talk with the treating physician to find out what specific things are going to fit with a particular patient’s treatment.

Where to Get More Information

Dr. Winkfield: ASCO has a wonderful website, Cancer.Net, which actually has some wonderful information about radiation therapy and what potential side effects persons might experience.  It also has some information about things that patients can do to perhaps reduce those side effects as well.

[Closing and Credits]

Cancer.Net®: Doctor-Approved Patient Information from ASCO®

ASCO's patient education programs are supported by Conquer Cancer Foundation of the American Society of Clinical OncologyConquerCancerFoundation.org  

Special Thanks:

Dr. Mary Wilkinson, Dr. Raymund Cuevo, and the staff at Medical Oncology & Hematology Associates of Northern Virginia

Carolyn B. Hendricks, MD, The Cancer for Breast Health

Hasbro Children’s Hospital

Helen F. Graham Cancer Center at Christiana Care Health System

The Adele R. Decof Comprehensive Cancer Center at The Miriam Hospital. The Miriam Hospital is a teaching hospital of The Warren Alpert Medical School of Brown University

Video Footage and photography courtesy of:

St. Jude Children’s Research Hospital Biomedical Communications

Moffitt Cancer Center

University Hospitals Case Medical Center Seidman Cancer Center

The opinions expressed in the video do not necessarily reflect the views of ASCO or the Conquer Cancer Foundation.

Requests for commercial use of this video should be submitted to permissions@asco.org.

© 2017 American Society of Clinical Oncology®. All rights reserved

Sharing and personal publication of this video indicates your consent to the Terms of Use, viewable at: http://www.asco.org/VideoDisclaimer