The Difference Between Radiation Oncology and Chemotherapy

The difference between radiation oncology and chemotherapy

Cancer has an extremely large impact on the world as it is an extremely difficult disease to combat, and it affects so many individuals each year. While it’s no secret that cancer has such a devastating impact on people around the world, not everyone understands the differences between the different treatments.

As the most effective cancer treatments, chemotherapy and radiation therapy are the most common approaches to treating cancer. Many people already know that patients with cancer usually undergo chemo and radiation therapy, but they may not actually understand what they are and how they differ.

Understanding the different cancer treatments is very important especially when it comes to managing the side effects and process of it all. Knowing what to expect during your treatment can alleviate some stress, which is critical since the whole process will be stressful enough. This is true of course for both the patient and their loved ones, so here’s how they differ –


Chemotherapy involves treatment using a chemical or drug that is given to the patient’s body in order to destroy any cancer cells. The chemo drug is delivered to the patient’s body through an intravenous, or IV, injection. Since it’s given through an IV, the chemical/drug travels throughout the patient’s bloodstream. Because of this, chemotherapy can even kill cancer cells that have spread beyond the original cancerous area. The specific chemotherapy plan is prescribed by a medical oncologist.

Of course, chemotherapy side effects tend to be present as the chemo treatment has such a wide spread. The chemo usually has effects on other rapidly diving cells, not just the cancer cells, such as those in a patient’s mouth, nose, nails, vagina, blood, intestinal tract, and as many people already know, the body’s hair cells. This causes many side effects, like illness feelings and hair loss.

Radiation Therapy:

On the other hand, radiation therapy involves a localized treatment process. Radiation therapy utilizes localized, high-energy beams targeted at the cancerous area of the patient’s body. Radiation therapy can be prescribed in the form of multiple different treatment plans, such as image-guided radiation therapy and intensity-modulated radiation therapy. While there are many different possible forms of radiation treatment, a radiation oncologist will determine the best plan for each patient. In general, however, radiation kills cancer cells or prevents them from multiplying and spreading by making small breaks in the DNA of the cancer cells.

Since radiation therapy does not travel throughout the bloodstream, it does not have systemic side effects. Rather, the side effects of radiation are mostly localized and affect the direct area that’s being treated. Side effects of radiation include things such as dry mouth, difficulty swallowing, decreased appetite, diarrhea, constipation, nausea, or other effects depending on the location. The most common general, non-localized side effects include much fatigue and skin changes/irritations.

At the end of the day, knowing the differences between radiation therapy and chemotherapy can help you to better understand what to expect while you or your loved one is battling cancer. The experience will be tough enough, so there is no need for dealing with extra stress from confusion or from being unprepared in a preventable manner.

In many cases, the patient often undergoes both chemotherapy and some type of radiation therapy to effectively battle cancer, so it might be best to understand both procedures. Of course, never be scared or hesitant to ask your doctor or health care provider any questions about either treatment, as they might have more specific answers that better fit to the individual circumstances of your case. And, never feel like it’s too late to ask any questions you have, as your oncology team is there to help you and make your cancer battle the easiest experience possible. 

By Russell McBurnie