What to Expect During Radiation Therapy


A cancer diagnosis can be a frightening life change for anyone. There is no reason you need the added stress of not knowing what is to come for your treatment. I have written this book as a guide for what to expect when undergoing radiation therapy. As a Radiation Therapist, I see people daily who do not understand what is about to happen to them and this causes added anxiety and stress. Let this book serve as a preview of what to expect for your treatment as well as important key things to understand to ensure your best experience. Always communicate with your healthcare team and ask any questions you have, this book is not to replace that communication, but give you a little more understanding prior to treatment.


There are numerous appointments, emotions and decisions being made from the time of a cancer diagnosis. There are so many things going on and new information to learn that it is overwhelming and can make for a difficult time. You will find an explanation of what to expect from the time you have your consultation until you finish treatment. This book is not to serve as a replacement for communication with your health care team, but rather to help you understand what is going to come and give you a resource to reference as an educational part of your treatment. There can be a lot to remember with everything you are told and with all that is going on, so reference back here when needed.

We will cover some common myths and debunk some things you may have been told by others or seen on the internet. Then we will discuss simulation and scheduling. The treatment section of this book will be divided into sections for you to find your general area of treatment and learn more about what to expect and what is expected of you for your treatments. Lastly, we will cover some other tips and additional things to be expected. Please understand that each facility has their own protocols and procedures that may be different from what I outline here. This serves as a guide and general overview that is intended to be able to be read within a few days.

Chapter 1

Laser beams and Star Wars

“Will I glow in the dark?” is one of many misconceptions associated with radiation treatment. No, you will not glow and no you will not be radioactive! You can feel at ease when you go home to your loved ones knowing you are not transferring anything to them. It is important to spend time with those you love and unnecessary to feel like you cannot because of radiation.

Another common thought is that the radiation will burn while being delivered. While a skin reaction is to be expected with certain treatments, not all, you will not feel an immediate burning. A skin reaction over time with treatments like a sunburn can be expected and covered further in the skin cancer section. This section would be good to review for breast patients as well as that is a common treatment site with skin reactions. You will not see or feel the radiation as it is being delivered. There are no red or green beams that are going to pierce through you.

Another important aspect of your treatment to keep in mind is that it is just that, your treatment. What side effects occur for one person may not be what happens to you. While it is great to talk with others who have been through this process already, don’t hold every outcome they had to yourself. One breast patient may experience a more severe skin reaction while another may not even see a reaction. Everyone’s body is different, and everyone’s treatment is different. Radiation is often used in conjunction with other forms of treatment, such as chemotherapy, which also may have its own side effects.

Will you be able to drive yourself to treatments? Yes, unless otherwise instructed by your doctor. Almost all patients can drive themselves to and from the treatment center.

Ladies, you may wear makeup for treatment. Unless you are having radiation to your skin on your face makeup will not be an issue.

I am sure I haven’t covered everything possible you could read out there on the internet of what “could be” to come, but I hope this has helped to set aside some possible false apprehension you may have about your treatment and helps to put you at ease. Most patients are very surprised at the ease and quickness of the entire process.

Chapter 2


Once you’ve consulted with your Radiation Oncologist your next appointment will be for a simulation, or also referred to as mapping. You might be wondering why you need another CT Scan, by now you’ve probably had multiple imaging done. This will be a short scan just of the needed treatment area and surrounding area. This is an additional needed scan as the doctor and healthcare team will use it to create your treatment plan. You will be put in your treatment position so keep in mind that this position will need to be reproducible daily and you will need to remain still in this position for at least 15 minutes daily.

At the time of this appointment, you will most likely be given a set of temporary marks, I say most likely as there are different procedures practiced by different facilities, so they may do things a little different don’t be alarmed. There are many ways to reach the same destination. These temporary marks will serve as a starting point for your plan. It is important for you to maintain and keep these marks, simply use any permanent marker as needed to trace over them as needed until your next appointment,

Now if you are receiving treatment to your head or neck area and will require a mask, you will not receive these marks, as they will be placed on your mask. You will be wearing a mask daily for treatment. It will be custom made and created at this appointment. It gets heated in a water bath and is warm and wet when placed on your face. A method of fanning, cool towels or just waiting will be used while the mask is drying. So, ladies, it’s a good idea to skip the makeup for this appointment unless it’s waterproof. The mask will be tight as it is to keep you in position and prevent any movement. The mask is then secured to the table.  If you are claustrophobic it would be a good idea to discuss this with your doctor if you haven’t already, so you can be prescribed a medication if necessary to allow you to tolerate treatment. Your treatments will take about 15 mins, but these first two appointments will be longer. Some patients will require a custom head and neck support also, this is very simple and will be explained if necessary. For your knowledge we will be using either the custom or a standard head holder to support your head in a neutral position, so know under or overextension of your chin.

If you will be receiving treatment in the thorax, chest, or abdomen area you will likely have a mold made this appointment (again not all facilities follow this and may choose to not use a mold). This mold is like a bean bag and as it is confirmed to your body as air is sucked from it until it hardens. This mold will be used daily for your treatments. For breast and lung treatments you will be asked to raise your arms above your head and hold onto a handlebar. Depending on the side, usually the left, and your doctor you may be asked to hold your breath during treatment. It is dependent on the tumor location, movement, and location of your critical organs. If this is the case, you will do this for simulation and your breathing will be recorded and used when creating your treatment plan. An important tip to remember if this is the case for you is to take a breath you will be able to hold and reproduce daily. Do not be alarmed if you cannot hold your breath for too long. You can breathe in between breaths and radiation cannot be delivered if you are not holding.

Pelvis treatments are probably the simplest setup. You will simply lay straight and flat on the table with a pillow under your head and hands on your chest. If you have issues laying your legs flat a small cushion may be used to support under your knees. You may be asked to have a full bladder or empty bladder depending on the area and your doctor. For a prostate treatment, a full bladder is important. You want to feel the urge to go, it is not necessary to get overfull but is important that you are full. You will also need to do an enema 1 hour prior to the appointment. Your doctor may also give you some dietary restrictions as you want to avoid becoming gaseous. For any area in the pelvis, it is important to wear the kind of shoes you will be wearing daily for treatment, if you are not asked to remove your shoes, you will want to wear them daily for your treatment. A difference in shoe height could change the tilt of your pelvis. It is easiest to remove shoes.

Overall just understand that this position you are placed in at this appointment will need to be reproduced daily. So, any issues you may have with the position let your therapist know because once your treatment plan is created your set up must remain the same. Also, remember to maintain the marks you are given if this applies to you. And lastly, don’t stress! You have a road ahead that you will be able to make it down, and you will have a support system to help get you there in your Radiation team.

If you will be receiving radiation to the skin, then you will not be getting a CT scan. Rather you will be set up on the treatment table in a comfortable position, as comfortable as possible, and the area to be treated will be drawn on the skin. If this area is in the face, then there is a chance you will have lead shields placed over your eyes. For areas of the nose, you may also have plugets placed inside your nose, to help reduce the reaction on the inside of the nose. A type of bolus material will be used to bring the radiation closer to the skin’s surface. You see radiation is prescribed at a depth, this material acts as skin to pull that depth to the surface.

That should help you to better understand what to expect at your simulation appointment. Now all you do is wait for the treatment plan to be completed and you will be scheduled to start your radiation treatments.

Chapter 3

Your treatments and scheduling

You can expect to have all your treatments scheduled and a time is given to you at your next appointment. Treatments are Monday through Friday and the same time daily. If you have upcoming appointments simply let the therapists know a day or two ahead of time and change your treatment time as needed. We understand you have a lot of appointments and other things going on in your life right now. Most likely your first day after simulation you will not be receiving an actual radiation treatment. You can expect to see the treatment console (where we treat you from), the vault (the treatment room), and the linear accelerator with a table where you will be positioned for treatment. The treatment machine is open, unlike an MRI or CT. You can expect to see the machine rotate around you, but nothing will touch you. You will have a series of photos, measurements, and x-rays taken. A dry run of your treatment is performed so that the doctor can approve the set-up with the treatment plan and that everything looks correct. If you are receiving a longer number of treatments, you may opt to have permanent tattoos placed (covered in a later section).

There are a few other things to consider when it comes to scheduling. Our schedule allows for a 15-minute time slot, so that means we have 15 minutes from the time you arrive to set you up and deliver your treatment. Understandably life happens and sometimes we cannot help but to be late but try to minimize this as it disrupts the entire schedule for the remaining day. This is one appointment we never try to keep our patients waiting on. But understandably, again, that thing called life happens and we may run behind. Don’t get too upset with us, we are just as frustrated as you are trying to keep you from waiting longer! You are usually scheduled at the same time daily Monday through Friday. If you have a conflicting appointment time during your treatment schedule, simply notify your therapist and they will be able to adjust your time accordingly.

Another important consideration when in the waiting room smells! Understand that some patients, especially those going through chemo, are more vulnerable to strong smells so go easy on the perfume or cologne. Smoke smell is another big one! Now I am not here to tell anyone what decisions to make in life, so if you choose to continue to smoke while receiving cancer treatment that is your choice, however, it is rather offensive to patients who do not make that decision. We all know smoking causes cancer so not everyone wants to breathe it in. Just be respectful of that fact and don’t light up right before entering the waiting area, you may not smell it, but everyone else does!


Chapter 4

What to expect and what you need to know by area


Men, this ones for you! You can expect to need a full bladder daily for treatment. You may have a scan done either daily or weekly to check that your bladder is full. It is important because it helps to decrease side effects you may encounter from treatment. It helps to stabilize the prostate and move the bowel out of the treatment field. So, this means less chance of diarrhea later, so it is important to make sure you have a full bladder for treatment. It is very important to remember this as if you are not receiving a scan daily we cannot see if your bladder is full, so it is your responsibility to ensure it is. The scan is performed right on the treatment table and is used in place of x-rays to align your position and check bladder fullness. If you are not full you will be taken off the treatment table and asked to drink more.

To have a full bladder you will want to have the urge to need to urinate, but it doesn’t need to be so full to the point it hurts! You want to be as full as you were on simulation day. Feel free to drink other beverages than just water, if your bladder is full that is all we need, it doesn’t have to be water, although this is the best choice for your body! You should start filling your bladder 45 minutes to an hour before your appointment. It takes some time for the liquid to make to the bladder. Also, consider if you are dehydrated you will need to drink more than usual as your body will pull the water needed to other areas before filling the bladder.



Ok, ladies your turn. The breast is a more common treatment area. There may be a few variations in how you are positioned and what devices are used as there are multiple options. I will focus on the basics of what to expect. You will need to be able to raise your arms above your head. So, if your range of motion is limited you will want to do some stretching and work on this. It’s important to understand that your arms need to be raised above your head to allow the breast tissue only to be treated. You will also need to turn your head out of the radiation field and lift your chin. You will turn to the opposite side that is being treated. This is a common area for the skin reaction to occur. Not everyone has a significant skin reaction. Some people react well while others have a reaction more quickly. It is important to put cream on the skin daily to promote healing and lessen the reaction effects. Your doctor will recommend a cream they find the best to use. Aloe vera without alcohol is also good for the skin. Do not use fresh aloe vera plant if your skin is broken open as this can allow for bacteria to cause an infection. Also, do not use any cream 4 hours prior to your treatment as this can cause a more severe skin reaction. Another helpful tip would be to not wear bras with underwire once and if your skin begins to have a reaction. You can expect it will start as a light pink and can worsen like a sunburn,  so it is important to maintain the area with the creams. If the skin becomes open blisters there is a prescription the doctor can provide you for some relief and healing.

If you are being treated on the left side, you may need to hold your breath. This is due to the location of the heart. You will be given instructions of when to breath in and out. If you’re on oxygen this won’t be a problem as you can continue to use it during simulation and treatment if needed.



If you will be receiving radiation to the skin this is for you. You’re most likely to see a reaction as the dose is concentrated on the skin. You’re also going to need to go in for a simulation appointment, only this will not be a CT scan. The doctor or therapist will draw the area on your skin to be treated, figure out the need for a block (this shapes the radiation and contains it only to the area being treated). All parameters for treatment will be collected at this point to create the treatment plan. You will also have a piece of material called bolus applied to the area daily for treatment. This serves as tissue and mimics your skins effect with radiation to pull the dose to the skin’s surface. It is important to maintain creams and help keep up the integrity of the skin. You will see a reaction with these treatments so stay on top of your self-care. But the reaction will be limited only to the area being treated. Your treatment time is super quick, and it takes longer to get you set up and then to actually deliver your treatment, so you will be in and out in a few minutes. Also, avoid sun exposure to the area altogether if possible. If you have an actual tumor growth you may notice some changes to it as you go through the course of treatment. You may notice that it opens and drains and oozes. You want to keep it uncovered as much as possible so it can dry out. Which will be the next change, drying out. It may start to dry up and turn dark before possibly falling off.



For this treatment, you can anticipate lifting your arms above the head. Typically, you will have your head straight and a headrest of comfort under your head and neck. You may also be prescribed an anti-nausea medication to take before treatment. Due to the area and possible side effects, you may find it hard to eat or become nauseated. If you are having dietary problems, it is important to bring it to your healthcare professionals awareness as you want to keep your body as nourished as possible. Not all people see side effects and some people make it through treatment with minimal discomfort, so please do not let these possibilities worry you, as they are not guarantees.


Head and Neck

You will have the most uncomfortable treatment position if you are claustrophobic. Your treatment will require a mask to be made that fits rather snuggly to your face and is fastened to the table. You will lie on a headrest, this may be a standard headrest, or this too may need to be custom made. The mask will be hot and wet when placed on. It takes a few minutes to dry so a method may be utilized to help cool the mask quicker such as with cool towels or fanning. If you are claustrophobic you may want to talk to your doctor about prescribing something for anxiety, you will need to be in your mask for about 15 minutes for your treatment without moving. You are on cameras and being monitored always from outside the treatment room, so if you ever need to get up you simply can raise your hand and a therapist will be right in immediately in emergency situations. And please do not chew gum or eat candy as we will ask you to spit it out, it is a choking hazard. Your side effects will also be dependent on your exact treatment location. If the oral cavity or throat is to be treated, you may discuss with your doctor the placing a feeding tube prior to treatment as it is a likely side effect of not being able to eat due to difficulty swallowing. There will be a prescription medication that you may also be prescribed to swish and swallow to help ease the discomfort of the mouth and throat. If you’re having your brain treated, you may also be prescribed steroids to take during treatment. It is important to take all medications as prescribed.


Final Tips and Expectations

I would like to cover a few more tips and things to expect with your treatment. Depending on the number of treatments you will be having you will receive an option to have tattoos. Remember those markings we discussed in simulation and the importance of keeping them? Well, you will be able to have permanent tattoos to replace markings where you do not need to worry about keeping them. The tattoos are little dots about the size of a small freckle, but they are permanent. It is up to you if you choose to go this route, it just makes it easier for you not to worry about the markings or if you have an adhesive allergy this may be a better option for you. Not all facilities use tattoos, so this may or may not be an option. If you are receiving 15 or fewer treatments, we generally do not tattoo unless it is requested.

Also refrain from taking any OTC vitamins A, C, or E. They can cause free-radical interaction with the radiation and should be avoided. It is all right to get these natural from your diet, you will only want to avoid them as supplements.

Radiation is a cumulative dose and continues working weeks after you have finished treatment. So, you will not receive a follow-up appointment or diagnostic scan until at least one month after completing treatment. It is also important to remember that if you miss a treatment for whatever reason that appointment will be added to the end, so you will complete the exact number of prescribed treatments. Sometimes your missed appointment may be a result of the treatment machine going down, you are getting sick or needing to miss a day for a family emergency. For this reason, we do not recommend setting up any cruises or special trips right after your treatment as the final day may change.

The treatment machine, known as a linear accelerator, does have days when it is unable to treat and requires maintenance. Due to the nature of the treatments and the need for precise accuracy, this is a good thing because if anything may be off or not working fully it will need to be repaired before continuing treatment, this helps to ensure accurate treatment. So frustrating as missing a day maybe it is for the best.

The most important tip I can give anyone reading this book is to keep a positive attitude because it can make all the difference in your treatment. Relax, don’t stress yourself out about if it’s working or whatever terrifying story you read on the internet that happened 20 years ago. Get to know your healthcare team, ask questions, understand your treatment, and know there is always hope.