A cancer diagnosis is indubitably stressful, life-altering and overwhelming. Cancer not only affects us physically but it also influences us psychologically. And, in the midst of dealing with a diagnosis, you may struggle with understanding new medical jargon, learning about seemingly foreign treatment modalities and handling myriad appointments with different specialists. This basic guide may aid you in understanding radiation therapy as it applies to the head and neck and what to expect when receiving head and neck radiation therapy. (Please note that this does not constitute or replace medical advice. For questions relating to your treatment, please consult with your medical team.)
So, the first question you may have is: what type of radiation therapy?
There are multiple types of radiation therapy? Radiation treatment is extremely complicated and the tumor stage and grade will affect the type of radiation therapy you will receive. To over-simplify this, there are three main types of radiation therapy: external beam, brachytherapy (also known as internal beam) and systemic radiation therapy. If you are receiving head and neck therapy, you will most likely be receiving external beam radiation. There are multiple types of external beam radiation treatments, but the most common are 3-D conformal radiation therapy, intensity-modulated radiation therapy (IMRT), and proton therapy. Other types of external beam radiation therapy include: image-guided radiation therapy, tomotherapy, stereotactic radio surgery and stereotactic body radiation therapy. The radiation oncologist will treatment plan the type of radiation depending on the type of cancer a patient has.
Intensity-modulated radiation therapy (IMRT) is well established and has become a popular treatment modality in the past 10 to 15 years. Before 1995, conventional radiation therapy was the mainstay which involved radiation being delivered through opposing lateral portals. In other words, everything between the portals was treated with the same dosage of radiation. But, now, IMRT has become popular in treating head and neck cancers. What is great about IMRT is that it is extremely precise, and with IMRT, the doses of radiation delivered to the area vary depending on the site. So, the tumor receives the highest doses, but the other anatomical structures are spared and receive less. IMRT is planned with a computer-controlled linear accelerator and allows for extreme accuracy. The planning is complicated and involves multiple types of imaging such as MRI’s or CT’s and complex dose calculations. Is IMRT associated with side effects? Yes, unfortunately, but they are reduced in comparison to conventional radiation. And, the side effects are related to the radiation dosage delivered.
Another type of external beam radiation therapy is called proton therapy. In contrast to IMRT which uses X-rays, proton therapy consists of a beam of protons. It is extremely specific and is not indicated for all types of cancer.
What is fractionation?
Radiation delivery is usually “fractionated,” or spread out, into small doses over a period of weeks.
Simulation
Before you receive your radiation, you will be given an appointment for a 'simulation' date. The simulation appointment is the treatment planning session during which your radiation treatment is mapped out. This is an extremely important appointment as the dosage and exact location of the radiation that will be delivered are determined at this time.
Since the treatment planning session is completed during the simulation appointment, it is recommended that you visit a dental oncologist prior to the simulation. Why? The measurements and planning are based on how you present the day of the simulation so any changes in your mouth such as loss of teeth will result in changes in the measurements and planning of the radiation dosage. Additionally, visiting a dental oncologist before receiving radiation therapy to the head and neck is important, as the dentist may recommend that you wear radiation mouth guards to prevent backscatter and help minimize the risk of developing mouth sores. Whether or not you are a candidate for radiation mouth guards will be determined by the dentist. If your dental oncologist fabricates radiation mouth guards for you, you should bring the mouth guards to the simulation appointment as you will wear them during every session.
After Simulation
After the simulation appointment, you will be given an appointment to return for a set-up appointment as well as treatment sessions.
What are some of the side effects of radiation therapy to the head and neck?
The side effects of radiation therapy to the head and neck may include dry mouth (xerostomia), taste alterations, increased risk for dental decay, mucositis, decreased opening of your mouth, and osteoradionecrosis of the jaw.
It is important to visit a dental oncologist before beginning radiation therapy for a thorough dental evaluation. At this evaluation, the dentist will determine if you need any dental treatment prior to beginning radiotherapy. Dental treatment may be recommended before beginning treatment depending on where you will be receiving radiation and the dosage that will be delivered. If extractions are recommended, it is ideal to allow 10-14 days of healing time prior to starting radiation therapy.
Take Home Points
It is important to visit a dental oncologist prior to receiving head and neck radiation therapy to help minimize the risks of developing the side effects associated with head and neck radiation therapy.
If you are given radiation mouth guards, remember to bring them to your simulation appointment and leave them there so that you wear them at every radiation treatment session.
If you have a tooth/teeth extracted, you should ideally allow for 10-14 days of healing time prior to starting radiation therapy.
After receiving radiation therapy to the head and neck, be sure to inform your dentist of your radiation history before any invasive dental procedures as they may not be indicated depending on the dosage and location of your radiotherapy.
DISCLAIMER: Please note that this does not constitute or replace medical advice. For questions relating to your treatment, please consult with your medical team.
Further Reading
Epstein, Joel, Carl Haveman, Michaell Huber, Douglas Peterson, Jacqueline Plemons, Spencer Redding, Nicholas Sanfilippo, Mark Schubert, and Stephen Sonis. Oral Health in Cancer Therapy: A Guide for Health Care Professionals. 2008. Monograph compilation from 2008 Conference. University of Texas Health Science Center, San Antonio.
"Radiation Therapy for Cancer." National Cancer Institute. National Cancer Institute, n.d. Web. 08 Oct. 2014.
"Radiation Therapy to the Head and Neck." Memorial Sloan Kettering Cancer Center. Memorial Sloan Kettering Cancer Center, n.d. Web. 09 Oct. 2014.