Head and Neck Cancer Radiotherapy

Cancers that affect the nose, sinuses, eyes, ears, mouth and its contents as well as the tonsils, nasopharynx, throat, voice box and scalp are considered head and neck cancers. Skin cancers that affect these regions and which may have spread to glands or nodes in the neck as well as neck lumps are also included in this group.

If there are concerns you have a head and neck cancer, you will need specialised examinations including in some cases, an endoscopy. A biopsy is required and scans such as ultrasounds, MRI and CT or PET CT may be needed in assessing the extent of the disease. The biopsy and scans may confirm the site where the head and neck cancer originated from and may also allow clarification if the Human Papilloma Virus (HPV) virus caused it. Such HPV associated head and neck cancers such as that affecting the tonsils, behave differently and may alter your treatment plan.

The scans used will also show the spread of the cancer, for instance to the glands in the neck or if it has spread to even more distant sites such as the lungs. In most instances, head and neck cancers that have been found early enough, have very high rates of cure. Unfortunately, head and neck cancers that have metastasized to distant sites such as the lung may no longer be curable. This information will guide your clinician in treatment recommendations.

Due to the nature of the sensitive structures in the head and neck region and the challenges you will face in treatment to these sites, a specialized group of clinicians and allied health staff are best suited to help you. This group is referred to as a multidisciplinary team or tumour board. Their aim is to help guide your diagnosis and recommend treatments. Often the best decisions are made when a head and neck surgeon, a plastic surgeon or a maxillofacial surgeon works closely with a radiation oncologist in evaluating your head and neck cancer and counselling you on your treatment options.
It may be that you have a number of equally good but different treatment options, for instance, surgical removal or radiotherapy with or without the addition of chemotherapy. Due to the side effect each treatment brings, one of the guiding principles that will be used in counselling you will be to use only the treatments you need. For instance, if surgical removal is possible but associated with a high likelihood of you requiring not just radiotherapy afterwards but also chemotherapy, then it would be preferable to choose radiotherapy with chemotherapy upfront. This means you have 2 different treatments used rather than 3-sparring you the side effects of surgery.

Radiotherapy for head and neck cancers does require a number of other aspects to be planned for. If the oral cavity is going to be in the radiotherapy field, then a careful assessment by a dentist is required prior to treatment. Any unhealthy teeth should be removed as extracting them after radiotherapy may be associated with complications such as non-healing ulcers and fractures. A nutrition plan is also required and the expertise of a dietician will be made available during your treatment. A feeding tube may be required to sustain your nutrition if you cannot eat enough due to the side effects you experience with radiotherapy. In some centers this can be a naso-gastric tube and in others it may be a PEG tube, which is placed directly into the stomach through the skin of the abdomen. A naso-gastric tube does not require any skin punctures but the end of the tube sticks out the nose. A PEG tube can be hidden under your clothes but it is invasive and may require a 1 day stay in hospital after the procedure for monitoring. Swallowing may be compromised during your radiotherapy treatment and a speech therapist may be very helpful in helping you cope during this time and improving your swallow after your treatment is completed. Most head and neck centers will have a specialist head and neck cancer nurse to help you with your journey as well.

A radiotherapy planning session is carried prior to your treatment. This is done at least 1 week after any required teeth extractions and also when your wounds have recovered after any initial surgeries. In that session, a mouth guard may be made for you and the scars may be marked with a felt pen and a bolus, a piece of rubbery material, may be made over the scar. A customized head and neck mask is made. A CT simulation scan is performed and then your radiation oncologist and the radiotherapy team can then design the treatment for you. Most treatments are usually 6 to 7 weeks long, on week days and done on an outpatient basis. Sometimes a period of inpatient stay is required depending on the severity of the side effects you encounter. It is very important your treatment is completed within the planned duration and does not get interrupted.

The sites of the treatment including the extent as well as the dose, duration and techniques will affect the efficacy as well as the severity of side effects. The side effects you experience also depends on a number of factors such as any surgeries you’ve had, previous radiotherapy, if chemotherapy is added in as well and your underlying medical condition and pre radiotherapy levels of function. Speak to your radiation oncologist about this.

Common side effects include fatigue, skin inflammation, peeling of skin, inflammation of the lining of the mouth and throat, a dry mouth, painful swallow, altered taste, changes to your voice quality, cough and loss of facial hair. You will recover from some of these but ongoing dryness, and altered taste tend to persist. Your risk of dental caries continues post radiotherapy and you must continue good oral cares lifelong. Skin changes such as firmness and colour changes are common and the neck muscles can get stiffer with time. Swelling due to lymphoedema can also occur as can reduced mouth opening over time. This is called trismus. Ongoing lifelong jaw and tongue exercises are needed to counter some of these. In some situations, ongoing swallowing difficulties occur and dependence on a feeding tube may be ongoing. Years after your treatment, you may be at risk of carotid arterosclerosis which may increase the risk of strokes.

The thyroid gland can become underactive and I would recommend lifelong monitoring of your thyroid function. Radiotherapy can be associated with other significant side effects such as osteo-radionecosis of the jaw and this can be very difficult to treat. Injury to the nerves which supply the arms, called the brachial plexus can also occur rarely as can injury to the spinal cord resulting in myelopathy. Many years after radiotherapy, there is a small chance of developing another cancer. These side effects and their likelihoods can vary from person to person and I do recommend you speak to your clinicians about them.

Radiotherapy, despite being a demanding treatment, achieves very good cancer outcomes with a number of head and neck cancers being cured with this treatment. Please do look up more information on the Targeting Cancer website, and the EVIQ website. I hope this information helps you and do recommend you clarify any concerns or further questions you have with your oncologist.

© Ramesh Pandey March 2025

REFERENCES
1. What Cancer Screening Tests Check for Cancer? | National Cancer Institute (Link).
2. Cancer Screening Tests | CDC (Link).