Intensity-modulated radiotherapy (IMRT) is an advanced radiotherapy technique that concentrates the radiation dose to the cancer and limits exposure to nearby normal tissues such as the salivary glands.
A person with nasopharyngeal cancer often presents with a lump in the neck, but this can be preceded by nasal symptoms a few months prior to the emergence of the neck lump.
WONG had not been feeling well. He had been troubled by a blocked nose and reduced hearing for a couple of months. He became more worried after he noticed a lump in his neck one morning while shaving.
He went to see his panel doctor, who then referred him to an ear, nose and throat (ENT) surgeon at his local hospital.
After listening to Wong describe his symptoms, the doctor inserted a thin scope into Wong's nostril. He found a large mass lying on the left wall of the nasopharynx, which is an area right behind the nose. A small part of the mass was biopsied and sent to the laboratory.
This confirmed nasopharyngeal cancer.
Nasopharyngeal cancer is the fourth commonest cancer in Malaysia. Nearly three Malaysians a day are diagnosed with this disease. It mainly affects Chinese men and more than two-thirds are diagnosed with stage 3 or 4 cancer.
Patients commonly present to hospital with a lump in the neck, but this is often preceded by nasal symptoms a few months prior to the emergence of the neck lump. The nasopharynx has many lymphatic vessels and therefore cancer cells spread easily to the lymph nodes in the neck, hence the lump that prompted Wong to go and see a doctor.
Wong was referred to an oncologist for further treatment. The oncologist arranged a magnetic resonance (MR) scan of the head and neck, a CT scan of the chest and abdomen, and a bone scan.
These showed that the cancer had spread to a few lymph nodes on both sides of the neck. Fortunately, it had not spread elsewhere in the body. The oncologist explained that Wong had stage 3 cancer of the nasopharynx and advised seven weeks of radiotherapy combined with chemotherapy.
He was also advised to stop his 10 cigarettes a day smoking habit and to see his dentist for a dental assessment prior to the start of treatment.
Once a cancer has been diagnosed, staging of the cancer is important to help guide treatment. Ideally, an MR scan is done to properly visualise the tumour in the nasopharynx, and its encroachment to surrounding tissues.
Cancers in stage 1-3 are curable and the treatment recommended is intended to eradicate the cancer completely. Certain stage 4 cancers may be curable, provided the cancer has not spread elsewhere. Although the public often associates stage 4 cancers as incurable, the staging of cancers very often differ in its details. For example, cancer of the nasopharynx that invades up towards the brain is classified as stage 4, but it is still curable with chemotherapy and radiotherapy.
As Wong has stage 3 nasopharyngeal cancer, the standard treatment in this situation would be concurrent chemoradiotherapy, which consists of 35 sessions of radiotherapy combined with weekly low-dose chemotherapy over seven weeks.
Prior to the start of radiotherapy, Wong underwent a planning CT scan while wearing a mask that helps to keep his head and neck still during treatment.
His radiotherapy started a few days later, once his plan was ready and approved by his oncologist.
Although Wong was worried about his radiotherapy (as his friends had said that he would feel "heaty"), he was surprised that the treatment session itself was very similar to having a CT scan.
He lay on the treatment table and wore his mask for about 10 minutes while the radiotherapy machine moved around him. Once his session finished, the radiographers came in to remove his mask and he was able to drive himself home.
For the first three weeks of treatment, Wong felt his usual self. He had some mild nausea for a couple of days after his weekly sessions of chemotherapy.
Towards the end of the third week, he began to develop a sore throat. His oncologist prescribed some medication to help with the sore throat but the soreness continued to worsen as Wong's treatment progressed. He could only manage soft foods. He also noticed some dry peeling of the skin on his neck.
His oncologist prescribed stronger medication to control the throat discomfort so that Wong could continue to eat.
Radiotherapy to the nasopharynx and lymph nodes in the neck commonly causes an inflammation of the lining of the throat. This inflammation usually appears after two weeks of treatment and develops slowly over the subsequent weeks.
It is this throat inflammation that causes the soreness and discomfort.
Careful attention needs to be given to prevent infection during this time as it can worsen the patient's symptoms. This can be done by regular mouthwashes and early treatment with antifungals or antibiotics.
The patient needs to avoid spicy food, alcohol and chillies as these can aggravate his symptoms.
He is strongly advised to avoid smoking cigarettes during radiotherapy for head and neck cancer as it worsens the throat inflammation and reduces the chance of cure.
Wong finally completed his seven weeks of chemoradiotherapy a few days ago. He lost about 5kg and still eats soft foods at the moment, but his oncologist assures him that this will improve and he can go on a normal diet again in a few weeks.
Although he currently has a dry mouth, this too will improve over the next few months as his oncologist treats him with intensity-modulated radiotherapy (IMRT) using the Hi-ART TomoTherapy system. This is an advanced radiotherapy technique that concentrates the dose to the cancer and limits doses to nearby normal tissues such as the salivary glands. This lower dose allows the salivary glands to recover faster and Wong's dry mouth will be much better in a few months.
With older 3D radiotherapy techniques, the salivary glands are permanently damaged. In addition to the patient suffering from a permanent dry mouth, dental and gum problems can also occur.
Wong is also reassured that compared to 3D radiotherapy, the chance of the cancer relapsing in the nasopharynx and neck is minimal with IMRT.
Cancer treatments are always evolving. Technological improvements in radiotherapy, new chemotherapy drugs, breakthroughs in understanding how cancers grow and develop as well as how our bodies fight cancers allow doctors to improve the chance of cure and minimise the side-effects of treatment so that patients can lead long and happy lives.