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.
Dr Muhammad Azrif
The Star/Asia News Network
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