Radiation Therapy

Before you can receive radiation treatment, you will need to be seen by a Radiation Oncologist, who is a doctor specially trained to give this type of treatment. He will assess your condition to see if radiation therapy is indeed required or appropriate.

Radiation Therapy can be given in two ways. The most common is called External Beam Radiation Therapy (EBRT), where the radiation is directed from the treatment machine to a particular area of your body. The other form is Internal Radiation Therapy or Brachytherapy where a small radioactive material is placed inside your body in or very close to the cancer. Depending on the type of cancer, you may be given just one form of radiation therapy or even a combination of both.

External Beam Radiation Therapy

In External beam radiation therapy (ERBT), the treatment unit or machine directs the radiation energy to the cancer. A number of different treatment units are available in the department. The one that is most suitable for your treatment will be chosen.

• Intensity Modulated Radiation Therapy (IMRT)

This is a form of 3-dimensional conformal radiotherapy that focuses multiple radiation beams onto the tumour. The beam intensities can be varied, so that the highest possible dose can be used to destroy cancerous tissue with relative sparing of normal structures. Sophisticated planning is required to determine the most accurate treatment plan.

• Image-guided Radiation Therapy (IGRT)

Image-guided radiation therapy (IGRT) is a process of using various imaging technologies to locate a tumour target prior to a radiation therapy treatment. This process is aimed to improve the treatment accuracy by reducing the need for large target margins which have traditionally been used to compensate for errors in localization. As a result, the amount of healthy tissue exposed to radiation can be reduced, minimizing the incidence of side effects. IGRT is complementary to IMRT. IMRT is used to improve the radiation delivery precision and IGRT is used to improve the radiation delivery accuracy.

• Volumetric Modulated Arc Therapy (VMAT)

Volumetric Modulated Arc Therapy refers to the delivery of IMRT in a volumetric arc fashion. Treatment is delivered as the machine rotates 360 degrees around the patient through one or more arcs whilst continuously keeping the radiation beam on. The shape of the beam varies as the machine rotates to achieve a complex high dose volume in 3D which encompasses the tumour. It is one more weapon in our arsenal where the main advantage of delivering IMRT in a very short time is greatly beneficial in reducing patient discomfort and the effects of motion.

• Stereotactic Radiosurgery and Radiotherapy System

This system of delivering radiation therapy combines the advantages of radiosurgery and IMRT in addition to having an image tracking (guidance) system to further enhance treatment accuracy. This involves an integrated treatment system that shapes focused high-energy radiation beams from a multitude of angles to deliver non-invasive, precise treatments that shrink or control the growth of tumour cells of the brain as well as in the head, neck, spine, liver, lung and prostate. The system reduces potential harm to surrounding normal tissue significantly.

- Radiosurgery

This form of radiotherapy is used to treat brain tumours. It involves a single or a few high-dose application of radiation to the tumour. Several radiation beams are precisely aimed to converge upon a small target within the brain. A device is used to stabilize the head so that it does not move during the treatment.

- Stereotactic Body Radiotherapy (SBRT)

This is the equivalent of radiosurgery in the brain for other parts of the body. It is the delivery of highly focused beams of x-rays to a well-imaged tumour of limited size. SBRT can deliver very high doses of radiation over a relatively short total treatment time (hypofraction) resulting in an increased probability of local tumour control. It is especially useful when patients cannot tolerate surgery or anaesthesia required for surgery. This advanced technology can be applied for the curative treatment of small lung cancers and control of liver tumours and selected spinal metastases.

3-dimensional (3D) Internal Radiation therapy or Brachytherapy

Internal Radiation therapy or Brachytherapy is another form of radiation therapy where a small radioactive material is place in the body or very close to where the cancer is. This is most commonly used in treating cancers in the cervix, uterus, vagina, head and neck regions and also in the oesophagus, lung, breast and prostate. This treatment can be given alone or in combination with external beam radiation therapy.

The 3D image-based Brachytherapy planning system has increased the accuracy of Brachytherapy, thereby making it possible to reduce normal tissue side effects and to increase the dose to the target volume. During the Brachytherapy procedure, multiplanar CT and MRI images are acquired. This is to help the treating doctor view the tumour size which is required to match the treatment applicators accurately. This in turn would ensure adequate dose of radiation is delivered to the targeted area sparing the normal tissues.

• Accelerated Partial Breast Irradiation (APBI)

Accelerated partial breast irradiation (APBI) is a breast conserving therapy approach for early stage breast cancer. The technique aims to kill remaining cancer cells after a breast-conserving surgery. Radiation is delivered to the tumour site with acceptable margins, instead of the whole breast. Normal organs around the tumour site such as skin, lungs, ribs and heart are spared of irradiation. A higher dose of radiation to the tumour site is now possible and the treatment duration is shortened from the usual six weeks regime needed to irradiate the whole breast. Suitable patients are selected based on the stage and aggressive nature of the tumour and node negative tumour.

APBI can be delivered via different methods – multicatheter interstitial brachytherapy, intraoperative radiation therapy and conformal external beam brachytherapy.

• Multicatheter Interstitial Brachytherapy

Multicatheter Interstitial Brachytherapy comprises of the precise placement of multiple plastic channels into the cavity where the tumour has been removed. The placement is carried out prior to treatment, followed by a treatment simulation. During treatment, the catheters will be connected to a high-dose-rate afterloader. The afterloader houses the radioactive material, Iridium 192, which is guided into the catheters and will stay for a calculated time in each allocated position. Radiation treatment is delivered twice daily over a period of one week and the catheters will be removed upon completion of treatment.

• Intraoperative Radiation Therapy (IORT)

Intraoperative Radiation Therapy (IORT) involves the use of the Intrabeam® to irradiate the tumour site during the surgery. An applicator of suitable size that fits against the walls of the excision cavity is carefully selected for each patient. The entire course of radiation is delivered to the patient in one single dose. The patient is under anaesthesia while the dose is administered thus sparing her of any inconvenience and discomfort that she may sometimes experience if radiation therapy was administered conventionally.

如何进行放射治疗?

Treatment for different patients varies from one day to a few weeks. Commonly, the external radiation treatment will be given once a day for 5 days from Monday to Friday. You will rest on Saturday and Sunday. This is done usually over a period of between 1 to 7 weeks. You may be required to receive treatment from one or more treatment machines during the course of your therapy.

Each dose will cause a little more damage to the cancer cells. Therefore, it is important that you go for all your treatments, as you will need the total dose of radiation to eventually kill the cancer cells.

一次疗程有多长?

Before the treatment:

At the first consultation, you will meet with the radiation oncologist to discuss the best treatment for you. Once the treatment has been determined, a series of appointments for necessary procedures to prepare you for radiation therapy will be made. As almost all radiation therapy treatment is given in supine position, it is important to inform your radiation oncologist if you have difficulty lying down for 30 to 45 minutes. Depending on each case, the patient may need one or more of the following procedures:

• Making of an immobilization device

• Making of treatment accessories (if necessary)

• Localization and marking of treatment area (Conventional or CT-Simulation) Treatment planning

• Verification of Treatment Plan

如何为治疗做好准备?

The side effects of radiation therapy differ from one patient to another. The types of side effects depend on the part of the body being treated and the duration of the treatment. Some patients may have very mild or no side effects, while others may experience more severe ones. Your general health can also affect how your body reacts to the treatment. The following information acts as a guide to the general effects of radiation. The most common are fatigue, skin changes and/or loss of appetite. These can result from radiation to any parts of the body. Other effects are specific to the area being treated. Inform your radiation oncologist or the radiation therapist about the side effects that you experience during your weekly review. Most of these can be prevented, controlled or treated with medication.

放射治疗的副作用

Hair loss (Alopecia)

Radiation therapy can cause hair loss but only to the area that is treated. If the entire head is within the treatment area then you will experience hair loss. This effect may be temporary or permanent, depending on the radiation dosage.

Helpful tips:

• Avoid exposing your scalp to sunlight, while you are on treatment. Use an umbrella, a hat or scarf to protect your scalp.

• Use a mild or baby shampoo for hair washing to prevent irritation and dryness of the scalp.

Skin and ears

The skin on the scalp and ear canal may become red. This effect is temporary and will subside soon after the treatment is completed. You can ask your doctor for creams to soothe the soreness. Do not self-medicate by applying medicated lotion on the treatment area.

• Use an electric shaver to prevent accidental cuts on your face and neck, if you need to shave.

Mouth and throat problems

Soreness of the mouth and/or throat generally appears two weeks after the start of treatment. You will notice that your mouth has less saliva than usual. You may also find it difficult to swallow food and that food tastes different. Do not let these stop you from eating. These side effects may persist even after treatment is over. Ask your radiation oncologist or the radiation therapist for advice to help you to better manage these effects.

Dental problems

If the oral cavity is within the treatment area, you are more likely to experience tooth decay. See a dentist before you start your treatment so that extra care will be taken during your dental check-ups. Discuss with your dentist and radiation oncologist on oral care, prevention of tooth decay and managing problems such as mouth ulcers. It is important that you follow their advice.

Helpful tips:

• Drink plenty of water throughout the day or suck on ice chips to keep your mouth moist.

• Avoid tobacco and alcoholic drinks because they will dry and irritate the mouth further.

• Drink more fluids, soups or fruit juices.

• Avoid the use of commercial mouthwashes as they may contain alcohol that will dry your mouth. Use the mouthwash prescribed by your doctor or gargle with salt water especially after meals to keep your oral cavity clean.

• Apply oral anaesthetics as prescribed by your doctor if your mouth is sore. Avoid eating food that is steaming hot or spicy as they can further irritate the mucus lining of your mouth.

• Avoid drinks and food that is piping hot or icy cold to prevent sensitivity to the teeth and gums.

• Avoid chewing on dry, hard and coarse foods such as nuts, crackers, crisps, and hard candy that may cause friction and abrasion to the already sensitive mouth lining.

• Brush your teeth with a soft bristled toothbrush to prevent injury to the gums.

头与颈部的放射治疗

Difficulty in swallowing

If your throat is within the treatment area, it may become sore a week or two after treatment. To minimize the problem:

• avoid smoking, drinking alcohol and eating hot, spicy food

• drink plenty of water, between 8 to 10 glasses a day

• eat softer foods such as porridge or soup based foods

• eat small frequent meals

• liquid nutritional supplements may be useful

• your doctor may prescribe you some medication to lessen the discomfort.

Cough

You may cough more and experience some breathlessness during or after treatment. If your cough is productive of greenish, yellowish, blood stained or foul smelling sputum, please consult your doctor. Some medication may be required to remedy these problems.

Skin changes

The skin on your chest and especially on your back may become darker, just like a suntan effect. This does not require any medication and the discoloration will lighten gradually after treatment.

胸部的放射治疗

Skin changes

The degree and intensity of the skin reaction will be greater in patients receiving a large daily dose of radiation and in patients who have fair skin. The skin on the treatment site can become red, sore and itchy after a few weeks of treatment. This reaction will remain until about 2 weeks after treatment. To avoid aggravating the skin, you can try the following measures:

• Avoid tight-fitting bras and clothes to prevent friction and irritation to the skin. Choose clothing made from soft material such as cotton.

• Do not apply deodorants, perfumes, talcum powder or medicated lotions on the treatment area. Consult your doctor if you need some skin soothing ointment. Wash the area with lukewarm water and gently pat dry. Avoid vigorous rubbing. If you need to shave your underarm, use an electric shaver to prevent accidental cuts.

Shoulder joint stiffness

You may experience some stiffness in your shoulder following breast surgery and/or radiation where the upper arm may be involved. Do daily gentle exercises, such as lifting your arm above your head. This will prevent permanent stiffness to the shoulder joint. For more information on arm exercises, contact your Breast Care Nurse or call the Cancer Helpline at (65) 6225 5655.

乳房的放射治疗

Loss of appetite

Radiation to the abdomen can cause you to have loss of appetite, sometimes even nausea and vomiting. If it is severe, inform your doctor or radiation therapist. Medication can be given to relieve this problem. You may feel tired and sleep more often than usual. These effects are temporary and should subside after your treatment ends.

Bowel changes

You may experience some discomfort or cramps during the treatment. This is caused by irritation to the digestive tract lining from the radiation treatment. The discomfort is usually mild and temporary. However, if it becomes severe or occurs frequently accompanied by vomiting or fever, please inform your doctor or radiation therapist at once.

Skin changes

The skin over the treatment area particularly over the back of the body may turn slightly red or become darker, just like a suntan effect. This is temporary and will subside after the entire treatment is completed. Do not self-medicate. Ask your doctor for some topical cream to soothe the irritation.

Skincare:

Do’s

• Do wear clothing of soft material. Some of the dye markings may rub off on your clothes; it is best to wear loose soft garments.

• Do protect the treatment area from the sun. Always cover your treated skin by wearing light, close-weaved clothing before going outdoors. Ask your doctor about using a sunscreen (SPF 15+ Broad Spectrum).

• Do inform your doctor at once about any skin changes such as cracks, blisters, skin peeling, rashes and signs of skin infection.

Don’ts

• Don’t rub, scrub or scratch treated skin or any sensitive spots.

• Do not scrub off the treatment markings on your skin after your treatment. Let them wear off gradually.

• Don’t put any soap, creams, deodorants, medicines, perfumes, cosmetics, talcum powder or other substances on the treatment area without doctor’s approval. Many over-the-counter skin products, such as lotions and petroleum jelly, leave a coating that can interfere with radiation therapy.

• Don’t put very hot or cold items such as a hot-water bottle or ice pack on the treatment area. Bathing or showering with hot water can also injure your sensitive skin. Use only lukewarm water.

• Don’t use a razor on the treatment area. If you must shave, use an electric shaver but first check with your doctor or nurse.

腹部的放射治疗

Bladder irritation

Radiation treatment to the bladder can cause some discomfort and irritation when passing urine. You may also feel the urge to go more often than usual. Increase your intake of fluids as this will help to relieve this uncomfortable symptom. If this discomfort persists or worsens, such as having blood stains in the urine, or if you develop a fever, please inform your doctor or radiation therapist at once.

Bowel changes

Diarrhoea may occur a few weeks after starting treatment. Reduce the intake of vegetables, fruits, milk and milk products to avoid aggravating the condition. If the diarrhoea worsens, inform your doctor.

Skin changes

Some redness and itch may occur on the skin over the buttocks and pubic area. Sometimes it may become sensitive and painful. Avoid wearing tight fitting pants or underwear. The hair on the pubic area may gradually fall if the area is within the treatment field. Request from your doctor some topical cream to soothe the discomfort. Do not apply your own cream or lotion and remember not to erase the treatment markings on the skin.

骨盆的放射治疗

Fertility problems

Having radiation therapy in areas near your reproductive organs can affect your fertility or your ability to have children. This can either be temporary or permanent. In women, radiation therapy to the pelvic area can result in symptoms similar to those of menopause. Radiation therapy affects the ovaries and the production of female hormones. Menstruation may become irregular or stop completely. Sometimes this alteration reverses itself but some women may experience early menopause when the ovaries stop hormone production permanently.

For men, radiation to the pelvic area may affect the testicles, which may reduce sperm production either temporarily or permanently. However, this does not affect your ability to enjoy sex. Speak to your doctor about your concerns before you start your treatment.

Intimacy and sexual concerns

You may experience discomfort during sexual intercourse if the pelvic area is within the treatment field. This discomfort is temporary. You may also experience a lower desire to have intercourse because of this discomfort.

In women, the vagina may feel dry, sore and itchy. This can make intercourse painful. A woman’s vagina may feel tender during radiation therapy, and for a few weeks afterwards. As the irritation heals, scarring occurs making the vagina narrower and sexual intercourse painful. You may notice some light bleeding after intercourse because radiation therapy can also make the lining thin and fragile.

After the course of radiation therapy, your doctor will refer you to our Dilation Clinic for patient education and demonstration on the use of dilators. Regular dilation processes will reduce the narrowing of your vagina.

Even if a woman is not interested in staying sexually active, keeping her vagina normal in size allow comfortable gynaecologic examination, an important part of follow-up treatment.

Most men find radiation therapy to their pelvic area has little direct effect on their sexual function. This therapy may occasionally affect sexual function when used for cancers of the prostate, rectum and bladder. It affects erection by damaging the arteries that carry blood to the penis. The higher the total dose and the wider the section of the pelvis is irradiated, the greater the chance that an erection problem will develop.

This change usually develops gradually over the year or two following radiotherapy. Some men continue to have full erections but lose them before reaching climax, while others no longer get firm erections. Some feel a sharp pain when ejaculate, caused by radiation irritating the urethra, the passageway for semen during ejaculation.

In a small group of men, testosterone production slows after pelvic radiation that results in lowered sex drive.

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