What is radiotherapy?

Radiotherapy is the use of ionising radiation to treat cancer and some non-cancerous conditions.

Radiotherapy can be used alone or with systemic anti-cancer treatments, or both.

It’s used to:

Attempt to cure cancer (radical radiotherapy)
Control/slow down the growth of cancer
Relieve cancer symptoms (palliative radiotherapy)

How does radiotherapy work?

Radiation therapy does not kill cancer cells right away. It takes days or weeks of treatment before DNA is damaged enough for cancer cells to die.
Then, cancer cells keep dying for weeks or months after radiation therapy ends.
Although normal cells are also affected by radiation, they are better at repairing themselves than the cancer cells.
Radiotherapy is often delivered in several small doses, over a specified period of days or weeks.
The prescription written by your Consultant Clinical Oncologist will define the dose and number of treatments (fractions).
Both short and long-term side-effects are possible and these are thoroughly discussed with you prior to starting treatment as part of the consent process.

When radiation is combined with surgery, it can be given:

Before surgery, to shrink the size of the cancer so it can be removed by surgery and be less likely to return.
After surgery to kill any cancer cells that remain

Radiation therapy is crucial in the treatment of cervical, breast and head and neck cancers which happens to be the most common cancers in the PNG.

Importance of Radiotherapy in cancer care:

About 60% of cancer patients will require some form of radiotherapy in their caner treatment journey. Radiotherapy can be used as either

Curative: Either alone or in conjunction with surgery and/or chemotherapy
Palliative: Reduce symptoms to improve the quality of life

Benefits of Radiotherapy

Painless, minimal adverse effects on the patient’s daily lives
Treatment sessions are typically given on an outpatient basis
Benefits of organ preservation
Minimal impact on returning back to routine after treatment
Sessions typically take 10 to 20 minutes

Type of Radiation therapy

The type of radiation therapy that one may have depends on many factors, including:

The type of cancer
The size of the tumor
The tumor’s location in the body
How close the tumor is to normal tissues that are sensitive to radiation
Patient’s general health and medical history
Whether one will have other types of cancer treatment
Other factors, such as age and other medical conditions

The Radiation Oncology Care Path

External beam radiation therapy

What is External beam radiation therapy?

External beam radiation therapy comes from a machine that aims radiation at one’s cancer.
The machine is large and may be noisy.
It does not touch the patient, but can move around them, sending radiation to a part of their body from many directions.
External beam radiation therapy is a local treatment, which means it treats a specific part of a body.
For example, if one has cancer in their lung, they will have radiation only to their chest, not to their whole body.

Types of Beams Used in External Beam Radiation Therapy

Photons - Most radiation therapy machines use photon beams. Photons are also used in diagnostic x-rays, but x-rays use lower doses. Photon beams can reach tumors deep in the body. As they travel through the body, photon beams scatter little bits of radiation along their path.
Electrons - Electrons are particles with a negative charge. Electron beams cannot travel very far through body tissues. Therefore, their use is limited to tumors on the skin or near the surface of the body

Different modalities of External Beam Radiation Therapy

There are many types of external beam radiation therapy, all of which share the goal of delivering the highest prescribed dose of radiation to the tumor while sparing the normal tissue around it. Each type relies on a computer to analyze images of the tumor to calculate the most precise dose and treatment path possible.

3D Conformal Radiotherapy (3D-CRT)

What it is?

3D-CRT is a common type of external beam radiation therapy.
It uses images from CT, MRI and PET scans to precisely plan the treatment area, a process called simulation.
A computer program is used to analyze the images and to design radiation beams that conform to the shape of the tumor

How it works?

3D-CRT conforms to the shape of the tumor by delivering beams from many directions.
The precise shaping makes it possible to use higher doses of radiation to the tumor while sparing normal tissue

Treatment schedule?

Most people have treatment once a day, Monday through Friday.
The number of treatments vary from person to person based on details about your cancer, such as the type and stage of the cancer and the size and location of the tumor

Intensity Modulated Radiotherapy (IMRT)

What is it?

IMRT is a type of 3D-CRT.
Treatment time per fraction: 20 minutes

How it works?

Like 3D-CRT, radiation beams are aimed at the tumor from several directions.
Usually more beams are used than conventional 3D-CRT

Treatment schedule?

Most people have treatment once a day, Monday through Friday.
The number of treatments vary from person to person based on details about your cancer, such as the type and stage of the cancer and the size and location of the tumor.

Volumetric Modulated Arc Therapy (VMAT)

What is it?

VMAT is a type of rotational IMRT.
Treatment time per fraction: 5 – 7 minutes
The treatment time is much quicker than IMRT.

Less patient discomfort
Less geometric uncertainty
Can treat more patients per machine - economical

How it works?

Like IMRT, radiation beams are aimed at the tumor from several directions.
Usually the beams are divided into small beamlets and they are aimed from every angle in an arc like fashion.
The gantry rotates continuously during treatment delivery and more than one arcs can be employed as required.

Treatment schedule?

Most people have treatment once a day, Monday through Friday.
The number of treatments vary from person to person based on details about your cancer, such as the type and stage of the cancer and the size and location of the tumor.

Image Guided Radiotherapy (IGRT)

What is it?

IGRT is a type of IMRT.
However, it uses imaging scans not only for treatment planning before radiation therapy sessions, but also during radiation therapy sessions.

How it works?

During treatment, you will have repeated scans, such as CT, MRI, or PET scans.
These scans are processed by computers to detect changes in the tumor’s size and location.
The repeated imaging allows for your position or the radiation dose to be adjusted during treatment, if needed.
These adjustments can improve the accuracy of treatment and help spare normal tissue.

Treatment schedule?

Most people have treatment once a day, Monday through Friday.
The number of treatments vary from person to person based on details about your cancer, such as the type and stage of the cancer and the size and location of the tumor.

Stereotactic Radiosurgery (SRS)

What is it?

SRS is the use of focused, high-energy beams to treat small tumors with well-defined edges in the brain and central nervous system.
It may be an option if surgery is too risky due to one’s age or other health problems or if the tumor cannot safely be reached with surgery.

How it works?

The patient will be placed in a head frame or some other device to make sure they do not move during treatment.
In SRS, many small beams of radiation are aimed at the tumor from different directions.
Each beam has very little effect on the tissue it passes through, but a precisely targeted dose of radiation is delivered to the site where all the beams come together.

Treatment schedule?

Treatment schedules can vary, but treatment is usually given in a single fraction.

In some cases, one may receive up to five fractions, each fraction given every alternate day.

Stereotactic Ablative Radiotherapy (SABR)

What is it?

SABR is similar to SRS, but it is used for small, isolated tumors outside the brain and spinal cord, often in the liver or lung.
It may be an option when one cannot have surgery due to age, health problems, or the location of the tumor.

How it works?

As in SRS, SABR also uses special equipment to hold the patient still during treatment.
It delivers a highly precise beam to a limited area.

Treatment schedule?

Tumors outside of the brain are more likely to move with the normal motion of the body, such as with breathing or digesting.
Therefore, the radiation beams cannot be targeted as precisely as they are in SRS.
For this reason, SABR is usually given in more than one fraction.
You may have up to five fractions, each fraction given every alternate day.

Importance of high precision radiotherapy in the treatment of cancer:

These can be delivered by the Halcyon and Truebeam linear accelerators
The probability of saving the normal structures with different modalities of radiotherapy are as follows.

Immobilization devices for external beam radiotherapy

Thermoplastic masks:

All cancer patients planned for radiotherapy might need

to have a radiotherapy mask or mould made before

starting treatment. They keep the treatment area of the

body still each time when having radiotherapy, so the

treatment is as accurate as possible.

It takes between 10 to 45 minutes to make a mask or mould.

2. Vacuum bag:

Vacuum bags are an excellent tool for precise,

comfortable and offers a reliable and reproducible

Linear Accelerators:

Halcyon – type E

Single energy (6MV) Linear accelerator with

Image guidance (KV CBCT – kilo voltage cone beam CT)

Can treat 75 patients / day

Modalities

3D-CRT
IMRT
IGRT
VMAT

Truebeam STx

Photon energies: 6 MV, 10 MV

Electron energies: 6MeV, 9 MeV, 12 MeV, 15Mev, 18MeV

Image guidance (KV CBCT – kilo voltage cone beam CT)

HD MLC – thin MLCs result in highly conformal treatment

Respiratory motion management – for lung tumors

Hypersight Imaging - for improved accuracy

Couch with 6 degrees of freedom

Modalities

· 3D-CRT

· IMRT

· IGRT

· VMAT

· SRS

· SABR

The External Beam Radiotherapy patient pathway

Frequenty asked questions on Radiotherapy

Is the treatment safe?

Each treatment is planned with careful consideration to avoid as much healthy tissue as possible.
Every patient is considered individually and a unique treatment plan is produced. Each department has careful checking procedures in place to minimise risk.
Radiotherapy does not make you radioactive and it is perfectly safe to be around loved ones and young children.

Who will be looking after me?

Your radiotherapy will be planned and delivered by a mixed team of specialist staff, including radiotherapy technologists (RTT), doctors, medical physicists and technical services.
The radiotherapy department is supported by an extensive team including reception and administration staff, assistants, RTTs and nurses, who will help to look after you and ensure your experience is as good as it can be.

Why am I having a different number of treatments to others with the same problem?

There are lots of different types of cancer.
Each type will have a variety of ways it can be treated.
Your doctor or consultant clinical oncologist will have discussed the most suitable treatment schedule for you.
Each patient is considered individually so you can be sure that the treatment you are receiving is the best for you.

Do I have to stay in hospital whilst having Radiotherapy?

Most patients are treated as outpatients and travel to the radiotherapy department for each treatment.
However, if the doctor anticipates any problems due to your health or the type of treatment you might be having you could be offered treatment as an inpatient.

Pregnancy

All female patients between 12 and 55 years will be asked to confirm their pregnancy status at their first appointment in department.
If you are or think you might be pregnant please ensure that you inform your consultant clinical oncologist or a radiographer as soon as possible.
It is important that you take precautions during your treatment not to become pregnant.

Pacemakers

It is important that you inform your consultant clinical oncologist or a member of their team if you have a pacemaker during your initial consultation.
This is required as it is known that radiation can affect pacemakers.
Your department will arrange for a cardiac consultation for clearance and ensure that any necessary precautions are taken.
Sometimes on your first day of treatment it is necessary for a member of the cardiac team to be present and for your heart rate to be monitored.
You may also be required to go for a pacing check once your whole treatment has been completed.

What happens before my Radiotherapy?

You will be asked to attend the radiotherapy department to prepare for the start of your treatment. You may have an appointment in the radiotherapy CT scanner (CT simulation), Mould Room or a combination.
These appointments allow the radiotherapy team to gain important information that will be used to plan your treatment and to decide on the best way to position you for your treatment.

I have only just had a CT scan; do I need another one?

Yes. The radiotherapy CT scan is different to ones you may have had before as you will be scanned in the position that is required to treat you.
Radiotherapy CT scanners are linked to a computer planning system so that the scanning information can be used to plan your treatment.

Will it hurt? Are there any side effects?

During treatment you will not see or feel anything.
The treatment does have some side effects but these are not immediate and vary from patient to patient.
Your treatment team will explain these to you and offer advice for reducing them.

Will I still be able to drive?

Most patients can continue to drive throughout treatment.
However, if you feel unwell or tired it is advised that you ask someone else to drive you.
Some patients are not allowed to continue driving and your doctor will advise you of this. You may need to inform the MVIL of your condition.

Will I lose my hair?

Most patients will not lose their hair.
However, if you are having radiotherapy to your head or neck you may suffer some hair loss.
Your consultant clinical oncologist should have discussed this with you and an appointment to discuss having a wig can be arranged for you by a radiographer or nurse.
Treatment to other parts of your body that have hair, for example your chest if you are male, can also be affected by hair loss.
Patients who suffer hair loss caused by radiotherapy may find that it takes longer to grow back and is often patchy.

Can I still wear make-up?

Make up and perfumes should not be placed directly on the skin within the treatment area, as many contain metallic traces that are left as residue and can increase skin sensitivity and redness.
A Nurse will advise you of which areas of your body to avoid with these products on the first day of your treatment.

Benefits of Radiotherapy

Type of Radiation therapy

Immobilization devices for external beam radiotherapy

Frequenty asked questions on Radiotherapy

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