Radiotherapy (radiation therapy)

Radiotherapy is an important pillar of treatment for cancer. It helps with various types of cancer. High-energy beams are used, which can be directed specifically at the malignant tumor. The cancer cells are damaged and die. Find out exactly how radiotherapy works, what types there are and how it works. Also: The most important tips for preparing for radiotherapy and aftercare.

Overview: What is radiotherapy?

Radiotherapy is a very important treatment option for people with cancer – alongside surgery, chemotherapy, targeted drugs, immunotherapy and hormone therapy. It is used for many different types of cancer, for example breast cancer, bowel cancer or prostate cancer. Radio-oncologists use high-energy radiation to combat malignant tumors. These beams are generated by a special device, usually a linear accelerator.

Cancer cells react more sensitively to radiation than healthy cells because they divide and multiply more quickly. The radiation damages the genetic material (DNA) of the cancer cells. In contrast to healthy cells, however, malignant tumor cells can no longer repair this damage. They can no longer divide and die. The aim is to eliminate all cancer cells with the help of radiation or to slow down the growth of a tumor.

Radiotherapy is a treatment that mainly acts locally and is very precise. It is only effective at the points where the rays actually hit – i.e. in the area of the tumor itself or, for example after an operation, in the former tumor bed. In contrast, chemotherapy unfolds its effect throughout the entire body (systemic). Healthy tissue should be spared as much as possible during irradiation. However, there are also healthy, rapidly dividing cells that can be affected by radiation. Examples are skin and mucous membrane cells. Reactions to the skin and mucous membranes are therefore frequent side effects of this cancer therapy.

There are different types and applications of radiotherapy:

  • With most types of cancer, the radiation enters the body from the outside via the skin (percutaneous radiotherapy).
  • There is also internal radiation (brachytherapy), for example for cervical cancer. A radiation source is introduced directly into the tumor and can therefore act from the inside.
  • Stereotactic radiotherapy is a high-precision radiation treatment. It is suitable for small tumors that are located deeper in the tissue. It can be compared to a “surgical knife made of rays”. This is why the method is also known as radiosurgery.

Experts also differentiate whether radiation is curative or palliative. In the latter case, the aim of radiation is to slow down the progression of the tumor, halt its growth or alleviate symptoms, for example due to metastases in the bones.

Radiotherapy can be used as the sole therapy or in combination with chemotherapy, targeted drugs, immunotherapies and hormone therapies.

Radiotherapy can also be used adjuvantly as support after surgery and chemotherapy to eliminate any remaining cancer cells. It can be used neoadjuvantly to shrink the tumor before surgery. Then it can be operated on better in selected cases.

X-ray machine for radiotherapy

Radiotherapy procedure

Make sure you are well informed in advance about the radiation therapy procedure and the possible side effects and long-term consequences. Then you know what you might have to expect. Radiotherapy can have some side effects, such as

  • Tiredness, exhaustion and even fatigue
  • Skin reactions, e.g. reddening of the skin, inflammation
  • Nutritional problems, for example if the esophagus or oropharynx is irradiated
  • Gastrointestinal problems if radiation is administered to the gastrointestinal tract
  • Hair loss
  • Damage to the teeth
  • Impairment of fertility

The side effects always depend on which region of the body is irradiated, how far the cancer has spread and which dose is chosen.

The radiation dose is usually not administered all at once in one session, but divided into smaller “portions”. You will therefore have to undergo radiotherapy every day during the week. The duration of treatment can vary and can last several weeks – depending on the type of cancer and the extent of the cancer.

Radiotherapy can usually be carried out on an outpatient basis. This means that you only come to the clinic for radiotherapy and can then go home again. Inpatient radiotherapy, where you stay in the clinic, is only necessary in a few cases. Always discuss this with the doctors treating you.

The course of radiotherapy (from the outside) can be described as follows:

  • Radiotherapy requires precise planning in advance (see section “Preparation” below).
  • For the radiotherapy itself, you will be seated on a radiotherapy table. It is a component of the radiation unit and can be adjusted to various positions. The specialist places them so that the rays hit your tumor precisely. You must adopt the same position for each session.
  • Before each therapy session, the specialist staff check the settings on the radiation device. Control images also show whether the storage is correct.
  • During the session, you must lie as still and as relaxed as possible.
  • You are alone in the room during irradiation. However, you are connected to the radiology staff in the next room via an intercom system and video camera.
  • The linear accelerator moves around you from a precisely defined direction and at specific intervals.
  • The radiotherapy itself only takes a few minutes. One session is therefore quickly completed.
  • Incidentally, after radiotherapy you are not a radioactive danger to others – you can have normal contact with other people.

Preparation: Radiotherapy needs to be well planned

Radiotherapy requires one thing above all: good planning, because it is real precision work for the treatment team. The aim is to irradiate the tumor with the highest possible doses and at the same time to spare healthy tissue sufficiently. You will also need to be patient until all the settings and the position are correct. Experts from various disciplines are involved in the planning process, including specialists from radio-oncology and physics as well as specialists in medical-technical radiology (MTRA).

The most important steps are:

  • Specialists use computer tomography (CT ) to plan radiotherapy. They read the images into a radiation planning computer. This allows the body area to be irradiated to be defined with millimeter precision.
  • The treatment team then creates a 3D image and determines the most favorable arrangement of the radiation fields. With the help of radiation planning on the computer, it is possible to calculate in advance which radiation dose will affect which region of the body.
  • Sometimes it may be necessary for specialists to make markings with a waterproof pen on the areas of the body that are to be irradiated. These markings are taped and remain there throughout the radiotherapy. You must not wash them off.

Radio-oncologists calculate the total dose with which you should be irradiated. The unit for this is “Gray” (Gy). They divide these into several meetings(individual fractions). The dose is therefore not usually administered all at once.

The schedule for radiotherapy can vary depending on the type of cancer. You usually have to undergo radiotherapy five times a week, with breaks at weekends. How many weeks you have to expect also depends on your individual cancer. Two radiation sessions per day (hyperfractionated) or only one to three radiation sessions per week (hypofractionated) are also possible. Always discuss your personal schedule carefully with the doctors treating you.

Before radiotherapy: tips

The following tips may be helpful for the time before the radiation treatments:

  • Clarify the arrival and departure in advance. In most cases, it is easy to travel to and from the event by public transport or by car. There are also appropriate transportation services if you don’t want to drive yourself and no relative or friend has time. For short distances, walking or cycling may be a good option – exercise is good for your health.
  • If you are not physically fit due to the strenuous cancer treatments – find out whether you can get a home help to support you.
  • You can normally eat and drink normally before the radiotherapy. An empty stomach is usually not necessary. However, there are also exceptions, for example radiation to the stomach and intestines. Discuss this question with your treatment team in advance.
  • Wear clothes that are comfortable and that you can take off quickly. Then you won’t waste too much time in the changing room.
  • Ask your treatment team whether you can use cosmetics such as creams, ointments, powders, deodorants, make-up or perfume before the radiation treatment. Personal care products that you use outside the radiation fields are generally not a problem.

Aftercare: tips for the time after radiotherapy

Immediately after radiotherapy, these tips may help you:

  • Skin care: Irradiated skin needs special care. Ask your treatment team to recommend products that are gentle on the skin – the aim is to avoid further irritating the skin. Some tips: Wash skin only with lukewarm water or pH-neutral soap; use products that are gentle on the skin; do not rub skin dry, but dab gently with a soft towel.
  • Make sure you have adequate sun protection – do not expose the irradiated areas to direct sunlight.
  • Do not scratch if your skin itches – it can become inflamed.
  • It is best to wear loose-fitting clothing made from natural materials rather than synthetic ones, such as linen, cotton or silk. You sweat less in them. Also avoid scratchy and abrasive clothing that stresses the skin.
  • Move as much as possible. Go for a walk, cycle or take a short hike. But don’t overextend yourself!
  • Make sure you relax sufficiently
  • Eat a healthy, balanced and varied diet and don’t forget to drink (e.g. tea, water, fruit juice spritzers – at least 1.5 liters per day)
  • Do not smoke and it is best to avoid alcohol, as this puts additional strain on your body. If this is not possible for you, keep it moderate!

Follow-up care after radiotherapy

Aftercare is an important part of any cancer treatment. Doctors check the success of the radiotherapy, look for signs of a relapse (recurrence) and ask you about symptoms, possible side effects and long-term consequences of the radiotherapy. Some, for example, struggle with skin problems after radiotherapy, others with chronic fatigue. Depending on the type of cancer, radiotherapy can cause various side effects and late effects. However, the symptoms can often be treated well.

Physical examinations, blood tests and imaging procedures such as computer tomography (CT) and magnetic resonance imaging (MRI = magnetic resonance imaging) are also part of aftercare.

Follow-up care after radiotherapy takes place at certain intervals. Initially, the intervals are shorter, but later they become longer and longer if no relapse is apparent. Follow-up care can be provided by clinics such as the University Hospital Zurich (USZ) or by specialized oncology practices. The family doctor’s practice or other specialist practices can also be involved in aftercare if necessary.

Information on

Radiotherapy is usually carried out in a radio-oncology department in a clinic or in an appropriate specialist practice. They have the appropriate equipment and specialist staff who have a lot of experience with radiation.

Collect all documents and findings before going to the radiotherapy center. These include the pathological findings, which contain the characteristics of your cancer as a kind of “fingerprint”, but above all the results of imaging procedures. The images are also important for planning radiotherapy.