Radiation is a special type of energy carried by waves or particles. It can be produced by special devices or released by substances called radioactive. This energy is used in medicine for imaging purposes, as well as to treat cancer and some other diseases. Special devices are needed to direct radiation to the diseased organ. In this way, the use of high-dose radiation energy for the purpose of treatment is called “radiation therapy” or “radiation therapy”.

High-dose radiation has the ability to kill cells or prevent them from dividing and multiplying. Because cancer cells divide and multiply much faster than normal cells, radiation therapy is more effective on cancer cells than normal cells. In addition, it is much easier for normal healthy cells to recover and become old than cancer cells. At the stage called” planning”, the treatment is applied to the target by making the necessary drawings so that the diseased tissues are exposed to the most and the normal tissues are exposed to the least radiation.

About 50% of cancer patients have radiotherapy in the type of cancer that can occur in almost every area of the body. In some types of cancer, radiation therapy is the only treatment. Radiation therapy is a treatment that can be performed alone or in combination with surgery and/or drug therapy (“chemotherapy”), and a full recovery can be achieved in a large number of patients.

Radiation therapy;

For the purpose of reducing the tumor before surgery,
For the purpose of cleaning cancer cells that may remain at the level of a microscope in the body after surgery,
During surgery for some types of cancer,
For the purpose of direct treatment without surgery, in combination with chemotherapy,
In some cases, when it is not possible to fully cure the disease, radiation therapy may be applied to reduce the patient’s complaints, such as pain, bleeding. This type of treatment is called “palliative therapy”.
“Radiation oncology specialist”, a physician specializing in the treatment of diseases with radiation, determines the type and plan of treatment that the patient needs.

During the course of treatment, radiation oncology specialists work with a special team. In this team; 0

Radiation physicist: checks that the devices work correctly and give the appropriate dose of radiation.
Dosimetrist: determines the number and duration of sessions in treatments.
Radiation therapy nurse: provides nursing services during treatment, helps the patient to minimize the side effects that may occur for the patient and to tolerate them.
Radiation therapy technician: prepares the patient before treatment and ensures that the treatment devices work.
Radiation therapy is applied in two ways. From the outside (external) and (internal). In some patients, these two forms can be applied consecutively.

From the outside (external):

In most patients, radiation therapy is performed externally. It is usually performed in treatment centers, outpatient clinics, and is performed in the form of directing rays to diseased tissue using radiotherapy devices. External treatments were carried out in 2 dimensions with devices called Cobalt-60 or linear accelerators until recent years. In two-dimensional treatments, normal tissue damage and side effects were greater, as wide safety margins were required to give a sufficient dose to the target volume. But thanks to technological changes in radiotherapy devices in recent years, three-dimensional conformal radiotherapy, IMRT (intensity-adjusted radiotherapy), sterotactic radiotherapy (linac-based, gamachnife, cyberknife) can be applied to the target volume, while the maximum dose can be applied to normal tissue to receive the minimum dose. When it is decided to undergo radiation therapy, the doctor will also decide which device is more suitable for the patient.

Inside (internal):

In radiation applied from the inside (internal), a radioactive substance or source is placed either directly into the tumor or in the body cavity with thin wire or tubes. Sometimes placement can be done in the space left after surgery.

Radiation sources used in radiation therapy are varied. The doctor can use an X-ray or an electron beam. The choice of the source of radiation to be used is determined by the type of tumor, its placement in the body, and in particular its depth. High-energy X-rays are used to treat many types of cancer. Electron bundles, on the other hand, can treat some skin diseases.
Before starting treatment, a preparation session is performed together with a computerized planning tomography. The goal is to personify treatment and determine the irradiation technique that should be selected based on the type and prevalence of cancer. Details about this preparation session and the treatment itself (especially the frequency and duration of the sessions) are reported to the patient by a radiation oncology specialist during the first examination. First, during radiation therapy sessions, the position that the patient has to take inside the device is determined, and then computed tomography is performed in this position. Performing a treatment plan with computed tomography allows you to determine the most risky areas with a tumor and/or the spread of the tumor, as well as the detection of normal tissues that need to be protected. During tomography, an injection into the vein, depending on the area to be displayed, may also sometimes require a urine probe.
By marking the patient’s skin by the radiation therapist, the “target volume” from one radiotherapy session to another is irradiated under the same conditions. For this purpose, ink pens that do not come out easily are used or tatuaj can be made. However, it is necessary to take care that these signs do not come out when washing. Because these signs will be needed until the patient’s treatment is finished. If there’s a deletion, you should notify the therapist. The patient must not complete the deleted signs himself.
After determining the target volume and normal tissue by tomography sections by the doctor, the doctor again meets with the dosimetrist and radiation physicist to determine how much radiation dose the patient needs and how to give this dose, how many sessions it will take. This condition usually lasts for a few days.
After starting treatment, the doctor monitors the patient’s response to treatment, general condition, and possible side effects of treatment. This check is usually done once a week, but the frequency may vary depending on the patient’s needs. It is very important that planned treatments are taken on time. Disruptions to the plan may reduce the expected effectiveness of the treatment.
Radiation therapy is given by dividing daily doses according to the type and location of the tumor. In hyperfractional radiation therapy, The Daily Dose is also divided into several small parts. If several treatments are to be given to an area divided into a day, the application is usually performed with intervals of 4-6 hours.

In intraoperative radiation therapy, surgery and radiation therapy are performed simultaneously. The surgeon removes the tumor tissue as much as possible and radiation therapy is given to the tumor bed immediately after surgery to remove the tumor cells that may have remained in the resulting area.

The patient takes off their clothes and wears an apron before starting treatment. For this reason, it is recommended that he come to treatment with clothes that he can easily change.

A Radiotherapy Technician uses lines that he has already marked on the patient’s skin to determine the treatment area. The patient must sit in a special chair or lie on the treatment table. Although 15 to 30 minutes remain in the treatment room for each session, radiation dose administration occurs in a period of 1 to 5 minutes. The process of receiving external radiation therapy is painless, as in the process of taking an X-ray.

The patient does not need to hold breath during the procedure, and only normal breathing is sufficient. In radiotherapy sessions, it is important that the defined dose is given in the most precise way and the rays reach the right place in the body, that the patient’s position is not disturbed throughout the treatment and that the same position is created in each treatment and that the environment is immobilized in order to ensure the patient’s comfort in the best way. In this process called immobolization, accessories such as head and neck masks, vacuum beds, under-knee stabilizers or shoulder pullers can be used according to the area treated.

The Radiotherapy Technician leaves the room before the beam is given. The devices are controlled from a small area nearby. The patient can also monitor through a monitor or window. At this time, when the patient speaks, his voice can be heard on the speaker and the technician can be contacted. A noisy environment can occur when radiotherapy devices rotate at different angles around the treatment area due to their large structure. But it should be noted that patients, the devices are operated by the relevant technicians and their work is regularly checked. Any questions about the treatment room or devices can be asked to the technician or doctor.

It is not possible to see, hear or feel the radiation in any way. If a condition occurs during the treatment session in which the patient feels very bad or uncomfortable, the technician should be informed immediately. If necessary, the operation of the devices can be stopped immediately.

External radiation therapy does not make the body radioactive. Therefore, there is no need to avoid contact with people receiving treatment. Even in contact situations such as hugging, kissing, there is no risk that will negatively affect other people.

Radiation Oncology (Radiotherapy)