Truebeam Era in Radiotherapy
Truebeam Period in Radiotherapy
In recent years, both in our country and in the world, Truebeam device which can use all radiotherapy techniques together and at a higher level is preferred in oncology treatment. By this means, thanks to high dose beams, cancer patients can be treated both faster and without getting damage to their nearby tissues and organs.
In the treatment of cancer patients, radiotherapy and chemotherapy are the most prominent. In this group, radiation oncology is concerned with a considerable number of the patients. In radiotherapy, extermination of the cancerous cells by giving high dose beams to the tumorous regions is aimed. However, with the classic method, beams may be given to the regions out of the target and damage may be caused on the skin. On the other hand, both 3D treatments and intensity modulated radiotherapy and volumetric ARC treatments can be performed together by Truebeam device which is frequently used recently in the world and in Turkey. At the same time, the device enables stereotactic body radiotherapy and Prof. Esra Sağlam, MD (Head of Radiation Oncology Department in Memorial Şişli Hospital) states that it is the most advanced linear accelerator in Turkey now. She says “Truebeam is a device with a broad spectrum in terms of providing all kinds of treatment. Along with the model that applies intensity modulated radiotherapy, stereotactic body radiotherapy can also be performed with TrueBeam STX”.
Stereotactic body radiotherapy applied with TrueBeam STx comes forward as a very practical treatment because by this way, hospital stay periods of the patients are shortened notably and the dose rate given in a single day is increased. Prof. Sağlam, MD states that while 2 gray doses are given in a day in normal treatments, 10 or even 20 gray doses of higher and tumorous area destroying doses can be given in a single day in stereotactic body radiotherapy. She explains the procedure with these words: “By this method, probability of tumour disposal in one session is very high and the time spent becomes very short. As an example in lung cancers, treatment can be completed within a week by administering three doses on alternate days. This device is also quite effective in liver metastases. In the metastases of 3 cm or below, stereotactic body radiotherapy with 4 fractions or by increasing to 5 fractions according to size, it can completely be focused on the region with metastasis. Here, repressing the respiration and detecting the target accurately by using certain applicators is important. By holding the patient in correct position, a completely fatal dose can be applied to the metastasis region of liver in three-four times.”
Organs are different, device is the same
TrueBeam is significant in the treatment of breast, lung, gastrointestinal system and especially rectum region cancers. Apart from this group, there are patients who receive the treatment in esophagus region. Prof. Sağlam, MD states that these patients have some special conditions and says, “Since disease area is very large in this group, probability of toxic effect on lung increases. Since this probability is diminished considerably in the plans made with TrueBeam, higher doses can be applied in esophageal tumours. Apart from these, Truebeam is helpful in brain tumors as well but it necessitates a bit more different applications”.
No effect on daily life
In oncologic treatments, surgery and chemotherapy procedures may affect the life quality of the patients. However, this problem isn’t encountered in radiotherapy. Especially when it is performed correctly and if normal tissues are protected with appropriate doses, it does not cause a significant effect on the daily performance of the patient. Prof. Sağlam, MD also tells that side effects such as decrease in blood values, nausea and alopecia are not seen and adds, “During radiotherapy treatment, only skin reaction may occur. However, with TrueBeam procedures, even in cases such as breast cancer in which skin reactions are frequently seen, no skin reaction that appears to be over Grade1 or Grade2 is encountered. Mild blushing on skin that resembles sunburn may occur. However this look disappears after a short time.”
Millimetric treatment is given
Radiotherapy procedures performed with TrueBeam lasts for approximately 10-15 minutes beginning from the preparation process of the patient to the completion of the treatment. Therefore, the patients can go to work, can drive and continue their social lives after this treatment in which they don’t feel any pain.
In TrueBeam, which is an open-topped device, there is a handle rotating around the patient. Thus, patients, who feel uncomfortable about covered areas such as MRI device, can easily receive treatment. Patients lie down in supine position in a comfortable area. After they are fixed, they lie down in this way for 10 minutes. Meanwhile, the treatment is given. The device has the possibility of retrieving image from different angles. The rotating handle can target the intended field from a very broad angle. The board on which the patient lies moves in six directions making it possible to apply treatment to very thin and sensitive regions with millimetric accuracy.
In which diseases is TrueBeam preferred?
TrueBeam is a treatment device which can perform a more developed way of 3D radiotherapy. Along with this, it is also very suitable for use in intensity modulated radiotherapy (IMRT) and radiotherapy with the guidance of image developed afterwards (IGRT). To define the target and to give the necessary dose by preserving normal tissues carry major importance in radiation oncology. However, the patients are living organisms so many tissues and organs continue their routine. The heart and the continuity of respiration cause movement and change of location of many organs. Prof. Esra Sağlam, MD states that when an area inside the abdomen will be irradiated, intestines continue their functions and she says: “In 3 dimensional and intensity modulated radiotherapy procedures, these moves are ignored a bit. In fact, in small areas and in regions where movement is important, implementing the treatment by considering also the movement provides a great advantage.”
Getting effective results in a short time
The plans made with TrueBeam can be placed on the patient's body during the treatment and three-dimensional images can be obtained. First, a tomography like a Computerized Tomography is obtained. The location of the tumor in the patient is checked and based on its accuracy, the treatment is continued guided by the three-dimensional image. Prof. Sağlam says that in a patient with early-stage pulmonary tumors, high-dose treatment of the area concerned is one of the areas where radiotherapy and surgery are equal and adds: "It is necessary to irradiate a 3 cm tumor in the lung correctly and to give a specific dose in a direct manner. In planning this, the respiratory movement of the patient is calculated. The results of the examinations are applied on the patient's body. Therefore, during the treatment, the motion of the tumor in the patient is calculated and the required volume is obtained via tomography after which intensive radiotherapy can be administered. Likewise, when treating certain tumors via TrueBeam, the respiration and intensity can also be adjusted. This is the intent of intensity modulated radiotherapy. For example, when the pancreas is irradiated in the abdomen, it is possible to perform intermediate doses such as grey and its tones, rather than just black and white, administering higher doses and lower doses to certain locations. Despite the fact that there are other devices that can do this, TrueBeam stands out in terms of speed and comfort. For example, IMRT type treatment can be performed with different devices, but the duration takes 35 minutes and sometimes up to one hour. However, with TrueBeam, the treatment of a patient whose checks were performed with FFF technology for example can be completed in only three to four minutes with a very fast and high monitor unit at the IMRT. This is due to the fact that the device can go to the high monitor unit very quickly and can quickly perform intensity-modulated radiotherapy, dynamic radiotherapy or ARC treatments. When used in early-stage pulmonary tumors, stereotactic body radiotherapy can be used as well and radiosurgery can be performed with image guidance. "
Prof. Esra Sağlam, MD explained treatments of tumors and procedures where TrueBeam stands out.
One of the diseases in which TrueBeam excels is breast cancer. When irradiating the breast, the intensity is modulated throughout the radiotherapy and a maximum dose is administered to the breast. At the same time, a different dose can be administered to the area where the tumor is located. On the other hand, the lungs, the esophagus and the heart are preserved at the same time and are not damaged at all. Treatment can also be completed quickly. Breast cancer patients can be treated with both long and short course radiotherapies. For example, a six-week period can be reduced to 16-18 days.
Tumors of the Rectum
CT and PET CT are used for the treatment planning of the tumors seen in this region. PET CT scan helps physicians. In this imaging method, after the patient is placed in the appropriate position, the data obtained from the online system can be seen. With the help of PET, the most and least prominent areas of the tumor and the areas where the disease is absent are determined and planning is performed accordingly. The limits of the region to be irradiated and the doses to be used are also adjusted accordingly. These features are the advantage of working with PET. By planning with PET CT, patients may be given higher doses, especially to areas where rectal tumors are present and lower doses at sites where pelvic lymph nodes are present.
Treatment of lung tumors using stereotactic body radiotherapy is planned with PET CT and is performed by high dose irradiation to the area where full illumination is present. Likewise, since PET takes a little more time, four-dimensional therapies can be performed by following the movement caused by respiration.
Especially in both early and advanced lung tumors, esophageal reactions are predominant in lung irradiation. When radiotherapy is administered with chemotherapy, a high level of esophageal sensitivity can prevent the completion of treatment. However, in TrueBeam treatments, the esophagus is much better preserved and the desired dose can be effectively applied to the lung tissue without any damage.
Advanced technology in cancer diagnostics
A number of methods are used to diagnose cancer in a patient. The predominant imaging method in this field is called positron emission tomography (PET CT). Two devices are unified in this method, which is an integrated form of the tomography system. Memorial Ankara Hospital Nuclear Medicine Department Professor Emel Öztürk, MD states that the PET CT, which is predominantly used in oncology patients, is used in the diagnosis of specific cancers, for the staging of the disease and in determining the efficacy of the treatment given and warns as follows: “It should not be forgotten that PET CT is definitely not used for cancer screening for those who are wondering if they have cancer. This is not a screening test. However, it needs to be done in cases where the relevant physicians deem it necessary.”
It is also Used Outside of Oncology
While the most common area of use of the PET CT is oncology, it is also used in other areas. PET CT is used, for example, in the selection of patients who need to undergo bypass surgery. This is because after a heart attack, some living tissue can remain. If this is the case, bypass surgery may be much more useful. Otherwise, it is not beneficial to perform a bypass on a patient and performing surgery can also create a risk. Apart from that, there is an important application area where PET CT is used less frequently. This device is also used in the differential diagnosis of Alzheimer's disease. PET CT stands out in detecting the presence of Alzheimer's in cases with a mild decrease in cognitive functions called early mild cognitive impairment and with family history.
There are many different agents in PET CT. By using these, it can be understood whether or not the treatment will be beneficial for the patient. The name of this agent, called "Theranostic", is a combination of the words therapeutic and diagnostic. This condition, which means that an agent used in diagnosis can be used for treatment later on, has maintained its place in the agenda for the last few years.
Professor Öztürk, MD explains the superiority of PET CT over other nuclear medicine methods used so far with the following words: “PET CT marks the molecules the body uses. While most other methods provide morphological assessment, PET CT provides information at the cellular level.”
May 13, 2017