The Radiation Oncology department of Koç University Hospital serves patients in collaboration with MD Anderson Radiation Oncology Center, one of the most notable cancer centers in the world. Thanks to this collaboration, innovative cutting-edge treatment methods and practices of the Texas University MD Anderson Cancer Center, which constitute a reference for the rest of the world in the field of radiation oncology, are made available to patients visiting us in Turkey. All treatments and practices at our department are planned under supervision of radiation oncologists who have been trained at MD Anderson Cancer Center and are actively conducting their studies at Texas University. All team members, from physics engineers to radiotherapy technicians and nurses, are also trained in their respective fields of activity over at MD Anderson Cancer Center, and operate in collaboration with the center. Radiotherapy protocols and practices that have been proven to be effective against cancer and other diseases are selected and carried out at the Radiation Oncology department of Koç University Hospital in line with the standards and guidelines of MD Anderson Cancer Center.

Equipped with the latest technological equipment and a high level of experience, our radiation oncology department draws a roadmap for every type of cancer. Treatment plans are tailored specifically for each patient, who are presented with special treatment options accordingly.  

Practices of Radiation Oncology

Intensity-modulated radiotherapy (IMRT) and volumetric arc therapy (VMAT)

Coupled with a planning method, this process is quite significant in terms of representing the latest achievements in adjustment of dosage distribution. It is essentially practiced for the purpose of mitigating exposure of healthy peripheral tissue to radiation to the minimum level possible. Instead of firing a single large beam of radiation on the body, IMRT divides the radiation into thousands of thin photons, which enter the body from various angles and intersect on the cancerous area at millimetric precision. This enables delivery of a high-dose of radiation to the target zone, while allowing only a low dose to reach peripheral healthy tissue. As IMRT requires absolute precision, the planning period also takes a long time. 

Stereotactic radiosurgery (SRS)

This procedure is performed particularly on small-sized lesions and involves a one-time or fractional delivery of high radiotherapy doses varying between 3 Gy to 24 Gy (Gy: Gray, dosage unit). Thanks to data collected through advanced imaging techniques, a maximum dose is delivered to the target tumor and a minimum to peripheral tissues. For this purpose, bundles of beams are fired to the targeted center at various angles. The procedure is described as ‘stereotactic radiotherapy’, if it takes place in more than one session. If it is otherwise completed in a single session, it is described as ‘stereotactic radiosurgery’. 

Stereotactic body radiotherapy (SBRT)

Radiosurgery performed on an organ other than the brain is defined as ‘stereotactic body radiotherapy’. Basically, this procedure concentrates and delivers quite high doses to a target lesion. 

4D computerized tomography simulation

The Big Bore Onco CT device installed at our center is a 4D computerized tomography (CT) device capable of obtaining 16-slice helical images. The tumor LOC function enables radiation oncologists to rapidly determine location of tumors, which are then laser-marked on the patient in accordance with coordinate data. Adapted to respiratory changes, our CT device is able to visualized tumors that can move while breathing in or out, particularly those located in the lungs or upper abdomen. 

4D radiotherapy (4DRT)

This mode of radiotherapy includes treatment planning after determination of target volume with the help of 4D tomography (4DCT). Radiotherapy can be performed while a patient is breathing in or out thanks to the respiration-adjusted and 4D images that are used in the planning phase. The integrated tumor volume can be treated during all phases of respiration in case of small and low-mobility tumors. 


Placement of radioactive sources in proximity of or directly in the diseased target area is described as brachytherapy or internal radiotherapy. Temporary resources are removed from the body after being kept inside for a specific period of time and gradually lose their active effect. Known as a standard method of radiotherapy around the world, brachytherapy is occasionally used as a curative therapy on its own, and sometimes it is used alongside radiotherapy to improve therapeutical effect. The brachytherapy device installed at our hospital is among the most preferred brachytherapy devices globally. 

Dosimetry equipment

Daily, weekly, monthly and annual quality assurance programs of MD Anderson Cancer Center are practiced at our department. For quality control and dose measurement of treatment devices, we utilize advanced dosimetry equipment, all determined and some specifically designed by MD Anderson Cancer Center. All quality control programs are supervised and reviewed online by MD Anderson Cancer Center as well.


The science of radiotherapy consists of planned and controlled use of ionizing beams in regional and predetermined doses. As a treatment method employed in treatment of at least one out of every two cancer patients, radiotherapy is performed for curative, adjuvant, palliative and prophylactic purposes. 

Radiation is produced by LINAC, linear acceleration, devices. Electrons are made to collide with a metal barrier to produce strong X rays called photons. Over a portal capable of moving 360 degrees, photon beams are conducted to the patient on the therapy pad. Each application of radiation is called a ‘fraction’.   

While radiotherapy ensures maximum impact on the tumor, it also aims to preserve healthy tissues around the tumor. Therefore, it requires careful planning, where the first step is simulation. In this process, the immobilization devices that are aimed at keeping the patient stable during treatment are tested. Tomography images are also obtained in the meantime. It may essentially be described as a rehearsal to radiotherapy. Data collected from the simulator allows radiation oncologists to calculate dosage prior to starting treatment.
Radiotherapy is one of the most significant approaches employed in treatment of various diseases, primarily cancer. More than half of all cancer patients receive chemotherapy. Concurrent chemotherapy and radiotherapy are preferred as a reliable and effective route of treatment in some cases.  

It is often chosen as the initial treatment approach especially in cases of lung, prostate, skin, head-neck cancers, early-stage Hodgkin’s disease, non-Hodgkin’s lymphoma and some tumors like cervical cancer. It is also widely used following surgical intervention in breast, endometrium, testis, bladder, thyroid, pancreas and brain cancers.  

Neoadjuvant radiotherapy is quite common in rectum and soft tissue cancers as well.

Pediatric cancer cases are evaluated individually in line with a multidisciplinary approach and guidelines.
A patient receiving radiotherapy may be treated at doses ranging between 20 to 78 Gy (1 Gy = 1 joule of energy absorbed per 1 kg of tissue) in accordance with the diagnosis, staging and purpose. The fact that the x-ray dosage a person is exposed to in a modern mammography device is approximately 1 per 10 thousand of 1 Gy could be a good indicator of the scope of radiotherapy. The total radiation dose is usually delivered in small doses over the course of 5 days in a week.
Physicians, radiotherapy technicians and patient relatives need to stay out of the room during radiotherapy in order to avoid exposure to radiation. Even though the patient is alone in the treatment room, they can be viewed on a monitor located out of the room. An audio system makes it possible to communicate as well.
A patient does not experience any kind of pain while radiation is being delivered to the target. There is actually no physical discomfort aside from mild irritations that may be experienced during brachytherapy practices. Furthermore, any pain that may be secondary to side effects can be communicated to the supervising physician throughout the term of treatment to receive necessary medical support.
Possible side effects of radiotherapy vary in accordance with numerous factors. Our physicians explain possible side effects that might occur during or after treatment to each patient. The majority of such side effects are entirely temporary and subside after treatment. It should also be noted that mitigating medication can be used for all side effects. In this regard, side effects should be conceived as temporary issues experienced almost by everyone, not at all as an indication of adverse course of treatment or disease.

Healthy cells that are within the target area radiotherapy are influenced by treatment too. Furthermore, the actual location and width of the treatment site matters. Side effects tend to be more frequent in wider areas. Daily doses, total doses and medication taken at the same time may modify side effects. Profile of side effects is directly relevant to performance and age status as well as to choice and quality of radiotherapy.   

Side effects on the skin occur in direct proportion to dosage increases and at later stages of treatment. Likewise, likelihood of side effect is higher in thin or creasing tissues where adequate hygiene and aeration may be difficult, such as the armpits, neck, anus and mouth. Initially appearing in the form of mild redness similar to sunburn, these may turn into purulent open wounds. Radiotherapy on the head and neck may impact the teeth, rendering them more prone to decay. This is why regular dentist checks are essential in these cases. As intraoral tissues are more sensitive to radiation, they may form oral sores. This also requires proper oral care. Other common side effects are drying in the mouth and difficulty swallowing because of lower salivary production. 

The patient’s sense of taste might become disrupted and skin sores could emerge during radiotherapy on the neck. Patients are advised to avoid alcohol and smoking while receiving radiotherapy because of their irritant effects. Impacts associated with lower appetite, voice changes, hair loss, difficulty swallowing in radiotherapy applications on the chest, vomiting, nausea, malaise, fatigue, dyspnea and dry coughs can be listed as the most common side effects. Diarrhea is also quite common with radiotherapy targeting the stomach and upper/lower abdomen. Gastric cramps and bloating may be accompanied with nausea, vomiting, low appetite, weight loss and painful urination.
Radiation oncologists draws up a treatment plan specifying the total days of treatment, number of sessions and radiation dose. They are also responsible for detecting and addressing medical problems that could occur during the course of treatment.
Taking into consideration the radiobiological characteristics of healthy and cancerous cells, high-dose radiotherapy is often performed in numerous sessions rather than at once. While this may change depending on the diagnosis, a period of 4 to 8 weeks on average is necessary for treatment. Spreading the process over time in this manner allows the body to dispose of the effects of radiation.