Radiation Oncology Services

Radiation Oncology Services

Radiotherapy is used to treat almost all types of cancer
Radiotherapy can be used to treat almost all types of cancer. The role of this treatment modality weakens slightly in treatment of pediatric cancers, such as leukemia, also called liquid tumor, due to the risk of side effects. Apart from this, it plays a very significant role especially in treatment of head & neck cancers, lung cancer, gynecological tumors, bladder tumor, skin cancers and brain tumors. For example, surgery is not an option for locally advanced cervical cancers and chemotherapy alone is not effective. If cervical cancer is confined to the uterus and chemotherapy is combined with radiotherapy, the success rate of treatment increases up to 90 percent. If cervical cancer spreads slightly beyond the womb, local and regional control can be obtained by 70 to 80 percent.

Side effects of radiotherapy is ever increasingly minimized
Technological advancements paved the way for significant developments in the field of radiotherapy. For example, two-dimensional radiotherapy caused irreversible dry mouth in patients with head & neck tumor in the past, while treatments are not, now, leading to dry mouth. Skin burns were among the most common side effects of radiotherapy in the past, but today intensity modulated radiotherapy can be performed that protects the skin. Briefly, advanced technology is ever increasingly minimizing the prevalence of acute and late side effects during and after radiotherapy.

Radiotherapy causes breaks in DNA that is found in nucleus of tumor cell
Radiotherapy uses ionizing radiation to treat diseases. If X-rays are used, the ionizing radiation ionizes largely the water molecules that are found in the cytoplasm. These ions facilitate generation of radicals. Generation of ion radicals is followed by free radicals that cause fragments in DNA of the cell. In fact, the effect of the radiation is not selective or in other words, it does not only affect tumor cells. The healthy cells located among or around tumor cells are also influenced. Since DNA repair genes of healthy tissues are intact, these cells can start a self-repair mechanism and survive. On the other hand, DNA repair genes are frequently mutated in tumor cells and therefore, tumor cells die. DNA breaks have two types; single-strand breaks or double-strand breaks. In case of double-strand break, the result is death, as there is serious loss of genetic structure. Cells can repair the defect in single-strand breaks. This phenomenon is called “radiation resistance”. The targeted effect of radiotherapy is to create double-strand breaks such that the genetic structure that is matched in two strands of DNA is broken.

Local control is the most important target of treatment
Local control is the most important target of radiotherapy. Treatment aims maximizing the local control, while side effects are minimized. Treatment should ensure strong local control, while acute and late side effects should be minimized.

Radiotherapy planning is a long and important process
As is the case with other therapies, the first and most important phase of radiotherapy is obtaining detailed medical history of the patient. There is no diagnostic method that is as valuable data source as the patient. Treatment process is maintained with detailed physical examination. Tests are reviewed in the next phase. If the resultant data indicates requirement of radiotherapy, planning tomography is scanned to determine the target zone and radiation oncologists draw target volumes – the body regions that are very likely to be involved by tumor and pose high risk of microscopic disease – one by one on the tomography images. Moreover, healthy tissues are also drawn on planning images. Next, the best treatment plan is created by physics engineers. Later, the treatment is jointly reviewed and amended, if necessary, by radiation oncologists and physics engineers. This process may take several days. Sometimes, tens of treatment plans can be created for a patient. If the plan serves the aim, next stage is the quality control. All data generated by the plan are digitally checked and the treatment phase is started, after all necessary checks are completed. .

Radiotherapy planning is a substantially long and important process. Today, high-tech devices are available almost in all centers. Success of treatment is almost equally affected by device quality and experience of the team members who operate the device.

Treatment should be planned and performed to minimize the risk of side effects
Radiotherapy may cause some acute or late side effects. Examples of acute side effects include nausea in a patient who receives radiotherapy for abdomen or diarrhea or hemorrhoid if radiotherapy is targeted to pelvis. These acute side effects disappear several weeks after radiotherapy is completed. Here, late side effects are what matters. In the absence of a good plan, the risk of a future myocardial infarction may increase, as the therapy that targets the heart may cause atherosclerosis.

Recent technological advancements minimized the side effects of radiotherapy. Undoubtedly, each treatment has certain side effects. Here, it is important to make and execute a plan that minimizes the risk of side effects.

Radiotherapy is a matter of teamwork and the team does not only comprise of radiation oncologists. Anti-cancer treatment requires multi-disciplinary approach. Tumor council of our hospital that consists of radiologists, pathologists, medical oncologists, surgeons and radiation oncologists work in full cooperation and harmony.