Special Practices

Cyberknife (Space Scalpel: Robotic Armed /Robotic Tabled Linear Accelerator)

Stereotactic radiotherapy or radiosurgery based on the ray beams that focus on the same center from several different angles in order to apply maximum dose over the tumor to be treated and minimum dose over the surrounding healthy tissues by using of the data obtained through imaging techniques (computed tomography, magnetic resonance, positron emission tomography, angiography). If the treatment is performed on more than one fractions, it is called “Stereotactic radiotherapy” and it is called “Stereotactic radiosurgery” when performed on a single fraction. One of the most important developments on recent years in this field is to begin applying stereotactic radiosurgery with Cyberknife® for cranial and extra-cranial lesions.

Determining optimal target and homogenous and more conformal treatments within 1 mm clinical correctness deviation are possible by the help of image fusion with Cyberknife (CT, MRI, PET/CT, 3D angiography fusion). Its significant differences with other treatment devices are that it does not require a framework that is screwed on head in the treatment of intracranial lesions, it can compensate the patient’s movements and organ movements during treatment by using dynamic ray, and it offers a safe treatment with control radiograms per 20-30 seconds. It uses the utmost radiotherapy technology as Image Guided Radiation Therapy (IGRT). It is the only device which called 4-dimensional radiotherapy and that can simultaneously treat and actively monitor the respiration movements in cases that involve organ tumors moving with respiration (early phase lung cancers and metastases of Lungs being in the first place). The linear accelerator of robotic arm offers a wide range of use in radiosurgery and radiotherapy:

Brain:

• Benign brain tumors
• Arteriovenous malformations
• Functional tumors
• Malignant brain tumors (combined with adulthood and childhood conventional external treatment)
• Metastases (1-3)

Whole body:

• Lung cancers
• Prostate cancer
• Head-neck cancers
• Vertebra tumors
• Certain gastrointestinal tumors (particularly pancreas)
• Metastases (1-3 liver and lung metastases)

Intensity-modulated radiotherapy (IMRT)

It is extremely difficult to apply maximum dose only to tumors or tissues highly possible to contain tumors by protecting normal tissues with conventional radiotherapy, especially in irregular areas. The maximum dose over the tissue has been applied by changing the radiation beam intensity and meanwhile protect the normal tissues sensitive to radiation with the help of three dimensional planning systems and linear accelerators with dynamic multi-leaf collimator systems developed in recent years. Intensity-modulated radiotherapy (IMRT) is a method that can appropriately perform complex treatment planning which result in calibrated flow of photon ray profiles and radiation of irregular structures by applying dynamic radiation. In this method the radiation density is changed along the beam and inverse treatment planning algorithms are benefited for this purpose. In inverse treatment planning procedure, target and critical organs and desired dose distribution are defined into the treatment planning computer and desired optimal dose distribution is tried to be get with various beam combinations. In recent years IMRT has increasingly been used in the treatment of particularly brain tumors, head–neck tumors, breast cancers, prostate cancers. In practices, while a more homogenous dose distribution at the target mass obtained by IMRT when compared to conventional chemotherapy, lesser toxicity in normal tissues due to the decrease in the radiation dose is reported.

Whole body irradiation

Whole body irradiation is a treatment method which is generally applied before bone marrow transplantation and for some other diseases. The Linear Accelerator on floor -1 is used for the treatment of the patient.

Before the treatment a serum and necessary medication are given to the patient to diminish side effects. During the treatment, which is teamwork, the patient is laid down on a stretcher. After the special measures are taken, the patient is treated from both side areas. Patient feels nothing during the treatment. Generally the treatment may take 20-40 minutes; it is significant for the patient not to move during this period. After the treatment, the patient is taken out from the device room. It is normally applied for 3 days by 6 sessions.