| Abstract [eng] |
Image-guided radiotherapy (IGRT) has been regarded as the state-of-the-art technology for most sites. The ultimate reason for using more sophisticated and expensive technology is the improvement of patients' health. IGRT is used to treat tumors in areas of the body that are prone to movement. While IGRT provides more accurate treatment delivery, it is not without its challenges. Therefore, the main advantages and disadvantages of different modalities of image-guided radiotherapy have been analyzed. A new linear accelerator Halcyon with an integrated Image-guided Radiotherapy system has been installed recently in the Hospital of Lithuanian University of Health Sciences Kaunas Clinics, Oncology Hospital. The patient positioning before the treatment usually starts with accurate visualization of regions of interest (ROIs) within the patient, using image quality assessment (IQA) for KV/MV CBCT. Quality control (QC) is a critical step using the image-guided system for the patient positioning regarding internal organs visualization. Due to this reason Hounsfield units (HU) accuracy, HU uniformity, signal to noise ratio (SNR), a contrast to noise ratio (CNR), low contrast variability, slice thickness, and geometric scaling have been evaluated by using commercially available phantoms (QUART and Gammex) that contain multiple inserts tailored to test various aspects of image quality, using treatment planning system (Eclipse), and software (RadiAnt) and (ImageJ). Each image quality parameter shows consistent imaging for the normalized mean and standard deviations. A conclusion can be stated that the KV CBCT image-guided system performance is accurate to perform IGRT and can be used clinically, but it is recommended to perform quality control tests due to prepared protocol monthly. |
