Background: Currently, CBCT system is an indispensable component of radiation therapy units. Because of that, it is important
in treatment planning and diagnosis. CBCT is also an crucial tool for patient positioning and verification in image-guided
radiation therapy (IGRT). Therefore, it is critical to investigate the patient organ doses arising from CBCT imaging. The purpose
of this study is to evaluate patient organ doses and effective dose to patients from three different protocols of Elekta Synergy
XVI system for kV CBCT imaging examinations in image guided radiation therapy.
Materials and methods: Organ dose measurements were done with thermoluminescent dosimeters in Alderson RA NDO
male phantom for head & neck (H&N), chest and pelvis protocols of the Elekta Synergy XVI kV CBCT system. From the measured
organ dose, effective dose to patients were calculated according to the International Commission on Radiological Protection
103 report recommendations.
Results: For H&N, chest and pelvis scans, the organ doses were in the range of 0.03–3.43 mGy, 6.04–22.94 mGy and 2.5–25.28
mGy, respectively. The calculated effective doses were 0.25 mSv, 5.56 mSv and 4.72 mSv, respectively.
Conclusion: The obtained results were consistent with the most published studies in the literature. Although the doses to
patient organs from the kV CBCT system were relatively low when compared with the prescribed treatment dose, the amount
of delivered dose should be monitored and recorded carefully in order to avoid secondary cancer risk, especially in pediatric
Key words: kV CBCT; equivalent organ dose; effective dose; image guided radiation therapy; Alderson Rando phantom
Rep Pract Oncol Radiother 2021;26(2):251–258