Feasibility Study of Using Kv-Cone Beam CT Images as Patient Specific Quality Assurance Tool

PURPOSE: Patient-specific quality assurance (PSQA) typically involves the comparison between the planned fluence and the delivered fluence of a routine CT (Computed Tomography)-based radiotherapy plan. In contrast the study focuses on evaluating the kV-CBCT (Kilovoltage Cone beam Computed Tomography) image set as a potential tool for assessing the delivered dose for  images of same cervical cancer patient, enabling the daily assessment and verification of planned dose distributions. METHODS: This research comprised 13 cervical cancer patients who received treatment at the Department of Radiation therapy and Oncology, Kasturba Hospital, Manipal, between 2023 and 2024. Monaco software-5.11.03 was used for image registration, segmentation and treatment planning. Planned fluence verification was analysed using the PTW MEPHYSTO software, a fluence comparison tool. RESULTS: Minor, statistically insignificant differences were observed in dose distribution between kVCBCT and routine CT image-based plans. The planned fluence on kVCBCT images met gamma criteria for most cases, with occasional deviations in specific anatomical planes. CONCLUSION: This study sums up that the dose distribution and planned fluence on kVCBCT images effectively correlated with planning CT images, thereby supporting the daily verification and assessment of planned dose distributions using kVCBCT images for cervical cancer cases.