Study of variation in dose calculation accuracy between kV cone-beam computed tomography and kV fan-Beam computed tomography

• DOI: 10.4103/jmp.jmp_24_17
• Publication Date: 2017-09-13T09:41:31Z
• Authors: PRamesh Babu; Venkatesan Kaliya...; CJomon Raphael; KMathew Varghese; Paul Gopu; S Sivakumar; Minu Boban; NArunai Nambi Raj; K Senthilnathan
• Keywords: Hounsfield scale; Image-guided radiation therapy; Cone-Beam CT

<br>Cone-beam computed tomography (CBCT) images are presently used for geometric verification daily patient positioning. In this work, we have compared the of CBCT with conventional fan beam CT (FBCT) in terms image quality and Hounsfield units (HUs). We also dose calculated using that FBCT. Homogenous RW3 plates Catphan phantom were scanned by FBCT CBCT. phantom, percentage depth (PDD), profiles, isodose distributions (for intensity modulated radiotherapy plans), volume histograms compared. The HU difference was within ± 20 (central region) 30 (peripheral homogeneous plates. central area peripheral areas. differences all ranges starting from −1000 to 990 images. treatment plans done simple symmetric asymmetric fields, (DD) between plan 1.2% both phantoms. (IMRT) plans, different target volumes, <2%. This feasibility study investigated variation calculation accuracy based planning has validated inverse algorithms our study, observed a larger deviation values region region. is due ring artifact scatter contribution which may prevent use as primary imaging modality planning. reconstruction algorithm needs be modified further improving values. However, TG-119 test targets shows can adaptive replanning recalculation anisotropic analytical full accord except build-up regions. Patient carefully analyzed any artifacts before them such calculations.<br>