BACKGROUND AND PURPOSE: This study explores methods to reduce dose due to kV-CBCT imaging for patients undergoing radiation therapy. MATERIAL AND METHODS: Doses resulting from kV-CBCT scans were calculated using Monte Carlo techniques and were analyzed using dose-volume histograms. Patients were modeled as were CBCT acquisitions using both 360° and 200° gantry rotations. The effects of using the half fan bow-tie and the full fan bow-tie filters were examined. RESULTS: Doses for OBI 1.3 are 15 times (head), 5 times (thorax) and 2 times (Pelvis) larger than the current OBI 1.4. When using 200° scans, the doses to eyes and cord are 0.2 (or 0.65) cGy and 0.35 (or 0.2) cGy when rotating the X-ray source underneath (or above) the patient, respectively. The 360° Pelvis scan dose is 1-2 cGy. The rectum dose is 1.1 (or 2.8) cGy when rotating the source above (or below) the patient with the 200° Pelvis scan. The dose increases up to two times as the patient size decreases. CONCLUSIONS: The dose can be minimized by reducing the scan length, the exposure settings, by selecting the gantry rotation angles, and by using the full fan bow-tie whenever possible.
BACKGROUND AND PURPOSE: This study explores methods to reduce dose due to kV-CBCT imaging for patients undergoing radiation therapy. MATERIAL AND METHODS: Doses resulting from kV-CBCT scans were calculated using Monte Carlo techniques and were analyzed using dose-volume histograms. Patients were modeled as were CBCT acquisitions using both 360° and 200° gantry rotations. The effects of using the half fan bow-tie and the full fan bow-tie filters were examined. RESULTS: Doses for OBI 1.3 are 15 times (head), 5 times (thorax) and 2 times (Pelvis) larger than the current OBI 1.4. When using 200° scans, the doses to eyes and cord are 0.2 (or 0.65) cGy and 0.35 (or 0.2) cGy when rotating the X-ray source underneath (or above) the patient, respectively. The 360° Pelvis scan dose is 1-2 cGy. The rectum dose is 1.1 (or 2.8) cGy when rotating the source above (or below) the patient with the 200° Pelvis scan. The dose increases up to two times as the patient size decreases. CONCLUSIONS: The dose can be minimized by reducing the scan length, the exposure settings, by selecting the gantry rotation angles, and by using the full fan bow-tie whenever possible.
Authors: R Mazzola; F Ricchetti; A Fiorentino; S Fersino; N Giaj Levra; S Naccarato; G Sicignano; S Albanese; G Di Paola; D Alterio; R Ruggieri; F Alongi Journal: Br J Radiol Date: 2014-10-28 Impact factor: 3.039
Authors: A Fiorentino; M Cozzolino; R Caivano; P Pedicini; C Chiumento; C Oliviero; S Clemente; V Fusco Journal: Clin Transl Oncol Date: 2012-10-13 Impact factor: 3.405
Authors: R Mazzola; F Ricchetti; A Fiorentino; G Di Paola; S Fersino; N Giaj Levra; R Ruggieri; F Alongi Journal: Eur J Clin Nutr Date: 2016-04-13 Impact factor: 4.016
Authors: A Fiorentino; R Caivano; V Metallo; C Chiumento; M Cozzolino; G Califano; S Clemente; P Pedicini; V Fusco Journal: Br J Radiol Date: 2012-05-09 Impact factor: 3.039
Authors: Sudesh Deshpande; Deepak Dhote; Kalpna Thakur; Amol Pawar; Rajesh Kumar; Munish Kumar; M S Kulkarni; S D Sharma; V Kannan Journal: J Med Phys Date: 2016 Jul-Sep