title: Personalized estimation of dose to red bone marrow and the associated leukaemia risk attributable to pelvic kilo-voltage cone beam computed tomography scans in image-guided radiotherapy.
abstract: The aim of this study is to investigate the imaging dose to red bone marrow (RBM) and the associated leukaemia risks attributable to pelvic kilo-voltage cone beam computed tomography (kVCBCT) scans in image-guided radiation therapy (IGRT). The RBM doses of 42 patients (age 2.7-86.4 years) were calculated using Monte Carlo simulations. The trabecular spongiosa was segmented to substitute RBM rather than the whole bone. Quantitative correlations between anthropometric variables such as age, physical bone density (PBD) and RBM dose were established. Personalized leukaemia risk was evaluated using an improved Boice model which included the age-associated RBM involvement. An incremental leukaemia risk of 29%-82% (mean = 45%) was found to be associated with 40 pelvic kVCBCT scans in the subject group used in a typical external beam radiation therapy course. Higher risks were observed in children. Due to the enhanced photoelectric effect in high atomic number materials, PBD was observed to strongly affect the RBM dose. Considerable overestimations (9%-42%, mean = 28%) were observed if the whole bone doses were used as surrogates of RBM doses. The personalized estimation of RBM dose and associated leukaemia risk caused by pelvic kVCBCT scans is clinically feasible with the proposed empirical models. Higher radiogenic cancer risks are associated with repeated kVCBCT scans in IGRT of cancer patients, especially children.
authors: Beijing Key Lab of Medical Physics and Engineering, Peking University, Beijing 100871, People's Republic of China.
authors: Yibao
authors: Y
authors: Zhang
authors: Yulong
authors: Y
authors: Yan
authors: Ravinder
authors: R
authors: Nath
authors: Shanglian
authors: S
authors: Bao
authors: Jun
authors: J
authors: Deng
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015519:Bone Density / Q000528:radiation effects; D001853:Bone Marrow / Q000528:radiation effects*; D002648:Child; D002675:Child, Preschool; D054893:Cone-Beam Computed Tomography / Q000009:adverse effects*; D005260:Female; D006801:Humans; D007938:Leukemia / Q000209:etiology*; D008297:Male; D008875:Middle Aged; D010388:Pelvis / Q000000981:diagnostic imaging*; D057285:Precision Medicine / Q000379:methods*; D011829:Radiation Dosage; D011881:Radiotherapy, Computer-Assisted / Q000009:adverse effects*; D012189:Retrospective Studies; D012306:Risk; D055815:Young Adult