title: Patient doses from PET-CT procedures.
abstract: Positron emission tomography (PET) was installed for the first time in Bulgaria in 2009, and nowadays two hybrid PET-computed tomography (CT) systems are in operation. The aim of this work is to estimate patient doses from PET-CT procedures and to explore potential for optimisation. Data were retrospectively collected for 50 patients examined with the system Philips Gemini TF and for 58 patients examined with the system GE Discovery 600. Whole-body examinations with radiopharmaceutical (18)F-2-fluoro-2-deoxy-D-glucose (FDG) were performed on all patients. Patient effective doses from the CT component of the examination were calculated with CT Expo software and compared with doses estimated applying the National Radiological Protection Board (NRPB) conversion coefficients. Effective doses from the PET component were calculated applying the ICRP 80 conversion coefficients. For the first system, average effective doses from CT component were 8.0 and 8.9 mSv, applying CT Expo and NRPB coefficients, respectively, and 4.9 mSv from PET component. For the second system, the corresponding values were 7.8, 8.7 and 5.9 mSv. These results for patient effective doses are relatively lower or comparable to other similar surveys. Reasons for the observed differences are analysed and presented.
authors.affiliation: National Centre of Radiobiology and Radiation Protection, Sofia, Bulgaria s_avramova@mail.bg.
authors.forename: S
authors.initials: S
authors.lastname: Avramova-Cholakova
authors.affiliation: University Multiprofile Hospital for Active Treatment 'St Marina', Varna, Bulgaria.
authors.forename: S
authors.initials: S
authors.lastname: Ivanova
authors.affiliation: University Multiprofile Hospital for Active Treatment 'Alexandrovska', Sofia, Bulgaria.
authors.forename: E
authors.initials: E
authors.lastname: Petrova
authors.affiliation: University Multiprofile Hospital for Active Treatment 'Alexandrovska', Sofia, Bulgaria.
authors.forename: M
authors.initials: M
authors.lastname: Garcheva
authors.affiliation: National Centre of Radiobiology and Radiation Protection, Sofia, Bulgaria.
authors.forename: J
authors.initials: J
authors.lastname: Vassileva
mesh_terms: D002031:Bulgaria; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008297:Male; D008545:Melanoma / Q000000981:diagnostic imaging; D064847:Multimodal Imaging / Q000379:methods*; D009369:Neoplasms / Q000000981:diagnostic imaging; D049268:Positron-Emission Tomography / Q000379:methods*; D011829:Radiation Dosage; D011835:Radiation Protection; D011874:Radiometry / Q000379:methods*; D019275:Radiopharmaceuticals; D012189:Retrospective Studies; D012984:Software; D014057:Tomography, X-Ray Computed / Q000379:methods*; D051598:Whole Body Imaging
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18