title: Radiation dose in cardiac SPECT/CT: An estimation of SSDE and effective dose.
abstract: OBJECTIVE
  The dose levels for Computed Tomography (CT) localization and attenuation correction of Single Photon Emission Computed Tomography (SPECT) are limited and reported as Volume Computed Tomography Dose Index (CTDIvol) and Dose-Length Product (DLP). This work presents CT dose estimation from Cardiac SPECT/CT based on new American Association of Physicists in Medicine (AAPM) Size Specific Dose Estimation (SSDE) parameter, effective dose, organ doses and also emission dose from nuclear issue.
  
  
  METHODS
  Myocardial perfusion SPECT/CT for 509 patients was included in the study. SSDE, effective dose and organ dose were calculated using AAPM guideline and Impact-Dose software. Data were analyzed using R and SPSS statistical software. Spearman-Pearson correlation test and linear regression models were used for finding correlations and relationships among parameters.
  
  
  RESULTS
  The mean CTDIvol was 1.34 mGy±0.19 and the mean SSDE was 1.7 mGy±0.16. The mean±SD of effective dose from emission, CT and total dose were 11.5±1.4, 0.49±0.11 and 12.67±1.73 (mSv) respectively. The mean±SD of effective dose from emission, CT and total dose were 11.5±1.4, 0.49±0.11 and 12.67±1.73 (mSv) respectively. The spearman test showed that correlation between body size and organ doses is significant except thyroid and red bone marrow. CTDIvol was strongly dependent on patient size, but SSDE was not. Emission dose was strongly dependent on patient weight, but its dependency was lower to effective diameter.
  
  
  CONCLUSIONS
  The dose parameters including CTDIvol, DLP, SSDE, effective dose values reported here are very low and below the reference level. This data suggest that appropriate CT acquisition parameters in SPECT/CT localization and attenuation correction are very beneficial for patients and lowering cancer risks.
authors.affiliation: Department of Medical Physics, School of Medicine, Iran University of Medical Sciences, Tehran, Iran. Electronic address: Hamid_rbp@yahoo.com.
authors.forename: Hamid
authors.initials: H
authors.lastname: Abdollahi
authors.affiliation: Department of Medical Physics, School of Medicine, Iran University of Medical Sciences, Tehran, Iran.
authors.forename: Isaac
authors.initials: I
authors.lastname: Shiri
authors.affiliation: Biomedical Engineering and Medical Physics Department, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors.forename: Yazdan
authors.initials: Y
authors.lastname: Salimi
authors.affiliation: Department of Medical Physics, School of Medicine, Iran University of Medical Sciences, Tehran, Iran.
authors.forename: Maghsoud
authors.initials: M
authors.lastname: Sarebani
authors.affiliation: Department of Medical Physics, School of Medicine, Iran University of Medical Sciences, Tehran, Iran.
authors.forename: Reza
authors.initials: R
authors.lastname: Mehdinia
authors.affiliation: Biomedical Engineering and Medical Physics Department, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors.forename: Mohammad Reza
authors.initials: MR
authors.lastname: Deevband
authors.affiliation: Department of Medical Physics, School of Medicine, Iran University of Medical Sciences, Tehran, Iran; Radiation Biology Research Center, Iran University of Medical Sciences, Tehran, Iran.
authors.forename: Seied Rabi
authors.initials: SR
authors.lastname: Mahdavi
authors.affiliation: Department of Biostatistics, School of Public Health, Iran University of Medical Sciences, Tehran, Iran.
authors.forename: Ahmad
authors.initials: A
authors.lastname: Sohrabi
authors.affiliation: Department of Medical Physics, School of Medicine, Iran University of Medical Sciences, Tehran, Iran; Department of Nuclear Medicine, Rajaei Cardiovascular, Medical and Research Center, Iran University of Medical Sciences, Tehran, Iran. Electronic address: bitarafan@hotmail.com.
authors.forename: Ahmad
authors.initials: A
authors.lastname: Bitarafan-Rajabi
mesh_terms: D000311:Adrenal Glands / Q000528:radiation effects; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D049628:Body Size; D001835:Body Weight; D005260:Female; D006321:Heart / Q000528:radiation effects; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D008099:Liver / Q000528:radiation effects; D008168:Lung / Q000528:radiation effects; D008297:Male; D008875:Middle Aged; D055414:Myocardial Perfusion Imaging / Q000379:methods*; D011829:Radiation Dosage; D019275:Radiopharmaceuticals; D012062:Relative Biological Effectiveness; D012189:Retrospective Studies; D000072098:Single Photon Emission Computed Tomography Computed Tomography / Q000379:methods*; D012984:Software; D017256:Technetium Tc 99m Sestamibi; D055815:Young Adult
chemical_list: D019275:Radiopharmaceuticals; D017256:Technetium Tc 99m Sestamibi
keywords: Cardiac imaging; Effective dose; Radiation dose; SPECT/CT; SSDE