Cellular dosimetry of 197Hg, 197mHg and 111In: comparison of dose deposition and identification of the cell and nuclear membrane as important targets. (2nd January 2023)

• Record Type: Journal Article
• Authors: Cai, Zhongli; Al-saden, Noor; Georgiou, Constantine J.; Reilly, Raymond M.
• Is Part Of: International journal of radiation biology. Volume 99:Number 1(2023)
• Page Start: 53
• Page End: 63
• Publication Date: 2023-01-02
• Subjects: 197Hg -- 197mHg -- 111In -- Auger electrons -- dosimetry; Radiation -- Physiological effect -- Periodicals; Radiobiology -- Periodicals; 571.45
• DOI: 10.1080/09553002.2020.1849850
• Languages: English
• ISSNs: 0955-3002

Abstract

Abstract: Purpose: To examine the reliability to model cellular S-values for the Auger electron (AE) emitters, 111 In, 197 Hg and 197m Hg with MCNP6 and their relative dose deposition in subcellular targets. Methods: A model cell was defined as four concentric spheres consisting of the nucleus (N), cytoplasm (Cy), cell and nuclear membranes (CM, NM) in which radionuclides distributed homogeneously. The transport of AE, conversion electrons and photons were simulated by MCNP6 to calculate cellular S values (SN←CM, SN←Cy, SN←NM, SN←N, SCM←CM, SNM←NM ). SN←CM, SN←Cy and SN←N were also calculated with MIRDcell. Results: MIRDcell and MCNP6-calculated SN←N were in excellent agreement, but a slight discrepancy on SN←Cy and SN←CM was observed. The ratios of SCM←CM or SNM←NM vs. SN←N were 9.7–51.0 or 10.5–37.4, 7.9–41.8 or 8.4–31.8 and 7.2–36.9 or 8.0–28.1 for 111 In, 197 Hg, 197m Hg, respectively. The mean S( 197 Hg)/S( 111 In) and S( 197m Hg)/S( 111 In) were 2.5 ± 0.5 and 2.5 ± 0.6, respectively. Conclusions: Cellular S-values were reliably calculated with MCNP6. 197 Hg and 197m Hg deposit two-fold more doses than 111 In at the subcellular scale. All AE emitters deposit a higher self-dose in the CM and NM than in the N, which warrants studies on the effects of targeting the CM and NM by AE emitters.