Fetal atomic bomb survivor dosimetry using the J45 series of pregnant female phantoms with realistic survivor exposure scenarios; Comparisons to dose estimates in the DS02 system

Paulbeck, C. J.*; Sato, Tatsuhiko   ; Funamoto, Sachiyo*; Lee, C.*; Griffin, K. T.*; Cullings, H. M.*; Egbert, S. D.*; Endo, Akira   ; Hertel, N. E.*; Bolch, W. E.*

In our prior study [Radiat Res 192, 538-561 (2019)], we presented a new J45 (Japanese 1945) series of high-resolution phantoms of the adult pregnant female at 8-week, 15-week, 25-week, and 38-week post-conception. In this present study, we extend this work using realistic angular fluences from the DS02 system for up to nine different radiation categories and five shielding conditions. General findings are that the current DS02 fetal dose surrogate overestimates values of fetal organ dose seen in the J45 phantoms towards the cranial end of the fetus, especially in the later stages of pregnancy. This work supports our previous findings that the J45 pregnant female phantom series offers significate opportunities for gestational age-dependent assessment of fetal organ dose without the need to invoke the uterine wall as a fetal organ surrogate.