The current knowledge on radiosensitivity of ovarian follicle development stages

Quantitative human data on the risks of genetically transmissible diseases and anomalies following exposure to ionizing radiation are scarce. As such, the most comprehensive data on these effects have come from experiments with laboratory animals. However, oocyte radiosensitivity as well as the pattern of oocyte radiosensitivity from the immature resting stage to the fully grown pre-ovulatory stage, differs tremendously between species. These features make it hard to extrapolate follicle radiosensitivity results found in different species to the human female population. Additionally, data describing radiosensitivity patterns is mostly coming from in-vivo studies that are not easy to interpret, since all phases of folliculogenesis are present at the same time in the ovaries. Results discussed in papers mostly describe the radiosensitivity at single or discrete moments during the cycle or around the moment of ovulation and is not always "translated" to the radiosensitivity of a well defined follicular class. The objective of this paper is to review the in-vivo studies that reported on the radiosensitivity of female germ cells and to “translate” the existing information in terms of follicle sensitivity at the different stages of development.