Ionizing radiation and male fertility

Abstract

Exposure to ionizing radiation (IR) is becoming more common in the medical field for disease diagnoses and cancer treatment. In addition to patients undergoing treatment, IR exposure also poses a big threat to health professionals. The majority of medical investigations require radiographic testing to diagnose the disease followed by treatment, which in case of cancer patients may also require radiotherapy. Although all living creatures are at the risk of damage in response to ionizing radiation, the mammalian testes are much more sensitive to ionizing radiation. In man and in majority of animals, the testes lie outside the body and are susceptible to radiation damage (Abuelhija et al. 2013). Damage to the testes is directly proportional to the dose and time of exposure to artificial radiation or treatment. Evidence exists for sperm count reduction after treatment with low-dose testis irradiation. Moderate- to high-dose irradiation can lead to prolonged drastic decline in sperm count or even azoospermia (Abuelhija et al. 2013). The human testes appear to be more sensitive, and the recovery of spermatogenesis after radiotherapy is significantly delayed compared to most other rodents (Meistrich and Samuels 1985). This delay suggests that during the treatment period, spermatogonial stem cells become arrested at a point of their differentiation; however, the underlying mechanism of the spermatogenesis arrest and subsequent recovery in human is not known. This raises an important question about the posttreatment fertility of the patients and also the consequences of IR exposure on the reproductive health in medical professionals.