APHON Pediatric Chemotherapy-Biotherapy Renewal

dependent; Table 1 presents the risks associated with various doses of radiation given in various locations.

Table 1. Risk of Infertility Associated with Radiation Therapy Doses and Sites

High Risk

Intermediate Risk

Total body irradiation for bone marrow transplant or stem cell transplant

Testicular radiation dose 1–6 Gy from scattered pelvic or abdominal radiation Pelvic or whole-abdominal radiation dose 5–10 Gy in postpubertal girls

Testicular radiation dose >2.5 Gy in adult men

Testicular radiation dose ≥6 Gy in prepubertal boys Pelvic or whole-abdominal radiation dose 10–15 Gy in prepubertal girls

Pelvic or whole-abdominal radiation dose ≥6 Gy in adult women Pelvic or whole-abdominal radiation dose ≥10 Gy in postpubertal girls Pelvic or whole-abdominal radiation dose ≥15 Gy in prepubertal girls

Craniospinal radiotherapy dose ≥25 Gy

Adapted from “Fertility Preservation for Young Adults, Adolescents, and Children with Cancer,” by K. A. Rodriguez-Wallberg, A. Anastacio, E. Vonheim, S. Deen, J. Malmros, and B. Borgström, 2020, Upsala Journal of Medical Sciences, 125 (2), 112–120; table 1, p. 114. https://doi.org/10.1080/03009734.2020.1737601. Copyright 2020 by the authors. Licensed under CC- BY-NC 4.0, https://creativecommons.org/licenses/by-nc/4.0/legalcode.

Although the connection between the radiotherapy dose and risks to fertility is clear, the connection is less clear for chemotherapy drugs. With chemotherapy, it is difficult to quantify the specific effects of individual drugs when they are given as part of a treatment regimen over time. Table 2 presents what we currently know about gonadotoxicity related to chemotherapy drugs for both males and females (Rodriguez-Wallberg et al., 2020). With females, gonadotoxicity is age-dependent because females are born with a finite quantity of oocytes that declines over time until menopause is reached, whereas spermatogenesis continues throughout a male’s lifespan. Pediatric diagnoses that have the highest risk of permanent sterility are testicular cancer, leukemia, and Ewing sarcoma (Del-Pozo-Lérida et al., 2019).