Review of Radiation Therapy in the Pregnant Cancer Patient

Abstract

Cancer diagnosed during pregnancy occurs in approximately 1:1000 gestations, and up to 4000 women per year in the United States receive radiation therapy during pregnancy. This article will review the effects of ionizing radiation exposure on the embryo and fetus, review the most common malignancies that present during pregnancy, review important treatment delivery considerations in those cases when radiotherapy is necessary during the pregnancy, and in a related topic, review fertility issues in females who receive therapeutic radiation before or during their reproductive years.

Adolescent and Young Adult Oncology, Version 2.2018, NCCN Clinical Practice Guidelines in Oncology

“…However, in very rare instances when RT is necessary, it should be delivered in low therapeutic doses (with adequate uterine shielding to minimize fetal exposure) with the goals of controlling maternal cancer and providing the fetus the best chance for survival with normal development. 168 The dose to the fetus can be reduced by using modified RT administration techniques or adding additional shielding between the treatment machine and the patient. 168 Early collaboration among the radiation oncologist, medical physicist, medical and/or surgical oncologist, and obstetrician is essential.…”

“…168 The dose to the fetus can be reduced by using modified RT administration techniques or adding additional shielding between the treatment machine and the patient. 168 Early collaboration among the radiation oncologist, medical physicist, medical and/or surgical oncologist, and obstetrician is essential. The American College of Radiology has developed guidelines with an objective to assist practitioners in identifying pregnancy, preventing unnecessary irradiation of pregnant AYA women, tailoring examinations to effectively manage RT dose, and developing strategies to quantify and evaluate the potential effects of RT delivered to patients who are pregnant.…”

Cancer Treatment in Pregnancy

“…Shielding can be used when treating malignancies outside the abdomen to decrease exposure to the fetus, but scatter still occurs, with its effect depending upon the radiation source, as well as the size and proximity to the fetus of the radiated fi eld. The most common indications for radiotherapy in pregnancy are breast cancer, cervical cancer, lymphoma, melanoma, and brain tumors, either primary or metastatic [ 12 ].…”

The Management of Lymphoma in the Setting of Pregnancy

“…Fetal outcomes are largely influenced by the timing of therapy with regards to gestational age [10]. The vulnerability of the fetus at various periods throughout pregnancy are reflected in the events occurring in fetal development.…”