Fetal Implications of Diagnostic Radiation Exposure During Pregnancy: Evidence-based Recommendations

Hybrid computational pregnant female phantom construction for radiation dosimetry applications

The number of patients undergoing diagnostic radiology and radiation therapy procedures has increased drastically owing to improvements in cancer diagnosis and treatment and, consequently, patient survival. However, the risk of the occurrence of secondary malignancies due to radiation exposure remains a matter of concern. There are concerns about the fetus's health when pregnant women are exposed to and/or treated with ionizing radiation at various stages of pregnancy. We previously published three hybrid computational fetus phantoms, which contained 27 fetal organs, as a beginning point for developing the whole hybrid computational pregnant phantom set, which is the second objective of this study. An ICRP reference female voxel model was converted to a non-uniform rational basis spline (NURBS) surface model in order to construct a hybrid computational female phantom as a pregnant mother to each fetus model. Both the fetal and maternal organs were matched with ICRP-89 reference data. In order to create a complete standard pregnant computational phantom set at 20, 30, and 35 weeks of pregnancy, the model mother's reproductive organs were removed, and the fetus phantoms with appropriate placental and uterine models were added female pelvis using a 3D-modeling software. With the aid of radiological image sets that had been initially used to construct the fetus models, each fetus' position and rotation inside the uterus were carefully adjusted to represent the real fetal locations inside the uterus. The resulting fetus phantom was positioned in the appropriate location, matching the original radiological image sets. An obstetrician-gynecologist reviewed the complete internal anatomy of all fetus phantoms and the pregnant female for accuracy, and suggested changes were implemented as needed. This new set of hybrid computational pregnant phantom models has realistic anatomical details that can help evaluate fetal radiation doses where realistic fetal computational human phantoms are needed.

Diagnostic Imaging of Pregnant Women and Fetuses: Literature Review

Healthcare providers have acknowledged the dangers of radiation exposure to embryonic and fetal health, yet diagnostic imaging of pregnant women is increasing. Literature that pertains to the topic of interest was reviewed to collect tertiary data. The purpose of this literature review was to present the various radiation risks for pregnant women and the fetus depending on the gestational age of the pregnancy. The specific effects of radiation on pregnant women and the fetus, X-ray risks depending on the gestational age of the pregnancy, and other potential health effects when performing diagnostic imaging procedures on pregnant women were discussed in this review. In addition, ethical issues have been considered by improving overall communication to minimize unnecessary radiation exposure to pregnant women and fetuses.

[Principles of intensive medical care in pregnant patients]

As the incidence of diseases during pregnancy or in the puerperium necessitating intensive medical care is very low, intensive care physicians are faced with a multitude of unfamiliar challenges in the treatment of this patient collective. The physiological and pathophysiological alterations during pregnancy induce some specific features with respect to the intensive medical treatment of pregnant or postpartum patients. Therefore, the first article in this CME series summarizes the most important principles and current recommendations on the care of pregnant or postpartum patients who need intensive medical treatment, always under consideration of the well-being of mother and child. The second article describes the diagnostics and treatment of special selected pathologies.

Lymphoma Occurring During Pregnancy: Current Diagnostic and Therapeutic Approaches

PURPOSE OF REVIEW

Pregnancy-associated lymphoma (PAL) is an uncommon entity that lacks detailed prospective data. It poses significant management challenges that incorporate maternal and fetal risks associated with treatment or delayed intervention. Herein, we review the current literature for the diagnosis, management, and supportive care strategies for PAL.

RECENT FINDINGS

Establishment of a multidisciplinary team, including hematology-oncology, maternal-fetal medicine, and neonatology, is critical in the management of PAL. For staging, ultrasound and MRI are preferred modalities with use of computerized tomography in select situations. Data for the safety and effectiveness of therapy for PAL is largely based on retrospective studies. The timing of lymphoma-directed antenatal systemic therapy depends on the trimester, gestational age, lymphoma subtype and aggressiveness, and patient wishes. Therapy in the first trimester is usually not advocated, while treatment in the second and third trimesters appears to result in similar outcomes for PAL compared with non-pregnant patients with lymphoma. An overarching goal in most PAL cases should be to plan for delivery at term (i.e., gestational age > 37 weeks). For supportive care, most antiemetics, including agents such as neurokinin-1 receptor antagonists, have been used safely during pregnancy. For prevention or treatment of infections, particular antibiotics (i.e., macrolides, cephalosporins, penicillins, metronidazole), antivirals (i.e., acyclovir, valacyclovir, famciclovir), and antifungals (amphotericin B) have demonstrated safety and with use of growth factors reserved for treatment of neutropenia (vs. primary prophylaxis). Therapy for PAL should be individualized with goals of care that balance maternal and fetal well-being, which should include a multidisciplinary care team and overall intent for term delivery in most cases.

Construction of realistic hybrid computational fetal phantoms from radiological images in three gestational ages for radiation dosimetry applications

Radiation exposure and associated radiation risks are major concerns for fetal development for pregnant patients who undergo radiation therapy or diagnostic imaging procedures. In order to accurately estimate the radiation dose to the fetus and assess the uncertainty of fetal position and rotation, three hybrid computational fetus phantoms were constructed using magnetic resonance imaging (MRI) for each fetus model as a starting point to construct a complete anatomically accurate fetus, gravid uterus, and placenta. A total of 27 fetal organs were outlined from radiological images via the Velocity Treatment Planning System. The DICOM-Structure set was imported to Rhinoceros software for further reconstruction of 3D fetus phantom model sets. All fetal organ masses were compared with ICRP-89 reference data. Our fetal model series corresponds to 20, 31, and 35 weeks of pregnancy, thus covering the second and third trimester. Fetal positions and locations were carefully adapted to represent the real fetus locations inside the uterus for each trimester of pregnancy. The new series of hybrid computational fetus models together with pregnant female models can be used in evaluating fetal radiation doses in diagnostic imaging and radiotherapy procedures.

Breast Cancer Screening in High-Risk Patients during Pregnancy and Breastfeeding: A Systematic Review of the Literature

There are currently no clear guidelines for high-risk breast cancer screening during the pregnancy and breastfeeding periods. The objective of this systematic review (SR) was to assess the available evidence pertaining to breast cancer screening recommendations in this population with the aim of supporting future guidelines. We performed a SR of the literature using the electronic databases MEDLINE and Embase. Predetermined inclusion and exclusion criteria were used during the abstract screening and full-text data extraction phases. We retrieved 2,274 abstracts after removal of duplicates, from which 16 studies were included based on predetermined eligibility criteria. Most of the studies found were narrative reviews and expert opinions. Clinical breast exam (CBE) was recommended by 12 studies during pregnancy and by 6 studies in the breastfeeding period. Mammography was recommended in the breastfeeding period by 2 studies. Magnetic resonance imaging was recommended in the breastfeeding period by 2 studies. Ultrasound was considered not appropriate for screening in this population. The information extracted from this SR is based primarily on expert opinion and anecdotal evidence, which explains the lack of standardized guidelines for high-risk breast cancer screening in this population. However, expert opinion may be a surrogate outcome for high-risk breast cancer screening recommendations in this subset of patients, and as such, may justify the clinical management to be tailored accordingly. This SR summarizes the evidence pertaining to high-risk breast cancer screening during pregnancy and breastfeeding, which could serve as a catalyst for future research on the topic.

Current treatment of lymphoma in pregnancy

Introduction: Lymphoproliferative diseases occurring during pregnancy present the treating physician with unique diagnostic and therapeutic challenges, aiming to achieve maternal cure without impairing fetal health, growth, and survival. Due to the rarity of this complication, there is limited data to guide clinical decision-making, especially regarding the safety of novel emerging therapies. Areas covered: The presented review describes the current practice of treatment for Hodgkin's (HL) and non-Hodgkin's (NHL) lymphoma in the pregnant patient, according to disease stage and trimester of pregnancy. Novel agents for treatment of lymphoma in the setting of pregnancy are discussed. Therapeutic dilemmas and areas of uncertainty are illuminated. Expert opinion: HL and NHL are potentially curable diseases in the pregnant patient with generally good outcomes for the mother and the offspring, when tailoring the treatment according to the individual patient. The complexity of the situation merits shared decision-making with the patient and her family, explicitly outlining the risks and benefits. The pregnant patient is best managed by a multidisciplinary team, familiar with the intricacies of the gestational period, and providing the necessary support and sensitivity. Further studies are needed regarding the safety of novel agents in pregnancy.

Cancer in Pregnancy

This article reviews some of the more common types of cancer that may be encountered during pregnancy. It reviews the unique challenges with the diagnosis and treatment of breast, cervical, hematologic, and colon cancers in pregnant patients.

Breast cancer in pregnant patients: A review of the literature

Breast cancer diagnosed during pregnancy is a rare occurrence at present; however, in recent years a trend towards delayed childbirth is generating an increase in its incidence. This situation requires a multidisciplinary approach involving obstetricians, oncologists and surgeons. In this review we analyse diagnostic methods, different possible treatments and long-term patient prognosis. We conducted a search for articles published in PubMed, or in abstract form from the San Antonio Breast Cancer Symposium (SABCS), the European Society for Medical Oncology (ESMO), and the American Society of Clinical Oncology (ASCO) annual meeting, using the search terms: "Breast cancer and pregnancy". Breast cancer occurring during pregnancy requires extra effort to offer patients the best multidisciplinary management. There is no difference in the pathology-based classification, but breast cancer during pregnancy seems to be associated with different patterns of gene expression. Chemotherapy and surgery are generally safe and well-tolerated by patients during the second and third trimesters of pregnancy. The poorer prognosis could be attributed mainly to a delay in diagnosis and because breast cancer in young patients is a more aggressive disease. Finally, balancing the health of mother and child must be paramount.

The Management of Lymphoma in the Setting of Pregnancy

The diagnosis of lymphoma in pregnant patients poses a therapeutic challenge necessitating consideration of the developing fetus without compromise of therapy with curative potential for the mother. The decision to initiate therapy during pregnancy is heavily influenced by fetal, maternal, and disease-related factors, of which the most influential are the trimester at diagnosis, the stage, and aggressiveness of the disease and the presence of life-threatening symptoms. Recent data suggest that deferral of therapy until after the first trimester is desirable if it is perceived that postponement of therapy will not compromise maternal outcome. For some patients, delay of therapy to the postpartum period is feasible.