Radiation oncology department policy development for patients who may become pregnant.

In the context of radiation oncology, radiation exposure from radiation therapy simulation, image guidance, and radiation therapy procedures can have severe adverse biological effects on a developing embryo or fetus. Patients who may be pregnant are screened for the possibility of pregnancy to prevent unnecessary or excessive exposure of radiation in utero. Some radiation therapy patients for whom a pregnancy test is indicated may elect to decline the test. In addition, some patients who are found upon screening to be pregnant may decide, with their attending radiation oncologist, to continue with treatment. A radiation oncology department policy was developed to provide guidelines regarding screening and consent. The policy was designed to prevent unnecessary exposure to patients who may be pregnant, and to limit dose to the embryo or fetus in patients for whom treatment is medically indicated. The policy is presented as an example for physicists intending to develop or revise their own practice's policy regarding patients who may become pregnant.

Fetal dose assessment in a pregnant patient with brain tumor: A comparative study of proton PBS and 3DCRT/VMAT radiation therapy techniques.

PURPOSE: The treatment of brain tumors in pregnant patients poses challenges, as the out-of-field dose exposure to the fetus can potentially be harmful. A pregnant patient with prior radiation treatment was presented with a brain tumor at our clinic. This work reports on our pre-treatment study that compared fetal dose exposure between intensity-modulated proton therapy (IMPT) using pencil beam scanning (PBS) and conventional photon 3D conformal radiation therapy (3DCRT) and volumetric-modulated arc therapy (VMAT), and the subsequent pregnant patient's radiation treatment. MATERIALS AND METHODS: Pre-treatment measurements of clinical plans, 3DCRT, VMAT, and IMPT, were conducted on a phantom. Measurements were performed using a device capable of neutron detections, closely following AAPM guidelines, TG158. For photon measurements, fetus shielding was utilized. On patient treatment days, which was determined to be proton treatment, shielding was used only during daily imaging for patient setup. Additionally, an in vivo measurement was conducted on the patient. RESULTS: Measurements showed that IMPT delivered the lowest fetal dose, considering both photon and neutron out-of-field doses to the fetus, even when shielding was implemented for photon measurements. Additionally, the proton plans demonstrated superior treatment for the mother, a reirradiation case. CONCLUSION: The patient was treated with proton therapy, and the baby was subsequently delivered at full term with no complications. This case study supports previous clinical findings and advocates for the expanded use of proton therapy in this patient population.

The role of curcumin during pregnancy on the exposed fetuses' tissues of Wistar rats to electromagnetic field.

To investigate curcumin (CUR) as the protector against the harmful effects of low-frequency electromagnetic field(LF- EMF, 50 Hz) during pregnancy period, 5 males and 15 females of Wistar rat mated and vaginal plaques were observed. Then, the pregnant rats were divided into six groups. During pregnancy(21 days), the EMF group was exposed to EMF for 30 min/day, the CUR group received a single dose of 50 mg/kg/daily CUR intraperitoneal, the EMF+CUR group was injected CUR and exposed to EMF daily. The DMSO(dimethyl sulfoxide) group was injected solvent of CUR (DMSO) intraperitoneal with the same volume of CUR solvent, the sham group was placed through the solenoid in the same conditions as the first group without exposure and the control group was kept in their cage in normal condition. After four weeks, babies born were divided according to the mother groups and sacrificed. Then, the three tissues injuries were investigated. EMF exposure led to an increase in outstanding necrotic areas in hippocampal tissue, an increase in the amount of hyperemia(p = 0.017) and necrotic(p = 0.005) in kidneys, and degeneration in liver tissue(p = 0.007) in the EMF group compared with EMF+CUR groups. A single dose of CUR daily during pregnancy can protect these tissues from injuries caused by LF-EMF exposure in rat fetuses.

Electromagnetic fields (EMFs) are able to penetrate and be absorbed by the body. The researchers showed that these radiations might be harmful and lead to cancers, cardiovascular diseases, mental disorders, and fetal abnormalities. Curcumin as an active component in turmeric has anti-inflammatory, antioxidant and anti-hyperlipidemia properties. It can protect the body against diseases such as arthritis, anxiety, and metabolic syndrome. This study examined the effects of curcumin as the protector against the harmful effects of EMF (50Hz) during pregnancy period. So the pregnant rats were divided into six groups. During pregnancy, a group was exposed to EMF for 30 min/day, the second group was injected a dose of curcumin 50mg/kg/daily, the third group was injected curcumin and exposed to EMF daily. The fourth group was injected a curcumin solvent dose, the sham group was placed through the field generator in the same conditions as the first group without exposure and the control group was kept in their cage in normal condition. After four weeks, babies born were divided according to the mother groups and sacrificed. Then, the liver, kidney, and hippocampal tissues were investigated. EMF exposure led to an outstanding increase in necrotic areas in hippocampal tissue, a notable increase in the amount of hyperemia and necrosis in kidneys, and degeneration in liver tissue(p=0.007) in the EMF group compared with the third group that was exposed to EMF and received curcumin. A single dose of curcumin daily during pregnancy can protect these tissues from injuries caused by EMF(50Hz) exposure in rat fetuses.

Effect of Transplanted Bone Marrow on Spleen of Irradiated Pregnant Rats and Their Fetuses.

<b>Background and Objective:</b> Prenatal ionizing radiation exposure may hinder fetal and embryonic growth depending on the dose and gestational age. The current study's objective was to discover how bone marrow transplants affected the spleens of pregnant rats that had been subjected to γ (Gamma) radiation. <b>Materials and Methods:</b> Sixty rats that were pregnant were separated into five different groups, each with 6 females. The pregnant rats in the second Group were exposed to 2Gy of γ-rays. Group III; pregnant rats subjected to 2Gy of γ-rays, followed by an intraperitoneal injection of newly prepared bone marrow transplantation (BMT). The fifth Group were exposed to 2Gy γ-rays and received 1 dosage of BMT an hour later. Spleen samples from the pregnant rats as well as their fetuses were taken for histological and histochemical analyses. <b>Results:</b> Gamma rays damaged the splenic tissue of women and their fetuses on days 7 or 14 of pregnancy in a variety of histological and histochemical ways, although bone marrow transplantation significantly reduced the damage. Treated mothers with bone marrow post-radiation showed a noticeable recovery in spleen of their fetuses. Improved spleen architecture was accompanied by appearance of normal content of collagen, polysaccharides and total protein in the fetal spleen tissue especially on day 7 of gestation. <b>Conclusion:</b> Bone marrow transplantation can lessen the damage caused by gamma radiation.

Estimated Fetal Radiation Dose From 18 F-FDG PET/CT During the Second and Third Trimesters of Pregnancy.

PURPOSE: Data published in the literature concerning the doses received by fetuses exposed to a 18 F-FDG PET are reassuring but were obtained from small and heterogeneous cohorts, and very few data are available concerning the fetal dose received after exposure to both PET and CT. The present study aimed to estimate the fetal dose received following a PET/CT exposure using methods that include anthropomorphic phantoms of pregnant women applied on a large cohort. PATIENTS AND METHODS: This retrospective multicenter study included 18 pregnant patients in the second and third trimesters. For PET exposure, the fetal volume and mean concentration of radioactivity in the fetus were measured by manually drawing regions of interest. Those data, combined with the time-integrated activities of the fetus and the mother's organs, were entered into the OLINDA/EXM software 2.0 to assess the fetal dose due to PET exposure. To estimate the fetal dose received due to CT exposure, 2 softwares were used: CT-Expo (based on geometric phantom models of nonpregnant patients) and VirtualDose (using pregnant patient phantoms). RESULTS: The fetal dose exposure for PET/CT examination in the second trimester ranged from 5.7 to 15.8 mGy using CT-Expo (mean, 11.6 mGy) and from 5.1 to 11.6 mGy using VirtualDose (mean, 8.6 mGy). In the third trimester, it ranged from 7.9 to 16.6 mGy using CT-Expo (mean, 10.7 mGy) and from 6.1 to 10.7 mGy using VirtualDose (mean, 7.6 mGy). CONCLUSIONS: The estimated fetal doses were in the same range of those previously published and are well below the threshold for deterministic effects. Pregnancy does not constitute an absolute contraindication for a clinically justified hybrid 18 F-FDG PET/CT.

Comparing fetal phantoms with surrogate organs in female phantoms during CT exposure of pregnant patients.

With the rising use of Computed Tomography (CT) in diagnostic radiology, there are concerns regarding radiation exposure to sensitive groups, including pregnant patients. Accurately determining the radiation dose to the fetus during CT scans is essential to balance diagnostic efficacy with patient safety. This study assessed the accuracy of using the female uterus as a surrogate for fetal radiation dose during CT imaging. The study used common CT protocols to encompass various scenarios, including primary beam, scatter, and partial exposure. The computational program NCICT was used to calculate radiation doses for an adult female and a fetus phantom. The study highlighted that using the uterus for dose estimation can result in consistent underestimations of the effective dose, particularly when the fetus lies within the primary radiation beam. These discrepancies may influence clinical decisions, affecting care strategies and perceptions of associated risks. In conclusion, while the female uterus can indicate fetal radiation dose if the fetus is outside the primary beam, it is unreliable when the fetus is within the primary beam. More reliable abdomen/pelvic organs were recommended.

Assessment of fetal radiation exposure in pregnant women undergoing computed tomography and rotational angiography examinations for pelvic trauma.

This study aimed to assess fetal radiation exposure in pregnant women undergoing computed tomography (CT) and rotational angiography (RA) examinations for the diagnosis of pelvic trauma. In addition, this study aimed to compare the dose distributions between the two examinations. Surface and average fetal doses were estimated during CT and RA examinations using a pregnant phantom model and real-time dosemeters. The pregnant model phantom was constructed using an anthropomorphic phantom, and a custom-made abdominal phantom was used to simulate pregnancy. The total average fetal dose received by pregnant women from both CT scans (plain, arterial and equilibrium phases) and a single RA examination was ~60 mGy. Because unnecessary repetition of radiographic examinations, such as CT or conventional 2D angiography can increase the radiation risk, the irradiation range should be limited, if necessary, to reduce overall radiation exposure.

Evaluation of twin fetal exposure to radiofrequency field during magnetic resonance imaging.

Fetal development is essential to the human lifespan. As more and more multifetal gestations have been reported recently, clinical diagnosis using magnetic resonance imaging (MRI), which introduced radiofrequency (RF) exposure, raised public concerns. The present study developed two whole-body pregnant models of 31 and 32 gestational weeks (GWs) with twin fetuses and explored RF exposure by 1.5 and 3.0 T MRI. Differences in the relative position of the fetus and changes in fetal weight can cause differences in fetal peak local specific absorption rate averaged over 10 g tissue (pSAR10g). Variation of pSAR10g due to different fetal positions can be ~35%. Numerically, twin and singleton fetal pSAR10g results were not significantly different, however twin results exceeded the limit in some cases (e.g. fetuses of 31 GW at 1.5 T), which indicated the necessity for further research employing anatomically correct twin-fetal models coming from various GWs and particular sequence to be applied.

A phantom study investigating effective strategies for reducing fetal dose in pregnant patients with head and neck cancer.

PURPOSE: To measure the out-of-field doses for various treatment planning techniques and assess the impact on fetal dose with and without the use of custom shielding. MATERIALS AND METHODS: A total of six treatment plans were generated with different treatment techniques such as 3-dimensional conformal radiation therapy (3DCRT), intensity modulated radiation therapy (IMRT) and volumetric-modulated arc therapy (VMAT), utilizing both 6 MV flattened beams and flattening filter-free (FFF) beams. The measurements were carried out both out-of-field at the surface and at depth to assess the dose reduction achieved by removing the flattening filter and incorporating shielding. RESULTS: The custom-made frame shielding can effectively reduce the surface dose with a maximum reduction of 15.2% observed in VMAT plans and achieve a maximum reduction of 100% for cone beam computed tomography (CBCT) imaging. Out-of-field dose measurements conducted at depth, positioned 58 cm inferior to the target isocenter, reveal that the shielding effectiveness consistently remains the greatest for 3DCRT technique. A maximum reduction of 21% is observed when utilizing a flattening filter-free beam. CONCLUSION: The results of this study indicate that the 3DCRT technique exhibits the least amount of scatter radiation both near and far from the treatment isocenter, which is the most suitable approach for radiation therapy of pregnant patients. In cases where meeting dose constraints for critical organs becomes challenging, VMAT technique emerges as the most suitable treatment technique for reducing out-of-field doses. Additionally, a flattening filter-free beam significantly reduces out-of-field doses due to lower contributions from head scatter.

Estimation of maternal and foetal risk of radiation-induced cancer from a survey of computed tomography pulmonary angiography and ventilation/perfusion lung scanning for diagnosing pulmonary embolism during pregnancy.

INTRODUCTION: While there are many papers on maternal and foetal radiation doses from computed tomography pulmonary angiography (CTPA) and ventilation/perfusion (V/Q) lung scanning examinations for diagnosing pulmonary embolism in pregnant patients, few have used clinical data to examine the patient lifetime attributable risk (LAR) of different cancer types. This paper aims to estimate the cancer risk from maternal radiation doses from CTPA and V/Q examinations and associated foetal doses. METHODS: Dosimetric data were determined for 267 pregnant patients who received CTPA and/or V/Q examinations over 8 years. Organ and foetal doses were determined using software allowing patient size variations for CTPA and using two different activity-to-organ dose conversion methods for V/Q scans. The LAR of cancer incidence was estimated using International Commission on Radiological Protection (ICRP) modelling including estimates of detriment. RESULTS: Estimated total cancer incidence was 23 and 22 cases per 100,000 for CTPA and V/Q examinations, respectively, with detriment estimates of 18 and 20 cases. Cancer incidence was evenly divided between lung and breast cancer for CTPA with lung cancer being 80% of all cancer for V/Q. The median foetal doses were 0.03 mSv for CTPA and 0.29 mSv for V/Q. Significant differences in estimated foetal dose for V/Q scans were obtained by the two different methods used. The differences in dose between the modes of CTPA scan acquisition highlight the importance of optimisation. CONCLUSION: Maternal cancer incidence and detriment were remarkably similar for each examination. Optimisation of examinations is critical for low-dose outcomes, particularly for CTPA examination.

Dosis al feto en radiodiagnóstico / Dose to the fetus in radiodiagnostic

Se discute los efectos de la irradiación al feto y sus consecuencias, según dosis recibida, considerando la eventual suspensión de embarazo por esta causa.

Sistema on-line para o cálculo de doses fetais de pacientes e trabalhadoras ocupacionalmente expostas em radiologia diagnóstica / On-line software for the estimation of fetal radiation dose to patients and staff members in diagnostic radiology

Neste trabalho descrevemos um sistema on-line, chamado “Dose Fetal Web”, que calcula a dose fetal e os riscos radiológicos devido a exposições clínicas ou ocupacionais de gestantes. O sistema utiliza a metodologia matemática onde são usados coeficientes de conversão de dose uterina para dose fetal, gerados por meio de simulações pelo método de Monte Carlo. Para exposição médica de uma paciente gestante, uma base de dados de informações de operação de equipamentos acompanhados por um programa de garantia de qualidade e parâmetros fetais e maternos coletados durante exames de ultrassonografia obstétrica são incorporados na estimativa da dose fetal. No caso de dose fetal de uma trabalhadora gestante sujeita à exposição ocupacional (IOE),informações de uma base de dados de monitoração pessoal como dose ocupacional e carga de trabalho são usadas nos cálculos. No primeiro caso, considerando-se uma paciente gestante de 26 semanas submetida a um procedimento abdominal AP (tensão aplicada ao tubo de 70 kVp e filtração total de 3 mmAl), a dose fetal calculada pelo sistema foi 4,61 mGy e os riscos radiológicos obtidos foram 5,0·10-4 e 0,14 para a probabilidade de indução de retardamento mental e declínio de pontos de QI, respectivamente. No segundo caso, considerando-se uma IOE gestante, e assumindo-se que ela utilize um avental de proteção de 0,5 mm de equivalência em chumbo durante cada procedimento de radiologia intervencionista, e que a leitura pessoal de um dosímetro TLD portado fora do avental foi de 2 mGy/mês, a dose fetal calculada pelo sistema foi 0,02 mSv/mês.

In this paper we describe an online software, named “Dose Fetal Web”, which calculates the dose of the fetus and the radiological risks from both medical and occupational exposures of pregnant women. The software uses a mathematical methodology where coefficients for converting uterus to fetal dose, NUD, have been calculated by using Monte Carlo simulation. In the fetal dose from diagnostic medical examination of the pregnant patient, database information regarding output and other equipment related parameters from the QA database, maternal and fetal parameters collected by ultrasound procedures were used for the fetal dose estimation. In the case of fetal dose of the pregnant staff member the database information regarding routine individual monitoring dosimetry, such as occupational dose and workload, were used for the estimation. In the first case, suppose a 26 weeks pregnant patient had to undergo a single AP Abdomen procedure (70 kVp peak tube voltage and total filtration 3 mmAl), the fetal dose calculated by the software was 4.61 mGy and the radiological risks would be 5.0·10-4 and 0.14 to the probability of mental retardation induction and decline in the IQ score, respectively. In the second case,considering that the staff member can be pregnant, and assuming that she wore a 0.5 mm lead equivalent apron during every interventional radiology procedure and a personal dosimetry reading of 2 mGyTLD/month measured with the TLDs outside the apron, the fetal dose calculated by the software was 0.02 mSv/month.

Radiología diagnóstica en la embarazada: consideraciones sobre exposición a radiación y riesgo del feto / Diagnostic radiology in the pregnant: radiation exposure and risk to the fetus

El uso de exámenes de imágenes para el diagnóstico de condiciones no obstétricas puede ser requerido durante cualquier etapa del embarazo. Existe un riesgo teórico de defectos en el desarrollo fetal, el que se ha considerado no relevante con el nivel de dosis aportada por la radiología diagnóstica habitual. La comprensión de los efectos de la radiación en las diferentes etapas del desarrollo fetal y las dosis aportadas por las diferentes técnicas de imágenes debieran colaborar en la elección del tipo de examen a realizar y del mejor momento para hacerlo.

Diagnostic imaging studies can be required during any phase of the pregnancy for the diagnosis of not obstetric conditions. A theoretical risk of defects in the fetal development exists, but it has been considered insignificant at the dose level used for regular radiology practice. Comprehension of radiation effects over fetal development at different pregnancy stages and the relation between imaging modality and dose can help to make a choice, selecting the best radiologic examination and the best moment to do it.

Determinaçäo da dose no feto em pacientes submetidas a radioterapia com câncer de mama / Dose determination of fetus in patients with breast cancer subjected to radiotherapy

O tratamento do câncer da mama durante a gravidez é um problema especial em oncología, uma vez que tal fato constitui elemento de importância para o prognóstico e indicaçäo terapêutica. Em certas condiçöes, o tratamento näo pode ser adiado nem a gravidez interrompida, pois acarretaria um prejuízo das chances de sobrevida para a paciente. Assim, o tratamento deve ser intensivo e, mesmo quando a associaçäo terapêutica é agressiva ao feto, esta deve ser recomendada, desde que realmente venha a ajudar a paciente e produzir o menor dano ao feto. Medidas foram feitas em diversos níveis do útero, onde o feto se localiza durante os diferentes períodos da gestaçäo, com a finalidade de definir a exposiçäo por radiaçäo secundária que o feto recebe durante o tratamento radioterápico. Para esse estudo foram efetuadas medidas em "phantom" Alderson para cada campo individualizado de irradiaçäo, em pacientes de câncer de mama tratadas por cobalto 60 e acelerador linear de 6 MV