Review of Radiation Therapy in the Pregnant Cancer Patient

A Case of Radiotherapy During Pregnancy for Oropharyngeal Cancer: Long-Term Pediatric Outcome Evaluation and Literature Review

Oropharyngeal cancer (OphC) is extremely rare during pregnancy, although its incidence is expected to increase in the years to come. Any delay in treatment can heavily affect cancer control and survival. Information regarding radiation therapy during pregnancy and long-term pediatric outcomes is lacking. In this article, we discuss a case of OphC in a pregnant woman, treated with surgery and radiation therapy, offering also an updated review with respect to the limited current evidence of the feasibility and clinical results of radiation therapy during pregnancy. A 39-year-old pregnant woman (through assisted fertilization) with locally advanced OphC underwent surgery and subsequent radiation therapy. A special fetal shielding device and a modified planning optimization strategy were used to reduce the dose to the fetus as much as possible. Phantom and in vivo dosimetry were performed to estimate the dose to the fetus and the related risks, according to International Commission on Radiological Protection (ICRP) publication 90. Thanks to the actions taken, the mean dose to the fetus was estimated to be around 50 mSv. A healthy baby was born at 33 weeks of gestation + 6 days. After a 10-year follow-up, the patient is in complete remission, and her 16-year-old daughter is healthy with good school performance. Adjuvant radiation therapy in OphC during pregnancy may be optimized to reduce the dose to the fetus, and the measures taken represent a realistic option to ensure the mother and baby's health.

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.

A review on fetal dose in Radiotherapy: A historical to contemporary perspective

This paper aims to review on fetal dose in radiotherapy and extends and updates on a previous work¹ to include proton therapy. Out-of-field doses, which are the doses received by regions outside of the treatment field, are unavoidable regardless of the treatment modalities used during radiotherapy. In the case of pregnant patients, fetal dose is a major concern as it has long been recognized that fetuses exposed to radiation have a higher probability of suffering from adverse effects such as anatomical malformations and even fetal death, especially when the 0.1Gy threshold is exceeded. In spite of the low occurrence of cancer during pregnancy, the radiotherapy team should be equipped with the necessary knowledge to deal with fetal dose. This is crucial so as to ensure that the fetus is adequately protected while not compromising the patient treatment outcomes. In this review paper, various aspects of fetal dose will be discussed ranging from biological, clinical to the physics aspects. Other than fetal dose resulting from conventional photon therapy, this paper will also extend the discussion to modern treatment modalities and techniques, namely proton therapy and image-guided radiotherapy, all of which have seen a significant increase in use in current radiotherapy. This review is expected to provide readers with a comprehensive understanding of fetal dose in radiotherapy, and to be fully aware of the steps to be taken in providing radiotherapy for pregnant patients.

Fetal dose from proton pencil beam scanning craniospinal irradiation during pregnancy: a Monte Carlo study

Objective. We conducted a Monte Carlo study to comprehensively investigate the fetal dose resulting from proton pencil beam scanning (PBS) craniospinal irradiation (CSI) during pregnancy.Approach. The gestational-age dependent pregnant phantom series developed at the University of Florida (UF) were converted into DICOM-RT format (CT images and structures) and imported into a treatment planning system (TPS) (Eclipse v15.6) commissioned to a IBA PBS nozzle. A proton PBS CSI plan (prescribed dose: 36 Gy) was created on the phantoms. The TOPAS MC code was used to simulate the proton PBS CSI on the phantoms, for which MC beam properties at the nozzle exit (spot size, spot divergence, mean energy, and energy spread) were matched to IBA PBS nozzle beam measurement data. We calculated mean absorbed doses for 28 organs and tissues and whole body of the fetus at eight gestational ages (8, 10, 15, 20, 25, 30, 35, and 38 weeks). For contextual purposes, the fetal organ/tissue doses from the treatment planning CT scan of the mother's head and torso were estimated using the National Cancer Institute dosimetry system for CT (NCICT, Version 3) considering a low-dose CT protocol (CTDIvol: 8.97 mGy).Main results. The majority of the fetal organ/tissue doses from the proton PBS CSI treatment fell within a range of 3-6 mGy. The fetal organ/tissue doses for the 38 week phantom showed the largest variation with the doses ranging from 2.9 mGy (adrenals) to 8.2 mGy (eye lenses) while the smallest variation ranging from 3.2 mGy (oesophagus) to 4.4 mGy (brain) was observed for the doses for the 20 week phantom. The fetal whole-body dose ranged from 3.7 mGy (25 weeks) to 5.8 mGy (8 weeks). Most of the fetal doses from the planning CT scan fell within a range of 7-13 mGy, approximately 2-to-9 times lower than the fetal dose equivalents of the proton PBS CSI treatment (assuming a quality factor of 7).Significance. The fetal organ/tissue doses observed in the present work will be useful for one of the first clinically informative predictions on the magnitude of fetal dose during proton PBS CSI during pregnancy.

Radiotherapy and pregnancy

We present the updated recommendations of the French society for radiation oncology on radiotherapy and pregnancy. The occurrence of cancer during pregnancy is a rare event (approximately 1 in 1000 pregnancies). The risks for the embryo or the foetus depend on the gestational age at the time of irradiation. The main risks are malformations with microcephaly and mental retardation. There is also a risk of radiation-induced cancer in the unborn child. In the case of only supradiaphragmatic irradiation, radiotherapy can be performed most often in pregnant women without risk to the foetus. On the other hand, in the case of an indication for subdiaphragmatic irradiation, therapeutic termination of the pregnancy should be proposed. In all cases, when radiotherapy is chosen, a phantom estimation of the dose delivered to the foetus, confirmed by in vivo measurement, is recommended. Conformational radiotherapy is the preferred technique because of the lower dose delivered to the foetus (except in tumour locations where other techniques such as IMRT are recommended).

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.

Management and outcome of colorectal cancer during pregnancy: report of 41 cases

BACKGROUND

Colorectal cancer in pregnancy is rare, with an incidence of 0.8 per 100,000 pregnancies. Advanced disease (stage III or IV) is diagnosed more frequently in pregnant patients. We aimed to review all cases of colorectal cancer in pregnancy from the International Network on Cancer, Infertility and Pregnancy database in order to learn more about this rare disease and improve its management.

METHODS

Data on the demographic features, symptoms, histopathology, diagnostic and therapeutic interventions and outcomes (obstetric, neonatal and maternal) were analysed.

RESULTS

Twenty-seven colon and 14 rectal cancer cases were identified. Advanced disease was present in 30 patients (73.2%). During pregnancy, 21 patients (51.2%) received surgery and 12 patients (29.3%) received chemotherapy. Thirty-three patients (80.5%) delivered live babies: 21 by caesarean section and 12 vaginally. Prematurity rate was high (78.8%). Eight babies were small for gestational age (27.6%). Three patients (10.7%) developed recurrence of disease. Overall 2-year survival was 64.4%.

CONCLUSION

Despite a more frequent presentation with advanced disease, colorectal cancer has a similar prognosis in pregnancy when compared with the general population. Diagnostic interventions and treatment should not be delayed due to the pregnancy but a balance between maternal and foetal wellbeing must always be kept in mind.

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.

Treatment of oral cancers during pregnancy: a case-based discussion

Background

Malignancies occur in approximately 1:1000 pregnancies; the most common being breast (46%) and hematological (18%) malignancies. Oral cancers account for only 2% of all cancers in pregnant women, and there are no standard guidelines for the treatment of oral cancer during pregnancy.

Methods

Between 2007 and 2014, our department managed 1109 patients with oral cancers; four (0.4%) had tongue carcinomas during pregnancy. These cases were retrospectively reviewed.

Results

The four women were aged 29–39 (median 32.5) years. Two underwent partial glossectomy at 39 and 40 weeks’ gestation, respectively, one received radiotherapy at 17 weeks’ gestation, and one underwent supraomohyoid neck dissection and hemi-glossectomy with a forearm flap reconstruction.

Conclusion

In addition to tumor factors, the wishes of the patient and her family, gestational age, and fetal and maternal conditions are important factors in deciding on a treatment protocol. Moreover, treatment decisions require multidisciplinary approach.

Advanced gastrointestinal carcinoma with massive ascites and hydrothorax during pregnancy: A case report and review of the literature

RATIONALE

Gastrointestinal carcinoma is rare during pregnancy. It is usually diagnosed at an advanced stage because special gastrointestinal symptoms are generally overlooked during pregnancy, and there are many limitations and contraindications for using diagnostic tools during pregnancy.

PATIENT CONCERNS

We present a case of a 29-year-old patient with 27 weeks and 5 days of gestation due to massive ascites and hydrothorax.

DIAGNOSES

The patient was diagnosed with an advanced gastrointestinal cancer. Pathological report showed poorly differentiated tumor with the signet ring cell component.

INTERVENTIONS

Caesarean section was performed. At the same time, an abdominal exploration showed that the omentum was like biscuits . There were extensive and firm intestinal adhesions, and many tumor lesions were found on the surface of greater curvature of stomach, spleen, intestine, peritoneum, ascending colon and descending colon.

OUTCOMES

Gastrointestinal surgeon was invited during operation, and palliative gastrectomy was not performed because of extensive metastases. The patient died 30 days after caesarean section.

LESSONS

This study present a case with advanced gastrointestinal cancer during pregnancy. We suggest that endoscopic exam is recommended if the patient is highly suspicious.

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.

Monte Carlo Simulation of Radiotherapy for Breast Cancer in Pregnant Patients: How to Reduce the Radiation Dose and Risks to Fetus?

This study estimated the fetal dose and risks from radiotherapy for breast cancer with 6 MV X-rays. Breast irradiation was simulated with the MCNP code using two mathematical phantoms corresponding to patients in the early and middle periods of pregnancy. Monte Carlo simulations were performed to determine the appropriate fetal shielding. For a 50-Gy tumor dose, the unshielded fetal dose reached up to 133.1 mGy. Fetal protection with a lead shield of dimensions 30 × 30 × 5 cm3 placed besides the treatment couch resulted in maximum doses of 22.0 and 70.3 mGy at the first and second trimesters of gestation, respectively. These shielded fetal doses may be associated with a fatal cancer risk during childhood up to 0.42% and a maximum probability for the appearance of heritable effects of 0.17%. The use of fetal shielding ensures the absence of deterministic effects from radiotherapy during the first 24 weeks of gestation.

Multiple meningiomas in a woman irradiated in utero

Meningiomas are a common central nervous system tumour and radiation is a known risk factor for their development. In utero radiation exposure correlates to developmental abnormalities and carcinogenesis in a dose- and gestational age-related manner. Radiation induced meningioma has been reported in detail in the literature in patients who had been irradiated earlier in life. At the time of publication, there was no data on radiation exposure whilst in utero and meningioma. We report on a 42-year-old woman with multiple intracranial meningiomas and no other risk factors except a history of in utero exposure to low dose X-ray radiation at 12weeks gestational age.

Spot scanning proton therapy minimizes neutron dose in the setting of radiation therapy administered during pregnancy

This is a real case study to minimize the neutron dose equivalent (H) to a fetus using spot scanning proton beams with favorable beam energies and angles. Minimum neutron dose exposure to the fetus was achieved with iterative planning under the guidance of neutron H measurement. Two highly conformal treatment plans, each with three spot scanning beams, were planned to treat a 25‐year‐old pregnant female with aggressive recurrent chordoma of the base of skull who elected not to proceed with termination. Each plan was scheduled for delivery every other day for robust target coverage. Neutron H to the fetus was measured using a REM500 neutron survey meter placed at the fetus position of a patient simulating phantom. 4.1 and 44.1 44.1 μSv/fraction were measured for the two initial plans. A vertex beam with higher energy and the fetal position closer to its central axis was the cause for the plan that produced an order higher neutron H. Replacing the vertex beam with a lateral beam reduced neutron H to be comparable with the other plan. For a prescription of 70 Gy in 35 fractions, the total neutron H to the fetus was estimated to be 0.35 mSv based on final measurement in single fraction. In comparison, the passive scattering proton plan and photon plan had an estimation of 26 and 70 mSv, respectively, for this case. While radiation therapy in pregnant patients should be avoided if at all possible, our work demonstrated spot scanning beam limited the total neutron H to the fetus an order lower than the suggested 5 mSv regulation threshold. It is far superior than passive scattering beam and careful beam selection with lower energy and keeping fetus further away from beam axis are essential in minimizing the fetus neutron exposure.

PACS number(s): 87.53.Bn, 87.55.D‐, 87.55.N‐

Management of Hematologic Malignancies: Special Considerations in Pregnant Women

The diagnosis and management of hematologic malignancy during pregnancy is a significant challenge. This is due to both medical and ethical considerations regarding when and how to treat this special sub-group of patients. Recurring uncertainties remain around appropriate imaging techniques, timing and dosage of chemotherapy, and timing of delivery. In this article we examine and summarize current literature in this field to assist physicians in their understanding and management of this patient group. Special attention has been given to diagnostic and staging procedures, risks associated with chemotherapy at different stages of gestation, and chemotherapy-dose adaption during pregnancy. In addition, recommended guidelines for management of lymphoma, leukemia, and planning delivery are discussed. A multidisciplinary team approach is critical for patient care, as is shared decision making with the patient and family.

Evaluation and management of the pregnant patient with suspected primary musculoskeletal tumor or metastatic carcinoma to bone

Primary musculoskeletal cancer and metastatic disease to bone in pregnant patients presents major treatment challenges. Although uncommon, musculoskeletal malignancies in pregnant women have been reported. When diagnosing and treating these patients, the mother's health must be managed appropriately while ensuring that fetal development is not deleteriously affected. Extensive radiographic imaging and more advanced techniques are often necessary to fully characterize the extent of disease. When possible, magnetic resonance imaging should be used instead of computed tomography to limit exposure of the conceptus to radiation. If treatment is needed, therapeutic radiation, chemotherapy, and surgery should be considered. Surgical resection is the foundation of treatment of early-stage primary bone tumors and soft-tissue sarcomas during pregnancy. With surgery, anesthesia and thromboprophylaxis are important considerations. If chemotherapy is required, administration should be avoided in the first trimester to limit harm to the fetus. Therapeutic radiation should similarly be avoided during the first trimester and often can be postponed until after delivery.

Unique epigenetic influence of H2AX phosphorylation and H3K56 acetylation on normal stem cell radioresponses

Normal stem cells from tissues often exhibiting radiation injury are highly radiosensitive and exhibit a muted DNA damage response, in contrast to differentiated progeny. These radioresponses can be attributed to unique epigenetic regulation in stem cells, identifying potential therapeutic targets for radioprotection.

Normal tissue injury resulting from cancer radiotherapy is often associated with diminished regenerative capacity. We examined the relative radiosensitivity of normal stem cell populations compared with non–stem cells within several radiosensitive tissue niches and culture models. We found that these stem cells are highly radiosensitive, in contrast to their isogenic differentiated progeny. Of interest, they also exhibited a uniquely attenuated DNA damage response (DDR) and muted DNA repair. Whereas stem cells exhibit reduced ATM activation and ionizing radiation–induced foci, they display apoptotic pannuclear H2AX-S139 phosphorylation (γH2AX), indicating unique radioresponses. We also observed persistent phosphorylation of H2AX-Y142 along the DNA breaks in stem cells, which promotes apoptosis while inhibiting DDR signaling. In addition, down-regulation of constitutively elevated histone-3 lysine-56 acetylation (H3K56ac) in stem cells significantly decreased their radiosensitivity, restored DDR function, and increased survival, signifying its role as a key contributor to stem cell radiosensitivity. These results establish that unique epigenetic landscapes affect cellular heterogeneity in radiosensitivity and demonstrate the nonubiquitous nature of radiation responses. We thus elucidate novel epigenetic rheostats that promote ionizing radiation hypersensitivity in various normal stem cell populations, identifying potential molecular targets for pharmacological radioprotection of stem cells and hopefully improving the efficacy of future cancer treatment.

Cancer treatment in pregnant women

In general, strategies for the treatment of cancer in pregnancy should not differ significantly from the treatment regimens in non-pregnant women. However, this is difficult due to either the effects of anticancer drugs on the developing foetus or the possibility of long-term complications after the exposure to drugs and radiation. The decision about the introduction and continuation of treatment in the event of pregnancy should be preceded by a detailed analysis of the potential benefits and risks. There are no data to suggest that pregnancy termination alters the biological behaviour of the tumour or patient prognosis in the presence of appropriate antineoplastic therapy. All patients should be given appropriate advice and informed that there are insufficient scientific data to determine any generally accepted consensus. It is very important to always respect the will of the patient, and the moral judgment of the physician should have no impact on the decisions taken by the woman. If the woman decides to undergo active treatment and maintain her pregnancy, it is necessary to carry out consultations with experts in the field appropriate to the type of cancer. This paper presents a basic review of the literature on the targeted therapies currently used in selected cancers diagnosed during pregnancy: breast cancer, cervical cancer, Hodgkin's disease, melanoma, thyroid cancer, ovarian cancer, and colorectal cancer.

An Update on the Management of Hematologic Malignancies in Pregnancy

Hematological malignancies during pregnancy are rare, which results in the absence of large prospective studies. The diagnosis is often delayed due to the symptom similarity to those of pregnancy and the recommendation to avoid imaging studies during gestation. Management of hematological malignancies during pregnancy poses challenges both to the patient and the medical team, given the therapy-attributable risks for mother and fetus and the need to consider patient's preferences regarding pregnancy continuation. Chemotherapy during the first trimester is associated with an increased risk for fetal demise and congenital malformations, while these risks diminish as pregnancy progresses. We hereby present a review of updated literature on the management of hematologic malignancies (Hodgkin and non-Hodgkin lymphomas, acute leukemia, multiple myeloma, chronic myeloid leukemia and myeloproliferative neoplasms) during pregnancy.

Rectal cancer in pregnancy: a diagnostic and therapeutic challenge

INTRODUCTION

The occurrence of colorectal cancer during pregnancy is rare and is associated with diagnostic and therapeutic challenges. Herein, we report such a case of rectal cancer in pregnancy and review the literature.

CASE REPORT

A 31-year-old multiparous, pregnant woman, in the 20th week of gestation, presented with rectal bleeding progressing to spasmodic abdominal pain and right flank vague pain. A flexible rectosigmoidoscopy showed a large ulcerative mass located in the rectosigmoid junction, 15 cm away from anal verge. Imaging studies and biopsy proved it to be rectal adenocarcinoma with single liver metastasis. The patient's pregnancy was terminated and neoadjuvant therapy followed by curative surgery was performed. She is currently receiving adjuvant systemic therapy to eradicate potential micrometastatic disease.

CONCLUSION

This case suggests that colorectal cancer can mimic the signs and the symptoms of pregnancy and tends to present at an advanced stage in pregnant women.

Breast cancer in pregnancy

Pregnancy-associated breast cancer is defined as breast cancer diagnosed during pregnancy or in the first postpartum year. Breast cancer is one of the more common malignancies to occur during pregnancy and, as more women delay childbearing, the incidence of breast cancer in pregnancy is expected to increase. This article provides an overview of diagnosis, staging, and treatment of pregnancy-associated breast cancer. Recommendations for management of breast cancer in pregnancy are discussed.

Challenges in managing breast cancer during pregnancy

Pregnancy-associated breast cancer (PABC) is defined as breast cancer occurring anytime during gestation, lactation or within one year after delivery. The optimal management of pregnant women with breast cancer is challenging and not well established; the main concern is the effect of the drugs on the developing fetus and long-term complications after in utero exposure to anti-cancer drugs. Surgical resection is the mainstay of treatment for early breast cancer diagnosed during pregnancy. Modified radical mastectomy is standard of care in first trimester, whereas breast-conserving surgery (lumpectomy with lymph node dissection) can be performed preferably in the second and third trimester. Of note, breast-conserving surgery is not contraindicated per se during the first trimester, but owing to the potential impact of delaying radiotherapy. Radiation therapy is not favored during pregnancy. Moreover, tamoxifen is contraindicated during pregnancy; the agent has been associated with birth defects in up to 20% of exposures. Chemotherapy is generally contraindicated during the first trimester because of the possible damage to organogenesis. Anthracyclines-based regimens are the most widely used is breast cancer treatment and were been shown to be associated with favourable safety profile when administered during pregnancy. As for taxanes, more limited data is available. The use of trastuzumab is contraindicated during pregnancy, given the apparent risk of oligo- and/or anhydramnios as well as the unknown long-term sequelae on the fetus. It is obvious that, diagnosis of breast cancer during pregnancy adds complexity to cancer treatment recommendations. In all cases, a multidisciplinary therapeutic approach among obstetricians, gynaecologists, surgical oncologists, radiation oncologists, medical oncologists, pediatricians and hematologists is clearly warranted.