The Role of Positron Emission Tomography/Magnetic Resonance Imaging in Gynecological Malignancies.

Accurate oncological staging for early detection is of utmost importance in patient care and increasing the overall patient survival outcome. Hybrid imaging in the form of positron emission tomography (PET)/computed tomography has been successfully implemented in oncological imaging and, where available, has been used consistently in patients with gynecologic malignancies. The implementation of PET/magnetic resonance imaging (MRI) enables high-quality assessment of gynecological malignancies by combining the diagnostic advantages of metabolic information of PET along with the high-resolution anatomical and functional information from the MRI to provide precise information about staging, recurrence, and metastases. This article will review the various applications of PET/MRI in gynecological cancer.

Imaging and Staging of Cervical Cancer.

Cervical carcinoma remains a common gynecologic malignancy. Physical examination has historically served as the predominant tool for staging and assessment, in part due to lack of availability of additional diagnostic resources in many parts of the world. Cross-sectional imaging in the evaluation of cervical cancer has become standard of care in developed countries, and has recently been incorporated into the official staging classification of the International Federation of Gynecology and Obstetrics. This article will describe the use of computed tomography, magnetic resonance imaging, and positron emission tomography/computed tomography and positron emission tomography/magnetic resonance imaging in cervical cancer patients, review optimal techniques for MR evaluation of the cervix, and describe key aspects of staging and management of cervical carcinoma.

Leukemic Involvement in the Thorax.

Leukemias are malignancies in which abnormal white blood cells are produced in the bone marrow, resulting in compromise of normal bone marrow hematopoiesis and subsequent cytopenias. Leukemias are classified as myeloid or lymphoid depending on the type of abnormal cells produced and as acute or chronic according to cellular maturity. The four major types of leukemia are acute myeloid leukemia, chronic myeloid leukemia, acute lymphoblastic leukemia, and chronic lymphocytic leukemia. Clinical manifestations are due to either bone marrow suppression (anemia, thrombocytopenia, or neutropenia) or leukemic organ infiltration. Imaging manifestations of leukemia in the thorax are myriad. While lymphadenopathy is the most common manifestation of intrathoracic leukemia, leukemia may also involve the lungs, pleura, heart, and bones and soft tissues. Myeloid sarcomas occur in 5%-7% of patients with acute myeloid leukemia and represent masses of myeloid blast cells in an extramedullary location. ©RSNA, 2019.

Low-grade epithelial ovarian cancer: what a radiologist should know.

Ovarian cancer accounts for the death of over 100,000 females every year and is the most lethal gynecological malignancy. Low-grade serous ovarian carcinoma (LGSOC) and high-grade serous ovarian carcinoma (HGSOC) have been found to represent two distinct entities based on their molecular differences, clinical course, and response to chemotherapy. Currently, all ovarian cancers are staged according to the revised staging system of the International Federation of Gynecology and Obstetrics (FIGO). Imaging plays an integral role in the diagnosis, staging, and follow-up of ovarian cancers. This review will be based on the two-tier grading system of epithelial ovarian cancers, with the main emphasis on serous ovarian cancer, and the role of imaging to characterize low-grade vs high-grade tumors and monitor disease recurrence during follow-up.

PET/CT Interpretative Pitfalls in Thoracic Malignancies.

Applications of positron emission tomography/computed tomography (PET/CT) in the thorax include the evaluation of solitary pulmonary nodules, staging and restaging of oncologic patients, assessment of therapeutic response, and detection of residual or recurrent disease. Accurate interpretation of PET/CT requires knowledge of the physiological distribution of [18F]-fluoro-2-deoxy-D-glucose, as well as artifacts and quantitative errors due to the use of CT for attenuation correction of the PET scan. Potential pitfalls include malignancies that are PET negative and benign conditions that are PET positive. Awareness of these artifacts and potential pitfalls is important in preventing misinterpretation that can alter patient management.

Imaging on Lung Cancer and Treatment with Targeted Therapy.

The identification of genetic mutations known as oncogenic driver mutations that lead to the growth and survival of cancer cells has been an important advance in the field of oncology. Treatment in advanced non-small-cell lung cancer (NSCLC) has transitioned from a more general approach to a more personalized approach based on genetic mutations of the cancer itself. Common mutations detected in patients with advanced NSCLC include mutations of epidermal growth factor receptor and anaplastic lymphoma kinase (ALK). Targeted therapies are aimed at the products of these gene mutations and include erlotinib (used in epidermal growth factor receptor mutant NSCLC) and crizotinib (used in anaplastic lymphoma kinase positive NSCLC). In this review, we discuss common genetic mutations in advanced NSCLC, the role of targeted therapies, and imaging findings that can be associated with various genetic mutations.

Staging Lung Cancer: Metastasis.

The updated eighth edition of the tumor, node, metastasis (TNM) classification for lung cancer includes revisions to T and M descriptors. In terms of the M descriptor, the classification of intrathoracic metastatic disease as M1a is unchanged from TNM-7. Extrathoracic metastatic disease, which was classified as M1b in TNM-7, is now subdivided into M1b (single metastasis, single organ) and M1c (multiple metastases in one or multiple organs) descriptors. In this article, the rationale for changes in the M descriptors, the utility of preoperative staging with PET/computed tomography, and the treatment options available for patients with oligometastatic disease are discussed.

Lung Cancer: Posttreatment Imaging: Radiation Therapy and Imaging Findings.

In this review, we discuss the different radiation delivery techniques available to treat non-small cell lung cancer, typical radiologic manifestations of conventional radiotherapy, and different patterns of lung injury and temporal evolution of the newer radiotherapy techniques. More sophisticated techniques include intensity-modulated radiotherapy, stereotactic body radiotherapy, proton therapy, and respiration-correlated computed tomography or 4-dimensional computed tomography for radiotherapy planning. Knowledge of the radiation treatment plan and technique, the completion date of radiotherapy, and the temporal evolution of radiation-induced lung injury is important to identify expected manifestations of radiation-induced lung injury and differentiate them from tumor recurrence or infection.

[18F]-2-Fluoro-2-Deoxy-D-glucose-PET Assessment of Cervical Cancer.

This article provides an overview of PET in cervical cancer, primarily with regard to the use of 18F-2-fluoro-2-deoxy-d-glucose-PET/computed tomography. A brief discussion of upcoming technologies, such as PET/MR imaging, is presented.

FDG-PET Assessment of Other Gynecologic Cancers.

PET and PET/computed tomography play a role in the staging, monitoring of response to therapy, and surveillance for cervical and ovarian cancers. Currently, it is also an integral part of the assessment of patients with endometrial cancer and other gynecologic malignancies, such as vaginal and vulvar cancers and uterine sarcomas. In this article, we discuss in detail and highlight the potential role of PET and PET/computed tomography in evaluating these gynecologic malignancies using illustrative cases with relevant imaging findings.

Genetics of pancreatic cancer and implications for therapy.

Pancreatic cancer is a highly lethal disease with a dismal 5-year prognosis. Knowledge of its genetics may help in identifying new methods for patient screening, and cancer treatment. In this review, we will describe the most common mutations responsible for the genesis of pancreatic cancer and their impact on screening, patterns of disease progression, and therapy.

Imaging of Metastases in the Chest: Mechanisms of Spread and Potential Pitfalls.

Pulmonary and pleural metastases are routinely identified on thoracic computed tomography. Pulmonary metastases are the most common pulmonary neoplasms and commonly originate from primary malignancies of the lung, breast, colon, pancreas, stomach, skin (ie, melanoma), head and neck, and kidney. Metastatic disease to the lungs may occur via 3 routes of spread: hematogenous, lymphatic, and endobronchial. Pleural metastases most commonly originate from primary malignancies of the lung and breast. Mechanisms of pleural metastatic involvement include hematogenous spread, direct invasion from a neighboring tumor, and retrograde lymphatic spread from the mediastinum. Awareness of the spectrum of appearances of metatastic disease in the chest is important in avoiding misinterpretation.

Lung Cancer: Posttreatment Imaging: Radiation Therapy and Imaging Findings.

Over the last few decades, advances in radiation therapy technology have markedly improved radiation delivery. Advancements in treatment planning with the development of image-guided radiotherapy and techniques such as proton therapy, allow precise delivery of high doses of radiation conformed to the tumor. These advancements result in improved locoregional control while reducing radiation dose to surrounding normal tissue. The radiologic manifestations of these techniques can differ from radiation induced lung disease seen with traditional radiation therapy. Awareness of these radiologic manifestations and correlation with radiation treatment plans are important to differentiate expected radiation induced lung injury from recurrence, infection and drug toxicity.

Targeted Therapy and Imaging Findings.

Non-small cell lung cancer (NSCLC) is usually diagnosed when it is not amenable to curative surgery or radiation. Many of these patients are candidates for systemic therapy. Median survival is only approximately 10 months, and, accordingly, treatment in advanced NSCLC is evolving toward a more personalized approach with the identification of genetic abnormalities based on biomarkers. For example, gene mutations in EGFR (epidermal growth factor receptor) and ALK (anaplastic lymphoma kinase) lead to a cascade of pathways resulting in uncontrolled growth, proliferation, and survival of tumor cells. Targeted therapies are aimed at the products of these mutated genes and include agents such as erlotinib and gefitinib (in EGFR-mutant NSCLC) or crizotinib (in ALK-positive NSCLC). Antiangiogenesis agents such as bevacizumab are another category of targeted therapy that inhibits vascular endothelial growth factors. The imaging characteristics of advanced NSCLC with genetic abnormalities, the evolution of targeted therapies and their imaging manifestations will be discussed.

Challenges in Interpretation of Staging PET/CT in Thoracic Malignancies.

18F-fluorodeoxryglucose (18F-FDG) PET/CT imaging is routinely performed in the evaluation of patients with known or suspected thoracic malignancy. Indications for its use include staging of malignancy, assessment of response to therapy, evaluation of suspected disease recurrence, and evaluation of a solitary pulmonary nodule. In this article, we will discuss specific technical artifacts and also review potential pitfalls in the interpretation of PET/CT in thoracic malignancies including normal variations in physiologic uptake of FDG, benign conditions (such as infection, inflammation, posttreatment changes, and iatrogenic factors) that can result in increased FDG uptake, and malignancies that demonstrate scarce to no FDG uptake.

Overview of the Role of Imaging in Pelvic Exenteration.

Pelvic exenteration is a radical surgery that is used in an attempt to cure patients with locally advanced central pelvic malignancies. Exenteration is a salvage operation that is considered only after other therapies, such as chemoradiation, have been exhausted. The high morbidity from exenteration's multiorgan resection warrants careful patient selection. Preoperative imaging plays a major role in the selection process, allowing the exclusion of patients with unresectable pelvic disease or distant metastases. Imaging is also crucial to surgical planning, providing the surgeon with a map of the distribution and extent of the pelvic disease.