Imaging for Early Detection of Pancreatic Ductal Adenocarcinoma: Updates and Challenges in the Implementation of Screening and Surveillance Programs.

Pancreatic ductal adenocarcinoma (PDA) is one of the most aggressive cancers. It has a poor 5-year survival rate of 12%, partly because most cases are diagnosed at advanced stages, precluding curative surgical resection. Early-stage PDA has significantly better prognoses due to increased potential for curative interventions, making early detection of PDA critically important to improved patient outcomes. We examine current and evolving early detection concepts, screening strategies, diagnostic yields among high-risk individuals, controversies, and limitations of standard-of-care imaging.

Malignancy in pregnancy: Multimodality imaging and treatment.

The diagnosis of cancer is increasingly made in the pregnant population, thought to be from the increasing average age of pregnancy and the use of prenatal fetal noninvasive screening techniques, leading to incidental detection of cancer in the mother. Complex challenges are associated with imaging, diagnosis, staging, and treatment of cancers in this patient population, which require highly specialized interdisciplinary management. This report discusses the use of multimodality imaging and safety considerations in pregnant patients, reviews the current guidelines for ionizing radiation imaging techniques, and presents a series of commonly and uncommonly encountered cancers in pregnancy with current diagnostic imaging guidelines. The authors also discuss the role of multidisciplinary management and treatment options and provide an overview of therapy-related considerations in the age of novel anticancer therapies. PLAIN LANGUAGE SUMMARY: The diagnosis and management of pregnant patients who have cancer are actively evolving as novel imaging techniques and anticancer therapies are being developed. Radiologically, there are inherent difficulties in balancing the minimization of fetal ionization while acquiring diagnostic quality imaging necessary for the diagnosis, staging, and treatment of maternal disease. Standardized imaging protocols are still being developed, with evolving imaging guidelines coupled with rapidly expanding research and development of novel anticancer therapies, which come with their side effects and complications. Caring for this patient population is especially challenging and requires specialized multidisciplinary attention.

Added Value of FDG PET/MRI in Gynecologic Oncology: A Pictorial Review.

Fluorine 18-fluorodeoxyglucose (FDG) PET and MRI independently play a valuable role in the management of patients with gynecologic malignancies, particularly endometrial and cervical cancer. The PET/MRI hybrid imaging technique combines the metabolic information obtained from PET with the excellent soft-tissue resolution and anatomic details provided by MRI in a single examination. MRI is the modality of choice for assessment of local tumor extent in the pelvis, whereas PET is used to assess for local-regional spread and distant metastases. The authors discuss the added value of FDG PET/MRI in imaging gynecologic malignancies of the pelvis, with a focus on the role of FDG PET/MRI in diagnosis, staging, assessing treatment response, and characterizing complications. PET/MRI allows better localization and demarcation of the extent of disease, characterization of lesions and involvement of adjacent organs and lymph nodes, and improved differentiation of benign from malignant tissues, as well as detection of the presence of distant metastasis. It also has the advantages of decreased radiation dose and a higher signal-to-noise ratio of a prolonged PET examination of the pelvis contemporaneous with MRI. The authors provide a brief technical overview of PET/MRI, highlight how simultaneously performed PET/MRI can improve stand-alone MRI and PET/CT in gynecologic malignancies, provide an image-rich review to illustrate practical and clinically relevant applications of this imaging technique, and review common pitfalls encountered in clinical practice. ©RSNA, 2023 Quiz questions for this article are available in the supplemental material.

Characterizing morphologic subtypes of high-grade serous ovarian cancer by CT: a retrospective cohort study.

OBJECTIVE: A novel classification system of high-grade serous ovarian carcinoma based on gross morphology observed at pre-treatment laparoscopy was recently defined. The purpose of this study was to identify radiographic features unique to each morphologic subtype. METHODS: This retrospective study included 109 patients with high-grade serous ovarian cancer who underwent pre-operative computed tomography (CT) scanning and laparoscopic assessment of disease burden between 1 April 2013 and 5 August 2015. Gross morphologic subtype had been previously assigned by laparoscopy. Two radiologists independently reviewed CT images for each patient, categorized disease at eight anatomic sites, and assessed for radiographic characteristics of interest: large infiltrative plaques, mass-like metastases, enhancing peritoneal lining, architectural distortion, fat stranding, calcifications, and lymph node involvement. Demographic and clinical information was summarized with descriptive statistics and compared using Student's t-tests, χ² tests, or Fisher exact tests as appropriate; kappa statistics were used to assess inter-reader agreement. RESULTS: Certain radiographic features were found to be associated with gross morphologic subtype. Large infiltrative plaques were more common in type 1 disease (88.7% (47/53) vs 71.4% (25/35), p=0.04), while mass-like metastases were more often present in type 2 disease (48.6% (17/35) vs 22.6% (12/53), p=0.01). Additionally, radiographic presence of disease at the falciform ligament was more common in type 1 morphology (33.9% (19/56) vs 13.2% (5/38), p=0.02). CONCLUSION: Morphologic subtypes of high-grade serous ovarian cancer were associated with specific CT findings, including the presence of large infiltrative plaques, mass-like metastases, and falciform ligament involvement.

Performance of Multidetector Computed Tomography and Negative Versus Positive Enteric Contrast for Evaluation of Gastrointestinal Neuroendocrine Neoplasms.

BACKGROUND: Routine computed tomography (CT) scans are thought to have poor performance for detection of gastrointestinal (GI) neuroendocrine neoplasms (NENs), which leads to delayed workup. Detection of even 1 bowel tumor can guide diagnostic workup and management. The purposes of this study were to assess the accuracy of multidetector computed tomography (MDCT) and to compare negative versus positive enteric contrast in detecting at least 1 GI tumor per patient with suspected or confirmed diagnosis of a NEN. METHODS: This retrospective study included 107 patients with intravenous and oral contrast (65 positive, 40 negative, and 2 no oral contrast) abdominopelvic MDCT. Two abdominal radiologists independently analyzed the CTs for detection and localization of bowel NENs. Surgical pathology was considered the reference standard. Analyses included κ and summary statistics, McNemar test, Pearson χ2 test, and Fisher exact test. RESULTS: Among the 107 CT scans, there were 30 pathology negative studies and 77 studies with positive pathology for GI NEN. Interreader agreement for CT evaluation was substantial (κ = 0.61). At least 1 GI NEN per patient was detected with 51% to 53% sensitivity, 87% to 93% specificity, 91% to 95% positive predictive value (PPV), 42% negative predictive value, and 63% accuracy for each reader, and 57% accuracy when only the concordant (ie, matching) results of the 2 readers were considered. Computed tomography scans with negative enteric contrast had significantly higher sensitivity for concordant results than CTs with positive enteric contrast (58% vs 30%, P = 0.01). Specificity (100% vs 95%, P = 0.5), PPV (100% vs 93%, P = 0.49), negative predictive value (39% vs 39%, P = 0.99), and accuracy (67% vs 51%, P = 0.10) were not significantly different for negative versus positive enteric contrast for the concordant results. There was no significant difference in GI NEN localization between the readers. CONCLUSIONS: Routine MDCT with either positive or negative enteric contrast can detect at least 1 GI tumor per patient with more than 90% PPV and more than 50% accuracy in patients suspected of GI NEN. Using negative enteric contrast improves sensitivity for GI NEN versus positive enteric contrast. In addition, there is high accuracy in localizing the bowel tumor with positive or negative enteric contrast, which may guide surgery. Radiologists should have heightened awareness that evaluating such scans closely may lead to detection of primary bowel NENs at a higher rate than previously reported.

Clinicopathological correlation of radiologic measurement of post-therapy tumor size and tumor volume for pancreatic ductal adenocarcinoma.

OBJECTIVES: Tumor size measurement is critical for accurate tumor staging in patients with pancreatic ductal adenocarcinoma (PDAC). However, accurate tumor size measurement is challenging in patients who received neoadjuvant therapy before resection, due to treatment-induced fibrosis and tumor invasion beyond the grossly identified tumor area. In this study, we evaluated the correlation between the tumor size and tumor volume measured on post-therapy computed tomography (CT) scans and the pathological measurement. Also, we investigated the correlation between these measurements and clinicopathological parameters and survival. MATERIALS AND METHODS: Retrospectively, we evaluated 343 patients with PDAC who received neoadjuvant therapy, followed by pancreaticoduodenectomy and had pre-operative pancreatic protocol CT imaging. We measured the longest tumor diameter (RadL) and the radiological tumor volume (RadV) on the post-therapy CT scan, then we categorized RadL into four radiologic tumor stages (RTS) based on the current AJCC staging (8th edition) protocol and RadV based on the median. Pearson correlation or Spearman's coefficient (δ), T-test and ANOVA was used to test the correlation between the radiological and pathological measurement. Chi-square analysis was used to test the correlation with the tumor pathological response, lymph-node metastasis and margin status and Kaplan-Meier and Cox-proportional hazard for survival analysis. P-value < 0.05 was considered significant. RESULTS: As a continuous variable, RadL showed a positive linear correlation with the post-therapy pathologic tumor size in the overall patient population (Pearson correlation coefficient: 0.72, P < 0.001) and RadV (δ: 0.63, p < 0.0001). However, there was no correlation between RadL and pathologic tumor size in patients with ypT0 and those with pathologic tumor size of ≤1.0 cm. Post-therapy RTS and RadV group correlated with ypT stage, tumor response grades using either CAP or MDA grading system, distance of superior mesenteric artery margin and tumor recurrence/metastasis. CONCLUSION: Although RadL tends to understage ypT in PDAC patients who had no radiologically detectable tumor or small tumors (RTS0 or RTS1), radiologic measurement of post-therapy tumor size may be used as a marker for the pathologic tumor staging and tumor response to neoadjuvant therapy.

Radiology Education Amid COVID-19 Pandemic and Possible Solutions.

Along with the rest of the world, the United States is inundated by the COVID-19 pandemic. The medical services in the country have been severely affected. The pandemic poses extraordinary challenges to academic institutions including radiology residency and fellowship programs. Herein, we delineate major difficulties faced by our radiology training program and mitigating countermeasures. The primary objective is to discuss the changes in our radiology training programs due to COVID-19 to allow for continued radiology education.

Ovarian Cancer Genetics and Implications for Imaging and Therapy.

Ovarian cancer is the second most common gynecologic malignancy in the United States. Ovarian cancer has a dismal prognosis when diagnosed at an advanced stage. Therapy for these cancers is determined not only by stage but also by their heterogeneous pathologic features, genetic mutations, and biology. In this review, we will discuss types of epithelial ovarian cancer, and their associated genetic mutations and the implications for imaging and treatment.

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.

Immunotherapy and the role of imaging.

Significant advances in the genetic and molecular characterization of cancer have led to the development of effective immunotherapies. These therapeutics help the host immune system recognize cancer as foreign, promote the immune system, and relieve the inhibition that allows growth and spread of tumors. Experience with various immunotherapies, particularly the immunomodulatory monoclonal antibody ipilimumab, has demonstrated that unique patterns of response may be encountered that cannot be adequately captured by traditional response criteria, such as the World Health Organization (WHO) criteria and Response Evaluation Criteria in Solid Tumors (RECIST), which have been used primarily with cytotoxic chemotherapies. In response to these observations, several novel response criteria have been developed to evaluate patients who receive immunotherapy, including immune-related response criteria (irRC), immune-related RECIST (irRECIST), and immune RECIST (iRECIST). These criteria are typically used in conjunction with RECIST version 1.1 in the clinical trial setting, because approval of new therapeutics by the US Food and Drug Administration relies on the responses derived from RECIST version 1.1. Finally, a wide variety of immune-related adverse events may affect patients who receive immunotherapy, many of which can be identified on imaging studies such as computed tomography, magnetic resonance imaging, and 2-deoxy-2-(fluorine-18)fluoro-D-glucose-positron emission tomography/computed tomography. In this review, the authors present the role of imaging in the evaluation of patients treated with immunotherapy, including the background and application of irRC, irRECIST, and iRECIST; the imaging of immune-related adverse events; and future directions in advanced imaging of immunotherapy. Cancer 2018;124:2906-22. © 2018 American Cancer Society.

BRCA-associated Cancers: Role of Imaging in Screening, Diagnosis, and Management.

Harmful mutations of the BRCA tumor suppressor genes result in a greater lifetime risk for malignancy-breast and ovarian cancers in particular. An increased risk for male breast, fallopian tube, primary peritoneal, pancreatic, prostate, and colon cancers also has been reported. The BRCA gene is inherited in an autosomal dominant pattern and tends to be highly penetrant; thus, there is an increased incidence of these cancers in affected families. Compared with sporadic tumors, BRCA-associated malignancies have unique manifestations, clinical features, and pathologic profiles. Manifestation at an early patient age, high-grade tumors, and an aggressive clinical course are common features of BRCA-associated malignancies. Understanding the behavior of these cancers aids in identification of affected individuals and families, who can then make informed decisions regarding their future health. Enhanced screening, prophylactic surgery, and chemoprevention are options for managing cancer risk factors in these individuals. Imaging has an important role in the screening, evaluation, staging, and follow-up of BRCA-associated malignancies. Supplemental screening of BRCA mutation carriers often begins at an early age and is critical for early and accurate cancer diagnoses. The authors review the etiopathogenesis and imaging features of BRCA-associated malignancies, the importance of a multidisciplinary approach to determining the diagnosis, and the treatment of patients who have these mutations to improve their outcomes. © RSNA, 2017.

Fat-Containing Hypermetabolic Masses on FDG PET/CT: A Spectrum of Benign and Malignant Conditions.

OBJECTIVE: This article focuses on identifying the imaging appearances of hypermetabolic fatty masses and masslike lesions on PET/CT and understanding the diagnostic challenges radiologists may face while interpreting findings of these lesions on PET/CT. This article provides an approach to aid in the diagnosis of these lesions and the appropriate management of patients. CONCLUSION: Both malignant and benign fat-containing masses and masslike lesions can show hypermetabolic activity on PET/CT. Although the differential diagnosis is broad, clinical history, anatomic location, and knowledge of anatomic variants and imaging features can help radiologists avoid misinterpretation of benign fatty lesions as malignancy.

Evaluation of Magnetic Resonance (MR) Biomarkers for Assessment of Response With Response Evaluation Criteria in Solid Tumors: Comparison of the Measurements of Neuroendocrine Tumor Liver Metastases (NETLM) With Various MR Sequences and at Multiple Phases of Contrast Administration.

PURPOSE: Our aim was to compare the interobserver and intraobserver variability for the measurement of the size of liver metastases in patients with carcinoid tumors with various magnetic resonance (MR) series. MATERIALS AND METHODS: In this retrospective institutional review board-approved study, 30 patients with liver metastases from a carcinoid primary had a complete MR examination of the abdomen at 1.5 T with gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid (Gd-EOB-DTPA). The complete MR examination included T1 (in-phase [IP]/out-of-phase [OOP], T2, diffusion-weighted imaging, pre-Gd-EOB-DTPA and post-Gd-EOB-DTPA 3D gradient echo (4 phases plus 20-minute hepatobiliary phase [HBP] Gd]). Four readers reviewed each series independently. The measurement for each lesion was compared to HBP-Gd images. The sensitivity for detection of each lesion was compared to HBP-Gd. Variance component analysis was used to estimate variance due to patient, lesion within patient, and reader by sequence. Linear mixed model was used to compare lesion size between sequences. RESULTS: The HBP-Gd had the smallest interreader variability. There was no significant difference between series with respect to interreader variability. Lesion sizes measured in diffusion-weighted imaging was significantly higher. T2-weighted imaging was the closest to HBP-Gd. Lesion sizes measured with the other sequences were significantly smaller. There was significant difference in sensitivity of lesion detection of some series when compared to HBP-Gd. CONCLUSION: The HBP-Gd series had the smallest interreader variability and is the recommended series to measure lesion size for evaluation of response to treatment.

Tumor thrombus as a rare presentation of lymphoma: a case series of 14 patients.

OBJECTIVE: We present a case series of 14 patients with lymphoma presenting with tumor thrombus to highlight this rare but important manifestation of lymphoma. CONCLUSION: The dominant mass leading to tumor thrombus formation was nodal disease in nine patients and extranodal disease in five patients. Lymphoma should be considered in the differential diagnosis in the setting of tumor thrombus with solid organ involvement when there are other imaging features suggestive of lymphoma.

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.

Multimodality imaging of common and uncommon peritoneal diseases: a review for radiologists.

Peritoneal disease can be caused by a wide spectrum of pathologies. While peritoneal disease is usually caused by primary or secondary malignancies, benign diseases can occur and mimic malignancies. This article begins with an overview of peritoneal embryology and anatomy followed by a detailed description of the multimodality imaging appearance of peritoneal diseases. Common diseases include peritoneal carcinomatosis, pseudomyxoma peritonei, lymphomatosis, sarcomatosis, and tuberculous peritonitis. The uncommon diseases which cause peritoneal disease include desmoid fibromatosis, desmoplastic small round cell tumor, malignant mesothelioma, well-differentiated mesothelioma, multicystic mesothelioma, papillary serous carcinoma, leiomyomatosis, extramedullary hematopoiesis, inflammatory pseudotumor and amyloidosis. This manuscript will help the radiologist become familiar with the different peritoneal spaces, pathways of spread, multimodality imaging appearance and differential diagnoses of peritoneal diseases in order to report the essential information for surgeons and oncologists to plan treatment.

Intra-tumoral heterogeneity of gemcitabine delivery and mass transport in human pancreatic cancer.

There is substantial heterogeneity in the clinical behavior of pancreatic cancer and in its response to therapy. Some of this variation may be due to differences in delivery of cytotoxic therapies between patients and within individual tumors. Indeed, in 12 patients with resectable pancreatic cancer, we previously demonstrated wide inter-patient variability in the delivery of gemcitabine as well as in the mass transport properties of tumors as measured by computed tomography (CT) scans. However, the variability of drug delivery and transport properties within pancreatic tumors is currently unknown. Here, we analyzed regional measurements of gemcitabine DNA incorporation in the tumors of the same 12 patients to understand the degree of intra-tumoral heterogeneity of drug delivery. We also developed a volumetric segmentation approach to measure mass transport properties from the CT scans of these patients and tested inter-observer agreement with this new methodology. Our results demonstrate significant heterogeneity of gemcitabine delivery within individual pancreatic tumors and across the patient cohort, with gemcitabine DNA incorporation in the inner portion of the tumors ranging from 38 to 74% of the total. Similarly, the CT-derived mass transport properties of the tumors had a high degree of heterogeneity, ranging from minimal difference to almost 200% difference between inner and outer portions of the tumor. Our quantitative method to derive transport properties from CT scans demonstrated less than 5% difference in gemcitabine prediction at the average CT-derived transport value across observers. These data illustrate significant inter-patient and intra-tumoral heterogeneity in the delivery of gemcitabine, and highlight how this variability can be reproducibly accounted for using principles of mass transport. With further validation as a biophysical marker, transport properties of tumors may be useful in patient selection for therapy and prediction of therapeutic outcome.

Pelvic reconstruction with pedicled thigh flaps: indications, surgical techniques, and postoperative imaging.

OBJECTIVE: This article will describe and illustrate the relevant anatomy and surgical techniques used in pelvic reconstruction using regional pedicled thigh flaps, which is often necessary in oncologic surgeries. Examples of normal postoperative imaging and common complications that can accompany pelvic reconstruction with anterolateral, gracilis myocutaneous, and posterior thigh fasciocutaneous flaps will be provided. CONCLUSION: Pelvic reconstruction using regional pedicled thigh flaps is often needed with extirpative oncologic surgeries to eliminate dead space, provide pelvic organ support, restore form and function, and introduce vascularized tissue to promote wound healing. Radiologists need to be aware of the normal postoperative appearance of these flaps so that the flaps are not mistaken for residual or recurrent disease and so that residual or recurrent disease can be identified and treated.

Intraoperative sonography during open partial nephrectomy for renal cell cancer: does it alter surgical management?

OBJECTIVE: The purpose of this study is to evaluate whether intraoperative ultrasound (IOUS) during open partial nephrectomy alters the surgical management for renal cell cancer (RCC). MATERIALS AND METHODS: One hundred ninety-eight consecutive patients undergoing IOUS during open partial nephrectomy for RCC were selected for retrospective review of clinical and imaging data. Patient age and sex, the local extent of the primary lesion, and the presence of additional lesions were recorded. Ultrasound findings were compared with preoperative CT or MRI to determine whether the IOUS findings changed surgical management. Summary statistics were performed to assess what percentage of patients with additional IOUS findings had a change in their surgical management. The Kaplan-Meier method was used to estimate 5-year overall survival (OS) and event-free survival (EFS) rates for all patients. Patients were followed for 9-12 years to assess survival and measure recurrence rates. RESULTS: Twenty-one of 198 patients (10.6%; 95% CI, 6.7-15.8%) had additional findings on IOUS not seen on preoperative imaging. As a result, surgery was modified in 15 of these 21 patients (71.4%; 95% CI, 47.8-88.7%). The 5-year OS rate was 81%, and the EFS rate was 76% for the whole group; most deaths were due to unrelated causes. There was no statistically significant difference in OS (p = 0.867) and EFS (p = 0.069) rates among patients who had a change of management because of additional lesions seen by IOUS. CONCLUSION: IOUS performed during open partial nephrectomy for resection of RCC shows additional findings compared with preoperative cross-sectional imaging that may alter surgical management.

Abdominal and pelvic complications of nonoperative oncologic therapy.

Oncologic patients are treated with a combination of chemotherapy, radiation therapy, and surgery. Advances in therapeutic options have greatly improved the survival of patients with cancer. Examples of these advances are newer chemotherapeutic agents that target the cell receptors and advanced radiation therapy delivery systems. It is imperative that radiologists be aware of the variety of imaging findings seen after therapy in patients with cancer. Complications may occur with classic cytotoxic therapies (eg, 5-fluorouracil), usually at higher or prolonged doses or when administered to radiosensitive areas. Newer targeted systemic agents, such as bevacizumab and imatinib, have associated characteristic toxicities because their effects on cells do not depend on dose. Radiation may induce early and late effects in local normal tissues that may be seen at imaging. Imaging findings after chemotherapy include fatty liver, pseudocirrhosis, hepatic veno-occlusive disease, and splenic rupture. Complications of radiation therapy include large and small bowel strictures and radiation-induced hepatitis and tumors. Awareness of the various therapeutic options and knowledge of the spectrum of posttherapeutic complications allows radiologists to provide a comprehensive report that may impact patient management.