Liver Imaging in Gastroenteropancreatic Neuroendocrine Neoplasms.

ABSTRACT: The incidence of neuroendocrine neoplasms (NENs) has gradually increased over the past few decades with the majority of patients presenting with metastases on initial presentation. The liver is the most common site of initial metastatic disease, and the presence of liver metastasis is an independent prognostic factor associated with a negative outcome. Because NENs are heterogenous neoplasms with variable differentiation, grading, and risk of grade transformation over time, accurate diagnosis and management of neuroendocrine liver lesions are both important and challenging. This is particularly so with the multiple liver-directed treatment options available. In this review article, we discuss the diagnosis, treatment, and response evaluation of NEN liver metastases.

Mucinous Rectal Adenocarcinoma-Challenges in Magnetic Resonance Imaging Interpretation.

ABSTRACT: Mucinous rectal cancer (MRC) is defined by the World Health Organization as an adenocarcinoma with greater than 50% mucin content. Classic teaching suggests that it carries a poorer prognosis than conventional rectal adenocarcinoma. This poorer prognosis is thought to be related to mucin dissecting through tissue planes at a higher rate, thus increasing the stage of disease at presentation. Developments in immunotherapy have bridged much of this prognostic gap in recent years. Magnetic resonance imaging is the leading modality in assessing the locoregional spread of rectal cancer. Mucinous rectal cancer carries unique imaging challenges when using this modality. Much of the difficulty lies in the inherent increased T2-weighted signal of mucin on magnetic resonance imaging. This creates difficulty in differentiating mucin from the adjacent background fat, making the detection of both the primary disease process as well as the locoregional spread challenging. Computed tomography scan can act as a valuable companion modality as mucin tends to be more apparent in the background fat. After therapy, diagnostic challenges remain. Mucin is frequently present, and distinguishing cellular from acellular mucin can be difficult. In this article, we will discuss each of these challenges and present examples of such situations and strategies that can be used to overcome them.

Small Bowel Neuroendocrine Neoplasms-A Review.

ABSTRACT: Neuroendocrine neoplasms (NENs) are rapidly evolving small bowel tumors, and the patients are asymptomatic at the initial stages. Metastases are commonly observed at the time of presentation and diagnosis. This review addresses the small bowel NEN (SB-NEN) and its molecular, histological, and imaging features, which aid diagnosis and therapy guidance. Somatic cell number alterations and epigenetic mutations are studied to be responsible for sporadic and familial SB-NEN. The review also describes the grading of SB-NEN in addition to rare histological findings such as mixed neuroendocrine-non-NENs. Anatomic and nuclear imaging with conventional computed tomography, magnetic resonance imaging, computed tomographic enterography, and positron emission tomography are adopted in clinical practice for diagnosing, staging, and follow-up of NEN. Along with the characteristic imaging features of SB-NEN, the therapeutic aspects of imaging, such as peptide receptor radionuclide therapy, are discussed in this review.

Imaging of pediatric adrenal tumors: A COG Diagnostic Imaging Committee/SPR Oncology Committee White Paper.

Adrenal tumors other than neuroblastoma are uncommon in children. The most frequently encountered are adrenocortical carcinoma and pheochromocytoma. This paper offers consensus recommendations for imaging of pediatric patients with a known or suspected primary adrenal malignancy other than neuroblastoma at diagnosis and during follow-up.

Imaging of pediatric ovarian tumors: A COG Diagnostic Imaging Committee/SPR Oncology Committee White Paper.

Ovarian tumors in children are uncommon. Like those arising in the adult population, they may be broadly divided into germ cell, sex cord, and surface epithelium subtypes; however, germ cell tumors comprise the majority of lesions in children, whereas tumors of surface epithelial origin predominate in adults. Diagnostic workup, including the use of imaging, requires an approach that often differs from that required in an adult. This paper offers consensus recommendations for imaging of pediatric patients with a known or suspected primary ovarian malignancy at diagnosis and during follow-up.

Imaging of pediatric testicular tumors: A COG Diagnostic Imaging Committee/SPR Oncology Committee White Paper.

Primary intratesticular tumors are uncommon in children, but incidence and risk of malignancy both sharply increase during adolescence. Ultrasound is the mainstay for imaging the primary lesion, and cross-sectional modalities are often required for evaluation of regional or distant disease. However, variations to this approach are dictated by additional clinical and imaging nuances. This paper offers consensus recommendations for imaging of pediatric patients with a known or suspected primary testicular malignancy at diagnosis and during follow-up.

Imaging of pediatric liver tumors: A COG Diagnostic Imaging Committee/SPR Oncology Committee White Paper.

Primary hepatic malignancies are relatively rare in the pediatric population, accounting for approximately 1%-2% of all pediatric tumors. Hepatoblastoma and hepatocellular carcinoma are the most common primary liver malignancies in children under the age of 5 years and over the age of 10 years, respectively. This paper provides consensus-based imaging recommendations for evaluation of patients with primary hepatic malignancies at diagnosis and follow-up during and after therapy.

Restaging MRI of Rectal Adenocarcinoma after Neoadjuvant Chemoradiotherapy: Imaging Findings and Potential Pitfalls.

Rectal adenocarcinoma constitutes about one-third of all colorectal adenocarcinoma cases. Rectal MRI has become mandatory for evaluation of patients newly diagnosed with rectal cancer because it can help accurately stage the disease, impact the choice to give neoadjuvant therapy or proceed with up-front surgery, and even direct surgical dissection planes. Better understanding of neoadjuvant chemoradiotherapy effects on rectal tumors and recognition that up to 30% of patients can have a pathologic complete response have opened the door for the nonsurgical "watch-and-wait" management approach for rectal adenocarcinoma. Candidates for this organ-preserving approach should have no evidence of malignancy on all three components of response assessment after neoadjuvant therapy (ie, digital rectal examination, endoscopy, and rectal MRI). Hence, rectal MRI again has a major role in directing patient management and possibly sparing patients from unnecessary surgical morbidity. In this article, the authors discuss the indications for neoadjuvant therapy in management of patients with rectal adenocarcinoma, describe expected imaging appearances of rectal adenocarcinoma after completion of neoadjuvant therapy, and outline the MRI tumor regression grading system. Since pelvic sidewall lymph node dissection is associated with a high risk of permanent genitourinary dysfunction, it is performed for only selected patients who have radiologic evidence of sidewall lymph node involvement. Therefore, the authors review the relevant lymphatic compartments of the pelvis and describe lymph node criteria for determining locoregional nodal spread. Finally, the authors discuss limitations of rectal MRI, describe several potential interpretation pitfalls after neoadjuvant therapy, and emphasize how these pitfalls may be avoided. © RSNA, 2023 Quiz questions for this article are available in the supplemental material.

Paraneoplastic Syndromes from Head to Toe: Pathophysiology, Imaging Features, and Workup.

Patients often have symptoms due to the mass effect of a neoplasm on surrounding tissues or the development of distant metastases. However, some patients may present with clinical symptoms that are not attributable to direct tumor invasion. In particular, certain tumors may release substances such as hormones or cytokines or trigger an immune cross-reactivity between malignant and normal body cells, resulting in characteristic clinical features that are broadly referred to as paraneoplastic syndromes (PNSs). Recent advances in medicine have improved the understanding of the pathogenesis of PNSs and enhanced their diagnosis and treatment. It is estimated that 8% of patients with cancer develop a PNS. Diverse organ systems may be involved, most notably the neurologic, musculoskeletal, endocrinologic, dermatologic, gastrointestinal, and cardiovascular systems. Knowledge of various PNSs is necessary, as these syndromes may precede tumor development, complicate the patient's clinical presentation, indicate tumor prognosis, or be mistaken for metastatic spread. Radiologists should be familiar with the clinical presentations of common PNSs and the selection of appropriate imaging examinations. Many of these PNSs have imaging features that can assist with arriving at the correct diagnosis. Therefore, the key radiographic findings associated with these PNSs and the diagnostic pitfalls that can be encountered during imaging are important, as their detection can facilitate early identification of the underlying tumor, reveal early recurrence, and enable monitoring of the patient's response to therapy. © RSNA, 2023 Quiz questions for this article are available in the supplemental material.

PET/CT scan improves detection of metastatic disease compared with CT scan alone in women with high-grade neuroendocrine cervical cancer: a NeCTuR study.

OBJECTIVE: To determine the optimal imaging modality for women with high-grade neuroendocrine carcinoma of the cervix. METHODS: Women with high-grade neuroendocrine carcinoma of the cervix who had undergone a computed tomography (CT) scan and combined positron emission tomography with computed tomography (PET/CT) scan within 4 weeks of each other were identified from the NeCTuR Cervical Tumor Registry. One radiologist reviewed all CT scans, and another radiologist reviewed all PET/CT scans. The radiologists denoted the presence or absence of disease at multiple sites. Each radiologist was blinded to prior reports, patient outcomes, and the readings of the other radiologist. With findings on PET/CT used as the gold standard, sensitivity, specificity, and accuracy were calculated for CT scans. RESULTS: Fifty matched CT and PET/CT scans were performed in 41 patients. For detecting primary disease in the cervix, CT scan had a sensitivity of 85%, a specificity of 46%, and an accuracy of 74%. For detecting disease spread to the liver, CT scan had a sensitivity of 80%, a specificity of 89%, and an accuracy of 86%. For detecting disease spread to the lung, CT had a sensitivity of 89%, a specificity of 68%, and an accuracy of 77%. Of the 14 patients who had scans for primary disease work-up, 4 (29%) had a change in their treatment plan due to the PET/CT scan. Had treatment been prescribed on the basis of the CT scan alone, 2 patients would have been undertreated, and 2 would have been overtreated. CONCLUSION: A CT scan is inferior to a PET/CT scan in assessment of metastatic disease in women with high-grade neuroendocrine carcinoma of the cervix. Almost one-third of patients with newly diagnosed high-grade neuroendocrine cervical cancer would have received incorrect therapy had treatment planning been based solely on a CT scan. We recommend a PET/CT scan for both initial work-up and surveillance in women with high-grade neuroendocrine carcinoma of the cervix.

Diagnostic Approaches to Neuroendocrine Neoplasms of Unknown Primary Site.

ABSTRACT: Neuroendocrine tumors (NETs) are relatively uncommon heterogeneous neoplasms arising from endocrine and neuronal origin cells showing highly variable clinical behavior. By the time these tumors are discovered, up to 14% of patients with histologically proven NETs have metastasis, with the liver as the most frequently affected organ. Sometimes, no known primary site can be identified via routine imaging. Neuroendocrine tumors of unknown origin carry a poorer prognosis (compared with metastatic NETs with a known primary site) because of a lack of tailored surgical intervention and appropriate medical therapy (eg, chemotherapy or targeted therapy). A multimethod approach is frequently used in the trial to accurately determine the primary site for NETs of unknown primary sites and may include clinical, laboratory, radiological, histopathological, and surgical data. New molecular techniques using the genomic approach to identify the molecular signature have shown promising results. Various imaging modalities include ultrasound, computed tomography (CT), dual-energy CT, magnetic resonance imaging, and functional and hybrid imaging (positron emission tomography/CT, positron emission tomography/magnetic resonance imaging); somatostatin receptor imaging with new tracers is frequently used in an attempt for localization of the primary site.

Imaging Update for Hereditary Abdominopelvic Neuroendocrine Neoplasms.

ABSTRACT: Neuroendocrine neoplasms have shown a linear increase in incidence and prevalence in recent decades, primarily due to improved cross-sectional imaging, expanded use of endoscopic procedures, and advanced genetic analysis. However, diagnosis of hereditary neuroendocrine tumors is still challenging because of heterogeneity in their presentation, the variety of tumor locations, and multiple associated syndromes. Radiologists should be familiar with the spectrum of these tumors and associated hereditary syndromes. Furthermore, as the assessment of multiple tumor elements such as morphology, biochemical markers, and presence of metastatic disease are essential for the treatment plan, conventional anatomic and functional imaging methods are fundamental in managing and surveilling these cases. Our article illustrates the role of different cross-sectional imaging modalities in diagnosing and managing various hereditary abdominopelvic neuroendocrine tumors.

Malignant Gastrointestinal Neuroectodermal Tumor: A New Kid on the Block?

ABSTRACT: Also referred to as "osteoclast-rich, clear cell sarcoma-like tumor of the gastrointestinal tract (CCSLGT)," malignant gastrointestinal neuroectodermal tumor is a newly described, rare, aggressive sarcoma that commonly arises in the small bowel, stomach, and colon. Histogenesis is likely from an autonomous nervous system-related primitive cell of neural crest origin. The hallmark genetic finding of EWS-CREB1 or EWS-ATF1 fusion transcripts clinches the diagnosis. Annular constrictive lesions tend to be smaller, show homogenous contrast enhancement on computed tomography, and may present with bowel obstruction. Larger, expansile masses tend to be exophytic and show heterogeneous contrast enhancement. Surgical resection is the mainstay of treatment. Frequent recurrences, metastases, and death from disease in 75% of patients portend a poor prognosis. Targeted chemotherapy based on specific tumor pathways is being developed.

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.

Venetoclax and Decitabine in Pediatric Refractory T-cell Lymphoblastic Lymphoma.

BACKGROUND: Overall survival of adolescents with relapsed T-cell lymphoblastic lymphoma (T-LL) remains poor with limited options for salvage therapy. The BCL-2 inhibitor venetoclax combined with hypomethylating agents like decitabine, has shown favorable responses in elderly patients with acute myeloid leukemia. OBSERVATION: We present the case of a 19-year-old adolescent with stage III relapsed and refractory T-LL who did not respond to 3 lines of salvage therapy. The patient was treated with venetoclax and decitabine and achieved a dramatic response. CONCLUSION: This case highlights the potential clinical activity of venetoclax and decitabine in relapsed T-LL.

Machine Learning and Deep Learning in Oncologic Imaging: Potential Hurdles, Opportunities for Improvement, and Solutions-Abdominal Imagers' Perspective.

ABSTRACT: The applications of machine learning in clinical radiology practice and in particular oncologic imaging practice are steadily evolving. However, there are several potential hurdles for widespread implementation of machine learning in oncologic imaging, including the lack of availability of a large number of annotated data sets and lack of use of consistent methodology and terminology for reporting the findings observed on the staging and follow-up imaging studies that apply to a wide spectrum of solid tumors. This short review discusses some potential hurdles to the implementation of machine learning in oncologic imaging, opportunities for improvement, and potential solutions that can facilitate robust machine learning from the vast number of radiology reports and annotations generated by the dictating radiologists.

Clinical, Radiographic, Pathologic Characterization and Survival Outcomes of Nuclear Protein of the Testis Carcinoma.

INTRODUCTION: Nuclear protein of the testis (NUT) carcinoma (formerly NUT midline carcinoma) is an aggressive tumor with characteristic BRD4-NUTM1 translocation and a poor prognosis. The primary objective of this study was to describe the clinical and radiologic features, treatment response, and survival of NUT carcinoma (NC). MATERIALS AND METHODS: This retrospective single-center study was based on the review of medical records of NC patients with a specific genetic rearrangement or positive anti-NUT nuclear staining. Overall survival (OS) was analyzed according to primary tumor location. RESULTS: This series of 22 patients had a mean age of 36.27 ± 2.68 years with 68% women and 32% men. The median age at diagnosis was 34 years (range, 17-55 years). The primary tumor was located in the chest (n = 12/22; 55%), head and neck (n = 9/22; 40%), and 1 patient had a renal tumor. About 68% (n = 15/22) patients presented with regional lymph nodal involvement and 77% (n = 17/22) had distant metastases. All the bone metastases were lytic (100%) with mixed lytic and sclerotic metastases in 5 patients. Only 18% (n = 4/22) of the patients showed response to treatment, with progression in the remaining 18 patients. The median OS was 7 months. The OS was significantly (P = 0.024) more in patients with primary head and neck NC (n = 9; OS, 16 months) versus those with pulmonary and other locations (n = 13; OS, 6 months). CONCLUSIONS: Nuclear protein of the testis carcinoma is an aggressive disease refractory to conventional therapy. Imaging with the complementary use of computed tomography, magnetic resonance imaging, and positron emission tomography/computed tomography is important for staging, guiding management, assessing the treatment response, and surveillance.

Hepatic hemangioendothelioma: CT, MR, and FDG-PET-CT in 67 patients-a bi-institutional comprehensive cancer center review.

OBJECTIVE: To evaluate the imaging features of hepatic epithelioid hemangioendothelioma (HEH) on multiphasic CT, MR, and FDG-PET-CT. METHODS: Bi-institutional review identified 67 adults (mean age, 47 years; 23 M/44 F) with pathologically proven HEH and pretreatment multiphasic CT (n = 67) and/or MR (n = 30) and/or FDG-PET-CT (n = 13). RESULTS: HEHs were multifocal in 88% (59/67). Mean size of the dominant mass was 4.1 cm (range, 1.4-19 cm). The tumors were located in the peripheral, subcapsular regions of the liver in 96% (64/67). Capsular retraction was present in 81% (54/67 cases) and tumors were coalescent in 61% (41/67). HEH demonstrated peripheral ring enhancement on arterial phase imaging in 33% (21/64) and target appearance on the portal venous phase in 69% (46/67). Persistent peripheral enhancement on the delayed phase was seen in 49% (31/63). On MR, multilayered target appearance was seen on the T2-weighted sequences in 67% (20/30) and on the diffusion-weighted sequences in 61% (11/18). Target appearance on hepatobiliary phase of MRI was seen in 57% (4/7). On pre-therapy FDG-PET-CT, increased FDG uptake above the background liver parenchyma was seen in 62% (8/13). CONCLUSION: HEHs typically manifest as multifocal, coalescent hepatic nodules in peripheral subcapsular location, with associated capsular retraction. Peripheral arterial ring enhancement and target appearance on portal venous phase are commonly seen on CT. Similarly, multilayered target appearance correlating with its histopathological composition is typically seen on multiple sequences of MR including T2-weighted, diffusion-weighted, and dynamic contrast-enhanced multiphasic MR. KEY POINTS: • Hepatic epithelioid hemangioendotheliomas manifest on CT and MR as multifocal, coalescent hepatic nodules in peripheral subcapsular location, with associated capsular retraction. • Enhancement pattern on contrast-enhanced CT and MR can vary but peripheral ring enhancement on arterial phase and target appearance on portal venous phase are commonly seen. • Retrospective two-center study showed that cross-sectional imaging may help in the diagnosis.

Image Quality Assessment of Abdominal CT by Use of New Deep Learning Image Reconstruction: Initial Experience.

OBJECTIVE. The purpose of this study was to perform quantitative and qualitative evaluation of a deep learning image reconstruction (DLIR) algorithm in contrast-enhanced oncologic CT of the abdomen. MATERIALS AND METHODS. Retrospective review (April-May 2019) of the cases of adults undergoing oncologic staging with portal venous phase abdominal CT was conducted for evaluation of standard 30% adaptive statistical iterative reconstruction V (30% ASIR-V) reconstruction compared with DLIR at low, medium, and high strengths. Attenuation and noise measurements were performed. Two radiologists, blinded to examination details, scored six categories while comparing reconstructions for overall image quality, lesion diagnostic confidence, artifacts, image noise and texture, lesion conspicuity, and resolution. RESULTS. DLIR had a better contrast-to-noise ratio than 30% ASIR-V did; high-strength DLIR performed the best. High-strength DLIR was associated with 47% reduction in noise, resulting in a 92-94% increase in contrast-to-noise ratio compared with that of 30% ASIR-V. For overall image quality and image noise and texture, DLIR scored significantly higher than 30% ASIR-V with significantly higher scores as DLIR strength increased. A total of 193 lesions were identified. The lesion diagnostic confidence, conspicuity, and artifact scores were significantly higher for all DLIR levels than for 30% ASIR-V. There was no significant difference in perceived resolution between the reconstruction methods. CONCLUSION. Compared with 30% ASIR-V, DLIR improved CT evaluation of the abdomen in the portal venous phase. DLIR strength should be chosen to balance the degree of desired denoising for a clinical task relative to mild blurring, which increases with progressively higher DLIR strengths.

Improved Computed Tomography Contrast Injection Rates Through Implantable Chest Power Ports.

OBJECTIVE: The aim of this study was to optimize chest port contrast injections using stepwise improvements. METHODS: Ex vivo injections were tested. Two hundred scans using power port injections were then evaluated. RESULTS: The highest flow rate was achieved using a 19G access needle, larger diameter tubing, and warmed contrast.The mean injection rates in baseline and postimprovement groups were 2.7 ± 0.4 and 4.8 ± 0.4 mL/s, respectively (P < .0001). CONCLUSION: Component optimization of the port apparatus can maximize contrast flow rates.