What Is New in the 2017 World Health Organization Classification and 8th American Joint Committee on Cancer Staging System for Pancreatic Neuroendocrine Neoplasms?

The diagnosis and management of pancreatic neuroendocrine neoplasms (NENs) have evolved significantly in recent years. There are several diagnostic and therapeutic challenges and controversies regarding the management of these lesions. In this review, we focus on the recent significant changes and controversial issues regarding the diagnosis and management of NENs and discuss the role of imaging in the multidisciplinary team approach.

Bladder cancer local staging: multiparametric MRI performance following transurethral resection

PURPOSE

To evaluate the performance of multiparametric MRI (mpMRI) for the local staging of bladder cancer following transurethral resection of bladder tumor.

METHODS

This Institutional Review Board-approved, retrospective study identified 45 patients with pathology-proven bladder cancer who underwent transurethral resection followed by mpMRI between August 2011 and October 2016. Two radiologists reviewed each MRI independently and assigned T and N stage. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy were calculated for the presence of muscle invasion (T2 or higher), peri-vesical invasion (T3 or higher), and regional nodal disease compared to findings at cystectomy as the reference standard. Inter-observer agreement was measured using Cohen's κ coefficient.

RESULTS

Of 45 patients, 13% were stage T2, 27% T3, 16% T4; of 40 patients, 28% had regional nodal disease. Sensitivity, specificity, PPV, NPV, and accuracy of mpMRI for readers 1 and 2, respectively, were muscle invasion, 92% and 88%, 74% and 84%, 81% and 88%, 88% and 84%, 84% and 86%; peri-vesical invasion, 72% and 67%, 92% and 92%, 87% and 86%, 81% and 79%, 83% and 81%; regional nodal disease, 45% and 45%, 93% and 90%, 71% and 63%, 82% and 81%, 80% and 78%. Inter-observer agreement was good using all sequences.

CONCLUSIONS

mpMRI was both sensitive and specific in the detection of muscle invasive bladder cancer, and was specific but not sensitive for both peri-vesical invasion and nodal involvement. mpMRI may have a role at locally staging bladder cancer following transurethral resection.

Value of hepatocellular phase imaging after intravenous gadoxetate disodium for assessing hepatic metastases from gastroenteropancreatic neuroendocrine tumors: comparison with other MRI pulse sequences and with extracellular agent

OBJECTIVE

To compare hepatocellular phase imaging after intravenous gadoxetate disodium with other MRI pulse sequences and with extracellular agent for assessing hepatic metastases from gastroenteropancreatic neuroendocrine neoplasms (GEP-NEN).

MATERIALS AND METHODS

In this IRB-approved, HIPAA-compliant retrospective study, we included 30 patients (15 women, mean age: 58 years, range 44-77 years) with GEP-NEN metastatic to the liver, who underwent MRI with gadoxetate disodium. Six MRI sequences were reviewed by two radiologists to score tumor-liver interface (TLI) on a 5-point scale, to assess lesion detectability in different liver segments (divided into 3 zones/patient), and to measure lesion size. Contrast-to-noise ratio (CNR) was calculated on each sequence. In 19 patients, lesion size and CNR on dynamic imaging with gadopentetate dimeglumine was compared with hepatocellular phase. Wilcoxon signed-rank test was used to compare TLI scores, lesion size, and median CNR, using Bonferroni correction for multiple testing. Interobserver agreement for TLI was analyzed using Krippendorff's alpha, and for lesion size using concordance correlation coefficient (CCC) and mean relative difference.

RESULTS

Hepatocellular phase had the best TLI (mean TLI for reader 1 = 1.2, reader 2 = 1.3) compared to all other sequences (p < 0.0001) with excellent interobserver agreement (Krippendorff's alpha = 1.0), maximum lesion detectability (61/90 zones), highest interobserver agreement for lesion measurement (CCC 0.9875 and smallest mean relative difference - 1.567%), and highest median CNR (31.2, p < 0.008). Hepatocellular phase also had the highest CNR when compared with gadopentetate imaging.

CONCLUSION

Hepatocellular phase imaging offers significant advantages for assessment of hepatic metastasis in GEP-NEN, and should be routinely considered for follow-up of these patients.

Perception of Breast Oncologists and Physician Extenders on Imaging Consultation Service at a Tertiary Cancer Institute

OBJECTIVE

To evaluate the perception and ease of utilization of the imaging consultation service by different types of referring clinicians and physician extenders within the breast oncology disease center at our tertiary cancer institute using a survey-based questionnaire.

METHODS

An institutional review board-exempted survey was created using a freely available online survey software and questionnaire tool. The survey was sent to 83 clinicians associated with the breast oncology disease center at our tertiary cancer center through an institutional e-mail list. The survey included 2 questions about demographics and 8 statements regarding various aspects of the consultation service scored on a 5-point Likert-type scale. "1'' being "agree completely," "3" being "neutral/neither agree nor disagree," and "5" being "disagree completely." The survey was sent online and was answered anonymously. Responses were tallied and analyzed.

RESULTS

A total of 56 responses (67%) were received. The weighted average of each Likert item ranged from 1.07 to 1.58. Highest positive concordance (95%) pertained to the access to the consult radiologist having a positive impact on patient care. The least concordant statement (78%), though still strong (with weighted average of 1.58% and 78% of respondents agreeing or agreeing completely) pertained to the role of direct consultation with radiologist in clinical management. Although there was variability of agreement to all statements (including responders feeling neutral), there was no one that disagreed with any of the Likert items. The mean Likert score for all the statements together was 1.23 (range: 1.07-1.58).

CONCLUSION

Presence of dedicated oncologic imaging consultation service is perceived positively by the breast oncology team at our tertiary cancer center.

Imaging in Soft Tissue Sarcomas: Current Updates

Soft tissue sarcomas (STS) are heterogeneous malignant tumors that have nonspecific imaging features. A combination of clinical, demographic, and imaging characteristics can aid in the diagnosis. Imaging provides important information regarding the tumor extent, pretreatment planning, and surveillance of patients with STS. In this article, we illustrate the pertinent imaging characteristics of the commonly occurring STS and some uncommon sarcomas with unique imaging characteristics.

Updates for the radiologist in non-muscle-invasive, muscle-invasive, and metastatic bladder cancer

Urothelial bladder cancer is a common malignancy requiring a multidisciplinary approach to treatment. Significant recent advances have been made in terms of the genetic and molecular characterization of bladder cancer subtypes, and novel treatment approaches are being investigated and approved. Given the important role of imaging in the diagnosis, staging, and follow-up of this disease, it is necessary for radiologists to remain up-to-date in terms of nomenclature and standards of care. In this review, recent developments in bladder cancer characterization and treatment will be discussed, with reference to the contributions of imaging in non-muscle-invasive, muscle-invasive, and metastatic settings.

Imaging of hepatic toxicity of systemic therapy in a tertiary cancer centre: chemotherapy, haematopoietic stem cell transplantation, molecular targeted therapies, and immune checkpoint inhibitors

The purpose of this review is to familiarise radiologists with the spectrum of hepatic toxicity seen in the oncology setting, in view of the different systemic therapies used in cancer patients. Drug-induced liver injury can manifest in various forms, and anti-neoplastic agents are associated with different types of hepatotoxicity. Although chemotherapy-induced liver injury can present as hepatitis, steatosis, sinusoidal obstruction syndrome, and chronic parenchymal damages, molecular targeted therapy-associated liver toxicity ranges from mild liver function test elevation to fulminant life-threatening acute liver failure. The recent arrival of immune checkpoint inhibitors in oncology has introduced a new range of immune-related adverse events, with differing mechanisms of liver toxicity and varied imaging presentation of liver injury. High-dose chemotherapy regimens for haematopoietic stem cell transplantation are associated with sinusoidal obstruction syndrome. Management of hepatic toxicity depends on the clinical scenario, the drug in use, and the severity of the findings. In this article, we will (1) present the most common types of oncological drugs associated with hepatic toxicity and associated liver injuries; (2) illustrate imaging findings of hepatic toxicities and the possible differential diagnosis; and (3) provide a guide for management of these conditions.

Radiation Therapy for Soft-Tissue Sarcomas: A Primer for Radiologists

Radiation therapy (RT) plays an important role in multimodality therapy for soft-tissue sarcomas (STS). RT treatment paradigms have evolved significantly in recent years, and many different complex RT modalities are commonly used in STS. These include external-beam RT, intensity-modulated RT, stereotactic body RT, and brachytherapy. Imaging is essential throughout the treatment process. Plain radiographs, computed tomography (CT), magnetic resonance imaging, ultrasonography, and positron emission tomography/CT all play potential roles in the management of STS. Before RT, high-quality imaging is needed to direct management decisions, both by global tumor staging and detailed assessment of the extent of local disease. At the time of RT, precise planning imaging is required to delineate tumor volumes, including gross tumor volume, clinical target volume, and planning target volume, which are used to direct therapy. In addition, imaging at the time of RT must outline the location of adjacent vital organs, to optimize treatment efficacy and minimize toxicity. After RT, imaging is needed to assess the patient for tumor response to therapy. In addition, imaging at regular intervals is often required to monitor for recurrence of disease and potential complications of therapy. The purpose of this review is to familiarize radiologists with the indications for RT in STS, common therapeutic modalities used, roles of imaging throughout the treatment process, and complications of therapy.

Solitary Fibrous Tumors: 2016 Imaging Update

Optimal management of solitary fibrous tumor requires a multidisciplinary approach with proper histopathological mapping and use of various imaging modalities for exact delineation of primary tumor and metastatic disease if present. In this article, the authors present a comprehensive review of the spectrum of imaging findings of solitary fibrous tumors involving various organ systems and discuss the role of molecular targeted therapies in the management of metastatic disease.

Diffuse Large B-Cell Lymphoma in the Era of Precision Oncology: How Imaging Is Helpful

Diffuse large B cell lymphoma (DLBCL) is the most common histological subtype of Non-Hodgkin's lymphoma. As treatments continues to evolve, so do imaging strategies, and positron emission tomography (PET) has emerged as the most important imaging tool to guide oncologists in the diagnosis, staging, response assessment, relapse/recurrence detection,and therapeutic decision making of DLBCL. Other imaging modalities including magnetic resonance imaging (MRI), computed tomography (CT), ultrasound, and conventional radiography are also used in the evaluation of lymphoma. MRI is useful for nervous system and musculoskeletal system involvement and is emerging as a radiation free alternative to PET/CT. This article provides a comprehensive review of both the functional and morphological imaging modalities, available in the management of DLBCL.

Immune-Checkpoint Inhibitors in the Era of Precision Medicine: What Radiologists Should Know

Over the past five years immune-checkpoint inhibitors have dramatically changed the therapeutic landscape of advanced solid and hematologic malignancies. The currently approved immune-checkpoint inhibitors include antibodies to cytotoxic T-lymphocyte antigen-4, programmed cell death (PD-1), and programmed cell death ligand (PD-L1 and PD-L2). Response to immune-checkpoint inhibitors is evaluated on imaging using the immune-related response criteria. Activation of immune system results in a unique toxicity profile termed immune-related adverse events. This article will review the molecular mechanism, clinical applications, imaging of immune-related response patterns and adverse events associated with immune-checkpoint inhibitors.

Current Concepts in Non-Gastrointestinal Stromal Tumor Soft Tissue Sarcomas: A Primer for Radiologists

Non-gastrointestinal stromal tumor (GIST) soft tissue sarcomas (STSs) are a heterogeneous group of neoplasms whose classification and management continues to evolve with better understanding of their biologic behavior. The 2013 World Health Organization (WHO) has revised their classification based on new immunohistochemical and cytogenetic data. In this article, we will provide a brief overview of the revised WHO classification of soft tissue tumors, discuss in detail the radiology and management of the two most common adult non-GIST STS, namely liposarcoma and leiomyosarcoma, and review some of the emerging histology-driven targeted therapies in non-GIST STS, focusing on the role of the radiologist.

Beyond gastric adenocarcinoma: Multimodality assessment of common and uncommon gastric neoplasms

Despite advances in molecular biology, imaging, and treatment, gastric neoplasms remain a significant cause of morbidity and mortality; gastric adenocarcinoma is the fifth most common malignancy and third most common cause of death worldwide (Brenner et al., Methods Mol Biol 472:467-477, 2009; Howson et al. Epidemiol Rev 8:1-27, 1986; Roder, Gastric Cancer 5(Suppl 1):5-11, 2002; Ferlay et al., GLOBOCAN 2012 v1.0, Cancer Incidence and Mortality Worldwide: IARC CancerBase No. 11 [Internet]. International Agency for Research on Cancer, 2013). Because of both the frequency at which malignant gastric tumors occur as well as the worldwide impact, gastric neoplasms remain important lesions to identify and characterize on all imaging modalities. Despite the varied histologies and behaviors of these neoplasms, many have similar imaging features. Nonetheless, the treatment, management, and prognosis of gastric neoplasms vary by pathology, so it is essential for the radiologist to make every effort to differentiate between these lesions and raise the less common entities as differential diagnostic considerations when appropriate.

Update on Gastrointestinal Stromal Tumors for Radiologists

The management of gastrointestinal stromal tumors (GISTs) has evolved significantly in the last two decades due to better understanding of their biologic behavior as well as development of molecular targeted therapies. GISTs with exon 11 mutation respond to imatinib whereas GISTs with exon 9 or succinate dehydrogenase subunit mutations do not. Risk stratification models have enabled stratifying GISTs according to risk of recurrence and choosing patients who may benefit from adjuvant therapy. Assessing response to targeted therapies in GIST using conventional response criteria has several potential pitfalls leading to search for alternate response criteria based on changes in tumor attenuation, volume, metabolic and functional parameters. Surveillance of patients with GIST in the adjuvant setting is important for timely detection of recurrences.

Anorectal Cancer: Critical Anatomic and Staging Distinctions That Affect Use of Radiation Therapy

Although rectal and anal cancers are anatomically close, they are distinct entities with different histologic features, risk factors, staging systems, and treatment pathways. Imaging is at the core of initial clinical staging of these cancers and most commonly includes magnetic resonance imaging for local-regional staging and computed tomography for evaluation of metastatic disease. The details of the primary tumor and involvement of regional lymph nodes are crucial in determining if and how radiation therapy should be used in treatment of these cancers. Unfortunately, available imaging modalities have been shown to have imperfect accuracy for identification of nodal metastases and imaging features other than size. Staging of nonmetastatic rectal cancers is dependent on the depth of invasion (T stage) and the number of involved regional lymph nodes (N stage). Staging of nonmetastatic anal cancers is determined according to the size of the primary mass and the combination of regional nodal sites involved; the number of positive nodes at each site is not a consideration for staging. Patients with T3 rectal tumors and/or involvement of perirectal, mesenteric, and internal iliac lymph nodes receive radiation therapy. Almost all anal cancers warrant use of radiation therapy, but the extent and dose of the radiation fields is altered on the basis of both the size of the primary lesion and the presence and extent of nodal involvement. The radiologist must recognize and report these critical anatomic and staging distinctions, which affect use of radiation therapy in patients with anal and rectal cancers.

Patterns and Prognostic Importance of Hepatic Involvement in Patients with Serous Ovarian Cancer: A Single-Institution Experience with 244 Patients

Purpose To evaluate the frequency, patterns, and prognostic importance of metastatic hepatic involvement in serous ovarian cancer. Materials and Methods This institutional review board-approved retrospective study, with waived informed consent, included 244 patients with pathologically proven serous ovarian cancer (mean age ± standard deviation, 59 years ± 10.7; range 19-93 years). Electronic medical records and all available imaging studies over a median follow-up of 44 months (interquartile range [IQR], 27-70) were reviewed to identify the frequency of liver parenchymal invasion (LPI) from perihepatic peritoneal metastasis and hematogenous liver metastases. The associations and prognostic importance of LPI and hematogenous metastases were studied by using univariate and multivariate Cox proportional analysis. Results Eighty-four of 244 patients (34%) developed perihepatic metastases, of whom 55 (23%) developed LPI after median of 43 months (IQR, 25-63). Hematogenous hepatic metastases developed in 38 of 244 patients (16%) after median of 42 months (IQR, 26-64). At multivariate analysis, age (P = .008; hazard ratio [HR]: 1.03; 95% confidence interval [CI]: 1.009, 1.07) and suboptimal cytoreduction (P = .03; HR, 2.13; 95% CI: 1.12, 4.07) were associated with LPI. Increasing age (P = .01; HR, 1.04; 95% CI: 1.008, 1.08), high-grade tumor (P = .01; HR, 6.75; 95% CI: 1.44, 120.5), and advanced stage (P = .03; HR, 3.16; 95% CI: 1.94, 4.56) were associated with hematogenous metastases. Overall survival with and without LPI was similar (median, 80 months; IQR, 50-not reached vs 123 months; IQR, 49-279; P = .6). Hematogenous metastases were associated with significantly shorter survival at univariate (median 63 months, IQR 43-139 vs 145 months, IQR 50-not reached; P = .006) and multivariate analyses (P = .03; HR, 1.88; 95% CI: 1.14, 3.28). Conclusion Differentiating hematogenous metastases and LPI is important for radiologists; hematogenous metastases are associated with shorter survival, while LPI does not adversely affect survival and prognostically behaves like peritoneal disease. ^© RSNA, 2016.

Assessment of metastatic risk of gastric GIST based on treatment-naïve CT features

OBJECTIVE

To study whether the CT features of treatment-naïve gastric GIST may be used to assess metastatic risk.

METHODS

In this IRB approved retrospective study, with informed consent waived, contrast enhanced CT images of 143 patients with pathologically confirmed treatment-naïve gastric GIST (74 men, 69 women; mean age 61 years, SD ± 14) were reviewed in consensus by two oncoradiologists blinded to clinicopathologic features and clinical outcome and morphologic features were recorded. The metastatic spread was recorded using available imaging studies and electronic medical records (median follow up 40 months, interquartile range, IQR, 21-61). The association of maximum size in any plane (≤10 cm or >10 cm), outline (smooth or irregular/lobulated), cystic areas (≤50% or >50%), exophytic component (≤50% or >50%), and enhancing solid component (present or absent) with metastatic disease were analyzed using univariate (Fisher's exact test) and multivariate (logistic regression) analysis.

RESULTS

Metastatic disease developed in 42 (29%) patients (28 at presentation, 14 during follow-up); 23 (16%) patients died. On multivariate analysis, tumor size >10 cm (p = 0.0001, OR 9.9), irregular/lobulated outline (p = 0.001, OR 5.6) and presence of a enhancing solid component (p < 0.0001, OR 9.1) were independent predictors of metastatic disease. On subgroup analysis, an irregular/lobulated outline and an enhancing solid component were more frequently associated with metastases in tumors ≤5 cm and >5-≤10 cm (p < 0.05).

CONCLUSION

CT morphologic features can be used to assess the metastatic risk of treatment-naïve gastric GIST. Risk assessment based on pretreatment CT is especially useful for patients receiving neoadjuvant tyrosine kinase inhibitors and those with tumors <5 cm in size.

Multidetector computed tomography features of pancreatic metastases from leiomyosarcoma: Experience at a tertiary cancer center

AIM: To describe the multidetector computed tomography features of pancreatic metastasis from leiomyosarcoma (LMS).

METHODS: Between January 1995 and December 2012, 13 consecutive patients (11 women, 2 men; mean age of 57 years; range, 38-78 years) with pancreatic metastases from LMS were included in our study. Imaging features including location, number, largest dimension, tumor attenuation and enhancement characteristics, presence of necrosis, pancreatic ductal dilatation, common bile duct (CBD) dilatation, presence of pancreatitis, and atrophy were documented.

RESULTS: The most common site of origin of the pancreatic metastases from LMS was uterus (38.5%), followed by retroperitoneum (30.8%) and extremity (23.1%). None of the patients in our study had pancreas as the first site of metastasis. All patients developed pancreatic metastases at a median interval of 24 mo. Pancreatic metastases from LMS were solitary in 8/13 patients and multiple in 5/13 patients, had no predilection for any part of the pancreas, were hypovascular on arterial phase in 10/13 patients and associated with pancreatic duct dilatation in 3/13 patients. None had CBD dilatation. None of the pancreatic metastases in LMS cohort caused pancreatitis, and atrophy. Median duration of follow-up was 19 mo for LMS cohort during which two patients underwent resection of metastasis (median survival 45 mo) while the remaining underwent systemic therapy (median survival 13 mo).

CONCLUSION: Pancreatic metastases from LMS are often solitary and hypovascular masses and less commonly associated with pancreatic ductal dilatation, CBD dilatation, pancreatitis or pancreatic atrophy. Surgical resection of solitary LMS pancreatic metastasis can be considered due to the long survival of these patients.

Impact of histologic subtype and sarcomatoid transformation on metastasis in renal cell carcinoma: a single institute experience in 149 patients

PURPOSE

To compare the metastatic pattern and outcome of clear cell RCC (ccRCC) and papillary RCC (pRCC), and to assess the impact of sarcomatoid transformation on the disease spread and prognosis.

MATERIALS AND METHODS

This IRB-approved, HIPAA-compliant retrospective study included 149 consecutive patients (108 men; mean age 58 years; range 25-86) with metastatic RCC (ccRCC = 116, pRCC = 33), identified from imaging database. All available imaging studies and electronic records of these patients were reviewed to document pathological features, distribution and timing of metastasis, and survival. The metastatic pattern and survival was first compared between the ccRCC and pRCC groups, and then between those with and without sarcomatoid transformation; all 27 cases of sarcomatoid transformation occurred in the ccRCC group.

RESULTS

Metastases were noted at presentation in 62 (42%) and after median 13 months in the remaining 87 (58%) patients. Lymph nodes (134/149), lung (125/149), and bone (60/149) were the most common metastatic sites, which did not differ between the RCC subtypes. Pancreatic (p = 0.0014) and renal (p = 0.046) metastases were more common in ccRCC, lymphangitic spread (p = 0.0003) and peritoneal metastasis (p = 0.039) more common in pRCC. In ccRCC, sarcomatoid transformation was associated with high-grade tumors (p < 0.0001), more frequently demonstrated lymphangitic (p = 0.016), pleural (p = 0.0018), and peritoneal metastases (p = 0.0002), and had shorter metastasis-free survival and overall survival (log-rank test, p < 0.0001). In the absence of sarcomatoid transformation, ccRCC had longer metastasis-free interval (median 22 months compared to 6 months) (p = 0.0238) and overall survival (median survival 48 months vs. 25 months) (p = 0.0193) compared to pRCC.

CONCLUSION

Histologic subtype, as well as the presence of sarcomatoid transformation, affects the metastatic pattern and metastasis-free survival of RCC. In the absence of sarcomatoid transformation, ccRCC has a better outcome than pRCC.

Update on the imaging of malignant perivascular epithelioid cell tumors (PEComas)

Malignant perivascular epithelioid cell tumors (PEComas) are a histologic group of mesenchymal neoplasms that share a distinctive histological phenotype, the perivascular epithelioid cell. These tumors are known for their perivascular distribution. Malignant PEComas have a female predominance and are associated with aggressive disease and poor prognosis, making timely diagnosis critical to management. Imaging features of malignant PEComas are nonspecific and mimic other benign and malignant neoplasms. Surgery is the mainstay in the management of malignant PEComas. Promising novel molecular targeted therapies like m-TOR inhibitors have been shown to be effective in the metastatic setting. The aim of this review is to familiarize radiologists with the imaging appearances of and potential therapies for primary and metastatic malignant PEComa.

Cancer immunotherapy: imaging assessment of novel treatment response patterns and immune-related adverse events

Cancer immunotherapy is changing the imaging evaluation of cancer treatment response and treatment-related toxic effects. New emerging patterns of treatment response and treatment-related toxic effects after treatment with immunomodulating agents have been observed. Treatment response after immunomodulatory therapy can be associated with significantly delayed decrease in tumor size, and new or enlarging tumors observed soon after completion of treatment may not reflect disease progression. In addition, activation of the immune system to fight cancer may lead to unwanted autoimmune-mediated toxic effects that could be mistaken for metastatic disease or misdiagnosed as a non-treatment-related process and delay appropriate clinical management. Radiologists must recognize the novel treatment response patterns and the wide range of autoimmune toxic effects, which should not be mistaken for treatment failure or metastatic disease progression.