Distribution and Rate of Myxoid Liposarcoma Spine Metastases: Impact on Surveillance Imaging.

BACKGROUND: Myxoid liposarcoma (LPS) has a unique tendency to spread to extrapulmonary sites, including osseous sites such as the spine, and adjacent sites such as the paraspinous tissue. No clear consensus exists to guide the approach to imaging in these patients. OBJECTIVE: The aim of this study was to investigate the rate and distribution of spine metastases in patients with myxoid LPS and detection modality. METHODS: Records of all patients with myxoid LPS evaluated at our sarcoma center were retrospectively reviewed. Disease patterns and imaging modality utilization were analyzed. RESULTS: Between 2000 and 2020, 164 patients with myxoid LPS were identified. The majority (n = 148, 90%) presented with localized disease, with half (n = 82, 50%) of all patients developing metastases or recurrence during their disease course. With a median follow-up of 69.2 months, spine/paraspinous metastases developed in 38 patients (23%), of whom 35 (92%) already had synchronous, non-spine metastases. Spine disease was only visible on magnetic resonance imaging (MRI), as opposed to other imaging modalities, for over one-quarter of patients with spine metastases (n = 10). For patients with metastatic disease, spine metastases were associated with worse median overall survival (2.1 vs. 8.7 years, p < 0.001). CONCLUSION: Spine metastases occurred in nearly one-quarter of patients with myxoid LPS and represented an advanced disease state, as they primarily presented in the setting of synchronous, non-spine metastases, and were associated with worse overall survival. Routine surveillance with spine MRI in patients with localized disease likely provides no benefit but may be considered in those with known metastatic disease.

A Review of the Spectrum of Imaging Manifestations of Epithelioid Hemangioendothelioma.

OBJECTIVE. The purpose of this article is to review the spectrum of imaging manifestations of epithelioid hemangioendothelioma across different organ systems and briefly describe its current treatment strategies. CONCLUSION. Epithelioid hemangioendothelioma is a rare, locally invasive neoplasm with metastatic potential. Although most commonly occurring in liver, lungs, and bones, it can also present at multiple other sites. Because of its nonspecific clinical and imaging manifestations, it is often misdiagnosed. The possibility of epithelioid hemangioendothelioma must be considered in the presence of a slowly growing mass that invades adjacent structures. Imaging can help plan percutaneous biopsy, detect sites of disease, and identify poor prognostic factors.

Imaging of Waldenström Macroglobulinemia: A Comprehensive Review for the Radiologist in the Era of Personalized Medicine.

OBJECTIVE. We describe the range of organ systems involved and the spectrum of imaging findings seen in Waldenström macroglobulinemia (WM). CONCLUSION. Although imaging is not mandatory in the initial workup of a patient with WM, a multimodality imaging approach can lead toward the diagnosis of a lymphoproliferative disorder, establish the tumor burden, identify sites of involvement, and thus explain the clinical presentation, help in determining prognosis and monitoring response to therapy, and help identify treatment-induced toxicity.

Focal Liver Uptake on FDG PET/CT Without CT Correlate: Utility of MRI in the Evaluation of Patients With Known Malignancy.

OBJECTIVE. The purpose of this study was to determine the significance and utility of MRI in evaluation of focal hepatic uptake on FDG PET/CT without a CT correlate in patients with known malignancy. MATERIALS AND METHODS. In this retrospective study, we identified 36 of 1851 patients between 2005 and 2012 with known malignancy (19 women, 17 men; mean age, 56.1 years old) who had focal hepatic uptake on FDG PET/CT without a CT correlate and follow-up MRI within 100 days for assessment of uptake. Two radiologists reviewed the FDG PET/CT images together, reached consensus about presence of focal hepatic uptake, and measured maximum standardized uptake value (SUVmax) of the focal uptake and background liver. MR images were then reviewed to identify any correlate. Follow-up imaging and histopathologic data were reviewed to confirm or refute metastasis. Statistical correlation between intensity of FDG uptake and presence of focal lesions on MRI was performed. RESULTS. Fifty sites of focal hepatic uptake without CT correlate were identified. The median SUVmax was 4.1 (range, 2.1-10.1), whereas the ratio of median SUVmax of the hepatic lesion to that of normal parenchyma was 1.3 (range, 0.98-2.6). MRI confirmed focal lesions in 26 of 50 sites (52%). Seventy-seven percent of cases of hepatic uptake with an MRI correlate (20/26) were confirmed as metastatic disease (six cases at histopathology). Therefore, 40% of cases of hepatic uptake without a CT correlate (20/50) were metastases. We found no statistically significant difference in the SUVmax of hepatic lesions and SUVmax ratio between the groups with and without an MRI correlate (median SUVmax = 3.85 vs 4.2, p = 0.5; SUVmax ratio = 1.32 vs 1.31, p = 0.97) as well as between the groups with the final diagnosis of benign lesions and metastasis (SUVmax = 4.05 vs 3.95, p = 0.64; SUVmax ratio = 1.31 vs 1.32, p = 0.91). CONCLUSION. More than half of the cases of focal hepatic uptake on PET/CT without a CT correlate had an MRI correlate in our study, and more than 75% of these lesions were metastases, regardless of SUVmax.

Screening with whole-body magnetic resonance imaging in pediatric subjects with Li-Fraumeni syndrome: A single institution pilot study.

BACKGROUND: Li-Fraumeni syndrome (LFS) is an autosomal dominant hereditary cancer syndrome associated with germline mutations in the TP53 gene and a high risk of childhood-onset malignancies. Cancer surveillance is challenging in pediatric mutation carriers given the anatomic spectrum of malignancies and young age of onset. Whole-body magnetic resonance imaging (WB-MRI) may provide an acceptable method for early cancer detection. PROCEDURE: We conducted a prospective feasibility pilot study of pediatric subjects (age < 18 years) with LFS to determine return rates for annual WB-MRI scan. Secondary objectives included characterization of incident cancers (and how they were detected). RESULTS: Forty-five WB-MRI scans in 20 subjects were performed over 5 years; two patients enrolled without subsequently undergoing scans. Eighty-nine percent of participants scanned (95% confidence interval: 67-99%) returned for second examinations. Fifty-five percent of participants required general anesthesia, which was well tolerated in all cases. Six patients required dedicated follow-up imaging. One participant required biopsy of a detected brain lesion; pathology demonstrated reactive gliosis. Another participant, with prior choroid plexus carcinoma, had a new brain lesion detected on clinical follow-up MRI not seen on WB-MRI 6 months prior. All other participants remain well (median: 3 years, range: 0.08-4 years). CONCLUSIONS: WB-MRI in pediatric subjects is a well-tolerated approach to cancer surveillance despite the need for general anesthesia in some patients. A large multicenter trial would determine true test characteristics and efficacy of this approach for early cancer detection in children at high cancer risk.

Computer-Aided Diagnosis of Ground-Glass Opacity Nodules Using Open-Source Software for Quantifying Tumor Heterogeneity.

OBJECTIVE: The purposes of this study are to develop quantitative imaging biomarkers obtained from high-resolution CTs for classifying ground-glass nodules (GGNs) into atypical adenomatous hyperplasia (AAH), adenocarcinoma in situ (AIS), minimally invasive adenocarcinoma (MIA), and invasive adenocarcinoma (IAC); to evaluate the utility of contrast enhancement for differential diagnosis; and to develop and validate a support vector machine (SVM) to predict the GGN type. MATERIALS AND METHODS: The heterogeneity of 248 GGNs was quantified using custom software. Statistical analysis with a univariate Kruskal-Wallis test was performed to evaluate metrics for significant differences among the four GGN groups. The heterogeneity metrics were used to train a SVM to learn and predict the lesion type. RESULTS: Fifty of 57 and 51 of 57 heterogeneity metrics showed statistically significant differences among the four GGN groups on unenhanced and contrast-enhanced CT scans, respectively. The SVM predicted lesion type with greater accuracy than did three expert radiologists. The accuracy of classifying the GGNs into the four groups on the basis of the SVM algorithm was 70.9%, whereas the accuracy of the radiologists was 39.6%. The accuracy of SVM in classifying the AIS and MIA nodules was 73.1%, and the accuracy of the radiologists was 35.7%. For indolent versus invasive lesions, the accuracy of the SVM was 88.1%, and the accuracy of the radiologists was 60.8%. We found that contrast enhancement does not significantly improve the differential diagnosis of GGNs. CONCLUSION: Compared with the GGN classification done by the three radiologists, the SVM trained regarding all the heterogeneity metrics showed significantly higher accuracy in classifying the lesions into the four groups, differentiating between AIS and MIA and between indolent and invasive lesions. Contrast enhancement did not improve the differential diagnosis of GGNs.

Neoadjuvant radiation in primary extremity liposarcoma: correlation of MRI features with histopathology.

OBJECTIVE: To evaluate MRI features of response of primary extremity liposarcoma (LPS) to neoadjuvant radiation therapy (RT) with histopathologic correlation. METHODS: In this IRB-approved study including 125 patients with extremity LPS treated with neoadjuvant RT from 2000 to 2013, MRI of the primary tumour in 18 patients (5 pleomorphic LPS, 13 myxoid LPS) before and after RT were reviewed by two radiologists by consensus. Histopathology of the surgical specimens was reviewed by a pathologist with expertise in sarcomas. RESULTS: In the pleomorphic LPS cohort, 3/5 tumours increased in size; 3/5 decreased in enhancing component; and 3/5 increased in peritumoral oedema, intratumoral haemorrhage, and necrosis. In the myxoid LPS cohort, 12/13 tumours decreased in size, 8/13 decreased in enhancing component, and 5/13 increased in internal fat following RT. Histopathology showed ≥50% residual tumour in 1/5 pleomorphic LPS and 2/13 myxoid LPS. Hyalinization/necrosis of ≥75% was noted in 4/5 pleomorphic LPS and 11/13 myxoid LPS. Cytodifferentiation was noted in 1/5 pleomorphic and 9/13 myxoid LPS. CONCLUSION: While pleomorphic LPS showed an increase in size, peritumoral oedema, intratumoral haemorrhage, and necrosis on MRI following neoadjuvant RT, myxoid LPS showed a decrease in size and enhancement with an increase in internal fat. KEY POINTS: • Pleomorphic LPS commonly increase in size and necrosis on MRI following RT. • Myxoid LPS commonly decrease in size and enhancement on MRI following RT. • Myxoid LPS often increase in fatty component on MRI following RT.

MRI Findings in Patients With Leukemia and Positive CSF Cytology: A Single-Institution 5-Year Experience.

OBJECTIVE: The purposes of this study were to describe the spectrum of MRI findings and determine the prognostic role of MRI in adults with acute leukemia with positive CSF cytology. MATERIALS AND METHODS: In this retrospective study of 34 patients (19 women, 15 men; mean age, 51 years; range, 18-72 years) treated for CNS leukemia between 2006 and 2011, 31 (91%) contrast-enhanced brain and 14 (41%) spine MRI studies were reviewed by two radiologists to note patterns of enhancement. Interobserver agreement and correlation of enhancement with outcome were analyzed. RESULTS: MRI showed abnormal findings in 25 patients (74%). Pachymeningeal enhancement (n = 9/31, 29%), leptomeningeal enhancement (n = 6/31, 19%), cranial nerve enhancement (n = 9/31, 29%), masslike enhancement (n = 3/31, 10%), and spinal meningeal enhancement (n = 10/14, 71%) were identified. There was strong interobserver agreement (κ = 0.906). Survival rates were shorter to a statistically significant degree with pachymeningeal enhancement (median, 7 months; interquartile range [IQR], 5-8 months versus median, 26 months; IQR, 15 months to not reached; p = 0.004) and two or more sites of enhancement (median, 8 months; IQR, 3-13 months versus median, 19 months; IQR, 9 months to not reached; p = 0.046). CONCLUSION: Brain or spine MRI examinations (or both) showed abnormal findings in nearly three-fourths of adults with acute leukemia with positive CSF cytology who were imaged for neurologic symptoms. Pachymeningeal enhancement and two or more sites of brain involvement were associated with shorter survival.

A New Look at Toxicity in the Era of Precision Oncology: Imaging Findings, Their Relationship With Tumor Response, and Effect on Metastasectomy.

OBJECTIVE: As cancer care becomes increasingly personalized and patients with metastatic disease live longer, oncologists' approach to drug toxicity is also evolving. CONCLUSION: This article aims to broaden the radiologist's understanding of imaging-evident toxicity by describing how oncologists grade toxicity, exploring toxicity as a biomarker of treatment response, discussing the effect of toxicity in patients who are candidates for metastasectomy, and illustrating how combining drugs of varying classes amplifies toxicity.

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.

Role of Imaging in Management of Desmoid-type Fibromatosis: A Primer for Radiologists.

Desmoid-type fibromatosis (DF) is a locally aggressive fibroblastic neoplasm that has variable clinical and biologic behaviors ranging from indolent tumors that can undergo spontaneous regression to aggressive tumors with a tendency toward local invasion and recurrence. The management of DF has evolved considerably in the last decade from aggressive first-line surgery and radiation therapy to systemic treatment (chemotherapy, hormonal therapy, and targeted therapy) and symptomatic local control (surgery and radiation therapy). Imaging plays an important role in each of these treatment settings. In surgical candidates, computed tomography (CT) and magnetic resonance (MR) imaging are the modalities of choice for assessing resectability and surgical planning. For evaluating recurrence, MR imaging is the modality of choice for extra-abdominal recurrence, whereas CT is the preferred modality for intra-abdominal recurrence. Signal intensity changes at MR imaging can be used to monitor the biologic behavior of certain DFs chosen for expectant management. Response to systemic treatment with anti-inflammatory agents, hormonal therapy (eg, tamoxifen), cytotoxic chemotherapy (eg, doxorubicin, vinblastine, methotrexate), and targeted therapy (eg, sorafenib), as well as to radiation therapy, can be assessed at CT by monitoring size and attenuation changes or at MR imaging by monitoring size, T2 signal intensity, and degree of enhancement. Several patterns of response can be seen at imaging. Imaging also helps in detecting complications associated with systemic therapy and radiation therapy. (©)RSNA, 2016.

Primary Extremity Liposarcoma: MRI Features, Histopathology, and Clinical Outcomes.

OBJECTIVE: This study aimed to describe magnetic resonance imaging (MRI) features of extremity liposarcoma (LPS) subtypes, correlating with histopathology and clinical outcomes. METHODS: In this retrospective study, we included 125 patients (80 men, 45 women; mean age, 53 years) with extremity LPS [23 atypical lipomatous tumor (ALT), 9 dedifferentiated (DDLPS), 70 myxoid (MLPS), 23 pleomorphic (PLPS)]. Pretreatment MRI of primary tumors in 56 patients (10 ALT, 4 DDLPS, 28 MLPS, 14 PLPS) was reviewed. RESULTS: All subtypes were predominantly T1 isointense relative to skeletal muscle (DDLPS = 3/4, MLPS = 28/28, PLPS = 13/14) and T2 hyperintense (ALT = 10/10, DDLPS = 3/4, MLPS = 28/28, PLPS = 14/14) except for ALT which were T1 hyperintense (8/10). Within MLPS, high grade was associated with unencapsulated margins (P = 0.05) and solid, nodular enhancement (P < 0.0001). Peritumoral edema (P = 0.03) and T2 heterogeneity (P = 0.05) predicted pulmonary (rather than extrapulmonary) metastases in MLPS. Tumor subtype correlated with mortality (P = 0.04). CONCLUSIONS: The MRI features can help to distinguish between extremity LPS subtypes, and can predict histopathologic grade and metastatic pattern in myxoid LPS.

MRI findings of radiation-associated angiosarcoma of the breast (RAS).

PURPOSE: To describe the magnetic resonance imaging (MRI) characteristics of radiation-associated breast angiosarcomas (RAS). MATERIALS AND METHODS: In this Institutional Review board (IRB)-approved retrospective study, 57 women were diagnosed with pathologically confirmed RAS during the study period (January 1999 to May 2013). Seventeen women underwent pretreatment breast MRI (prior to surgical resection or chemotherapy), of which 16 studies were available for review. Imaging features, including all available mammograms, ultrasounds, and breast MRIs, of these patients were evaluated by two radiologists independently and correlated with clinical management and outcomes. RESULTS: The median age of patients at original breast cancer diagnosis was 69.3 years (range 42-84 years), with average time from initial radiation therapy to diagnosis of RAS of 7.3 years (range 5.1-9.5 years). Nine women had mammograms (9/16, 56%) and six had breast ultrasound (US) (6/16, 38%) prior to MRI, which demonstrated nonsuspicious findings in 5/9 mammograms and 3/6 ultrasounds. Four patients had distinct intraparenchymal masses on mammogram and MRI. MRI findings included diffuse T2 high signal skin thickening (16/16, 100%). Nearly half (7/16, 44%) of patients had T2 low signal intensity lesions; all lesions rapidly enhanced on postcontrast T1 -weighted imaging. All women underwent surgical resection, with 8/16 (50%) receiving neoadjuvant chemotherapy. Four women died during the study period. CONCLUSION: Clinical, mammographic, and sonographic findings of RAS are nonspecific and may be occult on conventional breast imaging; MRI findings of RAS include rapidly enhancing dermal and intraparenchymal lesions, some of which are low signal on T2 weighted imaging.

Imaging of Nervous System Involvement in Hematologic Malignancies: What Radiologists Need to Know.

OBJECTIVE: The purpose of this article is to provide a comprehensive review of the imaging features of neurologic involvement in hematologic malignancies. CONCLUSION: Neurologic involvement can be seen in lymphoma, leukemia, post-transplant lymphoproliferative disorder (PTLD), plasma cell neoplasms, and histiocytic and dendritic neoplasms. Imaging, MRI in particular, plays an important role in the workup of these patients. Familiarity with the imaging features of nervous system involvement in hematologic malignancies can help radiologists suggest the diagnosis and guide management.

Beyond the vascular endothelial growth factor axis: update on role of imaging in nonantiangiogenic molecular targeted therapies in oncology.

OBJECTIVE: This article provides a comprehensive review of molecular targeted therapies that do not act directly through vascular endothelial growth factor pathways, highlighting the role of imaging in assessment of treatment response and drug toxicities. CONCLUSION: A substantial number of molecular targeted therapies act on nonantiangiogenic pathways. Familiarity with these drugs, their personalized tumor response criteria, and class- and drug-specific toxicities will help radiologists to be an integral part of the multi-disciplinary oncology team.

Imaging of Fluid in Cancer Patients Treated With Systemic Therapy: Chemotherapy, Molecular Targeted Therapy, and Hematopoietic Stem Cell Transplantation.

OBJECTIVE: The purpose of this article is to provide a comprehensive review of the imaging features of various systemic treatment-related causes of fluid accumulation in cancer patients. CONCLUSION: Systemic treatment-related fluid accumulation can occur with chemotherapy, molecular targeted therapy, or hematopoietic stem cell transplantation. Imaging findings such as new ascites, pleural and pericardial effusions, and subcutaneous edema should be interpreted with caution on restaging studies.

Hormonal therapy in oncology: a primer for the radiologist.

OBJECTIVE: The purpose of this article is to provide a comprehensive imaging review of the common hormonal therapies used in oncology and the side effects associated with them. CONCLUSION: Commonly used hormones in oncology include corticosteroids, somatostatin analogues, progestins, gonadotropin-releasing hormone agonists and antagonists, antiandrogens, aromatase inhibitors, and selective estrogen receptor modulators. Familiarity with these hormones and their side effects can help radiologists to be vigilant for the side effects and complications of these agents.

Myxoid soft-tissue neoplasms: comprehensive update of the taxonomy and MRI features.

OBJECTIVE. The purpose of this article is to review the classification, clinical presentation, and histopathologic and MRI features of myxoid soft-tissue neoplasms. CONCLUSION. MRI is the modality of choice for characterization of myxoid soft-tissue tumors. A combination of imaging features (including certain characteristic signs), clinical features, and patient demographics can help the radiologist in coming to a specific diagnosis or in narrowing down the differential diagnoses.

Anti-VEGF molecular targeted therapies in common solid malignancies: comprehensive update for radiologists.

Angiogenesis is an essential component of the growth and dissemination of solid malignancies and is mediated by several proangiogenic factors. The most widely studied proangiogenic factor is vascular endothelial growth factor (VEGF). A major class of molecular targeted therapies (MTTs) inhibit the VEGF axis and are referred to as antiangiogenic MTTs. There are two main types of anti-VEGF MTTs: drugs targeting circulating VEGF and drugs interfering with the activity of the VEGF receptors. The cancers against which antiangiogenic MTTs have had the greatest effect are gliomas, non-small cell lung cancer, colorectal cancer, hepatocellular carcinoma, renal cell carcinoma, and gastrointestinal stromal tumor. These cancers respond to antiangiogenic MTTs in a different way than they respond to conventional chemotherapy. Instead of the traditional Response Evaluation Criteria in Solid Tumors (RECIST), each of these cancers therefore requires its own individualized treatment response criteria (TRC). Examples of individualized TRC include the Response Assessment in Neuro-oncology (RANO) criteria for gliomas, modified RECIST for hepatocellular carcinoma, and Morphology, Attenuation, Size, and Structure (MASS) criteria for renal cell carcinoma. Furthermore, antiangiogenic MTTs have a unique spectrum of class-specific and drug-specific toxic effects, some of which can be detected at imaging. Increasing use of antiangiogenic MTTs in clinical practice necessitates that radiologists be aware of these drugs, their response patterns, and TRC as well as their toxic effect profiles.