Imaging Features Of Tumors Research Articles

Chordomas

Although rare, chordomas can affect the entire axial skeleton, and they are the most common primary malignant bone tumor in both the sacrum and the spine. This article details tumor origin, epidemiology, pathology, and imaging features, in an effort to improve the ability of the radiologist to diagnose, provide a differential diagnosis, and further understand treatment of patients with chordomas.

Presurgical assessment of splenic tumors in dogs: a retrospective study of 57 cases (2012-2017).

The purpose of this study was to evaluate the clinical and imaging characteristics of canine splenic tumors and to establish guidelines for the presurgical assessment of splenic tumors in dogs. Fifty-seven dogs that underwent total splenectomy for the treatment of splenic tumors were evaluated by examining medical records, hematologic results, diagnostic imaging results, and histopathologic results. The maximum lesion size from ultrasonography was significantly different between malignant and benign tumors (p = 0.002). There was a correlation between tumor margination and type of splenic tumors (p = 0.045). Precontrast lesion attenuation on computed tomography was significantly different between splenic malignant and benign tumors (p = 0.001). The mean ± SD precontrast lesion attenuation of malignant tumors was 40.3 ± 5.9 Hounsfield units (HU), and for benign tumors, it was 52.8 ± 6.8 HU. In conclusion, some variables of the imaging examination could be used to distinguish the type of splenic tumor. Based on the study results, using a diagnostic flowchart would be effective in increasing the survival rate of patients with splenic malignant tumors. In addition, fine needle aspiration or magnetic resonance imaging prior to surgical exploration and histopathologic examination may be useful in achieving a more accurate diagnosis.

MR Imaging Features of Minor Salivary Gland Tumors

Aim: To retrospectively evaluate the MR imaging features of histologically proven minor salivary gland tumors (MSGTs). Materials and Methods: A retrospective review of MR imaging features of 29 histologically proven MSGTs was performed. Results: The commonest site of involvement was base of tongue (n=7) and the commonest pathology was adenoid cystic carcinoma (n=12). All the MSGTs revealed smooth surface with well-defined margins and polypoidal appearance (100% sensitivity, 100%PPV). T2w hyperintensity and enhancement results (ranged from intense to intermediate hyperintensity) were variable. Larger tumors (more than 3.5 cm) had a heterogeneous appearance. Discussion: All MSGTs showed smooth surface, well-defined margins and polypoidal appearance. The T2w hyperintense signal of the MSGTs (ranging from intermediate T2w hyperintensity to intense T2w hyperintensity) and the post contrast enhancement (also ranging from intermediate to intense enhancement) was variable. In the head and neck region, MSGTs need to be differentiated from the more common entities such as squamous cell ancers (SCC) and Lymphoma. While this differentiation is not always easy, orphologically SCCs typically present as locally infiltrative tumors with ill-defined margins. Lymphomas typically present as polypoidal masses with well-defined margins and hence may closely resemble MSGTs. Lymphomas are generally homogeneous masses showing intermediate T2w hyperintensity. Thus differentiation between lymphomas and MSGTs can sometimes be a challenge, however if the mass shows intense T2w hyperintensity with intense enhancement, it could point to a diagnosis of MSGT.

Basics of Imaging Techniques in Evaluation of Soft Tissue Tumors

Medical imaging plays a pivotal role in the detection, diagnosis, and clinical management of primary soft tissue tumors. Various imaging modalities have been used, and each modality offers unique advantages in the workup of soft tissue tumors by localizing the lesions in different compartments of the body and characterizing macroscopic tissue composition of the lesions in a noninvasive and safe manner. We review the clinical role and technical aspects of the frequently used imaging modalities, including magnetic resonance imaging (MRI), computed tomography, ultrasonography, positron emission tomography, and plain radiography with an emphasis on MRI as a mainstay imaging modality and a brief discussion of advanced techniques. We also review imaging features of common soft tissue tumors that can be detected and characterized using current imaging techniques. This review contains 54 figures, 1 table and 37 references. Key words: computed tomography, diffusion-weighted imaging, imaging, magnetic resonance imaging, positron emission tomography, soft tissue, technique, tumor, ultrasonography

Basics of Imaging Techniques in Evaluation of Soft Tissue Tumors

Medical imaging plays a pivotal role in the detection, diagnosis, and clinical management of primary soft tissue tumors. Various imaging modalities have been used, and each modality offers unique advantages in the workup of soft tissue tumors by localizing the lesions in different compartments of the body and characterizing macroscopic tissue composition of the lesions in a noninvasive and safe manner. We review the clinical role and technical aspects of the frequently used imaging modalities, including magnetic resonance imaging (MRI), computed tomography, ultrasonography, positron emission tomography, and plain radiography with an emphasis on MRI as a mainstay imaging modality and a brief discussion of advanced techniques. We also review imaging features of common soft tissue tumors that can be detected and characterized using current imaging techniques. Key words: computed tomography, diffusion-weighted imaging, imaging, magnetic resonance imaging, positron emission tomography, soft tissue, technique, tumor, ultrasonography

Ovarian collision tumors: imaging findings, pathological characteristics, diagnosis, and differential diagnosis

Collision tumors are uncommon neoplasms in which elements of differing histologic origins coexist in a single mass. Ovarian collision tumors are a rare subtype of such lesions. The identification of collision tumors by radiologic examinations is essential to ensure that comprehensive biopsies are performed to guide appropriate treatments. According to the clinical and imaging findings of 12 patients and reviews of previous studies, ovarian collision tumors are mixtures of different combinations of epithelial tumors, germ cell tumors, and sex-cord-stromal tumors. The smaller tumors are usually located inside ("nested tumor") or on the wall ("back to back") of the larger tumors. Each type of ovarian collision tumors presents specific CT/MRI features in accordance with their histologic origins and collision patterns. Knowledge of the imaging features of ovarian collision tumors is crucial to aid preoperative diagnostic accuracy.

Abstract 03: Imaging characteristics of head and neck tumors according to human papillomavirus (HPV) status in Bogotá, Colombia

Abstract Background: HPV-positive head and neck tumors (HNT) correspond to a unique entity given their clinical behavior and molecular characteristics. These tumors can show distinct features on pretreatment imaging, such as well-defined borders and cystic nodal metastases; therefore, the aim of our study was to evaluate the imaging characteristics and determine if there are differences between HPV-positive and HPV-negative HNT tumors in patients studied at our institution. Design: A retrospective pretreatment imaging review from 35 HNT cases recruited under INTERCHANGE- IARC project in Latin America between 11-2014 and 12-2016 was performed. Imaging evaluation included primary lesion and nodal metastases. Initial evaluation by radiologists was blinded for patients' histological findings and HPV status. Radiology was evaluated for: location, tumor size, tumor border morphology, contrast enhancement, nodal metastases, size of metastasis and morphology of nodal metastasis. Radiological findings were correlated with histology and p16 INK4a inmunohistochemistry using clone E6H4 (HPV surrogate marker). Results: Pretreatment images were available for review only in 17 of 35 cases (48,5%). 10 cases had computerized tomography (CT) examination, 1 case magnetic resonance (MR) and 6 cases had 18F-FDG PET-CT. 6/17 cases (35.3%) were excluded due to no visualization of the primary tumor or due to limitation artifacts (amalgam). From the 11 cases available for review, 7 were from the oropharynx (OP), 2 from the oral cavity (OC) and 1 from the larynx (LA). All OP tumors were positive for p16 and all the rest tumors were p16 negative. Tumor size ranged from 7 to 51 mm in greatest dimension. Well-defined borders were present in 4/7 p16 positive tumors vs 2/4 p16 negative tumors. Tumor enhancement with contrast was present and able to evaluate only in 5 out of 11 tumors (3 p16 + and 2 p16 -). All the OP p16 positive tumors presented with nodal metastasis greater than 10 mm in dimension. 6/7 had nodal cystic change and these p16 positive cases were more likely to have large cystic nodal metastases with a cystic component larger than 50% of the nodal size (6/7) than p16/HPV negative tumors (1 out of 4 cases had smaller nodal metastasis with cystic component <50%). Conclusion: Large nodal metastasis (>10 mm) with cystic component larger than 50% of the node size is an important finding seen in p16 HNT. One should consider these findings when examining neck images in patients with unknown primary in order to exclude malignancy given that usually cystic nodes could be misdiagnosed as benign. Our nondiagnostic imaging rate pretreatment was 35%; in order to improve the use of diagnostic tools we recommend the use of MR especially in patients with amalgams and/or tumor located at the oral cavity and oropharynx. Further studies are granted with a larger sample size in order to validate and confirm imaging characteristics in p16/HPV positive HNT. Citation Format: Nicolás Useche, Oscar Torres, Maria M. Rojas, Mauricio Palau-Lázaro, Marcela Mejía-Arango, Ana Margarita Baldión, José A. Hakim, Johanna Campos, Alberto Escallon, Aylen Vanessa Ospina, Sandra Perdomo, Paula A. Rodríguez-Urrego. Imaging characteristics of head and neck tumors according to human papillomavirus (HPV) status in Bogotá, Colombia [abstract]. In: Proceedings of the AACR-AHNS Head and Neck Cancer Conference: Optimizing Survival and Quality of Life through Basic, Clinical, and Translational Research; April 23-25, 2017; San Diego, CA. Philadelphia (PA): AACR; Clin Cancer Res 2017;23(23_Suppl):Abstract nr 03.

Secondary Malignancies of the Bladder: Avoiding the Diagnostic Pitfall.

Although rare, secondary tumors of the bladder can present a diagnostic dilemma to pathologists considering a differential diagnosis of primary bladder cancer. We investigated the clinicopathologic and imaging characteristics of metastatic tumors to the bladder. We retrospectively reviewed the surgical pathology databases from 2 sites from 2013 to 2016, identifying 66 cases of secondary bladder tumors. Clinical, pathologic, and imaging findings were reviewed. Mean age at diagnosis was 63 years (range = 25-87). Females had a significantly higher proportion (44/66, 66.7%) of secondary bladder tumors compared with males (22/66, 33.3%; P = .007). In total, 56/66 (84.8%) patients had a clinical history of an in situ or invasive malignancy in another organ, and 54/66 (81.8%) patients had imaging supporting a metastatic tumor. Only 2/66 (3.0%) patients had a prior history of urothelial carcinoma. In total, 4/66 (6.1%) cases (all females) were originally misdiagnosed as primary bladder malignancies and were corrected after clinicoradiologic correlation. Overall, colorectal origin was most common (15/66, 22.7%), followed by cervical and ovarian primaries (10/66, 15.2% each). Cervical and ovarian origins predominated in the female cohort (10/44, 22.7% each), followed by endometrial (8/44, 18.2%). Colorectal and prostate primaries were the most common among males (10/22, 45.5%, and 7/22, 31.8%, respectively). Secondary bladder tumors can mimic urothelial carcinomas. In our cohort, gynecological, colorectal, and prostatic origins were most common. Clinical history, imaging, and immunohistochemical studies can be useful in avoiding this diagnostic pitfall.

Reproducible imaging features of biologically aggressive gastrointestinal stromal tumors of the small bowel.

To identify reproducible CT imaging features of small bowel gastrointestinal stromal tumors (GIST) that are associated with biologic aggressiveness. Patients with histologically proven small bowel GISTs and CT enterography or abdominopelvic CT were included. Biologic aggressiveness was established based on initial histologic grading (very low risk to malignant), with "malignant" assigned if recurrence or metastases developed subsequently. CT exams were independently evaluated by three gastrointestinal radiologists for tumor size, growth pattern, enhancement, tumor borders, necrosis, calcification, ulceration, multiplicity, internal air or enteric contrast, nodal metastasis, liver metastasis, peritoneal metastasis, ascites, and draining vein size. Inter-observer variability and imaging features associated with high-grade and malignant small bowel GISTs were determined. Of 78 patients with small bowel GISTs, 10/78 (13%) were high grade and 18/78 (23%) were malignant. There was moderate to substantial inter-observer agreement (Kappa>0.4) for all findings except tumor border, ulceration, and nodal metastases. Tumor size, irregular or invasive tumor border, necrosis, liver metastasis, ascites, and iso-enhancement were associated with high-grade/malignant small bowel GISTs (p<0.04). Internal air or enteric contrast and peritoneal metastases additionally predicted malignant behavior (p<0.03). When imaging features predicting malignant small bowel GISTs were absent and size was≤3cm, 0% (0/16), 5% (1/19), and 5% (1/17) of patients had high grade, and 0% (0/16, 0/19, and 0/17) had malignant tumors for the three readers, respectively. Multiple, reproducibly identified, small bowel GIST imaging features suggest biologic aggressiveness. The absence of these imaging features may identify small tumors that can be followed in asymptomatic or high-risk patients.

The role of computed tomography and magnetic resonance imaging in diagnosing clear cell ameloblastoma: A case report.

Ameloblastoma is the most common and clinically relevant type of odontogenic tumor. Clear cell odontogenic carcinoma is histologically characterized by solid sheets and nests of clear cells, whereas clear cell ameloblastoma (CCAM) is histologically characterized by an ameloblastomatous component intermixed with an extensive clear cell component. A total of 12 reports have been published on the histological etiology for CCAM; however, no reports have made regarding the detailed computed tomography and/or magnetic resonance imaging features of tumors of this type. The present study describes a case of a well-circumscribed 20-mm radiolucent lesion of the anterior mandible that was misdiagnosed as a clear cell odontogenic carcinoma. The study describes the detailed radiological characteristics of a case of CCAM.

Quantitative Imaging Features Predict Clinical Survival: An Initial Analysis with Neural Network Models

Tumor imaging features may predict treatment outcome and guide individualized treatment in radiotherapy (RT). However, given high dimensional imaging features versus relatively small patient sample, identifying potential prognostic imaging biomarkers is typically challenging. The aim of the work is to identify prognostic imaging features that are most relevant with patient RT outcome (i.e., survival interval) via neural network models. Evolutionary optimization neural network (EONN), based on back propagation neural network (BPNN), was developed to explore the association between the large number of radiomic features and RT clinical outcome. The advanced convolutional neural network (CNN) was also used to cross check the findings. The EONN is constructed based on the optimized initial weights of the BPNN. Evolutionary algorithm (EA) is used to optimize the initial weights and thresholds fed into training model. The population of EA is encoded in real number, and the error between the prediction and the expected data is used as the fitness function. To evaluate the efficacy of the models, a group of 59 base-of-tongue patients and corresponding survival interval were analyzed, where 47 patients (80%) were used as a training cohort, and remaining 12 patients (20%) were used as a test cohort. For each patient, a large number of quantitative image features (including shape, texture, intensity, etc.) were extracted based on a pre-treatment CT images, resulting in 1387-dimensional data in six categories. Principal component analysis was used to remove redundant imaging features before the features fed into neural network. Table 1 summarizes the predicted survival results using neural networks. EONN resulted in the best performance among three models. The BPNN, based on simple training method, yielded the largest deviations. The CNN, usually requires more connection between neurons, didn’t achieve a good training result when a relatively small data sample involving high dimensional features. We demonstrated the application of the neural network models in RT radiomic analysis. The EONN resulted in decent prediction results of patient survival for high dimensional features in small sample. The identified prognostic image features can be adopted to design individualized radiation treatment to potentially improve clinical outcomes.Abstract 1031; Table 1Prediction results using three neural network modelsBPNNEONNCNNTest pt #Survival interval (Mon.)Predicted value (Mon.)DeviationPredicted value (Mon.)DeviationPredicted value (Mons)Deviation19.355.85.012.50.3433.6215.527.20.822.50.4130.2312.223.20.916.20.3271.243.431.98.53.10.130.18.0515.513.60.113.10.2140.1672.447.20.366.50.160.90.2775.522.60.776.50.026.90.68110.6-34.41.3930.22.91.092055.81.818.80.117.40.11015.9-17.32.17.20.5-7.81.51110.92.30.810.80.020.80.91221.1280.323.50.133.20.6Mean31.821.31.930.30.223.51.5 Open table in a new tab

Analysis of imaging characteristics of primary malignant bone tumors in children.

The present study aimed to investigate the imaging characteristics of primary malignant bone tumors in children. The imaging results of 34 children with primary malignant bone tumors confirmed by histopathological diagnosis between March 2008 and January 2014 were retrospectively analyzed. In total, 25 patients had osteosarcoma, with radiography and computed tomography (CT) showing osteolytic bone destruction or/and osteoblastic bone sclerosis, an aggressive periosteal reaction, a soft-tissue mass and cancerous bone. The tumors appeared as mixed magnetic resonance imaging (MRI) signals that were inhomogeneously enhanced. A total of 5 patients presented with Ewing sarcoma, with radiography and CT showing invasive bone destruction and a soft-tissue mass. Of the 5 cases, 2 showed a laminar periosteal reaction. The tumors were shown to have mixed low signal on T1-weighted images (T1WI) and high signal on T2-weighted images (T2WI); 1 case showed marked inhomogeneous enhancement. Another 3 patients exhibited chondrosarcoma. Of these cases, 1 was adjacent to the cortex of the proximal tibia, and presented with local cortical bone destruction and a soft-tissue mass containing scattered punctate and amorphous calcifications. MRI revealed mixed low T1 signal and high T2 signals. Another case was located in the medullary cavity of the distal femur, with radiography revealing a localized periosteal reaction. The tumor appeared with mixed MRI signals, and with involvement of the epiphysis and epiphyseal plates. Radiography and CT of the third case showed bone destruction in the right pubic ramus, with patchy punctate, cambered calcifications in the soft-tissue mass. MRI of the soft-tissue mass revealed isointensity on T1WI and heterogeneous hyperintensity on T2WI. Ossifications and the septum appeared as low T1WI and T2WI. Of the 34 patients, 1 patient presented with lymphoma involving the T12, L1 and L2 vertebrae. CT showed vertebral bone destruction, a soft-tissue mass and a compression fracture of L1. MRI showed a soft-tissue mass with low T1 signal and high T2 signal and marked inhomogeneous enhancement. Overall, osteosarcoma was the most common primary malignant bone tumor, followed by Ewing sarcoma, chondrosarcoma and lymphoma. Osteoblastic or osteolytic bone destruction, an invasive periosteal reaction, soft-tissue masses, a tumor matrix and inhomogeneous enhancement were important imaging features of malignant bone tumors.

Analysis of the lymphoepithelial carcinoma of the salivary gland: 12 cases report

Objective:To improve recognization of clinical, imaging and pathological characteristics of lymphoepithelial carcinoma (LEC) of the salivary glands.Method:The clinical manifestations, imaging features, histological and immunohistochemical characteristics of LEC of the salivary glands (n = 12) between 2003 and 2013 were retrospectively reviewed.Result: Four cases of male and 8 cases of female were enrolled, and the average age of 53.25 years. Ten lesions were located in the parotid gland, and 2 cases were in the submandibular gland. Two cases were unilateral multiple tumors, 10 cases were unilateral solitary tumor, 4 cases were with cervical lymph node metastasis and 1 case was with peripheral facial paralysis. Ten patients had positive EB VCA IgA test. Homogeneous density and obvious enhancement were achieved in all lesions on CT scan. 8 cases were with irregular shapes, partially or ill-defined margin, and heterogeneous enhancement. Incomplete capsule was found in 4 cases, while no obvious capsule was found in 6 cases. HE staining showed that the infiltrative tumors were formed by the presence of sheets or nests of epithelial cells and interstitial lymphoid tissue. Immunohistochemistry staining revealed that the epithelial cells were reactive for pan CK, the lymphoid cells showed reactivity for both CD20 and CD3 markers. All cases underwent primary tumor and involved gland resection with ipsilateral neck dissection, and postoperative radiotherapy, and 2 cases combined with postoperative chemotherapy. The 3 year survival rate of patients was 75.0%(9/12), and 3 cases died of local recurrence or (and) distant metastasis within 1-2 years of definite diagnosis.Conclusion: LEC of salivary gland is associated with EB virus infection. Most cases present with unilateral solitary mass, and incidence of regional lymph node involvement is high. The imaging characteristics of tumor seem to be malignant on CT scan in most cases. Treatment includes multimodality therapy including surgical resection, neck dissection, and radiotherapy. Local recurrence and distant metastasis are the main causes of death.

Computed Tomography in the Management of Adrenal Tumors: Does Size Still Matter?

We sought to evaluate computed tomography (CT) imaging as a predictor of adrenal tumor pathology. A retrospective review was conducted of patients who underwent unilateral adrenalectomy for an adrenal mass between January 2005 and July 2015. Tumors were classified as benign, indeterminate, or malignant based on preoperative CT findings. Of 697 patients who underwent unilateral adrenalectomy, 216 met the inclusion criteria. Pathology was benign in 88.4%, indeterminate in 2.3%, and malignant in 9.3%, with a median tumor diameter of 2.7 cm (interquartile range, 1.7-4.1 cm) and 9.5 cm (interquartile range, 7.1-12 cm) in the benign and malignant groups, respectively (P < 0.001). Of the tumors with benign features on CT, 100% (143/143) had benign final pathology. Imaging characteristics of adrenal tumors on CT scan predict benign pathology 100% of the time. Regardless of size, when interpreted as benign on CT scan, laparoscopic adrenalectomy, if technically feasible, should be the technique used when surgery is offered, or close surveillance may be a safe alternative.

177Lu-DOTATATE peptide receptor radionuclide therapy in metastatic or advanced and inoperable primary neuroendocrine tumors of rare sites

The present study aimed at exploring the patient and imaging characteristics of primary neuroendocrine tumors (NETs) of rare sites who presented with metastatic and/or advanced inoperable stages and therefore was considered for peptide receptor radionuclide therapy (PRRT) with 177Lu-DOTATATE. A retrospective analysis was undertaken of these patients focusing on the aforementioned aspects. All patients underwent dual-tracer molecular functional imaging with somatostatin receptor (SSTR)-based imaging (with either 99mTc-HYNIC-TOC or 68Ga-DOTATATE) and 18fluorine fludeoxyglucose positron emission tomography-computed tomography as the pretherapy assessment. Based on the qualitative uptake of tracer in SSTR imaging, the lesions were divided into four categories Grade 0–III. The response was assessed post-PRRT by three parameters: (i) symptomatic response, (ii) biochemical response (serum tumor marker), and (iii) objective imaging response. The response profiles under each of these scales were assessed utilizing predefined criteria (detailed in methods). The overall response classification into partial response, stable disease, and progressive disease was done based on documentation of similar scale/category of at least two parameters among the triple parametric assessment. A total of nine patients (7 males, 2 females; age range: 33–59 years) with rare site primary NET were found: The primary sites included ureter (n = 1), sacrococcygeal (n = 1), esophagus (n = 1), thymus (n = 3), and mediastinum (n = 3). Treatment response assessment was undertaken in eight patients who received more than 2 cycles of PRRT with 177Lu-DOTATATE. In this response assessment group (n = 8), the patients received 2–5 cycles and follow-up duration ranged from 5 to 48 months. Symptomatic responses and better quality of life were observed in 4/8 (50%) patients, stable symptomatic disease in 3/8 (37.5%), and progression in 1/8 patients (12.5%). Biochemically, partial response was seen in 3/8 (37.5%), stable values was seen in 3/8 (37.5%), and progression of tumor marker was seen in 2/8 (25%) patients. Morphologically, partial response was seen in 2/8 (25%), stable disease in 5/8 (62.5%), and progressive disease in 1/8 (12.5%) patients. On overall assessment, 2/8 patients (25%) demonstrated partial response, 4/8 stable disease (50%), and 2/8 progressive disease (25%) at the time of assessment. As per the RECIST 1.1, seven patients had stable disease and one patient had progressive disease. No specific correlation could be obtained between dual-tracer molecular imaging features and the response likely due to small population of the study group. Overall, there was evidence of excellent disease stabilization, and symptom palliation with 177Lu-DOTATATE PRRT was documented in these advanced or metastatic NETs of various rare sites.

Correlation of tumor enhancement and imaging features on multiphasic multidetector CT with microvessel density as a step toward a minimally invasive method to predict Fuhrman nuclear grade in patients with clear cell renal cell carcinoma.

e16049 Background: Clear cell renal cell carcinoma (ccRCC) is the most common tumor of the kidney. Up to 70% are incidentally detected on multiphasic CT. The prognosis for patients with ccRCC is related to Fuhrman grade (FG) and is diagnosed by biopsy or excision. There is a great need for a non-invasive method to assess tumor grade which may help inform clinical decision-making. The purpose of our study is to determine if contrast enhancement on CT predicts FG and microvessel density (MVD) of ccRCC lesions and to assess which combination of quantitative and qualitative radiological features and clinical features predict high FG ccRCC lesions. Methods: With IRB approval for this HIPAA-compliant retrospective study, our pathology and imaging databases were queried to obtain a cohort of ccRCC with a preoperative multiphasic (unenhanced (U), corticomedullary (C), nephrographic (N), and excretory (E)) CT scan. Tumors were stained with CD4 to quantify % MVD. Spearman’s rank correlation was calculated to test the strength of the association between CT enhancement, %MVD and FG. Stepwise logistic regression analysis was performed to determine the quantitative and/or qualitative feature with the highest performance in predicting high FG tumor. The multivariate logistic regression analysis was evaluated using ROC curves and AUCs. Results: Our cohort had 127 patients with 89 low-grade tumors and 43 high-grade tumors. The %wash-in of enhancement from the U to the C phase showed a significant correlation with %MVD of the tumor (R2= 0.181,p &lt; . 001) as did enhancement of the tumor in the early C phase with %MVD (R2= 0.159,p &lt; . 001). There was a significant inverse correlation with %MVD and FG (R2= 0.137,p &lt; . 001). T-stage, tumor size, %MVD and presence of renal vein invasion were determined to be significant independent predictors of high grade lesions with an AUC of .838 (95% CI .748-.927). Conclusions: Lower grade ccRCC tumors have a higher MVD. Therefore, contrast material washes in at a faster rate from the UN to the CM phase, enabling low grade to be discriminated from high-grade tumors on CT.

Radiological features of primitive neuroectodermal tumors in intra-abdominal and retroperitoneal regions: A series of 18 cases.

ObjectivesTo characterize the imaging and clinicopathological features of primitive neuroectodermal tumors (PNETs) arising in intra-abdominal and retroperitoneal regions.MethodsEighteen patients with histopathologically proven intra-abdominal and retroperitoneal PNET were enrolled; computed tomography was performed for all cases, and magnetic resonance imaging was performed for a single case. Typical computed tomography and magnetic resonance imaging findings, including morphology, texture and enhancement features, as well as clinicopathological characteristics and prognosis data were retrospectively analyzed.ResultsOf eighteen PNET patients, fifteen were male and three were female, with a median age of 36 years (range, 2–65 years). The onset of symptoms was most often nonspecific and insidious. The mean tumor diameter was 7.2 cm (range, 3.0–12.1 cm), with necrosis in fifteen cases, cystic changes in eight, partition structure in five, calcification in five, hemorrhage in two, and mural nodules in one. Contrast enhanced computed tomography showed multiple tiny feeding arteries within the masses in six cases, resulting in a crab-like appearance, and mild ring enhancement pattern in five cases. Eleven cases showed surrounding invasion and metastasis. Of the eighteen PNET cases, nine cases showed smooth, well-defined margins, and nine cases had irregular, ill-defined margins. A median survival was 10.0±1.6 months. However, chemotherapy had efficacy on patients even those with advanced disease.ConclusionsPrimary intra-abdominal and retroperitoneal PNETs are rare, and imaging features documented here may help the diagnosis of this severe disease. Notably, two signs present in retroperitoneal PNET tumors, including a mild ring enhancement pattern and a crab-like appearance of the tiny feeding arteries, may have the potential to help us improve the ability to make a relatively reliable diagnosis.

Photoacoustic imaging features of intraocular tumors: Retinoblastoma and uveal melanoma.

The purpose of this study is to examine the capability of photoacoustic (PA) imaging (PAI) in assessing the unique molecular and architectural features in ocular tumors. A real-time PA and ultrasonography (US) parallel imaging system based on a research US platform was developed to examine retinoblastoma in mice in vivo and human retinoblastoma and uveal melanoma ex vivo. PA signals were generated by optical illumination at 720, 750, 800, 850, 900 and 950 nm delivered through a fiber optical bundle. The optical absorption spectra of the tumors were derived from the PA images. The optical absorption spectrum of each tumor was quantified by fitting to a polynomial model. The microscopic architectures of the tumors were quantified by frequency domain analysis of the PA signals. Both the optical spectral and architectural features agree with the histological findings of the tumors. The mouse and human retinoblastoma showed comparable total optical absorption spectra at a correlation of 0.95 (p<0.005). The quantitative PAI features of human retinoblastoma and uveal melanoma have shown statistically significant difference in two tailed t-tests (p<0.05). Fully compatible with the concurrent procedures, PAI could be a potential tool complementary to other diagnostic modalities for characterizing intraocular tumors.

Genetically Defined Oligodendroglioma Is Characterized by Indistinct Tumor Borders at MRI.

In 2016, the World Health Organization revised the brain tumor classification, making IDH mutation and 1p/19q codeletion the defining features of oligodendroglioma. To determine whether imaging characteristics previously associated with oligodendroglial tumors are still applicable, we evaluated the MR imaging features of genetically defined oligodendrogliomas. One hundred forty-eight adult patients with untreated World Health Organization grade II and III infiltrating gliomas with histologic oligodendroglial morphology, known 1p/19q status, and at least 1 preoperative MR imaging were retrospectively identified. The association of 1p/19q codeletion with tumor imaging characteristics and ADC values was evaluated. Ninety of 148 (61%) patients had 1p/19q codeleted tumors, corresponding to genetically defined oligodendroglioma, and 58/148 (39%) did not show 1p/19q codeletion, corresponding to astrocytic tumors. Eighty-three of 90 (92%) genetically defined oligodendrogliomas had noncircumscribed borders, compared with 26/58 (45%) non-1p/19q codeleted tumors with at least partial histologic oligodendroglial morphology (P < .0001). Eighty-nine of 90 (99%) oligodendrogliomas were heterogeneous on T1- and/or T2-weighted imaging. In patients with available ADC values, a lower mean ADC value predicted 1p/19q codeletion (P = .0005). Imaging characteristics of World Health Organization 2016 genetically defined oligodendrogliomas differ from the previously considered characteristics of morphologically defined oligodendrogliomas. We found that genetically defined oligodendrogliomas were commonly poorly circumscribed and were almost always heterogeneous in signal intensity.

64Cu-Labeled Trastuzumab Fab-PEG24-EGF Radioimmunoconjugates Bispecific for HER2 and EGFR: Pharmacokinetics, Biodistribution, and Tumor Imaging by PET in Comparison to Monospecific Agents.

Heterodimerization of EGFR with HER2 coexpressed in breast cancer (BC) promotes tumor growth, and increased EGFR expression is associated with trastuzumab resistance. Our aim was to construct 64Cu-labeled bispecific radioimmunoconjugates (bsRIC) composed of trastuzumab Fab, which binds HER2 linked through a polyethylene glycol (PEG24) spacer to EGF, and to compare their pharmacokinetic, biodistribution, and tumor imaging characteristics by positron-emission tomography (PET). bsRICs were generated by linking maleimide modified trastuzumab Fab with thiolated EGF through a thioether bond. HER2 and EGFR binding were assessed in vitro in MDA-MB-231 (EGFRmod/HER2low), MDA-MB-468 (EGFRhigh/HER2neg), MDA-MB-231-H2N (EGFRmod/HER2mod), and SKOV3 (EGFRlow/HER2high) cells by competition and saturation cell binding assays to estimate the dissociation constant (Kd). The elimination of the 64Cu-NOTA-trastuzumab Fab-PEG24-EGF bsRICs from the blood of Balb/c mice was compared to monospecific 64Cu-NOTA-trastuzumab Fab and 64Cu-NOTA-EGF. MicroPET/CT imaging was performed in NOD/SCID mice bearing subcutaneous MDA-MB-468, MDA-MB-231/H2N, or SKOV3 human BC xenografts at 24 and 48 h postinjection (p.i.) of bsRICs. Tumor and normal tissue uptake were quantified by biodistribution studies and compared to monospecific agents. The binding of bsRICs to MDA-MB-231 cells was decreased to 24.5 ± 5.2% by excess EGF, while the binding of bsRICs to SKOV3 cells was decreased to 38.6 ± 5.4% by excess trastuzumab Fab, demonstrating specific binding to both EGFR and HER2. 64Cu-labeled bsRICs incorporating the PEG24 spacer were eliminated more slowly from the blood than 64Cu-bsRICs without the PEG spacer and were cleared much more slowly than 64Cu-NOTA-Fab or 64Cu-NOTA-EGF. All three tumor xenografts were visualized by microPET/CT at 24 and 48 h p.i. of bsRICs. Biodistribution studies at 48 h p.i. in NOD/SCID mice with MDA-MB-231/H2N tumors demonstrated significantly greater tumor uptake of 64Cu-NOTA-Fab-PEG24-EGF (4.9 ± 0.4%ID/g) than 64Cu-NOTA-Fab (1.9 ± 0.3%ID/g; P < 0.0001) and 64Cu-NOTA-EGF (0.7 ± 0.2%ID/g; P < 0.0001). Furthermore, preadministration of an excess of trastuzumab Fab or trastuzumab Fab-PEG24-EGF significantly decreased the tumor uptake of 64Cu-NOTA-Fab-PEG24-EGF in SK-OV-3 and MDA-MB-468 xenografts by 4.4-fold (P = 0.0012) and 1.8-fold (P = 0.0031), respectively. 64Cu-labeled bsRICs bound HER2 or EGFR and were taken up specifically in vivo in tumor xenografts expressing one or both receptors. The PEG24 linker prolonged the blood residence time contributing to the higher tumor uptake of the bsRICs than monospecific agents.