A systematic review reporting quality of radiomics research in neuro-oncology: toward clinical utility and quality improvement using high-dimensional imaging features.

BACKGROUND: To evaluate radiomics analysis in neuro-oncologic studies according to a radiomics quality score (RQS) system to find room for improvement in clinical use. METHODS: Pubmed and Embase were searched up the terms radiomics or radiogenomics and gliomas or glioblastomas until February 2019. From 189 articles, 51 original research articles reporting the diagnostic, prognostic, or predictive utility were selected. The quality of the methodology was evaluated according to the RQS. The adherence rates for the six key domains were evaluated: image protocol and reproducibility, feature reduction and validation, biologic/clinical utility, performance index, a high level of evidence, and open science. Subgroup analyses for journal type (imaging vs. clinical) and biomarker (diagnostic vs. prognostic/predictive) were performed. RESULTS: The median RQS was 11 out of 36 and adherence rate was 37.1%. Only 29.4% performed external validation. The adherence rate was high for reporting imaging protocol (100%), feature reduction (94.1%), and discrimination statistics (96.1%), but low for conducting test-retest analysis (2%), prospective study (3.9%), demonstrating potential clinical utility (2%), and open science (5.9%). None of the studies conducted a phantom study or cost-effectiveness analysis. Prognostic/predictive studies received higher score than diagnostic studies in comparison to gold standard (P < .001), use of calibration (P = .02), and cut-off analysis (P = .001). CONCLUSIONS: The quality of reporting of radiomics studies in neuro-oncology is currently insufficient. Validation is necessary using external dataset, and improvements need to be made to feature reproducibility, demonstrating clinical utility, pursuits of a higher level of evidence, and open science.

Hemangiomas orbitarios bilaterales: a propósito de un caso / Bilateral orbital hemangiomas: a case report

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68Ga-DOTANOC PET/CT in an Atypical Extraskeletal Paravertebral Hemangioma Mimicking as Neurogenic Tumor in a Known Case of Breast Cancer.

Ga-DOTANOC PET/CT is well documented in evaluation of well-differentiated neuroendocrine tumors and in other lesions with somatostatin receptor expression such as pheochromocytoma, paraganglioma, neuroblastoma, meningioma, and mesenchymal tumors causing oncogenic osteomalacia. Causes of interpretative pitfalls include prominent pancreatic uncinate process activity, inflammation, osteoblastic activity (degenerative bone disease/fracture/vertebral hemangioma), splenunculi/splenosis, and others. We present a case of extraskeletal paravertebral lesion detected in a known case of breast cancer with increased Ga-DOTANOC uptake later proved to be hemangioma. This is a novel finding and should be kept as a rare benign differential in evaluation of lesions with somatostatin receptor expression.

Assessment of paraspinal neurogenic tumors with diffusion-weighted MR imaging.

PURPOSE: To assess paraspinal neurogenic tumors with diffusion-weighted MR imaging. METHODS: Retrospective analysis was done upon 34 patients with paraspinal neurogenic tumors that underwent diffusion-weighted MR imaging. The ADC values of the mediastinal neurogenic tumors were calculated and correlated with biopsy results. RESULTS: The ADC of benign paraspinal neurogenic tumors (1.5 ± 0.28 × 10-3 mm2/s) was significantly higher (P = 0.001) than that of malignant peripheral nerve sheath tumors (0.995 ± 0.198 × 10-3 mm2/s). Selection of 1.15 × 10-3 mm2/s as a cut-off point for differentiating malignant from benign neurogenic tumors revealed an area under the curve of 0.885, an accuracy of 91.1%, a sensitivity of 90.9%, and specificity of 91.3%. There was significant difference (P = 0.04) in the ADC of schwannomas (1.55 ± 0.29 × 10-3 mm2/s) from neurofibromas (1.33 ± 0.08 × 10-3 mm2/s). The cut-off ADC value of 1.44 × 10-3 mm2/s was used to differentiate schwannomas and neurofibromas with an area under the curve of 0.86, an accuracy of 82.6%, a sensitivity of 100%, and a specificity of 76.5%. CONCLUSION: Diffusion-weighted MR imaging is imaging parameter that can be used for differentiation of benign from malignant paraspinal neurogenic tumors.

Multinodular and vacuolating neuronal tumor of the cerebrum. A rare entity. New case and review of the literature.

BACKGROUND: Multinodular and vacuolating neuronal tumor has been recently described and included in the World Health Organization Classification of Tumors of The Central Nervous System, even though its consideration as a true tumor is controversial. Patients with these lesions usually present with refractory seizures and inconclusive imaging findings that may be confused with other more common diagnoses such as dysembryoplastic neuroepithelial tumors or low-grade gliomas. Therefore, surgical resection is warranted to reach a pathologic diagnosis and seizure control. To the best of our knowledge, only 16 cases have been published in the English literature. CASE DESCRIPTION: We present the case of a 52-year-old male who presented at our institution with a 2-year-history of absence of seizures. Brain MRI showed a T2-hyperintense lesion with no contrast enhancement affecting his temporal lobe. Temporal craniotomy and microsurgical resection was scheduled. The procedure was uneventful and a grayish, gluey mass was sent for pathologic analysis. The tumor was formed by immature neuronal cells organized in nodules with a vacuolated matrix. A thorough immunohistochemical analysis showed positivity for: Protein Gene Product 9.5. ATRX. OLIG2. SOX10. p16. Nestin. Synaptophysin. The findings were consistent with multinodular and vacuolating neuronal tumor. The patient has been seizure-free after surgery and with no signs of tumor progression. CONCLUSION: We present a thorough review addressing this uncommon tumor along with a description of the 17th reported case of MVNT, a tumor that was described for the first time in 2013. Further studies and case studies are necessary to establish a well-defined morphological and immunohistochemical profile along with knowledge about its natural history.

A probabilistic assessment of the diagnosis of paraganglioma/pheochromocytoma based on clinical criteria and biochemical/imaging findings.

UNLABELLED: Paragangliomas (PGL) and pheochromocytomas (P) are rare neural-crest-derived neoplasms. Very recently guidelines on diagnosis and treatment of PGL/P have been presented by the US Endocrine Society. In the following overview we assessed the implementation of these guidelines with probabilistic reasoning (calculating with Fagan nomograms the post-test probability of PGL/P for a given pre-test probability). CONCLUSION: Biochemical evaluation of PGL/P showed excellent diagnostic characteristics with post-test probabilities that are very different from the pre-test probabilities, thus a positive biochemical test is usually indicative of disease whereas a negative one usually rules out disease. The post-test probabilities of anatomical and functional imaging modalities (i.e. in nuclear medicine) were different from the pre-test probabilities but to a lesser degree than the biochemical tests; furthermore in biochemically-proven PGL/P a negative imaging modality is not useful, while a positive one may indicate only one of multiple foci of metastatic/extra-adrenal disease. Thus, regarding imaging modalities, they should be combined in order to get the most of their characteristics for the localization of PGL/P.

[Neurolymphomatosis presenting as bilateral tongue atrophy: a case report].

A 62-year-old woman had progressive dysarthria for 2 months and was suspected of having amyotrophic lateral sclerosis because of the presentation of bilateral tongue atrophy and fasciculation. Brain magnetic resonance imaging (MRI) showed enlargement of the left hypoglossal nerve, and whole-body gallium scintigraphy showed abnormal uptake in the left pelvic cavity and left thigh. On the basis of the findings of biopsy of the mass lesion in the left thigh, she was diagnosed with diffuse large B-cell lymphoma. After chemotherapy for diffuse large B-cell lymphoma, the tongue atrophy improved. The patient subsequently developed left oculomotor nerve palsy, weakness of the right arm, and weakness of the right leg. The cause of these symptoms was thought to be neurolymphomatosis on the basis of the typical MRI findings observed. We report a rare case of neurolymphomatosis presenting as bilateral tongue atrophy, mimicking amyotrophic lateral sclerosis.

18F-FDG PET/CT diagnosis of vagus nerve neurolymphomatosis.

A 62-year-old woman was in remission from previously treated stage IV diffuse large B-cell lymphoma with cranial involvement. She presented with new-onset hoarseness of voice and choking; MRI of the brain showed disease recurrence in the left cavernous sinus. She was subsequently referred for F-FDG PET/CT with contrast for further evaluation of lymphomatous recurrence. F-FDG PET/CT not only revealed hypermetabolic activity in the left cavernous sinus correlating to the MRI findings but also showed an interesting manifestation explaining the patient's hoarseness of voice, being neurolymphomatosis along the left vagus nerve.

Intra-operative localisation of spinal level using pre-operative CT-guided placement of a flexible hook-wire marker.

Confident intra-operative localisation of thoracic spinal pathology remains challenging. Several strategies are routinely employed, including intra-operative fluoroscopy and pre-operative image-guided skin marking. These techniques are limited both by potential inaccuracy and inconvenience. Here we present a novel, efficient and accurate technique for intra-operative localisation of thoracic spinal pathology using pre-operative CT-guided placement of a flexible hook-wire marker.

Benign posterior mediastinal neurogenic tumors: results of a comparative study into video-assisted thoracic surgery and thoracotomy (13 years' experience).

OBJECTIVE: Mediastinal neurogenic tumors originate from the nerve tissues of the thorax and are generally located in the posterior mediastinum. The present study was performed to compare the results of thoracotomy with those of video-assisted thoracic surgery (VATS) for the surgical treatment of posterior mediastinal neurogenic tumors. METHODS: Twenty patients who underwent surgical resection for posterior neurogenic tumors between January 1996 and January 2009 were examined retrospectively. Thirteen (65%) patients were treated by thoracotomy (group T) and VATS was used in seven (35%) patients (group V). RESULTS: The duration of surgery was shorter in group V (83.5 ± 19 min) than in group T (124.6 ± 16.6 min; P < 0.0001). Chest drains were withdrawn earlier in group V (after 1 day) than in group T (1.6 ± 0.5 days; P = 0.005). The hospital stay was shorter for group V (1 day) compared with group T (3 ± 0.9 days; P < 0.0001) and group V required fewer analgesics than group T (P < 0.0001). CONCLUSION: VATS is the preferred treatment for posterior neurogenic tumors that show no preoperative signs of malignancy and do not involve the medulla spinalis.

Sonography of the neck: current potentials and limitations.

For many clinical conditions, sonography is the first line imaging modality in the evaluation of cervical soft tissue lesions. Cervical cysts, lipomas, paragangliomas, neurogenic tumours, haemangiomas or lymphangiomas usually display a typical sonographic morphology. Sonography can be used for evaluation of soft tissue lesions and cervical lymph node assessment. Most of the afflictions of the salivary glands can be diagnosed sonographically. Sonography is also used for guided biopsy of lymph nodes, cervical soft tissue tumours or salivary gland lesions. The relationship of tumours or lymph nodes to the great cervical vessels can be evaluated. Colour Doppler can visualise the vascularisation of cervical soft tissue lesions, often narrowing down the differential diagnosis.

Differential diagnosis in patients with ring-like thallium-201 uptake in brain SPECT.

UNLABELLED: This study was performed to investigate lesions with ring-like thallium-201 (201Tl) uptake and to determine whether SPECT provides any information in differential diagnosis. METHODS: A total of 244 201Tl SPECT images were reviewed. In each study, early (15 min postinjection) and late (3 hr) brain SPECT images were obtained with 111 MBq of 201Tl. The early uptake ratio (ER; lesion to normal brain average count ratio) and the late uptake ratio (LR) and the L/E ratio (ratio of LR to ER) were calculated. RESULTS: Ring-like uptake was observed in pre-therapeutic 26 SPECT images, including ten glioblastoma multiformes (ER, 3.45 +/- 0.64; LR, 2.74 +/- 0.54; L/E ratio 0.80 +/- 0.13), five meningiomas (6.48 +/- 2.34; 4.41 +/- 1.41; 0.72 +/- 0.19), four metastatic lung cancers (3.47 +/- 1.23; 2.40 +/- 0.98; 0.70 +/- 0.14), four brain abscesses (2.48 +/- 1.06; 1.59 +/- 0.30; 0.78 +/- 0.15), one invasive lesion of squamous cell carcinoma from the ethmoid sinus (1.54; 1.52; 0.99), one medulloblastoma (3.53; 3.52; 1.00) and one hematoma (3.32; 2.36; 0.71). The ER of meningioma was significantly higher than those of glioblastoma multiforme (p < 0.0005), metastatic lung cancer (p < 0.005) and brain abscess (p < 0.0005). There were no significant differences among these three entities. The LR of meningioma was significantly higher than those of glioblastoma multiforme (p < 0.005), metastatic lung cancer (p < 0.005) and brain abscess (p < 0.0001). The LR of brain abscess was significantly lower than that of glioblastoma multiforme (p < 0.05). The L/E ratio could not differentiate these four entities. CONCLUSION: High ER and high LR in a lesion with ring-like uptake is likely an indicator of meningioma. The LR of brain abscess was significantly lower than that of glioblastoma multiforme, but 201T1 SPECT has still difficulty in differentiating abscess from brain tumor.

[Clinical applications of single photon emission tomography in neuromedicine. 1. Neuro-oncology, epilepsy, movement disorders, cerebrovascular disease]. / Klinische Anwendungen der Single-Photon-Emissionstomographie in der Neuromedizin. Teil 1: Neuroonkologie, Epilepsien, Basalganglienerkrankungen, zerebrovaskuläre Erkrankungen.

Single photon emission tomography is, because of its availability and the relatively low costs, the functional imaging modality currently most widely used for clinical applications in the brain. Beside the application of radiopharmaceuticals for the assessment of regional cerebral blood flow there is an increasing clinical use of more selective SPECT-radiopharmaceuticals, like amino acid analogs or receptor ligands. This article gives in his first part a critical review of the clinical applications of SPECT in neuro-oncology, epilepsy, basal ganglia disorders and cerebrovascular disease.

Sonographic appearances of nerve tumors.

This article reviews the clinical and sonographic features of neurilemoma, neurofibroma, intraneural ganglion, traumatic neuroma, and Morton's neuroma. The sonographic characteristics and location at typical sites are important diagnostic features for nerve tumors.

Tendon and nerve sonography.

The refinement of high frequency transducers has improved the ability of ultrasound (US) to detect fine textural abnormalities of tendons and nerves and to identify a variety of pathologic conditions. Characteristic echotextural patterns, closely resembling the histologic ones, are typically depicted in these structures using high US frequencies. In tendon imaging, US can identify tendon dislocations, degenerative changes, differentiate partial from complete tears and determine whether the patient has to be treated surgically or conservatively. A spectrum of findings in inflammatory conditions, including paratendonitis and tenosynovitis, and tendon tumors also can be detected. In nerve imaging, US can support clinical and electrophysiologic testing for detection of compressing lesions caused by nerve entrapment in a variety of osteofibrous tunnels of the limbs and extremities. Nerve tears and tumors also can be diagnosed. Overall, US is an effective technique for imaging tendons and nerves.

Imaging of perineural tumor spread in head and neck cancer.

Perineural spread (PNS) of head and neck tumors is a well-described phenomenon whereby a lesion can migrate away from the primary site along the neural sheath. By this mechanism, tumor can spread a considerable distance and compromise vital neurologic structures, with significant impact on treatment and prognosis. It is crucial that radiologists search for PNS whenever imaging the head and neck cancer patient. Detection of PNS requires familiarity with common tumor types and locations that can give rise to it, an understanding of the relevant cranial nerve anatomy, and an awareness of the radiologic appearance and techniques best suited to imaging this important and often overlooked complication of head and neck cancer.

Spectrum of neurogenic tumors in the thorax: CT and pathologic findings.

Neurilemomas and neurofibromas appear as round soft tissue masses at CT. Variable enhancement with either homogeneity or heterogeneity is seen in neurilemomas. Attenuation of the tumors on enhanced CT depends on histology: the extent of Antoni A or B tissue and the amount of myxoid or cystic degeneration or hemorrhage. Neurofibromas are usually homogeneous low attenuation lesions on unenhanced CT. They show homogeneous enhancement or early central blush on enhanced scan. The extent of enhancement depends on the proportions of tumor components: nerve sheath cells, collagen bundles, and areas of myxoid degeneration. Malignant nerve sheath tumors show variable attenuation. Bony destruction, pleural effusion, and metastatic pulmonary nodules may also occur. Ganglioneuromas appear as oblong homogeneous low attenuation lesions on both enhanced and unenhanced CT. This low attenuation is due to their pathologic components, with an abundant amount of myxoid matrices and a relatively small amount of ganglion cells. Neuroblastomas appear as aggressive soft tissue lesions with calcification. Ganglioneuroblastomas may appear with features in between those of ganglioneuromas and neuroblastomas. The typical location of the posterior mediastinum or the aortopulmonary window and high enhancement with administration of contrast medium at CT suggest the diagnosis of paragangliomas.