Intraoperative 3 T MRI is more correlative to residual disease extent than early postoperative MRI.

PURPOSE: Extent of resection of low grade glioma (LGG) is an important prognostic variable, and may influence decisions regarding adjuvant therapy in certain patient populations. Immediate postoperative magnetic resonance image (MRI) is the mainstay for assessing residual tumor. However, previous studies have suggested that early postoperative MRI fluid-attenuated inversion recovery (FLAIR) (within 48 h) may overestimate residual tumor volume in LGG. Intraoperative magnetic resonance imaging (iMRI) without subsequent resection may more accurately assess residual tumor. Consistency in MRI techniques and utilization of higher magnet strengths may further improve both comparisons between MRI studies performed at different time points as well as the specificity of MRI findings to identify residual tumor. To evaluate the utility of 3 T iMRI in the imaging of LGG, we volumetrically analyzed intraoperative, early, and late (~ 3 months after surgery) postoperative MRIs after resection of LGG. METHODS: A total of 32 patients with LGG were assessed retrospectively. Residual tumor was defined as hyperintense T2 signal on FLAIR. Volumetric assessment was performed with intraoperative, early, and late postoperative FLAIR via TeraRecon iNtuition. RESULTS: Perilesional FLAIR parenchymal abnormality volumes were significantly different comparing intraoperative and early postoperative MRI (2.17 ± 0.45 cm3 vs. 5.47 ± 1.07 cm3, respectively (p = 0.0002)). A significant difference of perilesional FLAIR parenchymal abnormality volumes was also found comparing early and late postoperative MRI (5.47 ± 1.07 cm3 vs. 3.22 ± 0.64 cm3, respectively (p = 0.0001)). There was no significant difference between intraoperative and late postoperative Perilesional FLAIR parenchymal abnormality volumes. CONCLUSIONS: Intraoperative 3 T MRI without further resection appears to better reflect the volume of residual tumor in LGG compared with early postoperative 3 T MRI. Early postoperative MRI may overestimate residual tumor. As such, intraoperative MRI performed after completion of tumor resection may be more useful for making decisions regarding adjuvant therapy.

Automated Brain Metastases Detection Framework for T1-Weighted Contrast-Enhanced 3D MRI.

Brain Metastases (BM) complicate 20-40% of cancer cases. BM lesions can present as punctate (1 mm) foci, requiring high-precision Magnetic Resonance Imaging (MRI) in order to prevent inadequate or delayed BM treatment. However, BM lesion detection remains challenging partly due to their structural similarities to normal structures (e.g., vasculature). We propose a BM-detection framework using a single-sequence gadolinium-enhanced T1-weighted 3D MRI dataset. The framework focuses on the detection of smaller (<15 mm) BM lesions and consists of: (1) candidate-selection stage, using Laplacian of Gaussian approach for highlighting parts of an MRI volume holding higher BM occurrence probabilities, and (2) detection stage that iteratively processes cropped region-of-interest volumes centered by candidates using a custom-built 3D convolutional neural network ("CropNet"). Data is augmented extensively during training via a pipeline consisting of random ga mma correction and elastic deformation stages; the framework thereby maintains its invariance for a plausible range of BM shape and intensity representations. This approach is tested using five-fold cross-validation on 217 datasets from 158 patients, with training and testing groups randomized per patient to eliminate learning bias. The BM database included lesions with a mean diameter of ∼5.4 mm and a mean volume of ∼160 mm3. For 90% BM-detection sensitivity, the framework produced on average 9.12 false-positive BM detections per patient (standard deviation of 3.49); for 85% sensitivity, the average number of false-positives declined to 5.85. Comparative analysis showed that the framework produces comparable BM-detection accuracy with the state-of-art approaches validated for significantly larger lesions.

Metastasis development at the site of cervical spine arthrodesis.

Biologically, the site of arthrodesis provides a microenvironment replete of growth factors and active remodeling, which is propitious for bone regrowth. There is a theoretical possibility though that this microenvironment would also provide a fertile site for metastatic deposits to occur. Although spinal fusion with various types of instrumentation is commonly used to treat various disorders, development of tumors at the site of spinal arthrodesis has not been previously reported. We present the clinical, radiographic, and pathological features of a case of previously undiagnosed metastatic adenocarcinoma, occurring 1 year following anterior arthrodesis and fusion for cervical spondylotic myelopathy at the C3-C4 level. The patient's initial radiologic presentation suggested an epidural abscess with osteomyelitic destruction of C3 and C4. Our report alerts surgeons to the possibility that metastasis may occur at the site of a previous spinal arthrodesis.

Reversal of neurological deficit after chemotherapy in BCL-6-positive neurolymphomatosis. Case report.

Neurolymphomatosis, the infiltration of the peripheral nervous system (PNS) by malignant lymphatic cells, is a rare condition whose prognosis and treatment are not fully characterized. The authors report the case of a 69-year-old, previously healthy man who had a 1-month history of progressive pain in his right arm and associated weakness of several muscles of the right upper extremity when they first examined him. Initial MR imaging of the right brachial plexus showed no abnormalities, but over 3 months, symptoms gradually progressed to almost complete plegia of his right upper extremity. Subsequent MR imaging of his right brachial plexus showed an enhancing mass of the posterior cord of the plexus that encroached on the other cords. Positron emission tomography confirmed the presence of a hypermetabolic lesion in the right axillary region and also detected an asymptomatic hot spot in the gastric wall. Biopsy of the gastric lesion demonstrated a CD20+, diffuse large B-cell lymphoma that was immunohistochemically positive for BCL-6 and negative for p16. The patient underwent 6 cycles of dose-adjusted etoposide-vincristine-doxorubicin-cyclophosphamide-prednisone (EPOCH) and rituximab, intermixed with 3 cycles of high-dose intravenous and intrathecal methotrexate, and followed by 6 monthly doses of rituximab for consolidation. Follow-up MR imaging and PET of the plexus showed complete radiological response after 3 months of treatment, as demonstrated by normalization of brachial plexus caliber, contrast enhancement, and metabolic activity. Twenty-eight months after symptom onset and 20 months after beginning therapy, the patient was disease-free, had recovered most upper extremity neurological function, and had only minimal remaining weakness of the right wrist and finger extension.

Merged imaging and expanded target selection in gamma knife radiosurgical ablation of the sphenopalatine ganglion.

Sphenopalatine neuralgia, or Sluder's neuralgia, refers to a consistent clustering of clinical symptoms: intermittent episodes of vasomotor hyperactivity causing conjuctival injection, lacrimation, serous nasal discharge and unilateral nasal mucosal inflammation, sensory disturbances of the palate and oropharynx with distorted gustatory sensations, and lancing, unilateral pain most often located in the area of the inferomedial orbit and nasal base or at the region of the mastoid process. This particular clinical entity has also proven difficult to manage effectively, especially when not clearly secondary to other medical conditions such as paranasal sinus infection or bony nasal deformities. This condition has been treated with success using Gamma Knife radiosurgery in at least 1 other case reported in the literature. We present a second patient whose sphenopalatine neuralgia was treated successfully with stereotactic radiosurgery and discuss the possibilities of this modality as an option for patients with a refractory condition.

Intra-arterial carboplatin and intravenous etoposide for the treatment of metastatic brain tumors.

Metastatic brain tumors (MBT) are the most frequent complication of systemic cancer and often respond poorly to treatment. Median survival is only 16-24 weeks after conventional radiation therapy. Regional intra-arterial (IA) administration of chemotherapy results in increased tumor uptake of drug and may improve response rates and survival. Twenty-seven patients with MBT who had received prior irradiation were treated with IA carboplatin (200 mg/m2/d) and intravenous (i.v.) etoposide (100 mg/m2/d) for 2 days every 3-4 weeks. Eighteen patients (67%) had received prior systemic chemotherapy for their primary tumor. Patients ranged in age from 19 to 68 years (mean 48.1). Thirteen of 24 evaluable patients had objective responses (54.2%). There were 6 complete responses (25%), 6 partial responses (25%), 1 minor response (4.2%), 7 stable disease (32%), and 5 progressive disease (20.8%). Some patients with multifocal tumors had a mixture of responses. The median time to progression was 16.0 weeks overall and 30.0 weeks in responders (range 6-118 weeks). Overall median survival from the time of protocol initiation was 20.0 weeks. In six responders, death occurred due to systemic illness unrelated to MBT progression. Therapy was well tolerated, with predominantly hematologic toxicity. Angiographic complications were rare. Although these are preliminary results, IA carboplatin and IV etoposide is safe and well tolerated, appears to be active against brain metastases, and warrants further study.

Real-time CT-guided spinal biopsy with a disposable stereotactic device: a technical note.

We compared eight spinal needle biopsy procedures performed with an investigational disposable real-time stereotactic device and eight spinal needle freehand biopsies in which a standard technique was used, to determine whether the investigational device added value to the procedure. The device uses a simple stereotactic diaphragm pattern to define two vector points. The procedures in which the device was used were completed in 38% less time, using 50% fewer images, with considerably improved spatial accuracy and increased operator confidence, despite the device learning curve.