Spine

BACKGROUND: Vertebral discitis-osteomyelitis (VDO) is a devastating infection of the spine that is challenging to distinguish from noninfectious mimics using computed tomography and magnetic resonance imaging. We and others have developed novel metabolism-targeted positron emission tomography (PET) radiotracers for detecting living Staphylococcus aureus and other bacteria in vivo, but their head-to-head performance in a well-validated VDO animal model has not been reported. METHODS: We compared the performance of several PET radiotracers in a rat model of VDO...

Introduction: Despite the wide availability of clinical decision rules for imaging of the cervical spine after a traumatic injury (eg, NEXUS C-spine rule and Canadian C-spine rule), there is significant overutilization of computed tomography (CT) imaging in patients who are deemed to be at low risk for a clinically significant cervical spine injury by these clinical decision rules. The purpose of this study was to identify the major factors associated with the overuse of CT cervical spine imaging using a logistic regression model...

Pollen morphology varies at inter- and intraspecific levels. Its interaction with pollinator behavior and morphology determines the probability of successful pollination. We tested whether pollen morphology promoting successful pollination differs depending on pollinator taxa in a generalist shrub, Weigela hortensis (Caprifoliaceae). We identified flower visitors carrying pollen from anthers to stigmas and compared the spine length and diameter of the pollen grains they carried. We found that pollen on the bodies of bumble bees and hunch-back flies and the scopae of small bees (including andrenid bees) contributed to seed production...

PURPOSE: To develop a deep learning-based cascaded HRNet model, in order to automatically measure X-ray imaging parameters of lumbar sagittal curvature and to evaluate its prediction performance. METHODS: A total of 3730 lumbar lateral digital radiography (DR) images were collected from picture archiving and communication system (PACS). Among them, 3150 images were randomly selected as the training dataset and validation dataset, and 580 images as the test dataset...

BACKGROUND: Automatic segmentation has emerged as a promising technique for the diagnosis of spinal conditions. PURPOSE: To design and evaluate a deep convolution network for segmenting the intervertebral disc, spinal canal, facet joint, and herniated disk on magnetic resonance imaging (MRI) scans. MATERIAL AND METHODS: MRI scans of 70 patients with disc herniation were gathered and manually annotated by radiologists. A novel deep neural network was developed, comprising 3D squeeze-and-excitation blocks and multi-scale feature extraction blocks for automated segmentation of spinal structure and lesion...

Magnetic resonance imaging (MRI) is the most sensitive and specific imaging method for the detection of advanced spinal infections. However, the differential diagnosis of early spinal infection and Modic type I degenerative changes based on conventional MRI is difficult clinically, as they both may mimic each other by showing hypointensity on T1-weighted images and hyperintensity on T2-weighted spine MRI images. This review summarizes recent advancements in MRI, which may be useful in discriminating degenerative Modic type I endplate changes from early spinal infection, and evaluates the diagnostic accuracy and limitations of MRI...

Alkaptonuria is a rare autosomal recessive trait. Symptomatic lumbar disc herniation warranting surgical intervention is a rare scenario in alkaptonuria and only a few cases have been described in the literature. We present one such rare case of alkaptonuria in a 31-year-old female presenting with low back pain and left leg radiculopathy not relieved with conservative management. Roentgenograms of the lumbar spine revealed wafer-like disc calcifications and MRI showed a herniated disc at the L4-L5 level with deeply hypointense disc spaces in T2 suggestive of disc calcification and associated modic type 2 changes...

Alterations in SATB2 result in SATB2-associated syndrome (SAS; Glass syndrome, OMIM 612313), an autosomal dominant multisystemic disorder predominantly characterized by developmental delay, craniofacial anomalies, and growth retardation. The bone phenotype of SAS has been less explored until recently and includes a variety of skeletal deformities, increased risk of low bone mineral density (BMD) with a propensity to fractures, and other biochemical abnormalities that suggest elevated bone turnover. We present the results of ongoing surveillance of bone health from 32 individuals (47% females, 3-18 years) with molecularly-confirmed SAS evaluated at a multidisciplinary clinic...

PURPOSE/OBJECTIVE(S): Maintaining hydrostatic pressure -via Pascal's Principle- between vertebral bodies is essential to decrease the chance of vertebral compression fracture (VCF). Vertebral endplates (EP) play an essential role in this matter through maintaining the mechanical environment as well as the proper nutrition of avascular discs. The purpose of this study is to establish the correlation of VCF with disrupted EP by tumor involvement. MATERIALS/METHODS: A retrospective analysis of de novo spine metastases treated with stereotactic body radiotherapy (SBRT) between 2013-2019...

PURPOSE/OBJECTIVE(S): Spine stereotactic radiosurgery (SSRS) is effective in achieving durable local control (LC) and palliation of pain in patients with spinal metastases. Per institutional standards, SSRS prescription dose is tailored by primary site histology, with radioresistant disease receiving escalated doses. While the association between tumor histology and radioresistance is well studied, the association between specific genotypic mutations and radioresistance to SSRS is not well known...

PURPOSE/OBJECTIVE(S): A recent phase 2 study reported a significant difference in Bilsky grading of treated lesions before and after SBRT. This study reports rates of epidural downgrading following spine SBRT in a larger cohort of patients with high grade epidural disease. MATERIALS/METHODS: Patients with high grade epidural disease from solid spinal metastases treated with SBRT from 2009-2021 were retrospectively reviewed. High grade epidural disease was defined as Bilsky grade 1c-3 for lesions above the conus...

PURPOSE/OBJECTIVE(S): Spine stereotactic body radiotherapy (SBRT) results in improved local control and pain response compared to conventional external beam radiotherapy. Consensus stipulates MRI-based delineation of the clinical target volume (CTV) is critical and is based on spine segment sector involvement. The applicability of these contouring guidelines to metastases confined to the posterior elements is unknown. The purpose of this study was to determine the patterns of failure, as well as the safety of treating posterior element metastases when the vertebral body was intentionally excluded from the CTV...

PURPOSE/OBJECTIVE(S): As systemic therapies improve significantly, more patients with limited metastatic disease are undergoing spine stereotactic radiosurgery (sSRS). High dose (≥24 Gy) single fraction sSRS has been associated with a vertebral compression fracture (VCF) risk of up to 40%. Comparatively, lower dose (16-18 Gy) single fraction sSRS is associated with a fracture risk of 15-20%, with the risk increasing as the dose increases. To mitigate the risk of VCF, while optimizing higher dose delivery, some have advocated utilizing two-fraction sSRS regimen...

PURPOSE/OBJECTIVE(S): The vertebral bodies contain approximately 20-25% of all bone marrow in the body. Lymphopenia is a known negative prognostic factor in thoracic malignancies. Studies have previously demonstrated that patients receiving radiation to the lumbar spine and/or pelvis have shown increased fat deposition/bone marrow scarring following therapy, which leads to long term immunosuppressive effects. In anticipation for an open clinical trial, and based on previously published work, we explored whether retrospectively constraining the thoracic bone marrow is practically feasible and leads to minimal increase in dose to the remaining OARs (Organs at Risk)...

PURPOSE/OBJECTIVE(S): SBRT is highly effective against early-stage non-small cell lung cancer. Radiation Therapy (RT) is known to modulate the immune system and contribute to the generation of anti-tumor T cells and stimulate T cell infiltration into tumors. However, this anti-tumor activity is offset by radiation-induced immunosuppression (RIIS) which results in lower tumor control and survival. Lymphocytes are highly radiosensitive and RIIS means destroying existing as well as newly created cytotoxic and helper T lymphocytes...

PURPOSE/OBJECTIVE(S): Stereotactic body radiotherapy treatment (SBRT) is an effective modality for treating primary and oligometastatic malignant lesions. Appropriate planning target volume (PTV) margins are essential when delivering SBRT to maximize target prescription coverage while minimizing dose to surrounding organs-at-risk. Spine tracking uses boney spinal anatomy as a surrogate for tumor localization during treatment delivery on robotic linear accelerator platforms that employ intrafraction kV x-ray imaging...

PURPOSE/OBJECTIVE(S): To investigate the feasibility of a novel, streamlined radiotherapy treatment workflow in which simulation and treatment occur in a single on-table session. The efficiency, dosimetric accuracy, plan quality, and resource requirements were metrics used to evaluate the clinical potential of CT simulation-free radiotherapy. MATERIALS/METHODS: An adaptive radiotherapy treatment platform was upgraded to include a novel CBCT system reporting image quality and Hounsfield unit accuracy specifications comparable to standard fan-beam CT...

PURPOSE/OBJECTIVE(S): To describe the feasibility of treating a complex and diverse group of patients using pencil beam scanning (PBS) proton stereotactic body radiation therapy (SBRT: 5 or fewer fractions, with a fraction size of at least 5 Gy). MATERIALS/METHODS: Our center treats on average 105-120 PBS proton treatments daily, of which 9.5% of treatment courses are proton SBRT. Statistics of disease sites, treatment planning parameters (target volume, prescriptions, number of fields, SFO vs...

PURPOSE/OBJECTIVE(S): Acquiring MR images with minimized susceptibility artifacts is essential for spines with medical hardware to delineate clinical target volumes (CTVs) in radiation therapy for chordomas, chondrosarcomas, and other sarcomas. Since it can be more challenging to visualize the primary structures in high-tesla MR images due to metal-induced artifacts, we optimized imaging parameters to acquire high-quality, low-tesla MR images for clinical use. MATERIALS/METHODS: OptimalMR imaging parameters were investigated under general guidelines for artifact reduction techniques by testing several 3D spin echo and gradient echo sequences in a 0...

PURPOSE/OBJECTIVE(S): The aim of this study was to assess the feasibility of real-time motion tracking of the spinal cord using 2D-cine MRI on the MR-Linac system. Spinal SBRT delivers high-precision doses to targets near the spinal cord but with the dosimetric cord tolerance sometimes defined using a spinal cord PRV and the treatment alignment visualizing a surrogate measure (spinal canal) with cone beam CT guidance. MR-guided spine SBRT enables clear visualization of the true spinal cord and real-time monitoring of the cord during treatment, which may allow for increased cord dose constraints and offer new treatment options for patients with epidural disease...