Intravoxel Incoherent Motion and Dynamic Contrast-Enhanced Magnetic Resonance Imaging Can Differentiate Between Atypical Cartilaginous Tumors and High-Grade Chondrosarcoma: Correlation With Histological Vessel Characteristics.

OBJECTIVE: To differentiate between atypical cartilaginous tumors and high-grade chondrosarcoma of the major long bones using intravoxel incoherent motion (IVIM) and Dynamic Contrast-Enhanced magnetic resonance imaging (DCE-MRI), and explore the correlation of quantitative parameters with hypoxia inducible factor-1α (HIF-1α), vascular endothelial growth factor (VEGF) and microvessel density (MVD). METHOD: Between September 2016 and March 2022, 35 patients (17 atypical cartilaginous tumors, 18 high-grade chondrosarcoma) underwent MRI examination and pathological confirmation at our hospital. First, IVIM-derived parameters ( D , D* , and f ), and DCE-MRI parameters ( Ktrans , Kep , and V e ) were measured, and intraclass correlation efficient (ICC) and Mann-Whitney U test were performed. Second, receiver-operating characteristic curve analysis was performed to evaluate the diagnostic performance. Finally, Spearman's correlation analysis was performed between the quantitative parameters of IVIM-DWI and DCE-MRI and the immunohistochemical factors HIF-1α, VEGF, and MVD in chondrosarcoma tissue. RESULTS: D in atypical cartilaginous tumors was significantly higher than that in high-grade chondrosarcoma ( P = 0.003), whereas D* , Ktrans , and K ep in atypical cartilaginous tumors were significantly lower than those in high-grade chondrosarcoma (all P < 0.001). Ktrans demonstrated the highest area under the curve (AUC) of 0.979. The D* , Ktrans , and K ep were positively correlated with HIF-1α, VEGF, and MVD (all P < 0.001), whereas D had no correlation with HIF-1α, VEGF, and MVD ( P = 0.113, 0.077, 0.058, respectively). CONCLUSION: The IVIM-DWI quantitative parameters ( D , D* ) and DCE-MRI quantitative parameters ( Ktrans , Kep ) are helpful to differentiate between atypical cartilaginous tumors and high-grade chondrosarcoma and could be imaging biomarkers to reflect the expressions of HIF-1α, VEGF, and angiogenesis of chondrosarcoma.

Prognostic Factors and Surgical Impact of Non-metastatic Conventional Chondrosarcoma of the Extremities.

OBJECTIVE: Chondrosarcoma is a common bone malignancy, and the main treatment method is surgery. Different surgeries lead to different survival outcomes. The aim of this study was to construct a new clinical predictive tool to accurately predict the overall survival (OS) and cause specific survival (CSS) of patients with chondrosarcoma receiving different treatments. METHODS: A total of 620 patients with chondrosarcoma registered between January 1, 2000 and December 31, 2016 were recruited as study targets. The missing values are filled by multiple imputation. Two continuous variables, age and tumor size, were divided into binary variables based on Kaplan-Meier curve. Univariate and multivariate analyses were used to explore predictors and establish nomograms. Propensity score matching (PSM) analysis was used to reduce the impact of potential confounders to determine whether different surgical modalities had any survival benefits in subgroups. RESULTS: In a multivariate cox regression, age, grade, tumor size, radiotherapy, chemotherapy, and surgical methods were identified as independent prognostic factors for chondrosarcoma. To construct 1-, 3-, and 5-year nomogram maps of OS and CSS with prognostic factors and verify the c index internally (OS, 0.807; CSS, 0.847) above American Joint Committee on Cancer (AJCC) (OS, 0.685; CSS, 0.732). CONCLUSION: This study found that the 5 year overall survival rate of patients with non-metastatic chondrosarcoma of the extremities was about 80%. Age, high malignancy, large tumor, prior chemoradiotherapy, and poor surgical selection were independent risk factors. Therefore, the nomogram established in this study will help to optimize clinicians' personalized decision making for patients.

Genetic and functional analyses detect an EXT1 splicing pathogenic variant in a Chinese hereditary multiple exostosis (HME) family.

BACKGROUND: Hereditary multiple exostosis (HME) is an autosomal dominant skeletal disorder characterized by the development of multiple cartilage-covered tumors on the external surfaces of bones (osteochondromas). Most of HME cases result from heterozygous loss-of-function mutations in EXT1 or EXT2 gene. METHODS: Clinical examination was performed to diagnose the patients: Whole exome sequencing (WES) was used to identify pathogenic mutations in the proband, which is confirmed by Sanger sequencing and co-segregation analysis: qRT-PCR was performed to identify the mRNA expression level of EXT1 in patient peripheral blood samples: minigene splicing assay was performed to mimic the splicing process of EXT1 variants in vitro. RESULTS: We evaluated the pathogenicity of EXT1 c.1056 + 1G > T in a Chinese family with HME. The clinical, phenotypic, and genetic characterization of patients in this family were described. The variant was detected by whole-exome sequencing (WES) and confirmed by Sanger sequencing. Sequencing of the RT-PCR products from the patient's blood sample identified a large deletion (94 nucleotides), which is the whole exome 2 of the EXT1 cDNA. Splicing assay indicated that the mutated minigene produced alternatively spliced transcripts, which cause a frameshift resulting in an early termination of protein expression. CONCLUSIONS: Our study establishes the pathogenesis of the splicing mutation EXT1 c.1056 + 1G > T to HME and provides scientific foundation for accurate diagnosis and precise medical intervention for HME.

A Preliminary Study on a Novel Growth Guidance Rod System for Early-Onset Scoliosis in a Sheep Model.

STUDY DESIGN: An animal study with immature sheep to evaluate the effects of a multisegment growth guidance rod (MSGGR) on spine growth. OBJECTIVE: To determine whether the spine of the immature sheep can still grow after MSGGR fixation. SUMMARY OF BACKGROUND DATA: The disadvantages for current growing rod techniques are that they can partially correct only the spinal curve and have little control to the apex of the curve. The rigidity of the spine after a growing rod procedure may also interfere with the final correction. Current systems are complex and not always affordable, especially in the developing world. Newer, more inexpensive techniques that provide 3-dimensional deformity correction while allowing normal spinal growth without surgical lengthening are still desired. METHODS: The MSGGR is a rod consisting of segments. Spinal deformation in scoliosis is corrected and maintained by the rods without fusion. The system allows the growth of the fixed spinal segments. It is stable when twisted and bent but extendable when stretched. Rod extension occurs through sliding between the segments along the sockets in accordance to the growth of the spine. Ten 3-month-old immature sheep were used in this study. Dual MSGGRs were implanted to fix the lumber and low thoracic spine. Radiographs, magnetic resonance image, and computed tomographic scan of the spine were obtained to evaluate the fixation, rod extension, and spine health. RESULTS: All of the sheep spines grew with the implants in position. The spine segments within the instruments were 12.5 ± 0.8 cm and grew by 10.9% (range: 6%-18.4%) from their original length in 4 months. None of the implants failed. No MSGGR-related complications were observed. Magnetic resonance imaging showed normal disc within the instrumented segments. Motion of the instrumented spinal segments was conserved. CONCLUSION: Growth guidance with this novel MSGGR allowed for continued growth in this sheep model, and repeated surgical lengthening of the system is not needed. LEVEL OF EVIDENCE: N/A.

Preoperative evaluation of venous systems with computed tomography venography in parasagittal meningiomas.

OBJECTIVE: Parasagittal meningiomas (PSM) may pose a difficult surgical challenge because venous patency and collateral anastomoses have to be clearly defined for correct surgical planning. The aim of this study was to study the diagnostic accuracy of computed tomography venography (CTV) in assessing the superior sagittal sinus (SSS) obstruction and venous collaterals. METHODS: Twenty-four patients undergoing surgery for meningiomas located adjacent to the SSS were prospectively evaluated. All the patients underwent both conventional computed tomography examination and CTV. Computed tomography venography was evaluated by 2 expert neuroradiologists to assess (1) patency of the sinus (patent/occluded), (2) the extent of occlusion (in centimeters), and (3) the number of collateral anastomoses close to the insertion of the meningioma. Computed tomography venography assessment was compared with surgery. All patients were operated on, and intraoperative findings were taken as the criterion standard. RESULTS: Computed tomography venography showed the sinus to be occluded in 6 cases. Computed tomography venography data were confirmed by surgery, showing 6 patients to have have an occlusion of the SSS. The CTV sensitivity was thus 100%. Computed tomography venography depicted 83% of collateral venous anastomoses close to the meningioma as subsequently confirmed by surgery. CONCLUSIONS: In the preoperative planning for patients with meningiomas located close to the SSS, CTV can provide additional and more reliable information concerning venous infiltration and the presence of collateral anastomoses compared with noncontrast computed tomography.