Preoperative T1 Research Articles

Residual T1 tilt could lead to poor self-image for patients with Lenke type 1 adolescent idiopathic scoliosis.

Retrospective study. We aimed to investigate the clinical impact and risk factors for residual T1 tilt in patients with adolescent idiopathic scoliosis (AIS). We retrospectively analyzed data of patients with AIS and Lenke type 1 curves who underwent posterior fusion. Residual T1 tilt was defined as T1 tilt > 5° at 2years postoperatively. Patients were classified based on the presence of residual T1 tilt: residual T1 tilt ( +) and residual T1 tilt (-) groups. Radiographic parameters and clinical outcomes were compared between the two groups. Among 128 patients, 44 (34.4%) had residual T1 tilt. The residual T1 tilt ( +) group had a significantly greater preoperative proximal thoracic (PT) curve, greater preoperative T1 tilt, and main thoracic (MT) curve correction rate than the residual T1 tilt (-) group. Shoulder imbalance and neck tilt rates at 2years postoperatively were significantly higher in the residual T1 tilt ( +) group. The residual T1 tilt ( +) group had a significantly worse postoperative self-image score. Multivariate analysis identified the preoperative PT curve magnitude as an independent risk factor for residual T1 tilt. Receiver operating characteristic curve analysis identified a preoperative PT curve cutoff value of 26.5°. Achieving horizontalization of T1 tilt is vital to improve the self-image of patients with Lenke type 1 AIS. The study highlights the clinical impact of T1 tilt and identifies the preoperative PT curve magnitude as a significant independent risk factor. Level 4.

Preoperative quantitative imaging use in predicting intraoperative decision for hip labral repair versus reconstruction

Abstract Intraoperative assessment of labral quality determines arthroscopic repair versus reconstruction for hip labral tear treatment. T2 mapping technology discriminates between healthy and damaged cartilage. This study investigated if T2 mapping magnetic resonance imaging (MRI) can preoperatively predict labral repair versus reconstruction. This retrospective comparative study included patients with preoperative T2 mapping MRI who underwent hip labral repair or reconstruction at a single institution between March 2021 and February 2023. Three reviewers using Syngo.via recorded average T2 mapping values for the labrum, acetabular cartilage, and femoral cartilage on patients’ sagittal cut. Intraclass correlation values estimated rater agreement of T2 values. T2 means were compared using t-tests. Three Bayesian regression models were created, separately analyzing the labrum, acetabular cartilage, and femoral cartilage mapping values. The 95% credible intervals determined the significance of regression coefficients. A total of 63 operations were included: 14 reconstructions and 49 repairs. Participants were 14- to 50-years-old, with 35 females and 28 males. There was excellent agreement among raters for T2 measurements. There was no significant difference in average T2 values between the repair and reconstruction groups. All three models showed that the odds of labral reconstruction were negatively associated with T2 mapping values, positively associated with age, and increased in males. Preoperative T2 mapping values from the labrum, acetabular, and femoral cartilage are negatively associated with the odds of needing a labral reconstruction. Increased age and being male are associated with increased odds of needing a labral reconstruction. This study will allow further evaluation into other variables that predict labral repair versus reconstruction.

NIMG-82. DEVELOPMENT AND VALIDATION OF AN MRI-BASED DEEP LEARNING MODEL TO DIFFERENTIATEIDH-WILDTYPE GLIOBLASTOMA AND TUMEFACTIVE MULTIPLE SCLEROSIS

Abstract Clinical management of IDH wildtype glioblastoma (GBM) and tumefactive multiple sclerosis (tMS) is drastically different. GBM requires maximal safe resection followed by chemoradiation, while tMS outcome is worsened by surgery and radiotherapy. Noninvasive methods are needed to help with accurate diagnosis of tumor and non-tumor etiologies. To develop an MRI-based classification model, tMS subjects diagnosed prior to January 1, 2020, were matched to tMS by age at diagnosis, sex, index MRI date, and 2D/3D acquisition. Inclusion criteria included one cm minimal lesion size and pre-operative post-contrast T1 and T2 images available for analysis. A 3D-DenseNet121 was used to develop a classification model using prespecified parameters: 650 epochs, batch size 16, learning rate 10-3, cross-entropy loss, and AdamW optimizer. The stopping rule was defined as three sequential differences in epoch cross-entropy loss <0.02. Models were developed using both T1gd and T2, as well as from only T1gd and only T2. Training included 220 subjects (110 GBM, 110 tMS). A 2-stage validation design was used, which included both retrospective and prospective cohorts. Stage 1 consisted of 272 retrospective GBM (diagnosed prior to January 1, 2020). Stage 2 consisted of 69 and 34 prospective (diagnosed after January 1, 2020) GBM and tMS, respectively. External validation on the 272 retrospective GBM demonstrated accuracy of 91%, 84%, and 78% for T1gd+T2, T1gd only, and T2 only, respectively. External validation on the 69 prospective GBM demonstrated an accuracy of 87%, 64%, and 67% for T1gd+T2, T1gd only, and T2 only, respectively. The 34 prospective tMS demonstrated accuracy of 76%, 76%, and 82% for T1gd+T2, T1gd only, and T2 only, respectively. This shows the feasibility of deep learning to aid in differential diagnosis of brain lesions. Future work entails the integration of germline variants into the classification model, including variants associated with the risk of glioma or MS.

RADT-38. CLINICAL, MOLECULAR AND IMAGING FEATURES ASSOCIATED WITH LONG TERM SURVIVAL IN GLIOBLASTOMA PATIENTS

Abstract INTRODUCTION Glioblastoma (GBM) is the most common malignant brain tumor in adults and has poor prognosis despite standard of care treatment. Nevertheless, certain patients surpass survival expectations. This study seeks to identify the clinical, molecular, and imaging characteristics of GBM associated with extended patient survival. METHODS In this retrospective cohort study, we examined records of adult GBM patients (WHO 2016 classification) treated at Thomas Jefferson University Hospital from 2010 to 2023. Exclusion criteria included a preoperative Karnofsky Performance Status (KPS) below 60 and treatment with hypo-fractionated radiation therapy. Patients were categorized into two groups: short-term survivors (STS), who survived less than 36 months from diagnosis, and long-term survivors (LTS), who survived more than 36 months. We reviewed patient charts and pathology reports for comprehensive clinical and molecular data. For radiomics analysis, tumor segmentation was performed using CaPTk software on the initial diagnostic MRI (T1 pre and post-contrast, FLAIR and T2 sequences). The relationship between overall survival of more than three years was analyzed with univariable logistic models for potential predictors using R statistical software. RESULTS Of the cohort of 210 patients, 37 (17.6%) survived beyond three years. The median age at diagnosis was 55 years (range; 29-79) Twenty-two patients were male and 15 were female. Twenty-two percent had IDH mutation and 65% had MGMT methylation. Factors associated with long-term survival included younger age at diagnosis (p =0.007), MGMT hypermethylation (p =0.019), IDH mutation (p=0.001), absence of TERT mutation (p = 0.002), higher average number of adjuvant temozolomide cycles (10 vs. 5; p = 0.005), and smaller volume of enhancing tumor on T1 post-contrast imaging segmentation (p=0.022). But there was no significant difference in FLAIR abnormality or necrotic core volumes between the groups. CONCLUSION In our cohort of GBM patients, patients diagnosed at a younger age, MGMT hypermethylation, IDH mutation, absence of TERT mutation, receiving more cycles of adjuvant temozolomide treatment, and smaller enhancing tumor volume on preoperative T1 post-contrast imaging were associated with longer survival. Future research involving larger cohorts and validation of our findings is needed.

Habitat-based CT radiomics enhances the ability to predict spread through air spaces in stage T1 invasive lung adenocarcinoma.

Spread through air spaces (STAS) represents a novel invasive pattern in lung adenocarcinoma (LUAD) and is a risk factor for poor prognosis in stage T1 LUAD. This study aims to develop and validate a CT habitat imaging analysis model for predicting STAS in stage T1 invasive LUAD. We retrospectively analyzed 217 patients with preoperative stage T1 invasive LUAD (115 STAS-positive and 102 STAS-negative cases, including 151 in the train set and 66 in the test set). Semi-automatic segmentation was performed on the regions of interest (ROIs) in all CT images, with an automatic 3mm expansion around the tumor, considering the intratumoral and peritumoral 3mm area. This area was divided into three sub-regions via K-means clustering, and 1197 radiomic features were extracted from each sub-region and the overall combined region. After dimension reduction through the Mann-Whitney U test, Pearson correlation analysis, and least absolute shrinkage and selection operator(LASSO), the best features for each sub-region and overall were selected. Models were then built using the selected radiomic features through the Adaptive Boosting (AdaBoost) and Multilayer Perceptron (MLP) classifiers. Four different models were established based on different sub-regions and the overall features. The performance of these models was evaluated through receiver operating characteristic curves (AUC) under the DeLong test, calibration curves via the Hosmer-Lemeshow test, and decision curve analysis to assess the performance of these features. In this study, we evaluated the predictive performance of AdaBoost and MLP classifiers on rad feature models across various subregions and the overall dataset. In the test set, the AdaBoost classifier achieved a maximum AUC of 0.871 in Habitat 3, whereas the MLP classifier demonstrated slightly superior performance with an AUC of 0.879. Both classifiers exhibited high efficiency in habitat 3, with the MLP algorithm showing enhanced model performance. CT habitat imaging analysis for the preoperative prediction of STAS in stage T1 invasive LUAD shows satisfactory diagnostic performance, with the habitat3 model exhibiting the highest efficacy, reflecting tumor heterogeneity.

Mid- to long-term radiological and respiratory outcomes following surgery for older early-onset scoliosis patients with Marfan syndrome

This study aimed to elucidate mid- to long-term radiological and respiratory outcomes in patients aged 7–11 years at index surgery with Marfan syndrome and early-onset scoliosis (EOS) in a retrospective multicenter study. Primary outcomes were final thoracic height and final percentage of predicted vital capacity (%VC) at or after 16 years of age. We identified 21 (6 male and 15 female) patients with a mean age of 9.9 years and mean follow-up period of 149.3 months. Fifteen patients underwent primary fusion, whereas six underwent growth-friendly surgery (GFS). The mean preoperative and final T1–T12 heights were 204.0 mm and 248.0 mm, respectively. Final pulmonary function tests were available for 16 patients, and the mean final %VC was 54.0% with 10 patients exhibiting a final %VC < 60%. A significant moderate association was observed between the final T1–T12 height and final %VC. The predicted final T1–T12 height required for a final %VC of 60% was approximately 260 mm. Although most older patients with Marfan syndrome and EOS acquired a considerably large final T1–T12 height, a larger thoracic height was required for satisfactory respiratory function in many cases; hence, GFS may be indicated even in this population.

Rule breakers achieve successful shoulder balance: unraveling the myth of upper instrumented vertebrae selection criteria

PurposeThis study compared shoulder balance outcomes in “rule breakers” (RB) vs. “rule followers” (RF) based on commonly utilized upper instrumented vertebrae (UIV) selection guidelines.MethodsAdolescent idiopathic scoliosis (AIS) patients (Lenke 1–4) who underwent posterior spine fusion (PSF) with minimum 2-year follow-up had radiographic measurement of shoulder balance including first rib angle (FRA), T1 tilt, coracoid process height difference (CPHD), and clavicle angle (CA) at preop, postop, 6-month, 1-year, and 2-year timepoints. Postoperative outcomes were compared between RB and RF groups defined based on the UIV selection guidelines of Rose and Lenke.ResultsAmong 88 patients (43 RF, 45 RB), age, gender, preoperative T1 tilt, FRA, CA, and CPHD were not significantly different between groups (p > 0.05). Immediately post-surgery, the RF group had more balanced shoulders (CPHD: 11.6 mm vs. 15.7 mm, p = 0.033; CA: 2.8° vs. 3.6°, p = 0.045; FRA: 3.4° vs. 5.1°, p = 0.009; T1 tilt: 4.7° vs. 6.1°, p = 0.045). At 2 years, no difference was observed between RF vs. RB in CA (2.3 vs. 2.2°, p = 0.857) and CPHD (8.5 vs. 8.1 mm, p = 0.791). FRA and T1 tilt were higher in RB vs. RF (FRA: 4.6 vs. 2.9°, p = 0.002; T1 tilt: 5.6 vs. 3.9, p = 0.008). Shoulder balance (CPHD < 1 cm) was achieved in 73.1% of RB and 69.9% of RF at 2-year follow-up (p = 0.216).ConclusionAdherence to commonly accepted UIV selection guidelines did not predict better shoulder balance. The RB group had worse shoulder balance immediately post-surgery, but also improved more over time. These results suggest the need to refine current UIV selection and management.Level of evidenceIII.

Development and Validation of a Predictive Risk Score for Blood Transfusion in Patients Undergoing Curative-Intent Surgery for Intrahepatic Cholangiocarcinoma.

Among patients undergoing liver resection for intrahepatic cholangiocarcinoma (ICC), perioperative bleeding requiring blood transfusion is a common complication, yet preoperative identification of patients at risk for transfusion remains challenging. The objective of this study was to develop a preoperative risk score for blood transfusion requirement during surgery for ICC. Patients undergoing curative-intent liver surgery for ICC (1990-2020) were identified from a multi-institutional database. A predictive model was developed and validated. An easy-to-use risk calculator was made available online. Among 1420 patients, 300 (21.1%) received an intraoperative transfusion. Independent predictors of transfusion included severe preoperative anemia (OR = 1.65, 95% CI 1.10-2.47), T2 category or higher (OR = 2.00, 95% CI 1.36-3.02), positive lymph nodes (OR = 1.75, 95% CI 1.32-2.32) and major resection (OR = 2.56, 95%CI 1.85-3.58). Receipt of blood transfusion significantly correlated with worse outcomes. The model showed good discriminative ability in both training (AUC = 0.68, 95% CI 0.66-0.72) and bootstrapping validation (C-index = 0.67, 95% CI 0.65-0.70) cohorts. An online risk calculator of blood transfusion requirement was developed (https://catalano-giovanni.shinyapps.io/TransfusionRisk). Intraoperative blood transfusion was significantly associated with poor postoperative outcomes among patients undergoing surgery for ICC. The identification of patients at high risk of transfusion could improve perioperative patient care and blood resources allocation.

Preoperative prediction of CNS WHO grade and tumour aggressiveness in intracranial meningioma based on radiomics and structured semantics

Preoperative identification of intracranial meningiomas with aggressive behaviour may help in choosing the optimal treatment strategy. Radiomics is emerging as a powerful diagnostic tool with potential applications in patient risk stratification. In this study, we aimed to compare the predictive value of conventional, semantic based and radiomic analyses to determine CNS WHO grade and early tumour relapse in intracranial meningiomas. We performed a single-centre retrospective analysis of intracranial meningiomas operated between 2007 and 2018. Recurrence within 5 years after Simpson Grade I-III resection was considered as early. Preoperative T1 CE MRI sequences were analysed conventionally by two radiologists. Additionally a semantic feature score based on systematic analysis of morphological characteristics was developed and a radiomic analysis were performed. For the radiomic model, tumour volume was extracted manually, 791 radiomic features were extracted. Eight feature selection algorithms and eight machine learning methods were used. Models were analysed using test and training datasets. In total, 226 patients were included. There were 21% CNS WHO grade 2 tumours, no CNS WHO grade 3 tumour, and 25 (11%) tumour recurrences were detected in total. In ROC analysis the best radiomic models demonstrated superior performance for determination of CNS WHO grade (AUC 0.930) and early recurrence (AUC 0.892) in comparison to the semantic feature score (AUC 0.74 and AUC 0.65) and conventional radiological analysis (AUC 0.65 and 0.54). The combination of human classifiers, semantic score and radiomic analysis did not markedly increase the model performance. Radiomic analysis is a promising tool for preoperative identification of aggressive and atypical intracranial meningiomas and could become a useful tool in the future.

Cervical epidural blood patch treatment is a choice for spontaneous intracranial hypotension.

Epidural blood patch (EBP) is a minimally invasive and effective treatment for spontaneous intracranial hypotension (SIH). But, cervical epidural blood patch for SIH has little attention. In this study, The clinical data was recorded and the treatment efficacy and safety of cervical EBP in SIH were evaluated. : Fifty-nine cases of intractable SIH were examined by computed tomography (CT) guided cervical EBP at the Chinese PLA General Hospital from August 2014 to March 2024. The mean age of the fifty-nine patients at symptom onset was 40.8 ± 9.5 years. 54/59 (91.5%) patients experienced orthostatic headache. Preoperative spine T2 sacns with extensive fluid collection at the upper cervical region in 43/46 (93.5%). 45/59 (76.3%) patients had symptomatic relief with initial cervical EBP, and 14/59 (23.7%) patients received further cervical EBPs. In the first one to three days following the EBP procedure, 11 (18.6%) patients reported pain at the puncture site and 15 (25.4%) experienced neck pain. No other complications were observed during or after the procedure. At the latest follow-up, all patients showed good recovery. The mean follow-up was 28.9 ± 22.7 months. CT-guided cervical EBP is a effective and safe treatment for patients with intractable SIH, especially in patients who had extensive fluid collection at the upper cervical region.

The Spaghetti Sign: Nerve Root Redundancy in Lumbar Spinal Stenosis

Redundant nerve roots (RNRs) seen in conjunction with lumbar spinal stenosis (LSS) are well-described radiographic findings. Several studies suggest their presence may be a negative prognostic indicator of postoperative outcome. Our hypothesis was that severe RNR (informally known as the spaghetti sign [SS]) can serve as a reliable marker of LSS that would benefit from surgical decompression. We sought to evaluate a grading scale for RNR, characterize the association with stenosis, and investigate the clinical implications of RNR. We conducted a retrospective chart review of 72 patients who underwent lumbar spine surgery from 2016 to 2018 at 1 institution. Preoperative T2 magnetic resonance imaging scans were graded by 3 reviewers for severity of stenosis (0-4), severity of RNR (0-3), and rostral versus caudal RNR. SS was defined as RNR score ≥2 (clear-cut or marked nerve root irregularity). Preoperative and postoperative Oswestry Disability Index scores were analyzed by stenosis and RNR severity. Seventy-one (98%) patients had severe stenosis (score ≥3) and 25 (35%) had a SS. SS was 100% specific for high-grade stenosis. If patients had a SS, it was more likely rostral (P=0.02). Postoperative Oswestry Disability Index scores improved significantly, but there were no differences related to RNR score, presence of SS, or stenosis severity. The study demonstrated that there is a significant association between SS and severe LSS and that presence of RNR is not a negative prognostic indicator for postoperative outcomes.

Dose optimization of second window indocyanine green in meningioma patients

ObjectiveSurgery remains the first line treatment for meningiomas and can benefit from fluorescence-guided surgical techniques such as second-window indocyanine green (SWIG). In the current study, we compared the use of the standard SWIG dose of 5.0 mg/kg relative to 2.5 mg/kg indocyanine green (ICG) in meningioma patients. MethodsPatients were prospectively enrolled in an IRB-approved study of SWIG and received either the standard dose of 5.0 mg/kg or a reduced dose of 2.5 mg/kg of ICG around 24 h prior to their surgery. Intraoperative near-infrared fluorescence imaging was performed with exo- and endoscopic systems. Signal-to-background ratio (SBR) was calculated to quantify fluorescence and was compared between 5.0 mg/kg and 2.5 mg/kg ICG. All patients received pre-operative MRI and, in select cases, the pre-operative MRI was correlated to intraoperative fluorescence imaging. Results/DiscussionIn the current study, we found no significant difference in the SBR of meningiomas in patients that were administered with either 5.0 mg/kg or 2.5 mg/kg ICG. However, in five patients that received the standard-dose SWIG regimen of 5.0 mg/kg ICG we observed dose-related fluorescence quenching − referred to as “inversion” − that interfered with tumor visualization during fluorescence-guided surgery (FGS). When correlated to pre-operative MRI, a similar rim pattern was observed around the primary tumor on T2 FLAIR, which, in retrospect, could be used as a predictor for inversion during FGS in meningioma patients receiving standard-dose ICG. ConclusionThis study demonstrated that a reduced ICG dose was as effective as standard-dose SWIG in meningioma patients. We therefore recommend to adjust the standard ICG dose for meningioma patients to 2.5 mg/kg particularly when rim enhancement is observed on pre-operative T2 FLAIR.

Cervical kyphosis after posterior cervical laminectomy with and without fusion

BackgroundCervical posterior instrumentation and fusion is often performed to avoid post-laminectomy kyphosis. However, larger comparative analyses of cervical laminectomy with or without fusion are sparse.MethodsA retrospective, two-center, comparative cohort study included patients after stand-alone dorsal laminectomy with (n = 91) or without (n = 46) additional fusion for degenerative cervical myelopathy with a median follow-up of 59 (interquartile range (IQR) 52) months. The primary outcome was the C2-7 Cobb angle and secondary outcomes were Neck Disability Index (NDI), modified Japanese Orthopaedic Association (mJOA) scale, revision rates, T1 slope and C2-7 sagittal vertical axis (C2-7 SVA) at final follow-up. Logistic regression analysis adjusted for potential confounders (i.e. age, operated levels, and follow-up). Results: Preoperative C2-7 Cobb angle and T1 slope were higher in the laminectomy group, while the C2-7 SVA was similar. The decrease in C2-7 Cobb angle from pre- to postoperatively was more pronounced in the laminectomy group (− 6° (IQR 20) versus −1° (IQR 7), p = 0.002). When adjusting for confounders, the decrease in C2-7 Cobb angle remained higher in the laminectomy group (coefficient − 12 (95% confidence interval (CI) −18 to −5), p = 0.001). However, there were no adjusted differences for postoperative NDI (− 11 (− 23 to 2), p = 0.10), mJOA, revision rates, T1 slope and C2-7 SVA. Conclusion: Posterior cervical laminectomy without fusion is associated with mild loss of cervical lordosis of around 6° in the mid-term after approximately five years, however without any clinical relevance regarding NDI or mJOA in well-selected patients (particularly in shorter segment laminectomies of < 3 levels).

Survival implications and radiographic predictors of prognosis in patients with IDH-mutant astrocytoma with CDKN2A/b homozygous deletion: An international, multi-centered study.

e14035 Background: Isocitrate Dehydrogenase (IDH) 1 or 2 mutations are associated with improved prognosis in glioma patients. Despite their less aggressive clinical course when compared to IDH-wild type gliomas, molecularly-defined IDH-mutant glioma subtypes with poor prognosis have been identified. Among these, CDKN2A/B homozygous deletion represents the strongest negative genetic predictor of prognosis yet identified in IDH-mutant astrocytoma. With the WHO 2021 classification recognizing CDKN2A/B homozygous deletion as sufficient for the designation of astrocytoma, IDH-mutant, WHO Grade 4, the translational implications and potential for therapies targeting CDKN2A/B homozygous deletion are an area of active investigation. We sought to further characterize overall (OS) and progression-free survival (PFS) of CDKN2A/B deleted patients within a large, multi-centered, international cohort and identify clinical characteristics that predict survival for patients with CDKN2A/B deletion. Methods: Patients with IDH-mutant glioma with CDKN2A/B homozygous deletion were retrospectively identified across four institutions (Massachusetts General Hospital, USA; University Hospital Heidelberg, Germany; University Hospital Dresden, Germany, and Foudan-Shanghai, China). IDH-mutation status was determined by immunohistochemistry or next-generation sequencing. CDKN2A/B status was determined by hybridized DNA capture or FISH. Results: We identified 75 patients with IDH-mutant astrocytoma with CDKN2A/B homozygous deletion. The cohort had a median follow-up time of 5.0 years, was 56% male, and had an average age of 38.8 years. Patients were treated with chemotherapy and radiation following initial surgery in 77% of cases. Preoperative contrast enhancement and T2 FLAIR mismatch were identified in 56 and 44% of cases, respectively. Compared to a cohort of 51 patients with CDKN2A/B intact, grade 4, IDH-mutant astrocytoma, those with CDKN2A/B-deleted tumors had significantly shorter median OS and PFS (OS: 4 vs 13.5 years, HR = 6.8, HR 95% CI = 3.1, 14.6, p &lt; 0.0001; PFS: 2.8 vs 5.9 years, HR = 3.0, HR 95% CI = 1.7, 5.2, p = 0.0001). Within the CDKN2A/B deleted cohort, preoperative contrast enhancement predicted worse OS, but not PFS (OS: HR = 2.7, 95% CI = 1.1, 7.4, p = 0.04; PFS: HR = 1.17, 95% CI = 0.7, 3.7, p = 0.24). Conclusions: These data reinforce the strong negative prognostic impact of CDKN2A/B homozygous deletion on OS and PFS and identify a novel association between preoperative contrast enhancement and shorter OS in patients with CDKN2A/Bdeleted, IDH-mutant astrocytoma.

MRI Vertebral Bone Quality Correlates With Interbody Cage Subsidence After Anterior Cervical Discectomy and Fusion.

Retrospective observational study of consecutive patients. The purpose of the study was to evaluate VBQ as a predictor of interbody subsidence and to determine threshold values that portend increased risk of subsidence. Many risk factors have been reported for the subsidence of interbody cages in anterior cervical discectomy and fusion (ACDF). MRI Vertebral Bone Quality (VQB) is a relatively new radiographic parameter that can be easily obtained from preoperative MRI and has been shown to correlate with measurements of bone density such as DXA and CT Hounsfield Units. All patients who underwent 1- to 3-level ACDF using titanium interbodies with anterior plating between the years 2018 and 2020 at our tertiary referral center were included. Subsidence measurements were performed by 2 independent reviewers on CT scans obtained 6 months postoperatively. VBQ was measured on pre-operative sagittal T1 MRI by 2 independent reviewers, and values were averaged. Eight-five fusion levels in 44 patients were included in the study. There were 32 levels (38%) with moderate subsidence and 12 levels with severe subsidence (14%). The average VBQ score in those patients with severe subsidence was significantly higher than those without subsidence (3.80 vs. 2.40, P<0.01). A threshold value of 3.2 was determined to be optimal for predicting subsidence (AUC=0.99) and had a sensitivity of 100% and a specificity of 94.1% in predicting subsidence. VBQ strongly correlates with the subsidence of interbody grafts after ACDF. A threshold VBQ score value of 3.2 has excellent sensitivity and specificity for predicting subsidence. Spine surgeons can use VBQ as a readily available screening tool to identify patients at higher risk for subsidence. Level-IV.

The safety and use of perioperative dexamethasone in the perioperative management of primary sporadic supratentorial meningiomas.

Despite the lack of prospective evidence for the perioperative use of dexamethasone in meningioma surgery, its use is well established in the daily routine of several centers. The present study evaluates the effect of dexamethasone on postoperative complications, peritumoral T2/FLAIR hyperintensity, and progression-free survival in patients with supratentorial meningiomas undergoing resection. A total of 148 patients who underwent resection of a primary sporadic supratentorial meningioma at the authors' institution between 2018 and 2020 were included in this retrospective cohort. Safety criteria were side effects of dexamethasone (e.g. hyperglycemia), surgical morbidities, length of stay, and mortality. The individual Karnofsky Performance Scales (KPS) were evaluated regarding the individual development and the delta of KPS at 3- and 12-months compared to baseline KPS was calculated. Longitudinal assessment of the peritumoral T2-/FLAIR hyperintensity changes was performed. The use of both pre- and postoperative dexamethasone did not influence the incidence rates of wound infections, infarctions, postoperative seizures, pulmonary embolism, postoperative hemorrhage, mortality, length of stay, new-onset hyperglycemia and new neurological deficits. Perioperative Dexamethasone use was associated with an improved Karnofsky performance development at 3- (delta of KPS 3.3 vs. -1.9, p=0.001) and 12-months (delta of KPS 3.8 vs. -1.1, p=0.008) compared to the preoperative Karnofsky performance status. Multivariable analysis revealed that perioperative dexamethasone use enhances the KPS improvement (OR: 3.65, 95% CI: 1.01-13.18, p=0.048). Persistent peritumoral T2/FLAIR hyperintensity changes were observed in 35 cases of 70 patients with available follow-up images and a baseline edema (50.0%). Perioperative dexamethasone use enhanced the reduction of the preoperative peritumoral T2-/FLAIR hyperintensity changes (mean reduction of maximum diameter: 1.8 cm vs. 1.1 cm, p=0.023). Perioperative dexamethasone use was independently associated with a lower risk for persistent peritumoral T2-/FLAIR hyperintensity changes (OR: 3.77, 95% CI: 1.05-13.54, p=0.042) The perioperative use of dexamethasone did not influence the progression-free survival time in Simpson grade I or II resected WHO grade 1 meningiomas (log-rank test: p=0.27). Perioperative dexamethasone use seems to be safe in surgery for primary supratentorial meningiomas. Dexamethasone use might enhance the functionality by reducing postoperative peritumoral T2-/FLAIR hyperintensities. These findings highlight the need for prospective data.

Fully automatic mpMRI analysis using deep learning predicts peritumoral glioblastoma infiltration and subsequent recurrence.

Glioblastoma (GBM) is most aggressive and common adult brain tumor. The standard treatments typically include maximal surgical resection, followed adjuvant radiotherapy and chemotherapy. However, the efficacy of these treatment is often limited, as tumor often infiltrate into the surrounding brain tissue, often extending beyond the radiologically defined margins. This infiltration contributes to the high recurrence rate and poor prognosis associated with GBM patients, necessitating advanced methods for early and accurate detection of tumor infiltration. Despite the great promise traditional supervised machine learning shows in predicting tumor infiltration beyond resectable margins, these methods are heavily reliant on expert-drawn Regions of Interest (ROIs), which are used to construct multi-variate models of different Magnetic Resonance (MR) signal characteristics associated with tumor infiltration. This process is both time consuming and resource intensive. Addressing this limitation, our study proposes a novel integration of fully automatic methods for generating ROIs with deep learning algorithms to create predictive maps of tumor infiltration. This approach uses pre-operative multi-parametric MRI (mpMRI) scans, encompassing T1, T1Gd, T2, T2-FLAIR, and ADC sequences, to fully leverage the knowledge from previously drawn ROIs. Subsequently, a patch based Convolutional Neural Network (CNN) model is trained on these automatically generated ROIs to predict areas of potential tumor infiltration. The performance of this model was evaluated using a leave-one-out cross-validation approach. Generated predictive maps binarized for comparison against post-recurrence mpMRI scans. The model demonstrates robust predictive capability, evidenced by the average cross-validated accuracy of 0.87, specificity of 0.88, and sensitivity of 0.90. Notably, the odds ratio of 8.62 indicates that regions identified as high-risk on the predictive map were significantly more likely to exhibit tumor recurrence than low-risk regions. The proposed method demonstrates that a fully automatic mpMRI analysis using deep learning can successfully predict tumor infiltration in peritumoral region for GBM patients while bypassing the intensive requirement for expert-drawn ROIs.

368 Preoperative Soft Tissue Imaging Features Elucidated by Artificial Intelligence May Best Predict Radiographic Proximal Junction Kyphosis Following Adult Spinal Deformity Surgery

INTRODUCTION: Proximal junction kyphosis (PJK) following adult spinal deformity surgery (ASD) remains difficult to predict. In a cohort of patients undergoing ASD surgery, we used artificial intelligence to compare three models of preoperatively predicting PJK using: 1) traditional radiographic measurements and demographics 2) raw preoperative scoliosis x-rays, and 3) raw preoperative thoracic T1 MRIs. METHODS: A single-institution retrospective cohort study was undertaken for patients undergoing ASD surgery from 2009-21. PJK was defined as a sagittal Cobb angle of upper-instrumented vertebra (UIV) and UIV+2&gt;10° and a postoperative change in UIV/UIV+2&gt;10°. For Model-1, A support vector machine was used to predict PJK within 2 years postoperatively using clinical and traditional sagittal/coronal radiographic variables and intended levels of instrumentation. Next, for Model-2, a convolutional neural network (CNN) was trained on raw preoperative lateral/posterior-anterior scoliosis x-rays. Finally, for Model-3, a CNN was trained on raw thoracic T1 MRIs. RESULTS: A total of 187 patients underwent ASD surgery with at least 2-year follow-up and 89 (47.6%) developed radiographic PJK within 2 years. Model-1: Using clinical variables and traditional radiographic measurements, the support vector machine predicted PJK with a sensitivity:57.2% and specificity:56.3%. Model-2: a CNN with raw scoliosis x-rays predicted PJK with sensitivity:68.2% and specificity:58.3%. Model-3: a CNN with raw thoracic MRIs predicted PJK with sensitivity:73.1% and specificity:79.5%. Finally, an attention map outlined the imaging features used by Model-3 to predict PJK. Soft tissue features predominated all true positive PJK predictions. CONCLUSIONS: The use of raw MRIs in an artificial intelligence model improved the accuracy of PJK prediction compared to raw scoliosis X-rays and traditional clinical/radiographic measurements. The improved predictive ability using MRI may indicate that PJK is best predicted by soft-tissue degeneration and muscle atrophy.

Long-term outcome of surgically treated and conservatively managed Rathke cleft cysts

ObjectiveRathke cleft cysts (RCC) are benign lesions of the sellar region that require surgical treatment in case of visual deterioration or progression of the cyst. However, the natural course is often stable and asymptomatic.We aimed to investigate the characteristics of patients with cyst progression during follow-up (FU) and to compare the natural history of patients with RCC with patients who underwent surgery.MethodsPatients with an MR morphologic cystic sellar lesion classified as RCC between 04/2001 and 11/2020 were included. Functional outcomes, including ophthalmologic, endocrinologic, and MRI data, were retrospectively analyzed and compared between surgically treated patients, patients on a “watch and wait” strategy (WWS), and patients on a WWS who underwent secondary surgery due to cyst progression.ResultsOne hundred forty patients (median age 42.8 years) with RCC on MRI were identified. 52/140 (37.1%) underwent primary surgery. Of 88 patients (62.9%) with initial WWS, 21 (23.9%) underwent surgery for secondary cyst progression. Patients on the WWS had significantly smaller cyst volumes (p = 0.0001) and fewer visual disturbances (p = 0.0004), but a similar rate of hormone deficiencies (p = 0.99) compared with surgically treated patients preoperatively. Postoperatively patients suffered significantly more often from hormone deficiencies than WWS patients (p = 0.001).Patients who switched to the surgical group were significantly more likely to have preoperative T1 hyperintense signals on MRI (p = 0.0001) and visual disturbances (p = 0.001) than patients with continuous WWS. Postoperatively, these patients suffered more frequently from new hormonal deficiencies (p = 0.001). Endocrine and ophthalmologic outcomes in patients with primary and secondary surgery were comparable.Multivariate analysis showed that WWS patients were at a higher risk of requiring surgery for cyst progression when perimetric deficits (p = 0.006), hyperprolactinemia (p = 0.003), and corticotropic deficits (p = 0.005) were present.ConclusionSurgical treatment of RCC may cause new hormonal deficiencies, which are rare in the natural course. Therefore, the indication for surgery should be carefully evaluated. Hyperprolactinemia and corticotropic deficits were significant indicators for a secondary cyst progression in patients with RCC. However, a significant amount of almost 25% of initially conservatively managed cysts showed deterioration, necessary for surgical intervention.

Usefulness of the preoperative thoracic inlet angle in comparison to the T1 slope for predicting cervical kyphosis after laminoplasty.

Thoracic inlet angle (TIA) is a sagittal radiographic parameter with a constant value regardless of posture and is significantly correlated with the sagittal balance of the cervical spine. However, the practical use of TIA has not been studied. This study aimed to investigate the usefulness of the preoperative TIA for predicting the development of kyphotic deformity after cervical laminoplasty in comparison to the preoperative T1 slope (T1S). A total of 98 patients who underwent cervical laminoplasty without preoperative kyphotic alignment were included (mean age, 73.7years; 41.8% female). Radiography was evaluated before surgery and at the 2-year follow-up examination. The cervical sagittal parameters were measured on standing radiographs, and the TIA was measured on T2-weighted MRI in a supine position. Cervical alignment with a C2-C7 angle of ≥ 0° was defined as lordosis, and that with an angle of < 0° was defined as kyphosis. Postoperative kyphosis occurred in 11 patients (11.2%). Preoperatively, the kyphosis group showed significantly lower values in the T1S (23.5° vs. 30.3°, p = 0.034) and TIA (76.1° vs. 81.8°, p = 0.042). We performed ROC curve analysis to clarify the impact of the preoperative TIA and T1S on kyphotic deformity after laminoplasty. The optimal cutoff angles for TIA and T1S were 68° and 19°, respectively, with similar diagnostic accuracy. This study demonstrated the clinical utility of the preoperative TIA for predicting the risk of postoperative kyphotic deformity after cervical laminoplasty. These findings suggest the importance of the preoperative assessment of thoracic inlet alignment in cervical spine surgery.