MRI-based radiomics for prognosis of pediatric diffuse intrinsic pontine glioma: an international study.

Background: Diffuse intrinsic pontine gliomas (DIPGs) are lethal pediatric brain tumors. Presently, MRI is the mainstay of disease diagnosis and surveillance. We identify clinically significant computational features from MRI and create a prognostic machine learning model. Methods: We isolated tumor volumes of T1-post-contrast (T1) and T2-weighted (T2) MRIs from 177 treatment-naïve DIPG patients from an international cohort for model training and testing. The Quantitative Image Feature Pipeline and PyRadiomics was used for feature extraction. Ten-fold cross-validation of least absolute shrinkage and selection operator Cox regression selected optimal features to predict overall survival in the training dataset and tested in the independent testing dataset. We analyzed model performance using clinical variables (age at diagnosis and sex) only, radiomics only, and radiomics plus clinical variables. Results: All selected features were intensity and texture-based on the wavelet-filtered images (3 T1 gray-level co-occurrence matrix (GLCM) texture features, T2 GLCM texture feature, and T2 first-order mean). This multivariable Cox model demonstrated a concordance of 0.68 (95% CI: 0.61-0.74) in the training dataset, significantly outperforming the clinical-only model (C = 0.57 [95% CI: 0.49-0.64]). Adding clinical features to radiomics slightly improved performance (C = 0.70 [95% CI: 0.64-0.77]). The combined radiomics and clinical model was validated in the independent testing dataset (C = 0.59 [95% CI: 0.51-0.67], Noether's test P = .02). Conclusions: In this international study, we demonstrate the use of radiomic signatures to create a machine learning model for DIPG prognostication. Standardized, quantitative approaches that objectively measure DIPG changes, including computational MRI evaluation, could offer new approaches to assessing tumor phenotype and serve a future role for optimizing clinical trial eligibility and tumor surveillance

Radiomic signatures of posterior fossa ependymoma: Molecular subgroups and risk profiles

BACKGROUND: The risk profile for posterior fossa ependymoma (EP) depends on surgical and molecular status [Group A (PFA) versus Group B (PFB)]. While subtotal tumor resection is known to confer worse prognosis, MRI-based EP risk-profiling is unexplored. We aimed to apply machine learning strategies to link MRI-based biomarkers of high-risk EP and also to distinguish PFA from PFB. METHODS: We extracted 1800 quantitative features from presurgical T2-weighted (T2-MRI) and gadolinium-enhanced T1-weighted (T1-MRI) imaging of 157 EP patients. We implemented nested cross-validation to identify features for risk score calculations and apply a Cox model for survival analysis. We conducted additional feature selection for PFA versus PFB and examined performance across three candidate classifiers. RESULTS: For all EP patients with GTR, we identified four T2-MRI-based features and stratified patients into high- and low-risk groups, with 5-year overall survival rates of 62% and 100%, respectively (p < 0.0001). Among presumed PFA patients with GTR, four T1-MRI and five T2-MRI features predicted divergence of high- and low-risk groups, with 5-year overall survival rates of 62.7% and 96.7%, respectively (p = 0.002). T1-MRI-based features showed the best performance distinguishing PFA from PFB with an AUC of 0.86. CONCLUSIONS: We present machine learning strategies to identify MRI phenotypes that distinguish PFA from PFB, as well as high- and low-risk PFA. We also describe quantitative image predictors of aggressive EP tumors that might assist risk-profiling after surgery. Future studies could examine translating radiomics as an adjunct to EP risk assessment when considering therapy strategies or trial candidacy

Timing of antibiotic administration, wound debridement, and the stages of reconstructive surgery for open long bone fractures of the upper and lower limbs

Background Open fractures of the major long bones are complex limb‐threatening injuries that are predisposed to deep infection. Treatment includes antibiotics and surgery to debride the wound, stabilise the fracture and reconstruct any soft tissue defect to enable infection‐free bone repair. There is a need to assess the effect of timing and duration of antibiotic administration and timing and staging of surgical interventions to optimise outcomes. Objectives To assess the effects (risks and benefits) of the timing of antibiotic administration, wound debridement and the stages of surgical interventions in managing people with open long bone fractures of the upper and lower limbs. Search methods We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase and clinical trial registers in February 2021. We also searched conference proceedings and reference lists of included studies. Selection criteria We included randomised controlled trials (RCTs) or quasi‐RCTs that recruited adults with open fractures of the major long bones, comparing: 1) timings of prophylactic antibiotic treatment, 2) duration of prophylactic antibiotic treatment, 3) timing of wound debridement following injury or 4) timing of the stages of reconstructive surgery. Data collection and analysis We used standard methodological procedures expected by Cochrane. We aimed to collect data for the following outcomes: limb function, health‐related quality of life (HRQoL), deep surgical site infection, delayed or non‐union, adverse events (in the short‐ and long‐term course of recovery), and resource‐related outcomes. Main results We included three RCTs of 613 randomised participants with 617 open fractures. Studies were conducted in medical and trauma centres in the USA and Kenya. Where reported, there was a higher proportion of men and a mean age of participants between 30 and 34 years old. Fractures were in the upper and lower limbs in one study, and were tibia fractures in two studies; where reported, these were the result of high‐energy trauma such as road traffic accidents. No studies compared the timing of antibiotic treatment or wound debridement. Duration of prophylactic antibiotic treatment (1 study, 77 participants available for analysis) One study compared antibiotic treatment for 24 hours with antibiotic treatment for five days. We are very uncertain about the effects of different durations of antibiotic treatment on superficial infections (risk ratio (RR) 1.19, 95% CI 0.49 to 2.87, favours 5 day treatment; 1 study, 77 participants); this was very low‐certainty evidence derived from one small study with unclear and high risks of bias, and with an imprecise effect estimate. This study reported no other review outcomes. Reconstructive surgery: timing of the stages of surgery (2 studies, 458 participants available for analysis) Two studies compared the timing of wound closure, which was completed immediately or delayed. In one study, the mean time of delay was 5.9 days; in the other study, the time of delay was not reported. We are very uncertain about the effects of different timings of wound closure on deep infections (RR 0.82, 95% CI 0.37 to 1.80, favours immediate closure; 2 studies, 458 participants), delayed union or non‐union (RR 1.13, 95% CI 0.83 to 1.55, favours delayed closure; 1 study, 387 participants), or superficial infections (RR 6.45, 95% CI 0.35 to 120.43, favours delayed closure; 1 study, 71 participants); this was very low‐certainty evidence. We downgraded the certainty of the evidence for very serious risks of bias because both studies had unclear and high risks of bias. We also downgraded for serious imprecision because effect estimates were imprecise, including the possibility of benefits as well as harms, and very serious imprecision when the data were derived from single small study. These studies reported no other review outcomes. Authors' conclusions We could not determine the risks and benefits of different treatment protocols for open long bone fractures because the evidence was very uncertain for the two comparisons and we did not find any studies addressing the other possible comparisons. Well‐designed randomised trials with adequate power are needed to guide surgical and antibiotic treatment of open fractures, particularly with regard to timing and duration of antibiotic administration and timing and staging of surgery

Timing of antibiotic administration, wound debridement, and the stages of reconstructive surgery for open long bone fractures of the upper and lower limbs

Background Open fractures of the major long bones are complex limb‐threatening injuries that are predisposed to deep infection. Treatment includes antibiotics and surgery to debride the wound, stabilise the fracture and reconstruct any soft tissue defect to enable infection‐free bone repair. There is a need to assess the effect of timing and duration of antibiotic administration and timing and staging of surgical interventions to optimise outcomes. Objectives To assess the effects (risks and benefits) of the timing of antibiotic administration, wound debridement and the stages of surgical interventions in managing people with open long bone fractures of the upper and lower limbs. Search methods We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase and clinical trial registers in February 2021. We also searched conference proceedings and reference lists of included studies. Selection criteria We included randomised controlled trials (RCTs) or quasi‐RCTs that recruited adults with open fractures of the major long bones, comparing: 1) timings of prophylactic antibiotic treatment, 2) duration of prophylactic antibiotic treatment, 3) timing of wound debridement following injury or 4) timing of the stages of reconstructive surgery. Data collection and analysis We used standard methodological procedures expected by Cochrane. We aimed to collect data for the following outcomes: limb function, health‐related quality of life (HRQoL), deep surgical site infection, delayed or non‐union, adverse events (in the short‐ and long‐term course of recovery), and resource‐related outcomes. Main results We included three RCTs of 613 randomised participants with 617 open fractures. Studies were conducted in medical and trauma centres in the USA and Kenya. Where reported, there was a higher proportion of men and a mean age of participants between 30 and 34 years old. Fractures were in the upper and lower limbs in one study, and were tibia fractures in two studies; where reported, these were the result of high‐energy trauma such as road traffic accidents. No studies compared the timing of antibiotic treatment or wound debridement. Duration of prophylactic antibiotic treatment (1 study, 77 participants available for analysis) One study compared antibiotic treatment for 24 hours with antibiotic treatment for five days. We are very uncertain about the effects of different durations of antibiotic treatment on superficial infections (risk ratio (RR) 1.19, 95% CI 0.49 to 2.87, favours 5 day treatment; 1 study, 77 participants); this was very low‐certainty evidence derived from one small study with unclear and high risks of bias, and with an imprecise effect estimate. This study reported no other review outcomes. Reconstructive surgery: timing of the stages of surgery (2 studies, 458 participants available for analysis) Two studies compared the timing of wound closure, which was completed immediately or delayed. In one study, the mean time of delay was 5.9 days; in the other study, the time of delay was not reported. We are very uncertain about the effects of different timings of wound closure on deep infections (RR 0.82, 95% CI 0.37 to 1.80, favours immediate closure; 2 studies, 458 participants), delayed union or non‐union (RR 1.13, 95% CI 0.83 to 1.55, favours delayed closure; 1 study, 387 participants), or superficial infections (RR 6.45, 95% CI 0.35 to 120.43, favours delayed closure; 1 study, 71 participants); this was very low‐certainty evidence. We downgraded the certainty of the evidence for very serious risks of bias because both studies had unclear and high risks of bias. We also downgraded for serious imprecision because effect estimates were imprecise, including the possibility of benefits as well as harms, and very serious imprecision when the data were derived from single small study. These studies reported no other review outcomes. Authors' conclusions We could not determine the risks and benefits of different treatment protocols for open long bone fractures because the evidence was very uncertain for the two comparisons and we did not find any studies addressing the other possible comparisons. Well‐designed randomised trials with adequate power are needed to guide surgical and antibiotic treatment of open fractures, particularly with regard to timing and duration of antibiotic administration and timing and staging of surgery