The Image Biomarker Standardization Initiative: Standardized Convolutional Filters for Reproducible Radiomics and Enhanced Clinical Insights.

Filters are commonly used to enhance specific structures and patterns in images, such as vessels or peritumoral regions, to enable clinical insights beyond the visible image using radiomics. However, their lack of standardization restricts reproducibility and clinical translation of radiomics decision support tools. In this special report, teams of researchers who developed radiomics software participated in a three-phase study (September 2020 to December 2022) to establish a standardized set of filters. The first two phases focused on finding reference filtered images and reference feature values for commonly used convolutional filters: mean, Laplacian of Gaussian, Laws and Gabor kernels, separable and nonseparable wavelets (including decomposed forms), and Riesz transformations. In the first phase, 15 teams used digital phantoms to establish 33 reference filtered images of 36 filter configurations. In phase 2, 11 teams used a chest CT image to derive reference values for 323 of 396 features computed from filtered images using 22 filter and image processing configurations. Reference filtered images and feature values for Riesz transformations were not established. Reproducibility of standardized convolutional filters was validated on a public data set of multimodal imaging (CT, fluorodeoxyglucose PET, and T1-weighted MRI) in 51 patients with soft-tissue sarcoma. At validation, reproducibility of 486 features computed from filtered images using nine configurations × three imaging modalities was assessed using the lower bounds of 95% CIs of intraclass correlation coefficients. Out of 486 features, 458 were found to be reproducible across nine teams with lower bounds of 95% CIs of intraclass correlation coefficients greater than 0.75. In conclusion, eight filter types were standardized with reference filtered images and reference feature values for verifying and calibrating radiomics software packages. A web-based tool is available for compliance checking.

A common [18F]-FDG PET radiomic signature to predict survival in patients with HPV-induced cancers.

Locally advanced cervical cancer (LACC) and anal and oropharyngeal squamous cell carcinoma (ASCC and OPSCC) are mostly caused by oncogenic human papillomaviruses (HPV). In this paper, we developed machine learning (ML) models based on clinical, biological, and radiomic features extracted from pre-treatment fluorine-18-fluorodeoxyglucose positron emission tomography ([18F]-FDG PET) images to predict the survival of patients with HPV-induced cancers. For this purpose, cohorts from five institutions were used: two cohorts of patients treated for LACC including 104 patients from Gustave Roussy Campus Cancer (Center 1) and 90 patients from Leeds Teaching Hospitals NHS Trust (Center 2), two datasets of patients treated for ASCC composed of 66 patients from Institut du Cancer de Montpellier (Center 3) and 67 patients from Oslo University Hospital (Center 4), and one dataset of 45 OPSCC patients from the University Hospital of Zurich (Center 5). Radiomic features were extracted from baseline [18F]-FDG PET images. The ComBat technique was applied to mitigate intra-scanner variability. A modified consensus nested cross-validation for feature selection and hyperparameter tuning was applied on four ML models to predict progression-free survival (PFS) and overall survival (OS) using harmonized imaging features and/or clinical and biological variables as inputs. Each model was trained and optimized on Center 1 and Center 3 cohorts and tested on Center 2, Center 4, and Center 5 cohorts. The radiomic-based CoxNet model achieved C-index values of 0.75 and 0.78 for PFS and 0.76, 0.74, and 0.75 for OS on the test sets. Radiomic feature-based models had superior performance compared to the bioclinical ones, and combining radiomic and bioclinical variables did not improve the performances. Metabolic tumor volume (MTV)-based models obtained lower C-index values for a majority of the tested configurations but quite equivalent performance in terms of time-dependent AUCs (td-AUC). The results demonstrate the possibility of identifying common PET-based image signatures for predicting the response of patients with induced HPV pathology, validated on multi-center multiconstructor data.

Hyaluronic acid gel injection for dysthyroid upper eyelid retraction in Asian patients.

PURPOSE: To evaluate the role of hyaluronic acid (HA) filler injection in the management of upper eyelid retraction (UER) in thyroid eye disease (TED). METHODS: Retrospective interventional series of all patients with TED who had undergone HA injection, from February 2011 to April 2013 by a single surgeon (Y-DK) in a tertiary medical institution. Outcome measures: Mean margin reflex distance 1 (MRD1) pre- and post-filler. RESULTS: There was a total of 13 patients and 17 eyes included in the study. The injection dosage for 15 eyes was 0.5 ml, one patient had 0.35cc on the right eye and 0.65cc on the left eye. Mean MRD1 at presentation was 6.21 mm. There was a mean decrease in MRD1 of 2.01 mm (p < .001) at 1 month post filler, 2.06 mm (p < .001) at 6 months post filler and 2.61 mm (p < .001) at 1 year post filler. There was no correlation between pre-filler MRD1 and change in MRD1 at various time points post-filler, nor any correlation between pre-filler upper scleral show (USS) and change in USS post-filler. There was also no correlation found between clinical activity score (CAS) and change in MRD1, as well as duration of thyroid eye disease (TED) and change in MRD1. Complications included mild upper lid lumpiness on downgaze (n = 4, 23.5%) which improved but persisted with time. There were no untoward intravascular or vision-threatening complications. CONCLUSION: Transconjunctival HA injection is an effective treatment option for TED-related UER in both active and inactive TED patients in an East Asian population, with a potentially long-lasting effect.

European Society for Radiotherapy and Oncology and European Organisation for Research and Treatment of Cancer consensus on re-irradiation: definition, reporting, and clinical decision making.

Re-irradiation can be considered for local recurrence or new tumours adjacent to a previously irradiated site to achieve durable local control for patients with cancer who have otherwise few therapeutic options. With the use of new radiotherapy techniques, which allow for conformal treatment plans, image guidance, and short fractionation schemes, the use of re-irradiation for different sites is increasing in clinical settings. Yet, prospective evidence on re-irradiation is scarce and our understanding of the underlying radiobiology is poor. Our consensus on re-irradiation aims to assist in re-irradiation decision making, and to standardise the classification of different forms of re-irradiation and reporting. The consensus has been endorsed by the European Society for Radiotherapy and Oncology and the European Organisation for Research and Treatment of Cancer. The use of this classification in daily clinical practice and research will facilitate accurate understanding of the clinical implications of re-irradiation and allow for cross-study comparisons. Data gathered in a uniform manner could be used in the future to make recommendations for re-irradiation on the basis of clinical evidence. The consensus document is based on an adapted Delphi process and a systematic review of the literature was done according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA).

Computed tomography-based radiomics decodes prognostic and molecular differences in interstitial lung disease related to systemic sclerosis.

BACKGROUND: Radiomic features calculated from routine medical images show great potential for personalised medicine in cancer. Patients with systemic sclerosis (SSc), a rare, multiorgan autoimmune disorder, have a similarly poor prognosis due to interstitial lung disease (ILD). Here, our objectives were to explore computed tomography (CT)-based high-dimensional image analysis ("radiomics") for disease characterisation, risk stratification and relaying information on lung pathophysiology in SSc-ILD. METHODS: We investigated two independent, prospectively followed SSc-ILD cohorts (Zurich, derivation cohort, n=90; Oslo, validation cohort, n=66). For every subject, we defined 1355 robust radiomic features from standard-of-care CT images. We performed unsupervised clustering to identify and characterise imaging-based patient clusters. A clinically applicable prognostic quantitative radiomic risk score (qRISSc) for progression-free survival (PFS) was derived from radiomic profiles using supervised analysis. The biological basis of qRISSc was assessed in a cross-species approach by correlation with lung proteomic, histological and gene expression data derived from mice with bleomycin-induced lung fibrosis. RESULTS: Radiomic profiling identified two clinically and prognostically distinct SSc-ILD patient clusters. To evaluate the clinical applicability, we derived and externally validated a binary, quantitative radiomic risk score (qRISSc) composed of 26 features that accurately predicted PFS and significantly improved upon clinical risk stratification parameters in multivariable Cox regression analyses in the pooled cohorts. A high qRISSc score, which identifies patients at risk for progression, was reverse translatable from human to experimental ILD and correlated with fibrotic pathway activation. CONCLUSIONS: Radiomics-based risk stratification using routine CT images provides complementary phenotypic, clinical and prognostic information significantly impacting clinical decision making in SSc-ILD.

Prebending of Prefabricated Orbital Implants: Towards Improved Orbital Angle Symmetry Post Craniofacial Trauma Surgery.

PURPOSE: Reconstructive surgery after craniofacial trauma aim to restore orbital anatomy for function and aesthetic reasons. The purpose of this study is to improve postoperative orbital symmetry with the use of prebent prefabricated titanium implants. METHODS: In this retrospective study, patients with combined unilateral medial wall and floor fractures who underwent orbital reconstruction surgery were selected. The angle of inferomedial orbital strut (AIOS) was measured at 3 standard locations on preoperative facial computed tomography guided scans of the nonfractured orbit in the coronal view and used as a guide to bend the prefabricated titanium implants intraoperatively. The corresponding values were measured on the postoperative computed tomography and compared for symmetry. RESULTS: Out of 83 patients recruited for the study, 54 were in the prebent group while 29 were in the control group. All other demographics were similar among the 2 groups. Anterior AIOS has a difference of 4.9° between 2 orbits in the prebent group whereas a difference of 15.5° was noted in the nonprebent group. For middle AIOS, a difference of 4.7° was noted in the prebent group whereas nonprebent group had a difference of 14.1°. For posterior AIOS, the prebent group had a difference of 3.8° versus 14.1° in the nonprebent group. The difference in AIOS at all 3 points between the prebent and nonprebent group were significant. CONCLUSIONS: Anatomical prefabricated titanium plates are versatile implants that facilitate orbital reconstruction. Prebending of these implants according to the fellow orbit can achieve better surgical outcomes in a cost-effective manner.

Head and neck radiotherapy on the MR linac: a multicenter planning challenge amongst MRIdian platform users.

PURPOSE: Purpose of this study is to evaluate plan quality on the MRIdian (Viewray Inc., Oakwood Village, OH, USA) system for head and neck cancer (HNC) through comparison of planning approaches of several centers. METHODS: A total of 14 planners using the MRIdian planning system participated in this treatment challenge, centrally organized by ViewRay, for one contoured case of oropharyngeal carcinoma with standard constraints for organs at risk (OAR). Homogeneity, conformity, sparing of OARs, and other parameters were evaluated according to The International Commission on Radiation Units and Measurements (ICRU) recommendations anonymously, and then compared between centers. Differences amongst centers were assessed by means of Wilcoxon test. Each plan had to fulfil hard constraints based on dose-volume histogram (DVH) parameters and delivery time. A plan quality metric (PQM) was evaluated. The PQM was defined as the sum of 16 submetrics characterizing different DVH goals. RESULTS: For most dose parameters the median score of all centers was higher than the threshold that results in an ideal score. Six participants achieved the maximum number of points for the OAR dose parameters, and none had an unacceptable performance on any of the metrics. Each planner was able to achieve all the requirements except for one which exceeded delivery time. The number of segments correlated to improved PQM and inversely correlated to brainstem D0.1cc and to Planning Target Volume1 (PTV) D0.1cc. Total planning experience inversely correlated to spinal canal dose. CONCLUSION: Magnetic Resonance Image (MRI) linac-based planning for HNC is already feasible with good quality. Generally, an increased number of segments and increasing planning experience are able to provide better results regarding planning quality without significantly prolonging overall treatment time.

Management of multiple brain metastases: a patterns of care survey within the German Society for Radiation Oncology.

PURPOSE: The treatment of brain metastases (BM) has changed considerably in recent years and in particular, the management of multiple BM is currently undergoing a paradigm shift and treatment may differ from current guidelines. This survey was designed to analyze the patterns of care in the management of multiple BM. METHODS: An online survey consisting of 36 questions was distributed to the members of the German Society for Radiation Oncology (DEGRO). RESULTS: In total, 193 physicians out of 111 institutions within the German Society for Radiation oncology responded to the survey. Prognostic scores for decision making were not used regularly. Whole brain radiotherapy approaches (WBRT) are the preferred treatment option for patients with multiple BM, although stereotactic radiotherapy treatments are chosen by one third depending on prognostic scores and overall number of BM. Routine hippocampal avoidance (HA) in WBRT is only used by a minority. In multiple BM of driver-mutated non-small cell lung cancer origin up to 30% favor sole TKI therapy as upfront treatment and would defer upfront radiotherapy. CONCLUSION: In multiple BM WBRT without hippocampal avoidance is still the preferred treatment modality of choice regardless of GPA and mutational status, while SRT is only used in patients with good prognosis. Evidence for both, SRS and hippocampal avoidance radiotherapy, is growing albeit the debate over the appropriate treatment in multiple BM is yet not fully clarified. Further prospective assessment of BM management-ideally as randomized trials-is required to align evolving concepts with the proper evidence and to update current guidelines.

Radiomic biomarkers for head and neck squamous cell carcinoma.

Tumor heterogeneity is a well-known prognostic factor in head and neck squamous cell carcinoma (HNSCC). A major limitation of tissue- and blood-derived tumor markers is the lack of spatial resolution to image tumor heterogeneity. Tissue markers derived from tumor biopsies usually represent only a small tumor subregion at a single timepoint and are therefore often not representative of the tumors' biology or the biological alterations during and after treatment. Similarly, liquid biopsies give an overall picture of the tumors' secreted factors but completely lack any spatial resolution. Radiomics has the potential to give complete three-dimensional information about the tumor. We conducted a comprehensive literature search to assess the correlation of radiomics to tumor biology and treatment outcome in HNSCC and to assess current limitations of the radiomic biomarkers. In total, 25 studies that explored the ability of radiomics to predict tumor biology and phenotype in HNSCC and 28 studies that explored radiomics to predict post-treatment events were identified. Out of these 53 studies, only three failed to show a significant correlation. The major technical challenges are currently artifacts due to metal implants, non-standardized contrast injection, and delineation uncertainties. All studies to date were retrospective and none of the above-mentioned radiomics signatures have been validated in an independent cohort using an independent software implementation, which shows that transferability due to the numerous technical challenges is currently a major limitation. However, radiomics is a very young field and these studies hopefully pave the way for clinical implementation of radiomics for HNSCC in the future.

Definition and quality requirements for stereotactic radiotherapy: consensus statement from the DEGRO/DGMP Working Group Stereotactic Radiotherapy and Radiosurgery.

Stereotactic radiotherapy with its forms of intracranial stereotactic radiosurgery (SRS), intracranial fractionated stereotactic radiotherapy (FSRT) and stereotactic body radiotherapy (SBRT) is today a guideline-recommended treatment for malignant or benign tumors as well as neurological or vascular functional disorders. The working groups for radiosurgery and stereotactic radiotherapy of the German Society for Radiation Oncology (DEGRO) and for physics and technology in stereotactic radiotherapy of the German Society for Medical Physics (DGMP) have established a consensus statement about the definition and minimal quality requirements for stereotactic radiotherapy to achieve best clinical outcome and treatment quality in the implementation into routine clinical practice.

CT radiomics and PET radiomics: ready for clinical implementation?

INTRODUCTION: Today, rapid technical and clinical developments result in an increasing number of treatment options for oncological diseases. Thus, decision support systems are needed to offer the right treatment to the right patient. Imaging biomarkers hold great promise in patient-individual treatment guidance. Routinely performed for diagnosis and staging, imaging datasets are expected to hold more information than used in the clinical practice. Radiomics describes the extraction of a large number of meaningful quantitative features from medical images, such as computed tomography (CT) and positron emission tomography (PET). Due to the non-invasive nature and ability to capture 3D image-based heterogeneity, radiomic features are potential surrogate markers of the cancer phenotype. Several radiomic studies are published per day, owing to encouraging results of many radiomics-based patient outcome models. Despite this comparably large number of studies, radiomics is mainly studied in proof of principle concept. Hence, a translation of radiomics from a hot topic research field into an essential clinical decision-making tool is lacking, but of high clinical interest. EVIDENCE ACQUISITION: Herein, we present a literature review addressing the clinical evidence of CT and PET radiomics. An extensive literature review was conducted in PubMed, including papers on robustness and clinical applications. EVIDENCE SYNTHESIS: We summarize image-modality related influences on the robustness of radiomic features and provide an overview of clinical evidence reported in the literature. Today, more evidence has been provided for CT imaging, however, PET imaging offers the promise of direct imaging of biological processes and functions. We provide a summary of future research directions, which needs to be addressed in order to successfully introduce radiomics into clinical medicine. In comparison to CT, more focus should be directed towards harmonization of PET acquisition and reconstruction protocols, which is important for transferable modelling. CONCLUSIONS: Both CT and PET radiomics are promising pre-treatment and intra-treatment biomarkers for outcome prediction. Most studies are performed in retrospective setting, however their validation in prospective data collections is ongoing.

The ideal couch tracking system-Requirements and evaluation of current systems.

INTRODUCTION: Intrafractional motion can cause substantial uncertainty in precision radiotherapy. Traditionally, the target volume is defined to be sufficiently large to cover the tumor in every position. With the robotic treatment couch, a real-time motion compensation can improve tumor coverage and organ at risk sparing. However, this approach poses additional requirements, which are systematically developed and which allow the ideal robotic couch to be specified. METHODS AND MATERIALS: Data of intrafractional tumor motion were collected and analyzed regarding motion range, frequency, speed, and acceleration. Using this data, ideal couch requirements were formulated. The four robotic couches Protura, Perfect Pitch, RoboCouch, and RPSbase were tested with respect to these requirements. RESULTS: The data collected resulted in maximum speed requirements of 60 mm/s in all directions and maximum accelerations of 80 mm/s2 in the longitudinal, 60 mm/s2 in the lateral, and 30 mm/s2 in the vertical direction. While the two robotic couches RoboCouch and RPSbase completely met the requirements, even these two showed a substantial residual motion (40% of input amplitude), arguably due to their time delays. CONCLUSION: The requirements for the motion compensation by an ideal couch are formulated and found to be feasible for currently available robotic couches. However, the performance these couches can be improved further regarding the position control if the demanded speed and acceleration are taken into account as well.

Methotrexate as an Adjuvant in Severe Thyroid Eye Disease: Does It Really Work as a Steroid-Sparing Agent?

PURPOSE: To compare the efficacy and safety of adjunctive oral methotrexate with intravenous pulsed methylprednisolone against methylprednisolone alone in the treatment of severe thyroid eye disease. METHODS: Retrospective review of clinical data of patients with severe sight-threatening thyroid eye disease with compressive optic neuropathy treated with methylprednisolone with and without methotrexate. Eye disease outcome measures (e.g., VISA inflammatory score and vision) at 0, 3, 6, 12, and 18 months were recorded. RESULTS: There were 72 subjects including 33 who had methylprednisolone alone and 39 with methylprednisolone with methotrexate. There were no statistical differences in demographics and baseline measures of disease activity or vision between the 2 treatment groups. No significant statistical differences in the cumulative dosage of methylprednisolone or occurrence of restrictive myopathy, raised intraocular pressure, proptosis, and exposure keratopathy between the groups at 0, 3, 6, 12, and 18 months were found. However, subjects who received methylprednisolone with methotrexate had better visual acuity of more than 2 lines on Snellen chart (p = 0.026) and VISA inflammatory score (p = 0.034) at 3 months, but no differences at 6, 12, and 18 months. Three patients who received methylprednisolone with methotrexate had transient worsening of liver function. No patient developed severe adverse reaction. CONCLUSIONS: The results demonstrated improved vision and disease activity at 3 months in the combination treatment group. This may suggest that the addition of methotrexate to methylprednisolone is beneficial for accelerating suppression of disease activity and hastens visual recovery. Addition of methotrexate to methylprednisolone did not reduce the requirement for steroids.

Lowering of the High Eyelid Crease in Revision Upper Eyelid Surgery.

BACKGROUND: High placement of the lid crease is a common complication in upper eyelid surgery. Correction of the high crease by revision surgery is challenging and has not been well-reported. METHODS: This is a retrospective interventional study of patients who underwent revision eyelid surgery with lowering of the lid crease from 2008 to 2016 at a tertiary institution. Main outcome measures were pretarsal show (PTS) distance, lid crease symmetry, margin reflex distance 1 (MRD1), and lid height symmetry. Lid crease symmetry was graded as symmetrical, mild asymmetry (PTS difference ≤ 0.5 mm), moderate asymmetry (PTS difference > 0.5 mm but ≤ 1 mm), or obvious asymmetry (PTS difference > 1 mm). Lid height symmetry was graded as symmetrical, mild asymmetry (MRD1 difference ≤ 1 mm), moderate asymmetry (MRD1 difference > 1 mm but ≤ 2 mm), or obvious asymmetry (MRD1 difference > 2 mm). RESULTS: There were a total of 69 patients and 100 eyes. The majority (n = 42, 60.9%) of patients were females. The mean age was 38.3 ± 17.3 years, and mean follow-up was 16 months. Mean PTS decreased from 3.1 mm pre-surgery to 2.0 mm 2 years post-surgery. The proportion of patients with moderate or severe lid crease asymmetry decreased from 81.1% pre-surgery to 6.7% 2 years post-surgery. The mean MRD1 difference decreased from 1.54 mm pre-surgery to 0.23 mm 1 year post-surgery. The proportion of patients with moderate or severe lid height asymmetry improved from 64.5% preoperatively to 4.5% 1 year postoperatively. CONCLUSION: Revision eyelid surgery to correct a high crease is a challenging procedure. We present a technique that is effective in correcting the high lid crease, while simultaneously improving the lid height and lid crease symmetry. LEVEL OF EVIDENCE IV: This journal requires that authors assign a level of evidence to each article. For a full description of these evidence-based medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Efficacy and safety of pulsed intravenous methylprednisolone in early active thyroid eye disease.

Introduction: The mainstay of therapy for active inflammatory phase of thyroid eye disease (TED) is immunosuppression. Patients in our centre with early active TED are treated with pulsed intravenous methylprednisolone (IVMP). Two different protocols are offered in our centre: High dose (1g/day for 3 days, monthly for 6 months), or EUGOGO protocol (500 mg weekly for six weeks, followed by 250 mg weekly for the next 6 weeks). Methods: A prospective cohort study of patients undergoing the two IVMP protocols was performed from January 2009 to May 2015. Main outcome measures were improvement of Clinical Activity Score (CAS) and International Thyroid Eye Disease (ITEDS) - VISA Inflammatory Index. Results: We had a total of 63 patients. Mean age was 43.1 ± 13.1years, females comprised 49.2% (n = 31), and 31 (49.2%) had a positive smoking history. Following IVMP, 65.0% (n = 41) had good response, 31.7% (n = 20) partial, and 3.3% (n = 2) poor. There were significant differences (p < 0.001) in CAS and ITEDS scores between pre-IVMP and post-IVMP visits, for both protocols. A higher proportion of patients receiving the modified EUGOGO protocol (58.3%) had persistent activity and required additional immunosuppression compared to those who underwent the high dose protocol (33.3%). Mild side effects were experienced by 5 (7.9%) and 3 (4.8%) patients at 3 and 6 months, respectively. There were no severe side effects, cardiovascular events or liver failure. Conclusion: With adequate screening and follow-up, six repeated cycles of high dose pulsed IVMP is an effective treatment for TED and can significantly reduce the morbidity associated with this debilitating condition. None of the 51 patients from the high dose protocol met with any serious side effects.

Conservatively Treated Orbital Blowout Fractures: Spontaneous Radiologic Improvement.

PURPOSE: To determine if conservatively treated blowout fractures of the orbit undergo spontaneous improvement based on radiologic findings. DESIGN: Prospective, noncomparative series. PARTICIPANTS: Patients with conservatively treated orbital blowout fractures in a single tertiary institution from 2012 through 2016 with initial and follow-up computed tomography (CT) scans. METHODS: Comparison of initial and follow-up CT to assess for smoothening of bony contour, joining of bony edges, reduction in herniation of orbital contents, and new bone formation. Orbital and fracture volumes were calculated using a 3-dimensional reconstruction software program (3D Workstation; TeraRecon, Foster City, CA). MAIN OUTCOME MEASURES: Change in bony contour, new bone formation, and decrease in orbital and fracture volumes. RESULTS: Our study comprised 41 patients and 44 orbits, with 38 unilateral and 3 bilateral cases. Most were men (65.9%; n = 27), and the mean age was 34.3±13.5 years. The mean time from injury to follow-up scan was 4.6 months (range, 1-15 months). All orbits showed changes in bony contour from initial to follow up CT, including smoothening of the orbital contour (88.6%), joining of bony edges (90.9%), and reduction in herniation of orbital contents (65.9%). Most of the orbits (n = 41; 93.2%) showed features of neobone formation. Of the 44 orbits, 91.4% showed a decrease in orbital volume, whereas 94.3% showed a decrease in fracture volume. The reduction in volume was statistically significant for both orbital (from 23.7±4.0 to 21.8±3.9 ml) as well as fracture (from 1.2±0.8 to 0.7±0.6 ml) volumes from initial to follow-up scans, respectively (P < 0.001). CONCLUSIONS: A large proportion of patients showed improvement in radiologic findings despite being treated conservatively. This highlights the spontaneous improvement that can occur in untreated blowout fractures not just clinically, but radiologically, in terms of soft tissue and bony findings.

Influence of inter-observer delineation variability on radiomics stability in different tumor sites.

BACKGROUND: Radiomics is a promising methodology for quantitative analysis and description of radiological images using advanced mathematics and statistics. Tumor delineation, which is still often done manually, is an essential step in radiomics, however, inter-observer variability is a well-known uncertainty in radiation oncology. This study investigated the impact of inter-observer variability (IOV) in manual tumor delineation on the reliability of radiomic features (RF). METHODS: Three different tumor types (head and neck squamous cell carcinoma (HNSCC), malignant pleural mesothelioma (MPM) and non-small cell lung cancer (NSCLC)) were included. For each site, eleven individual tumors were contoured on CT scans by three experienced radiation oncologists. Dice coefficients (DC) were calculated for quantification of delineation variability. RF were calculated with an in-house developed software implementation, which comprises 1404 features: shape (n = 18), histogram (n = 17), texture (n = 137) and wavelet (n = 1232). The IOV of RF was studied using the intraclass correlation coefficient (ICC). An ICC >0.8 indicates a good reproducibility. For the stable RF, an average linkage hierarchical clustering was performed to identify classes of uncorrelated features. RESULTS: Median DC was high for NSCLC (0.86, range 0.57-0.90) and HNSCC (0.72, 0.21-0.89), whereas it was low for MPM (0.26, 0-0.9) indicating substantial IOV. Stability rate of RF correlated with DC and depended on tumor site, showing a high stability in NSCLC (90% of total parameters), acceptable stability in HNSCC (59% of total parameters) and low stability in MPM (36% of total parameters). Shape features showed the weakest stability across all tumor types. Hierarchical clustering revealed 14 groups of correlated and stable features for NSCLC and 6 groups for both HNSCC and MPM. CONCLUSION: Inter-observer delineation variability has a relevant influence on radiomics analysis and is strongly influenced by tumor type. This leads to a reduced number of suitable imaging features.

Transconjunctival Triamcinolone Injection for Upper Lid Retraction in Thyroid Eye Disease-A New Injection Method.

PURPOSE: To evaluate the role of transconjunctival triamcinolone acetonide (TA) injection in the management of upper eyelid retraction in thyroid eye disease. METHODS: Retrospective interventional review of all patients who underwent transconjunctival TA injection (40 mg/mL) for thyroid eye disease-related upper eyelid retraction from January 2010 to December 2016 in a single tertiary institution. The present study comprised 2 groups: Patients receiving only TA injection (group 1), and patients receiving both TA injection and other immunosuppressive therapy (group 2). RESULTS: There were a total of 99 patients and 135 eyes. Group 1 comprised of 36 eyes (26.7%), while group 2 comprised 99 (73.3%). Normalization or improvement of margin reflex distance 1 was seen in 77.4% and 97.2% of group 1 patients at early and late review, respectively, and 77.6% and 87.8% of group 2, respectively. Absence or improvement in International Thyroid Eye Disease Society inflammatory index was seen in 83.9% and 86.1% of group 1 at early and late review, respectively, and 71.9% and 76.8% of group 2, respectively. Both active (73.7%) and inactive (79.3%) groups showed good early success for improvement in margin reflex distance 1, with increased late success and no significant difference between the groups. For International Thyroid Eye Disease Society inflammatory index, the active group had better early and late success than the inactive group, with the difference being significant (P = 0.002) for late success. CONCLUSIONS: Transconjunctival TA injection is an effective treatment option for thyroid eye disease-related upper eyelid retraction, as a primary and adjunctive treatment, in both active and inactive thyroid eye disease patients.

Permanent Versus Bioresorbable Implants in Orbital Floor Blowout Fractures.

PURPOSE: To compare the outcomes of bioresorbable and permanent implants in the reconstruction of isolated orbital floor blowout fractures. METHODS: Retrospective series of all patients who had orbital floor fracture repair in a single tertiary trauma center from January 2005 to December 2014. The authors reviewed the case notes and CT scans of patients with orbital floor fracture repair with either bioresorbable or permanent implants. Main outcome measures were enophthalmos, diplopia, and ocular motility restriction 1.5 years after fracture repair. Implant-related complications were collected for analysis. RESULTS: There were a total of 88 patients in our study. Bioresorbable implants were used in 48 patients (54.5%) while 40 patients had permanent implants (45.5%). The authors analyzed the implants used in various sizes of orbital fractures: small (<13.3 mm), medium (13.3-20 mm), and large (>20 mm). One and a half years after fracture repair, both groups had comparable clinical outcomes (n = 2 and n = 0 for diplopia for permanent and bioresorbable implant groups, respectively, n = 0 for enophthalmos for both groups and n = 1 for ocular motility limitation for both groups) overall and across all fracture sizes. CONCLUSION: Bioresorbable implants degrade after fracture healing through hydrolysis and promote the gradual transfer of functional forces to healing bone during its disintegration. The clinical outcomes of diplopia, enophthalmos, and ocular motility restriction associated with the use of resorbable implants are comparable to that of permanent implants for all fracture sizes. Their study shows that bioresorbable and permanent implants are equally safe and effective for the treatment of patients with isolated orbital floor blowout fractures.