Radiographic Resolution Research Articles

Chronic Osteomyelitis of the Jaw: Pivotal Role of Microbiological Investigation and Multidisciplinary Management—A Case Report

A 15-year-old girl with a history of recurrent painful orofacial swelling was diagnosed on the basis of clinical findings, histopathological examination and imaging modalities as having primary chronic osteomyelitis of the jaw. Initial microbiological samples were performed but were inconclusive. She received multiple empirical antibiotic therapies and NSAIDs for 3 years without complete remission. Only MALDI-TOF (Matrix-Assisted Laser Desorption/Ionization–Time Of Flight) analysis after additional multiple microbiological bone samples with adequate techniques yielded the final diagnosis of bacterial chronic osteomyelitis of the jaw. Its management requires a multidisciplinary approach, involving oral and maxillofacial surgeons, infectiologists and microbiologists, to limit treatment failure. Antibiotic therapy without surgery for 6 months achieved the complete radiographic resolution of the CBCT (Cone Beam Computed Tomography) and the normalization of laboratory tests. After 2 years of follow-up, no relapse had been reported. Modern microbiological investigation and sampling techniques are critical for the accurate diagnosis and management of osteomyelitis of the jaw, especially in unusual and clinically misleading forms of this infection.

Invasive Aspergillosis Resistant to Double-Coverage of Antifungal Therapy in a Very Immunosuppressed Lung Transplant Recipient

<h3>Introduction</h3> Lung transplant (LT) recipients require intensive immunosuppressive regimens, which raises the risk of invasive fungal disease that can be challenging to clear. <h3>Case Report</h3> The patient is an 18-year-old male, bilateral LT (04/2021) recipient for cystic fibrosis, complicated by immediate posttransplant <i>de novo</i> DSA requiring plasma exchange and IVIG. At his 1-month post-discharge visit, significant DSA to multiple class I and class II alleles was found requiring augmented immunosuppression and admission for repeat inpatient plasma exchange and IVIG. Lavage cultures were remarkable for MDR-<i>Pseudomonas</i> with multiple subtypes, sensitive only to cefiderocol. Pulmonary function had not completely recovered since LT as FEV₁ had peaked at 1.5 L (47%) before dropping to 1.1 L (35%) in the current admission. Due to the ongoing DSA burden, we began treatment with antithymocyte globulin (ATG) to prevent the sequalae of antibody-mediated rejection. Additional imaging was remarkable for multiple, confluent, mass-like structures concerning for post-LT lymphoproliferative disorder, prompting biopsies that revealed angioinvasive <i>Aspergillus</i> (<b>Figure 1</b>). We started IV isavuconazole and continued cefiderocol, linezolid, and micafungin given his infectious history. The patient was symptomatic for dyspnea, which did not resolve despite the above antimicrobial coverage, prompting us to substitute voriconazole with some subjective improvement. Serial chest imaging showed worsening markings with new cavitation. Repeat lavage cultures were now significant for <i>Aspergillus terreus</i> and <i>Pseudomonas spp</i> superinfection. After nearly 2 months of ongoing IV antimicrobial therapy, we observed radiographic and symptomatic resolution. <h3>Summary</h3> Early DSA burden with decreasing pulmonary function justified treatment with ATG, but increased the risk of severe fungal infections, which required lengthy double-coverage antifungal therapy.

Development and Validation of a Scoring System for Assessment of Clinical Failure after Pediatric Robot-Assisted Laparoscopic Extravesical Ureteral Reimplantation: A Multi-Center Study.

We aimed to develop and validate a scoring system as an objective assessment tool for predicting clinical failure after pediatric robotic extravesical ureteral reimplantation. Data for this multi-institutional retrospective cohort was obtained from two tertiary referral hospitals. We defined clinical failure as incomplete radiographic resolution or post-operative febrile UTI. Patients were stratified into low, intermediate, and high-risk groups according to the score. External validation was performed using the model projected to the external validation cohort. An amount of 115 renal units in the development cohort and 46 renal units in the validation cohort were analyzed. The prediction score was calculated with weighted points to each variable according to their regression coefficient as age (year) + BMI + BBD times 10 + VUR grade times 7 + console time (h) + hospital stay times 6. The C-index of our scoring system was 0.850 and 0.770 in the development and validation cohorts, respectively. Clinical failure was significantly different among risk groups: 0% (low-risk), 3.3% (intermediate-risk), and 22.2% (high-risk) (p = 0.004) in the development cohort. A novel scoring system using multiple pre- and intra-operative variables provides a prediction of children at risk of failure after robotic extravesical ureteral reimplantation.

Calcium pyrophosphate dihydrate crystal deposition disease and retro-odontoid pseudotumor rupture managed via posterior occipital cervical instrumented fusion: illustrative case.

BACKGROUNDCraniocervical junction and subaxial cervical spinal manifestations of calcium pyrophosphate deposition disease are rarely encountered. The authors presented a severe case of retro-odontoid pseudotumor rupture causing rapid quadriparesis and an acute comatose state with subsequent radiographic and clinical improvement after posterior occipital cervical fusion.OBSERVATIONSThe authors surveyed the literature and outlined multiple described operative management strategies for compressive cervical and craniocervical junction calcium pyrophosphate deposition disease manifestations ranging from neck pain to paresthesia, weakness, myelopathy, quadriparesis, and cranial neuropathies. In this report, radiographic features of cervical and craniocervical junction calcium pyrophosphate deposition disease were explored. Several previously described surgical strategies were compiled, including patient characteristics and outcomes.LESSONSWith this case report, the authors presented for the first time an isolated posterior occipital cervical fusion for treatment of a compressive retro-odontoid pseudotumor with rupture into the brainstem. They demonstrated rapid clinical and radiographic resolution after stabilization of cranial cervical junction only 12 weeks postsurgery.

P24 Cefiderocol activity against a multidrug-resistant (MDR) strain of Pseudomonas aeruginosa: a case report

BackgroundMDR Gram-negative bacteria such as Pseudomonas aeruginosa represent the highest priority for addressing global antibiotic resistance. Moreover, selecting an appropriate empirical antibiotic treatment for MDR strains is a challenge. Cefiderocol, a novel siderophore cephalosporin, has demonstrated activity against Gram-negative strains resistant to other available antibiotics.Patient caseA 58-year-old female was admitted on to the ICU with type 1 respiratory failure as a consequence of COVID-19 pneumonitis. During the course of her ICU admission she developed persistent bilateral empyema and pneumothorax which did not resolve despite the use of pleural drains. The empyema samples grew P. aeruginosa.Treatment courseThe patient was treated with commonly used antibiotics for P. aeruginosa, including piperacillin/tazobactam, meropenem, ceftolozane/tazobactam and ciprofloxacin. However, repeated testing of empyema fluid and respiratory secretions identified an increasingly drug-resistant P. aeruginosa strain. Following left thoracotomy and pleural decortication, cefiderocol was approved for compassionate use and the patient was treated for 14 days. The patient experienced good resolution of clinical symptoms and C-reactive protein levels and was discharged to the ward after 105 days in the ICU. The patient was briefly readmitted to the ICU with worsening type 2 respiratory failure 2 weeks later. Ceftolozane/tazobactam and colistin treatment were recommenced as a bridging measure until cefiderocol became available in the hospital. Notably, the P. aeruginosa isolated remained susceptible to cefiderocol following the first course of treatment. Cefiderocol therapy (2 g t.i.d.) was recommenced for 14 days of ward based treatment. The patient demonstrated clinical and radiographic resolution of her infection and was eventually discharged home.ConclusionsThis patient case describes a heavily pretreated female with a MDR P. aeruginosa strain successfully managed with cefiderocol and source control. Cefiderocol was prescribed for compassionate use for treatment of MDR P. aeruginosa. Treatment was well tolerated and led to good resolution of clinical symptoms. Cefiderocol may help address the global issue of MDR P. aeruginosa.

Resolution of acute pulmonary embolism using anticoagulation therapy alone in coronavirus disease 2019

ObjectiveTo investigate the radiographic resolution of acute pulmonary embolism (PE) using contrast-enhanced computed tomography (CECT) examinations in patients diagnosed with acute PE while hospitalized with coronavirus disease 2019 (COVID-19) and to understand the mid-term and long-term implications of anticoagulation therapy. MethodsWe identified patients with acute PE per CECT and at least one follow-up CECT from March 11, 2020, to May 27, 2021, using a prospective registry of all hospitalized patients with COVID-19 infection receiving care within a multicenter Health System. Initial and follow-up CECT examinations were reviewed independently by two radiologists to evaluate for PE resolution. The Modified Miller Score was used to assess for thrombus burden at diagnosis and on follow-up. ResultsOf the 6070 hospitalized patients with COVID-19 infection, 5.7% (348/6070) were diagnosed with acute PE and 13.5% (47/348) had a follow-up CECT examination. The mean ± standard deviation time to follow-up imaging was 44 ± 48 days (range, 3-161 days). Of 47 patients, 47 (72.3%) had radiographic resolution of PE, with a mean time to follow-up of 48 ± 43 days (range, 6-239 days). All patients received anticoagulation monotherapy for a mean of 149 ± 95 days and this included apixaban (63.8%), warfarin (12.8%), and rivaroxaban (8.5%), among others. The mean Modified Miller Score at PE diagnosis and follow-up was 4.8 ± 4.2 (range, 1-14) and 1.4 ± 3.3 (range, 0-16; P < .0001), respectively. Nine patients (19%) died at a mean of 13 ± 8 days after follow-up CECT (range, 1-27 days) and at a mean of 28 ± 16 days after admission (range, 11-68 days). Seen of the nine deaths (78%) deaths were associated with progression of COVID-19 pneumonia. ConclusionsHospitalized patients with COVID-19 have a clinically apparent 5.7% rate of developing PE. In patients with follow-up imaging, 72.3% had radiographic thrombus resolution at a mean of 44 days while on anticoagulation. Prospective studies of the natural history of PEs with COVID-19 that include systematic follow-up imaging are warranted to help guide anticoagulation recommendations.

U-shaped GAN for Semi-Supervised Learning and Unsupervised Domain Adaptation in High Resolution Chest Radiograph Segmentation.

Deep learning has achieved considerable success in medical image segmentation. However, applying deep learning in clinical environments often involves two problems: (1) scarcity of annotated data as data annotation is time-consuming and (2) varying attributes of different datasets due to domain shift. To address these problems, we propose an improved generative adversarial network (GAN) segmentation model, called U-shaped GAN, for limited-annotated chest radiograph datasets. The semi-supervised learning approach and unsupervised domain adaptation (UDA) approach are modeled into a unified framework for effective segmentation. We improve GAN by replacing the traditional discriminator with a U-shaped net, which predicts each pixel a label. The proposed U-shaped net is designed with high resolution radiographs (1,024 × 1,024) for effective segmentation while taking computational burden into account. The pointwise convolution is applied to U-shaped GAN for dimensionality reduction, which decreases the number of feature maps while retaining their salient features. Moreover, we design the U-shaped net with a pretrained ResNet-50 as an encoder to reduce the computational burden of training the encoder from scratch. A semi-supervised learning approach is proposed learning from limited annotated data while exploiting additional unannotated data with a pixel-level loss. U-shaped GAN is extended to UDA by taking the source and target domain data as the annotated data and the unannotated data in the semi-supervised learning approach, respectively. Compared to the previous models dealing with the aforementioned problems separately, U-shaped GAN is compatible with varying data distributions of multiple medical centers, with efficient training and optimizing performance. U-shaped GAN can be generalized to chest radiograph segmentation for clinical deployment. We evaluate U-shaped GAN with two chest radiograph datasets. U-shaped GAN is shown to significantly outperform the state-of-the-art models.

Successful Nonsurgical Management of a Traumatic Dens Fracture in a Cat with Clinical and Radiographic Resolution

ABSTRACTAn adult domestic shorthair presented with obtundation, vestibular ataxia, head tilt, and visible evidence of facial injury following motor vehicle trauma. Plain radiographs and computed tomography imaging revealed a complete minimally displaced transverse fracture of the caudal aspect of the dens of the C2 vertebra and multiple minimally displaced cranial fractures. The dens fracture was managed with 8 wk of strict rest, followed by 4 wk of supervised activity at home. No external immobilization was performed. Neurological examinations at 8 days, 10 wk, and 9 mo following initial presentation were normal. Repeat radiographic and computed tomography examinations at 10 wk and 9 mo following the traumatic event demonstrated progressive and eventual complete osseous union of the fractured dens. To the authors’ knowledge, this is the first report of successful nonsurgical management of a traumatic dens fracture in an adult cat with documented radiographic and clinical resolution. This report suggests that nonsurgical management can be considered in such cats and that complete resolution with osseous union is feasible.

Approach to weld segmentation and defect classification in radiographic images of pipe welds

Detecting indications (points suspicious for defects) in weld radiographs is an important research topic in the field of industrial non-destructive testing. Many computer-aided detection techniques have been designed for such applications as detecting indications occurrence, segmentation of the indication area, classification of the indications. However, these techniques are mainly focused on only one of the listed problems. Different defects may exhibit different visual properties in shapes, sizes, textures, contrasts, and positions, that often leading to ad-hoc solutions. The paper investigates to the fine tuning of the machine learning approach to high resolution radiograph processing produced by real-time radiography using digital detector arrays (DDA) method. The main contributions of this work are the preprocessing feature for human readability of the radiographic images and the proposed neural network-based solutions for all stages, from weld detection on the radiographic images and its segmentation to indication segmentation and classification. The designed approach was implemented as a web service with web site front-end. The demo version of the software is available with this instruction https://github.com/NastyaMittseva/DefectRecognitionSystem.

High Precision Mammography Lesion Identification From Imprecise Medical Annotations.

Breast cancer screening using Mammography serves as the earliest defense against breast cancer, revealing anomalous tissue years before it can be detected through physical screening. Despite the use of high resolution radiography, the presence of densely overlapping patterns challenges the consistency of human-driven diagnosis and drives interest in leveraging state-of-art localization ability of deep convolutional neural networks (DCNN). The growing availability of digitized clinical archives enables the training of deep segmentation models, but training using the most widely available form of coarse hand-drawn annotations works against learning the precise boundary of cancerous tissue in evaluation, while producing results that are more aligned with the annotations rather than the underlying lesions. The expense of collecting high quality pixel-level data in the field of medical science makes this even more difficult. To surmount this fundamental challenge, we propose LatentCADx, a deep learning segmentation model capable of precisely annotating cancer lesions underlying hand-drawn annotations, which we procedurally obtain using joint classification training and a strict segmentation penalty. We demonstrate the capability of LatentCADx on a publicly available dataset of 2,620 Mammogram case files, where LatentCADx obtains classification ROC of 0.97, AP of 0.87, and segmentation AP of 0.75 (IOU = 0.5), giving comparable or better performance than other models. Qualitative and precision evaluation of LatentCADx annotations on validation samples reveals that LatentCADx increases the specificity of segmentations beyond that of existing models trained on hand-drawn annotations, with pixel level specificity reaching a staggering value of 0.90. It also obtains sharp boundary around lesions unlike other methods, reducing the confused pixels in the output by more than 60%.

Considerations for the real‐world management of ARIA from the aducanumab phase 3 studies EMERGE and ENGAGE

AbstractBackgroundAmyloid‐related imaging abnormalities (ARIA), a spectrum of imaging findings detected on brain magnetic resonance imaging (MRI), are associated with the investigational use of amyloid‐targeting monoclonal antibodies, including aducanumab, in patients with Alzheimer’s disease (AD). EMERGE (NCT02484547) and ENGAGE (NCT02477800) were Phase 3 studies that evaluated the efficacy and safety of aducanumab in patients with early AD.MethodsARIA risk minimization included dose titration, routine brain MRI monitoring, ad hoc MRI testing as clinically indicated, and among patients who developed ARIA, possible dose suspension or permanent discontinuation. The criteria for dose suspension or discontinuation were based on the radiographic severity of ARIA and presentation of clinical symptoms. On detection of an ARIA episode, follow‐up MRIs were conducted approximately every 4 weeks to document radiographic resolution of ARIA‐edema (ARIA‐E) or stabilization of ARIA‐hemorrhage (ARIA‐H), which refers to brain microhemorrhages and localized superficial siderosis.ResultsThe integrated data set from EMERGE and ENGAGE consisted of 3285 participants (aducanumab treated, n=2198; placebo treated, n=1087). In the 10‐mg/kg group (n=1029 with ≥1 postbaseline MRI), ARIA‐E was the most common adverse event (35.2%), with a higher incidence in apolipoprotein ε4 carriers compared with noncarriers (43.0% versus 20.3%, respectively). Radiographic severity of ARIA‐E was characterized as mild (30.1%), moderate (57.7%), or severe (12.2%). ARIA‐E typically occurred within the first 32 weeks of treatment with aducanumab and were mostly asymptomatic (74.0%). Among participants who reported symptoms in the setting of ARIA, the majority of symptoms during ARIA were characterized as mild (67.7%) or moderate (28.3); the most common symptoms were headache (46.6%), confusion (14.6%), dizziness (10.7%), and nausea (7.8%). ARIA‐E were transient but recurred in 10.6% of participants in the 10‐mg/kg group. ARIA‐H microhemorrhage and superficial siderosis were typically asymptomatic and more common in participants who had ARIA‐E (40.3% and 38.7%, respectively), compared with participants without ARIA‐E (7.6% and 1.6%, respectively). In participants with ARIA‐E and ARIA‐H, these events frequently overlapped temporally. There were no fatal events due to ARIA.ConclusionsARIA are mostly asymptomatic; evidence supports the use of routine brain MRI to monitor for events in clinical practice.

Lymphocele after anterior lumbar interbody fusion: a review of 1322 patients.

Anterior lumbar interbody fusion (ALIF) is an effective surgical modality for many lumbar degenerative pathologies, but a rare and infrequently reported complication is postoperative lymphocele. The goals of the present study were to review a large consecutive series of patients who underwent ALIF at a high-volume institution, estimate the rate of lymphocele occurrence after ALIF, and investigate the outcomes of patients who developed lymphocele after ALIF. A retrospective review of the electronic medical record was completed, identifying all patients (≥ 18 years old) who underwent at a minimum a single-level ALIF from 2012 through 2019. Postoperative spinal and abdominal images, as well as radiologist reports, were reviewed for mention of lymphocele. Clinical data were collected and reported. A total of 1322 patients underwent a minimum 1-level ALIF. Of these patients, 937 (70.9%) had either postoperative abdominal or lumbar spine images, and the resulting lymphocele incidence was 2.1% (20/937 patients). The mean ± SD age was 67 ± 10.9 years, and the male/female ratio was 1:1. Patients with lymphocele were significantly older than those without lymphocele (66.9 vs 58.9 years, p = 0.006). In addition, patients with lymphocele had a greater number of mean levels fused (2.5 vs 1.8, p < 0.001) and were more likely to have undergone ALIF at L2-4 (95.0% vs 66.4%, p = 0.007) than patients without lymphocele. On subsequent multivariate analysis, age (OR 1.07, 95% CI 1.01-1.12, p = 0.013), BMI (OR 1.10, 95% CI 1.01-1.18, p = 0.021), and number of levels fused (OR 1.82, 95% CI 1.05-3.14, p = 0.032) were independent prognosticators of postoperative lymphocele development. Patients with symptomatic lymphocele were successfully treated with either interventional radiology (IR) drainage and/or sclerosis therapy and achieved radiographic resolution. The mean ± SD length of hospital stay was 9.1 ± 5.2 days. Ten patients (50%) were postoperatively discharged to a rehabilitation center: 8 patients (40%) were discharged to home, 1 (5%) to a skilled nursing facility, and 1 (5%) to a long-term acute care facility. After ALIF, 2.1% of patients were diagnosed with radiographically identified postoperative lymphocele and had risk factors such as increased age, BMI, and number of levels fused. Most patients presented within 1 month postoperatively, and their clinical presentations included abdominal pain, abdominal distension, and/or wound complications. Of note, 25% of identified lymphoceles were discovered incidentally. Patients with symptomatic lymphocele were successfully treated with either IR drainage and/or sclerosis therapy and achieved radiographic resolution.

Phase II Trial of Response Adapted Ultra Low Dose (ULD) Orbital Radiation Therapy for Indolent B Cell Lymphoma

Phase II Trial of Response Adapted Ultra Low Dose (ULD) Orbital Radiation Therapy for Indolent B Cell Lymphoma

Comparison of Short- versus Long-Course Antimicrobial Therapy of Uncomplicated Bacterial Pneumonia in Dogs: A Double-Blinded, Placebo-Controlled Pilot Study.

Simple SummaryDogs diagnosed with bacterial pneumonia are often treated with long courses of antibiotics (3–6 weeks) and chest X-rays are used to help guide the duration of treatment. This is in stark contrast with humans with the same disease who are often treated for 5–10 days, and chest X-rays are not considered to be useful for monitoring response to treatment. The main goal of this study was to determine whether a shorter course of antibiotics (10 days) would be sufficient to treat dogs with bacterial pneumonia. Eight dogs with pneumonia were randomly assigned to receive 10 or 21 days of antibiotics. They were evaluated at 10, 30 and 60 days after diagnosis. At 10 days, 6/8 dogs had resolution of both clinical signs and evidence of inflammation on bloodwork and 5/8 dogs showed improvement in the chest X-rays. After 60 days, none of the dogs had clinical signs or evidence of inflammation on bloodwork regardless of antibiotic therapy duration. However, 3/8 dogs showed changes in the chest X-rays. This study suggests that a 10-day course of antibiotics may be sufficient to treat dogs with bacterial pneumonia, and chest X-rays may not be a reliable marker to monitor response to therapy.Current treatment for canine bacterial pneumonia relies on protracted courses of antimicrobials (3–6 weeks or more) with recommendations to continue for 1–2 weeks past resolution of all clinical and thoracic radiographic abnormalities. However, in humans, bacterial pneumonia is often treated with 5–10-day courses of antimicrobials, and thoracic radiographs are not considered useful to guide therapeutic duration. The primary study objective was to determine whether a short course of antimicrobials would be sufficient to treat canine bacterial pneumonia. Eight dogs with uncomplicated bacterial pneumonia were enrolled in this randomized, double-blinded, placebo-controlled study comparing clinical and radiographic resolution with differing durations of antimicrobial therapy. Dogs received a course of antimicrobials lasting 10 (A10) or 21 (A21) days. Dogs randomized to the A10 group received placebo for 11 days following antimicrobial therapy. Patients were evaluated at presentation and 10, 30 and 60 days after the initiation of antimicrobials. At 10 days, 6/8 dogs had resolution of both clinical signs and inflammatory leukogram, and 5/8 dogs had improved global radiographic scores. After 60 days, clinical and hematologic resolution of pneumonia was noted in all dogs regardless of antimicrobial therapy duration; however, 3/8 dogs had persistent radiographic lesions. Thoracic radiographs do not appear to be a reliable marker to guide antimicrobial therapy in canine bacterial pneumonia as radiographic lesions may lag or persist despite clinical cure. This pilot study suggests a 10-day course of antimicrobials may be sufficient to treat uncomplicated canine bacterial pneumonia.

CNS Radiation Necrosis in Pediatric Patients Treated With Pencil-Beam Scanning Proton Therapy: Interim Results From a Phase IV Surveillance Trial

<h3>Purpose/Objective(s)</h3> An interim analysis of a Phase IV clinical trial was performed to estimate the incidence of CNS radiation necrosis (CNS-RN) and identify predictive parameters. <h3>Materials/Methods</h3> At the time of analysis, the trial had accrued 366 patients with CNS and base of skull tumors treated with pencil beam scanning proton therapy (PBS-PT). Patients with a prior history of radiation therapy (n = 32), treatments with no reported dose to the brain (n = 4), or incomplete dosimetry (n = 39) were excluded. Cox proportional hazards models were used to evaluate the impact of interventions on time to resolution. Events were graded according to CTCAE v4 guidelines. Eloquent cortex was defined as a brain region which, when damaged, lead to severe focal neurologic deficits. Brain and brainstem dose volume histograms were pooled to create complication incidence maps for grade 1+ radiation necrosis. The total probability that the true rate of necrosis exceeded 5% in the brainstem and 10% in the brain was estimated at all dose-volume combinations. Intersections at volumes of 0.1cc and 1cc were assessed at probabilities of 10% and 50%. <h3>Results</h3> Twenty-three (n = 23) CNS-RN events, corresponding to 15 grade 1 and 8 grade 3 events, were observed in 291 patients resulting in a 2-year CI in grade 3 necrosis of 6.02% +/- 0.013 (s.e). CNS-RN (any grade) was more common in astrocytic-oligodendroglial, embryonal, and ependymal tumors. PBS-PT attribution was likely or plausible in all but 2 events. Although CNS-RN could not be attributed solely to end-of-range effects, 11 (48%) cases occurred in the region of the cervico-medullary junction. Complete resolution of CNS necrosis occurred in all 8 grade 3 patients and in 12 of 15 (80%) grade 1 events. Grade 3 or more severe events were treated with bevacizumab, corticosteroids, or hyperbaric oxygen therapy. Symptomatic resolution was comparable between treatments although bevacizumab showed an advantage for radiographic resolution (HR 4.3, 95% CI 1.6-11). Factors predictive of symptom resolution were eloquence of the region of necrosis (HR 0.15, 95% CI 0.035-0.67, <i>P</i> = 0.0003) and any chemotherapy exposure (HR 0.16, 95% CI 0.03-0.88, <i>P</i> = 0.034). The probability of true necrosis rate exceeding 5% in brainstem increased from less than 10% to greater than 50% at 58.5CGE to a volume of 0.1cc and 57.7CGE to a volume of 1cc. The probability that the true necrosis rate exceeded 10% in the brain increased from less than 10% to greater than 50% at a dose of 63.1CGE to a volume of 0.1cc. At a volume of 1cc, sparsity of data limited analysis to the less than 50% to greater than 50% probability level, which occurred at 60.5CGE. <h3>Conclusion</h3> Incidence of radiation necrosis was consistent with photon historical data. These data will aid the development of PBS-PT delivery guidelines aimed at minimizing CNS necrosis risk for children requiring RT which involves or approximates the CNS.

P12 Focal myositis—A case series of a rare cause of hip immobility and calf pseudotumor in children

Case report - IntroductionFocal myositis is a rare immune-mediated pseudotumour of a single skeletal muscle group. Only around 200 cases have been described in the literature, so little is known about incidence, prevalence, patient management and outcomes. This differs and should not be confused with post-viral myalgia which bears neither the histological changes nor chronicity of focal myositis. Treatment options are centred on immunomodulation and in severe cases surgical management of contractures.Case report - Case descriptionCase 1A systemically well 7-year-old girl presented with 5-weeks of right calf tenderness and swelling following a short episode of pharyngitis and generalised maculopapular rash. There was no gait abnormality, focal neurology or restriction in activity aside from fatigability on walking distances. There were no skin rashes, joint involvement, eye changes or involvement of other muscles. She had a raised creatine kinase, plasma viscosity and lactate dehydrogenase. Her other blood results were normal including an extended autoimmune screen, immunoglobulins, complement levels, ASOT and titres of mycoplasma, EBV and CMV. MRI showed evidence of extensive inflammation of the gastrocnemius and soleus. A muscle biopsy showed heavy interstitial inflammatory cell infiltrate of predominantly lymphocytes, features of fibre necrosis including phagocytosis and hyalinisation with concurrent fibre regeneration. Case 2A systemically well 14-year-old presented with 6-months of left-sided hip pain, weight loss and inability to weight-bear without crutches. On examination there was painful fixed limitation of the left hip to 45o on abduction and external rotation with bilateral mild swelling of the proximal interphalangeal (PIP) joints on both upper limbs. Otherwise, there was a full range of movement in all joints, with no rashes or other joint swelling or inflammation. Her blood tests were ANA positive 1:6000 and MRI of her hips demonstrated high T2 signal intensity in the left gluteus minimis and medius, obturator internus, obturator externus in keeping with myositis.Case report - DiscussionCase 1She was initially managed with physiotherapy and anti-inflammatory medications but then developed intermittent right calf pain, restriction in activity and tiptoe walking due to gastrocnemius contractures. She was commenced on an 8-week tapering course of oral steroids and is improving with weekly methotrexate.Case 2She received a pulse of corticosteroids followed by a course of methotrexate. There was immediate improvement in her PIP joint swellings and within a few weeks she was able to walk without crutches for the first time in 6 months; a surveillance MRI confirmed complete radiographical resolution of myositis. Unfortunately, 18 months after her diagnosis, she had developed anterior uveitis of her left eye with posterior synechiae; this responded well to steroid and cyclopentolate eye drops.Case report - Key learning pointsWe emphasise that clinicians should bear this rare differential diagnosis for in mind for consideration of early conservative management, assessment for uveitis, immunomodulation and possibly surgical correction to improve patient outcome.

Percutaneous CT-guided corticosteroid injection for the treatment of osseous Langerhans cell histocytosis: a three institution retrospective analysis.

The aim of this study is to evaluate the safety and effectiveness of CT-guided corticosteroid injection for the treatment of osseous Langerhans cell histiocytosis (LCH) in a multi-institutional study. This IRB-approved study included patients from three institutions. We retrospectively reviewed clinical, procedural, and imaging data for corticosteroid injections performed to treat osseous LCH. Location of the lesion, lesion maximum dimension and volume, corticosteroid type and dose, and time interval between injection and change in lesion size/volume and symptoms were recorded. Generalized estimating equations (accounting for multiple lesions per subject) were used to evaluate the association betweenpredictors (dose, maximum lesion dimension, and lesion volume) and outcomes (time to partial and complete radiographic resolution, and time to pain control). This analysis was adjusted by anatomic site. Forty corticosteroid injections were performed in 36 patients (20 (56%) females, and 16 (44%) males, ages 12 ± 11 (2-57) years). Mean lesion maximum dimension was 3.2 ± 1.7cm, and volume was 10 ± 17cm3. Imaging and clinical follow-up were available for 22/40 (55%) and 34/40 (85%) of injections, respectively. All lesions responded to corticosteroid injection. Times to partial and complete imaging resolution were 13 ± 9 and 32 ± 13weeks, respectively, and time to pain resolution was 22 ± 14weeks. There were no complications. CT-guided corticosteroid injection is a safe and effective treatment for LCH. Pain resolution was achieved in all patients and imaging did not show progressive disease in any of the patients.

Are Oral Antibiotics an Effective Alternative to Intravenous Antibiotics in Treatment of Osteomyelitis of the Jaw?

Osteomyelitis of the jaw (OMJ) is unlike osteomyelitis of long bone. It presents unique challenges to treatment due to odontogenic pathways of infection, polymicrobial nature, and need to preserve facial form and function. The majority of osteomyelitis research comes from orthopedic literature. Thus, there is limited guidance for antibiotic administration in OMJ when treated with surgical management1. Current recommendations suggest 6 weeks of intravenous (IV) antibiotics are necessary for resolution of infection2. However, there are numerous complications associated with IV therapy. Recent orthopedic literature has shown oral (PO) is noninferior to IV antibiotic therapy for complex orthopedic infection. The purpose of this study was to review cases of OMJ treated with surgery and adjunctive antibiotics and determine whether antibiotic route (PO versus IV) and/or length of administration impacted resolution of infection.The investigators designed a retrospective cohort study and enrolled a sample of patients treated at Harborview Medical Center (HMC) from January 1st 2009 to December 31st 2019. (STUDY00007337). The primary predictor variable was antibiotic administration route: oral (PO) only, intravenous (IV) only, IV transitioned to oral (IV+PO), or none. The secondary predictor was duration of antibiotic therapy (≤6 weeks or >6 weeks). The primary outcome variable was resolution of infection, deemed as clinical and radiographic resolution. The secondary outcome variable was number of operative interventions to resolution of infection. Statistical analysis was performed using IBM SPSS 27.0 (SPSS, Inc, Chicago, IL). Descriptive, bivariate, and multiple linear regression statistics were computed, with statistical significance set at p < 0.05.Sixty-seven subjects met the inclusion criteria (38 male), mean age 51 years (18-88). Forty-nine (73%) were treated with PO antibiotics only, 12 (18%) with IV+PO, 3 (4%) with IV only, and 3 (4%) received none. Both PO and IV antibiotics were significantly associated with clinical resolution (p=0.022, 0.005, respectively), compared to debridement alone. However, antibiotic duration of ≤6 weeks compared to >6 weeks was not significant. The majority (84% [41 out of 49]) of PO subjects achieved resolution with one surgery. Eight of 49 (16%) required additional surgeries with a mean of 1.27 (1-4). Fifteen (22%) subjects received IV antibiotics, including subjects who were in the IV only and IV+PO categories. Three of 15 (20%) were IV only, and 12 of 15 (80%) were IV+PO – meaning they were discharged with variable lengths of IV antibiotics and transitioned to PO. Seven of 15 (46%) had clinical resolution after one surgery, while 8 (54%) required additional procedures with a mean of 1.87 (1-5). Identified sources of OMJ were odontogenic (59%), trauma (31%), or dental implant-associated (13%). In the multivariate logistic regression, PO antibiotics were positively associated with clinical outcome (p=0.025, OR=5.05). Regardless of the length of antibiotic therapy, PO subjects were approximately 5 times more likely have clinical resolution without additional surgery. Penicillin allergy (p=0.049, OR=0.223) and diabetes (p=0.008, OR=0.104) were adversely associated with clinical resolution.OMJ can be successfully treated with PO antibiotics and appropriate surgery. IV therapy did not offer an advantage over PO medication in our cohort and is known to be associated with increased complications and cost. While further studies with larger cohorts are recommended, reflexively prescribing 6 weeks of IV antibiotics as preliminary therapy seems antiquated. Clinicians should consider oral penicillins as first line whenever possible.

Long term outcomes following pyeloplasty for unilateral pelviureteric junction obstruction in paediatric patients

Background: Pelviureteric junction obstruction (PUJO) is the most common cause of pediatric hydronephrosis. The gold standard treatment for PUJO is Anderson hynes (AH) dismembered pyeloplasty. The parameters to assess the post-operative outcomes of pyeloplasty include reduction in the AP diameter of the pelvis and increase in parenchymal thickness. The aim of the study was to find out the long-term outcomes following pyeloplasty for Ureteropelvic junction obstruction (UPJO) in paediatric patients.Methods: A prospective study was done from September, 2014 to January, 2019. All children above the age of 2 months who presented with unilateral PUJO were included in the study. All patients underwent ultrasound of the kidneys and diuretic renogram. All patients underwent AH dismembered pyeloplasty. Success was defined as both symptomatic relief and radiographic resolution of obstruction at the last follow-up visit.Results: 60 patients with unilateral intrinsic PUJO were included in this study. Post-operatively split renal function (SRF) improved in 42 patients, remained stable in 13, and deteriorated in 5 cases. Post-operative renal drainage improved in 40 patients, remained stable in 15 and deteriorated in 5. The degree of hydronephrosis deteriorated in 5 cases but improved or was preserved in 55 cases. The renal parenchyma deteriorated in 7 cases. Overall success rate of AH dismembered pyeloplasty was 92%.Conclusions: Dismembered pyeloplasty is a safe and effective treatment of PUJO in the pediatric population. Majority of the patients had an improved split renal function, renal drainage, cortical thickness, and decreased degree of hydronephrosis.

Endovascular embolization of high-grade cerebral dural arteriovenous fistulas - assessment of long-term recurrences.

Endovascular therapy has shown to be safe and effective for the treatment of cerebral dural arteriovenous fistulas; however, recurrence after complete occlusion is not uncommon, and the timing of recurrence remains unknown. A retrospective single-center cohort study was conducted from January 2005 to December 2020. Patients with high-grade (≥Borden II-Cognard IIB) dural arteriovenous fistulas treated with endovascular therapy were included in this study. Clinical and angiographic characteristics were collected for hospitalization and at follow-up. A total of 51 patients with a median age of 61 years were studied; 57% were female. High-flow symptoms related to the high-flow fistula were the most common presentation (67%), and 24% presented with intracranial hemorrhage. Transverse-sigmoid (26%) and cavernous (26%) sinuses were the most common dural arteriovenous fistula locations. A total of 40 patients (70%) had middle meningeal arterial feeders and 4 (7%) had deep cerebral venous drainage. The mean number of embolization procedures per patient was 1.4. Transarterial access was the most frequent approach (61%). Onyx alone was the most common embolic agent (26%). Complete occlusion rate was achieved in 46 patients (80.1%). Last mean radiographic follow-up time was 26.7 months for all 57 dural arteriovenous fistulas. Dural arteriovenous fistula recurrence after radiographic resolution at last treatment was seen in six cases (6/46, 13.1%). Mean time for recurrence was 15.8 months. Mean time of last clinical follow-up was 46.1 months for the 51 patients (100%). A total of 10 (20%) experienced any procedural complications, among which two (4%) became major thromboembolic events. Endovascular therapy is safe and effective for the treatment of high-grade dural arteriovenous fistulas. Given the significant recurrence rate of embolized dural arteriovenous fistulas even after 2 years, long-term angiographic follow-up might be needed.