Impact of 18F-FDG PET Intensity Normalization on Radiomic Features of Oropharyngeal Squamous Cell Carcinomas and Machine Learning-Generated Biomarkers

We aimed to investigate the effects of 18F-FDG PET voxel intensity normalization on radiomic features of oropharyngeal squamous cell carcinoma (OPSCC) and machine learning-generated radiomic biomarkers. Methods: We extracted 1,037 18F-FDG PET radiomic features quantifying the shape, intensity, and texture of 430 OPSCC primary tumors. The reproducibility of individual features across 3 intensity-normalized images (body-weight SUV, reference tissue activity ratio to lentiform nucleus of brain and cerebellum) and the raw PET data was assessed using an intraclass correlation coefficient (ICC). We investigated the effects of intensity normalization on the features' utility in predicting the human papillomavirus (HPV) status of OPSCCs in univariate logistic regression, receiver-operating-characteristic analysis, and extreme-gradient-boosting (XGBoost) machine-learning classifiers. Results: Of 1,037 features, a high (ICC ≥ 0.90), medium (0.90 > ICC ≥ 0.75), and low (ICC < 0.75) degree of reproducibility across normalization methods was attained in 356 (34.3%), 608 (58.6%), and 73 (7%) features, respectively. In univariate analysis, features from the PET normalized to the lentiform nucleus had the strongest association with HPV status, with 865 of 1,037 (83.4%) significant features after multiple testing corrections and a median area under the receiver-operating-characteristic curve (AUC) of 0.65 (interquartile range, 0.62-0.68). Similar tendencies were observed in XGBoost models, with the lentiform nucleus-normalized model achieving the numerically highest average AUC of 0.72 (SD, 0.07) in the cross validation within the training cohort. The model generalized well to the validation cohorts, attaining an AUC of 0.73 (95% CI, 0.60-0.85) in independent validation and 0.76 (95% CI, 0.58-0.95) in external validation. The AUCs of the XGBoost models were not significantly different. Conclusion: Only one third of the features demonstrated a high degree of reproducibility across intensity-normalization techniques, making uniform normalization a prerequisite for interindividual comparability of radiomic markers. The choice of normalization technique may affect the radiomic features' predictive value with respect to HPV. Our results show trends that normalization to the lentiform nucleus may improve model performance, although more evidence is needed to draw a firm conclusion.

Bench-to-bedside imaging in brain metastases: a road to precision oncology

Radiology has seen tremendous evolution in the last few decades. At the same time, oncology has made great strides in diagnosing and treating cancer. Distant metastases of neoplasms are being encountered more often in light of longer patient survival due to better therapeutic strategies and diagnostic methods. Brain metastasis (BM) is a dismal manifestation of systemic cancer. In the present scenario, magnetic resonance imaging (MRI), computed tomography (CT) and positron emission tomography (PET) are playing a big role in providing molecular information about cancer. Lately, molecular imaging has emerged as a stirring arena of dynamic imaging techniques that have enabled clinicians and scientists to noninvasively visualize and understand biological processes at the cellular and molecular levels. This knowledge has impacted etiopathogenesis, detection, personalized treatment, drug development, and our understanding of carcinogenesis. This article offers insight into the molecular biology underlying brain metastasis, its pathogenesis, imaging protocols, and algorithms. It also discusses disease-specific molecular imaging features, focusing on common tumors that spread to the brain, such as lung, breast, colorectal cancer, melanoma, and renal cell carcinoma. Additionally, it covers various targeted treatment options, criteria for assessing treatment response, and the role of artificial intelligence in diagnosing, managing, and predicting prognosis for patients with brain metastases.

Post-treatment imaging of gliomas: challenging the existing dogmas

Gliomas are the commonest malignant central nervous system tumours in adults and imaging is the cornerstone of diagnosis, treatment, and post-treatment follow-up of these patients. With the ever-evolving treatment strategies post-treatment imaging and interpretation in glioma remains challenging, more so with the advent of anti-angiogenic drugs and immunotherapy, which can significantly alter the appearance in this setting, thus making interpretation of routine imaging findings such as contrast enhancement, oedema, and mass effect difficult to interpret. This review details the various methods of management of glioma including the upcoming novel therapies and their impact on imaging findings, with a comprehensive description of the imaging findings in conventional and advanced imaging techniques. A systematic appraisal for the existing and emerging techniques of imaging in these settings and their clinical application including various response assessment guidelines and artificial intelligence based response assessment will also be discussed.

Cost-Effectiveness of CT, CTA, MRI, and Specialized MRI for Evaluation of Patients Presenting to the Emergency Department With Dizziness

BACKGROUND. Underlying stroke is often misdiagnosed in patients presenting with dizziness. Although such patients are usually ineligible for acute stroke treatment, accurate diagnosis may still improve outcomes through selection of patients for secondary prevention measures. OBJECTIVE. The purpose of our study was to investigate the cost-effectiveness of differing neuroimaging approaches in the evaluation of patients presenting to the emergency department (ED) with dizziness who are not candidates for acute intervention. METHODS. A Markov decision-analytic model was constructed from a health care system perspective for the evaluation of a patient presenting to the ED with dizziness. Four diagnostic strategies were compared: noncontrast head CT, head and neck CTA, conventional brain MRI, and specialized brain MRI (including multiplanar high-resolution DWI). Differing long-term costs and outcomes related to stroke detection and secondary prevention measures were compared. Cost-effectiveness was calculated in terms of lifetime expenditures in 2022 U.S. dollars for each quality-adjusted life year (QALY); deterministic and probabilistic sensitivity analyses were performed. RESULTS. Specialized MRI resulted in the highest QALYs and was the most cost-effective strategy with US$13,477 greater cost and 0.48 greater QALYs compared with noncontrast head CT. Conventional MRI had the next-highest health benefit, although was dominated by extension with incremental cost of US$6757 and 0.25 QALY; CTA was also dominated by extension, with incremental cost of US$3952 for 0.13 QALY. Non-contrast CT alone had the lowest utility among the four imaging choices. In the deterministic sensitivity analyses, specialized MRI remained the most cost-effective strategy. Conventional MRI was more cost-effective than CTA across a wide range of model parameters, with incremental cost-effectiveness remaining less than US$30,000/QALY. Probabilistic sensitivity analysis yielded similar results as found in the base-case analysis, with specialized MRI being more cost-effective than conventional MRI, which in turn was more cost-effective than CTA. CONCLUSION. The use of MRI in patients presenting to the ED with dizziness improves stroke detection and selection for subsequent preventive measures. MRI-based evaluation leads to lower long-term costs and higher cumulative QALYs. CLINICAL IMPACT. MRI, incorporating specialized protocols when available, is the preferred approach for evaluation of patients presenting to the ED with dizziness, to establish a stroke diagnosis and to select patients for secondary prevention measures.

Routine sterile glove and instrument change at the time of abdominal wound closure to prevent surgical site infection (ChEETAh): a model-based cost-effectiveness analysis of a pragmatic, cluster-randomised trial in seven low-income and middle-income countries

BACKGROUND

Surgical site infection (SSI) is a major burden on patients and health systems. This study assessed the cost-effectiveness of routine change of sterile gloves and instruments before abdominal wall closure to prevent SSI.

METHODS

A decision-analytic model was built to estimate average costs and outcomes of changing gloves and instruments before abdominal wall closure compared with current practice. Clinical data were obtained from the ChEETAh trial, a multicentre, cluster-randomised trial in seven low-income and middle-income countries (LMICs), and costs were obtained from a study (KIWI) that assessed costs associated with SSIs in LMICs. Outcomes were measured as the percentage of surgeries resulting in SSIs. Costs were measured from a health-care provider perspective and were reported in 2021 US$. The economic analysis used a partially split single-country costing approach, with pooled outcomes data from all seven countries in the ChEETAh trial, and data for resource use and unit costs from India (KIWI); secondary analyses used resource use and costs from Mexico and Ghana (KIWI).

FINDINGS

In the base case, the average cost of the intervention was $259∙92 compared with $261∙10 for current practice (cost difference -$1∙18, 95% CI -4∙08 to 1∙33). In the intervention group, an estimated 17∙6% of patients had an SSI compared with 19∙7% of patients in the current practice group (absolute risk reduction 2∙10%, 95% CI 2∙07-2∙84). At all cost-effectiveness thresholds assumed ($0 to $14 000), the intervention had a higher likelihood of being cost-effective compared with current practice, indicating that the intervention was cost-effective. Similar results were obtained when the analysis using data from India was repeated using resource use and unit cost data from Mexico and Ghana.

INTERPRETATION

Routine sterile glove and instrument change before abdominal wall closure is effective and the costs are similar to those for current practice. Routine change of gloves and instruments before abdominal wall closure should be rolled out in LMICs.

FUNDING

National Institute for Health and Care Research (NIHR) Clinician Scientist Award, NIHR Global Health Research Unit Grant, and Mölnlycke Healthcare.

Does Frontal Recess Cell Variation Associate with the Development of Frontal Sinusitis? A Narrative Review

Chronic rhinosinusitis (CRS) can have a significant impact on quality of life. With persistent symptoms and the failure of initial medical treatments, surgical management is indicated. Despite the excellent results of endoscopic sinus surgery for persistent CRS, it is quite a challenging procedure for frontal sinusitis given the complex anatomy and location of the frontal sinus. Frontal recess cells significantly contribute to the complexity of the frontal sinus, and numerous studies have sought to establish their association with sinusitis. This review offers a comprehensive understanding of frontal recess cells, their different classifications, their prevalence among different populations, and their relationship to sinusitis. After an extensive review of the current literature, the International Frontal Sinus Anatomy Classification (IFAC) is the most recent classification method and a preferred practical preoperative assessment tool. Although the agger nasi cell is the most prevalent cell among all reported populations, ethnic variations are still influencing the other cells' distribution. Studies are inconsistent in reporting a relationship between frontal recess cells and sinusitis, and that is mainly because of the differences in the classification methods used. More research using a standardized classification method is needed to understand the association between frontal recess cells and sinusitis.

Evaluation of a quality improvement intervention to reduce anastomotic leak following right colectomy (EAGLE): pragmatic, batched stepped-wedge, cluster-randomized trial in 64 countries

BACKGROUND

Anastomotic leak affects 8 per cent of patients after right colectomy with a 10-fold increased risk of postoperative death. The EAGLE study aimed to develop and test whether an international, standardized quality improvement intervention could reduce anastomotic leaks.

METHODS

The internationally intended protocol, iteratively co-developed by a multistage Delphi process, comprised an online educational module introducing risk stratification, an intraoperative checklist, and harmonized surgical techniques. Clusters (hospital teams) were randomized to one of three arms with varied sequences of intervention/data collection by a derived stepped-wedge batch design (at least 18 hospital teams per batch). Patients were blinded to the study allocation. Low- and middle-income country enrolment was encouraged. The primary outcome (assessed by intention to treat) was anastomotic leak rate, and subgroup analyses by module completion (at least 80 per cent of surgeons, high engagement; less than 50 per cent, low engagement) were preplanned.

RESULTS

A total 355 hospital teams registered, with 332 from 64 countries (39.2 per cent low and middle income) included in the final analysis. The online modules were completed by half of the surgeons (2143 of 4411). The primary analysis included 3039 of the 3268 patients recruited (206 patients had no anastomosis and 23 were lost to follow-up), with anastomotic leaks arising before and after the intervention in 10.1 and 9.6 per cent respectively (adjusted OR 0.87, 95 per cent c.i. 0.59 to 1.30; P = 0.498). The proportion of surgeons completing the educational modules was an influence: the leak rate decreased from 12.2 per cent (61 of 500) before intervention to 5.1 per cent (24 of 473) after intervention in high-engagement centres (adjusted OR 0.36, 0.20 to 0.64; P < 0.001), but this was not observed in low-engagement hospitals (8.3 per cent (59 of 714) and 13.8 per cent (61 of 443) respectively; adjusted OR 2.09, 1.31 to 3.31).

CONCLUSION

Completion of globally available digital training by engaged teams can alter anastomotic leak rates. Registration number: NCT04270721 (http://www.clinicaltrials.gov).

CT With CTA Versus MRI in Patients Presenting to the Emergency Department With Dizziness: Analysis Using Propensity Score Matching

BACKGROUND. CT with CTA is widely used to exclude stroke in patients with dizziness, although MRI has higher sensitivity. OBJECTIVE. The purpose of this article was to compare patients presenting to the emergency department (ED) with dizziness who undergo CT with CTA alone versus those who undergo MRI in terms of stroke-related management and outcomes. METHODS. This retrospective study included 1917 patients (mean age, 59.5 years; 776 men, 1141 women) presenting to the ED with dizziness from January 1, 2018, to December 31, 2021. A first propensity score matching analysis incorporated demographic characteristics, medical history, findings from the review of systems, physical examination findings, and symptoms to construct matched groups of patients discharged from the ED after undergoing head CT with head and neck CTA alone and patients who underwent brain MRI (with or without CT and CTA). Outcomes were compared. A second analysis compared matched patients discharged after CT with CTA alone and patients who underwent specialized abbreviated MRI using multiplanar high-resolution DWI for increased sensitivity for posterior circulation stroke. Sensitivity analyses were performed involving MRI examinations performed as the first or only neuroimaging examination and involving alternative matching and imputation techniques. RESULTS. In the first analysis (406 patients per group), patients who underwent MRI, compared with patients who underwent CT with CTA alone, showed greater frequency of critical neuroimaging results (10.1% vs 4.7%, p = .005), change in secondary stroke prevention medication (9.6% vs 3.2%, p = .001), and subsequent echocardiography evaluation (6.4% vs 1.0%, p < .001). In the second analysis (100 patients per group), patients who underwent specialized abbreviated MRI, compared with patients who underwent CT with CTA alone, showed greater frequency of critical neuroimaging results (10.0% vs 2.0%, p = .04), change in secondary stroke prevention medication (14.0% vs 1.0%, p = .001), and subsequent echocardiography evaluation (12.0% vs 2.0%, p = .01) and lower frequency of 90-day ED readmissions (12.0% vs 28.0%, p = .008). Sensitivity analyses showed qualitatively similar findings. CONCLUSION. A proportion of patients discharged after CT with CTA alone may have benefitted from alternative or additional evaluation by MRI (including MRI using a specialized abbreviated protocol). CLINICAL IMPACT. Use of MRI may motivate clinically impactful management changes in patients presenting with dizziness.

A bedside to bench study of anti-PD-1, anti-CD40, and anti-CSF1R indicates that more is not necessarily better

BACKGROUND

Stimulating inflammatory tumor associated macrophages can overcome resistance to PD-(L)1 blockade. We previously conducted a phase I trial of cabiralizumab (anti-CSF1R), sotigalimab (CD40-agonist) and nivolumab. Our current purpose was to study the activity and cellular effects of this three-drug regimen in anti-PD-1-resistant melanoma.

METHODS

We employed a Simon's two-stage design and analyzed circulating immune cells from patients treated with this regimen for treatment-related changes. We assessed various dose levels of anti-CSF1R in murine melanoma models and studied the cellular and molecular effects.

RESULTS

Thirteen patients were enrolled in the first stage. We observed one (7.7%) confirmed and one (7.7%) unconfirmed partial response, 5 patients had stable disease (38.5%) and 6 disease progression (42.6%). We elected not to proceed to the second stage. CyTOF analysis revealed a reduction in non-classical monocytes. Patients with prolonged stable disease or partial response who remained on study for longer had increased markers of antigen presentation after treatment compared to patients whose disease progressed rapidly. In a murine model, higher anti-CSF1R doses resulted in increased tumor growth and worse survival. Using single-cell RNA-sequencing, we identified a suppressive monocyte/macrophage population in murine tumors exposed to higher doses.

CONCLUSIONS

Higher anti-CSF1R doses are inferior to lower doses in a preclinical model, inducing a suppressive macrophage population, and potentially explaining the disappointing results observed in patients. While it is impossible to directly infer human doses from murine studies, careful intra-species evaluation can provide important insight. Cabiralizumab dose optimization is necessary for this patient population with limited treatment options.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT03502330.

Stereotactic Radiosurgery (SRS) for Large Brain Metastases: Dosimetric and Clinical Predictors of Local Progression and Radionecrosis

PURPOSE/OBJECTIVE(S)

Stereotactic radiosurgery (SRS) provides high rates of local control for small brain metastases with low rates of radionecrosis (RN). Larger targets are associated with increased risk of both local progression (LP) and RN. In this analysis, we hypothesized that dosimetric and clinical parameters predict for risk of LP and RN in SRS targets larger than two centimeters.

MATERIALS/METHODS

We retrospectively reviewed patients with one or more targets with either an intact versus post-operative cavity larger than 2.0 cm treated with LINAC-based SRS between 2017 and 2022 at one institution. We assessed for association between patient, treatment, and disease variables with LP and RN. Variables assessed included tumor resection status, PDL1 positivity, target volume, maximum and minimum target dose, EQD2 and BED (a/b = 2 for necrosis and a/b = 10 for tumor control), as well as receipt of steroids, bevacizumab, or systemic therapy before or after SRS. Radionecrosis was determined by characteristic radiographic changes. Analyses were performed for the entire cohort and within subsets including by resection status and dose fractionation.

RESULTS

A total of 178 lesions in 143 patients were included. Targets with volume diameters measuring at least 2 cm were used. Median follow-up was 2.3 years. Overall survival at 1 and 2 years was 56% and 32%, respectively. Most lesions (n = 119) were resected and treated with SRS post-operatively. The most common dose and fractionation schemes used were 30 Gy in 5 fractions (n = 89) and 27 Gy in 3 fractions (n = 63). For the entire cohort, the cumulative incidence of LP 1 and 2 years was 26% and 34%, respectively. The cumulative incidence of radiographic radionecrosis at 1 and 2 years was 12% and 17%, respectively. There was no difference in LP or RN between 27 Gy in 3 fractions versus 30 Gy in 5 fractions (p>0.5 for both). Median planning target volume (PTV) size was 18.5 cc for the 27 Gy in 3 fraction group compared to 21.9 cc in the 30 Gy in 5 fraction group. Minimum or maximum dose within the target was not associated with increased risk of LP or RN. Among patients receiving 27 Gy in 3 fractions, patients treated with resection followed by SRS had lower risk of LP compared to those treated with SRS alone (HR: 0.15, 95% CI: 0.03-0.64, p = 0.011). Among patients receiving 30 Gy in 5 fractions, patients who received corticosteroids prior to SRS had a lower risk of RN (HR: 0.14, 95% CI: 0.03-0.66, p = 0.013). For the entire cohort as well as within all subgroups, PD-L1≥1% was associated with increased risk of RN (p<0.001 for all).

CONCLUSION

Selecting the optimal SRS dose fractionation and planning parameters to minimize both LP and RN remains a challenge for large targets. In this analysis, 27 Gy in 3 fractions appeared to provide equivalent LP and RN compared to 30 Gy in 5 fractions, and may be more convenient for patients. Patients with PD-L1≥1% with large brain targets treated with SRS may be at increased risk of RN; corticosteroid prophylaxis may be considered in this population.

Memantine for Pediatric Patients Receiving Cranial Irradiation: A Pilot Study

PURPOSE/OBJECTIVE(S)

While memantine has become standard in certain adults receiving brain RT to decrease the cognitive impacts of RT, it is unknown whether pediatric patients can take and tolerate memantine or experience benefit. In this prospective single-arm feasibility study, we hypothesized pediatric patients receiving brain RT would tolerate memantine with good treatment adherence.

MATERIALS/METHODS

Patients aged 4-18 years with a primary CNS malignancy (excluding WHO Grade IV astrocytoma and glioblastoma) receiving intracranial RT were eligible. A 6-month course of memantine was given during and after RT. Dosing began once daily at 5 mg with up-titration in 5 mg increments over 4 weeks to a weight-based maximum (0.4 mg/kg to the closest 5 mg), not to exceed 10 mg BID. To reduce patient and clinical research associate (CRA) burden, medication adherence was tracked via the Medisafe Pill and Reminder application which study staff helped install on the patient or parent's smart phone. A paper pill diary was provided for those unable to use the app. The primary endpoint was to achieve 80% adherence rate to memantine in 80% of patients measured 1-month post-RT.

RESULTS

Eighteen patients (14 male and 4 female, median age 11.5 years (range: 4-18)) were enrolled from 2020-2022. The study closed early after enrolling 18 of 20 planned patients to avoid competing with the phase III randomized Children's Oncology Group (COG) study AACL2031. One patient withdrew for cognition-altering substance-use, leaving 17 patients with data available for analysis. Histologies included germ cell tumor (n = 6), craniopharyngioma (n = 3), choroid plexus papilloma (n = 2), ependymoma (n = 2), glial/astrocytoma (n = 2), medulloblastoma (n = 1), and meningioma (n = 1). Thirteen had surgery, and 9 received chemotherapy. Eight received craniospinal irradiation (CSI). Median RT dose was 54 Gy (range 36-59.4) in 30 fractions (range: 20-33). At data freeze, all 17 had passed the 1-month post-RT time point. One patient discontinued memantine after a single dose due to nausea. Pill-reports were available for 14 of the remaining 16; two patients did not complete digital pill logs. For those with complete logs, all adherence rates were above 80%, with a median of 99.32% pill completion rate (range: 92.67-100). Seven (50%) took 100% of prescribed doses. Irrespective of adherence for the 2 unavailable for evaluation, the primary endpoint was still achieved. Grade 1 toxicities included headache (n = 6, 35%) and constipation (n = 1, 6%); there were no grade 2+ toxicities. At last follow-up, 15/16 have completed the full 6-month memantine course. Secondary endpoints including neurocognitive evaluations have not yet been met and will be the subject of future reports.

CONCLUSION

Memantine is a feasible and well-tolerated addition to multi-modality treatment for pediatric brain tumors. Secondary endpoints of this study and results of the ongoing COG study are awaited to define the value of memantine in this population.

Clinical Outcomes for Chest Wall Ewing Sarcoma: A Multi-Center Single Institution Experience

PURPOSE/OBJECTIVE(S)

We report tumor and treatment characteristics, oncologic outcomes, and treatment-associated toxicities in a cohort of chest wall Ewing sarcoma (cwES) patients treated at a single tertiary care institution.

MATERIALS/METHODS

After IRB approval, patients with cwES treated from 1997-2022 were retrospectively reviewed. Patient, tumor, treatment, outcomes, and toxicity data were abstracted. Local control (LC), progression-free survival (PFS), and overall survival (OS) were defined from end of treatment and assessed using the Kaplan-Meier method. Log-rank test and unadjusted Cox models were performed to determine factors associated with outcomes.

RESULTS

The cohort includes 45 patients. Median age at diagnosis was 19.8 years (range: 3.5 - 57.8 years). Five patients (11.1%) presented with pleural effusion and eight patients with lung metastases (17.8%). Two (4.4%) patients had metastatic disease outside the thorax. Median tumor volume (TV) was 138.6 mL (range: 3.0-6762.0 mL). All patients received VDC/IE chemotherapy. LC modality was surgery (S) in 21 patients (47%), radiation therapy (RT) in 5 (11%), and S+RT in 19 (42%). Median TV was larger in S+RT patients (319.4 mL, range: 5.3-6761.9 mL) compared to RT (152.3 mL, range: 20.4-366.9 mL) or S (70.4 mL, range: 3.1-1037.8 mL) (p = 0.03). R0 and R1 resections were performed in 36 (90%) and 4 (10%) patients, respectively. Proton beam therapy was used in 15 (63%) patients. Median dose was 50.40 Gy (range: 34.2 - 60 Gy) in 28 fractions to the primary tumor or post operative bed. Median dose for hemithorax (1 patient, 2.2%) and whole lung irradiation (7 patients, 15.6%) was 15.0 Gy (range: 15.0-15.0 Gy) in 10 fractions. Median follow-up was 2.38 years (range: 0 - 21.90 years). Five-year LC, PFS, and OS for all patients was 77.9% (95% CI, 65.3 - 92.9%), 54.2% (95% CI, 39.9 - 73.5%), and 63.5% (95% CI, 49.3 - 81.8%), respectively. In patients with localized disease, 5-year LC, PFS, and OS were 82.4% (95% CI, 67.9-99.8%), 66.4% (95% CI, 49.7-88.8%), and 71.3% (95% CI, 54.2-93.9%), respectively. Two-year LC by modality was 100% for RT (95% CI, 100-100%), 84.2% (95% CI, 69.3- 100%) for S and 73.3% (95% CI, 54 - 99.5%) for S+RT (p = 0.51). On univariate analysis, TV ≥ 200 mL was associated with a significantly worse 5-year OS (49.5%, TV ≥ 200 mL vs. 80.8%, TV < 200 mL; HR 4.44, p = 0.032) and PFS (35.2%, TV ≥ 200 mL vs. 76%, TV < 200 mL; HR 3.55, p = 0.025). TV ≥ 200 mL trended towards worse 5-year LC: 69.2% for TV ≥ 200 mL versus 81.5% for TV <200 mL [HR 2.26(95% CI 0.49 - 10.47), p = 0.287]. Overall, low rates of grade ≥2 toxicity were observed: 4 (8.9%) fatigue, 4 (8.9%) radiation dermatitis, 1 (2.2%) chyle leak, 3 (6.6%) scoliosis, 4 (8.9%) infection, 1 (2.2%) pneumonia, and 1 (2.2%) chest wall deformity.

CONCLUSION

RT is a safe, effective local therapy for small to moderate cwES tumors. Patients with TV ≥ 200 mL had significantly worse survival outcomes and an inferior LC rate. This suggests large cwES tumors may benefit from an aggressive multi-modality approach.

Spot Scanning Proton Therapy for Pregnant Patients with Brain and Head and Neck Tumors

PURPOSE/OBJECTIVE(S)

When radiotherapy is medically necessary, x-ray based treatments (XRT) have traditionally been used to treat pregnant patients. Treatment planning and delivery techniques may be modified to minimize dose to the fetus but results in less optimal plans due to avoiding posterior beams or arcs. Monte Carlo calculations and published case studies suggest spot scanning proton therapy (PRT) reduces the equivalent dose to the fetus by a factor of 10 compared to XRT and does not require modified treatment planning techniques. However, due to concern for dose uncertainties and neutron scatter with PRT, few centers have adopted PRT over XRT for pregnant patients. The purpose of this work is to perform a retrospective study on the pregnant patients previously treated at our institution with XRT to measure the equivalent dose that would be delivered to the fetus with spot scanning PRT compared to XRT.

MATERIALS/METHODS

PRT plans were made for seven pregnant patients, 4 brain tumors and 3 head and neck tumors, who had received XRT. Due to the finite range of protons, the fetal exposure is dominated by neutrons and not the primary beam. Thus, no beam arrangement modifications were required to minimize fetal dose for PRT plans. Fetal dose measurements were performed with the patient plans using a Rando phantom and Wendi-2 (Thermo Scientific) meter placed at the phantom's abdomen. The Wendi-2 measures ambient dose equivalent, which accounts for the biological effect of the neutron energies. Measurements were made at various distances from isocenter to the center of the detector. The total dose equivalent from PRT at several out of field distances was compared to that from XRT. Patient specific measurements were used to determine the total fetal dose from each modality, accounting for the changing position of the fetus each week of the mother's treatment. The imaging dose for standard of practice imaging, including verification CT scans and daily alignment imaging, was also evaluated using a similar setup with a Fluke 451 dose meter.

RESULTS

The average measured fetal equivalent dose for the brain plans was 0.4 mSv for PRT and 7 mSv for XRT. For the head and neck plans, it was 6 mSv for PRT and 90 mSv for XRT. The dose from PRT was consistently at least a factor of 10 less than the XRT plans. In addition, the PRT plans were preferred by the physicians when considering tumor coverage and other normal tissue sparing. Daily imaging added between 0.05 and 1.5 mSv to the total dose in the PRT treatments.

CONCLUSION

This retrospective study showed that when treating brain or head and neck tumors in pregnant patients, the equivalent dose a fetus would receive with PRT is approximately a factor of 10 less than XRT without making any compromises in treatment planning. These results support changing the standard of practice to utilizing spot scanning PRT as the preferred method for treating pregnant patients with brain or head and neck tumors when available instead of XRT. We have brought this process to clinic at our center.

Trends of surgical-care delivery during the COVID-19 pandemic: A multi-centre study in India (IndSurg Collaboration)

Context

The COVID-19 pandemic and subsequent lockdowns adversely affected global healthcare services to varying extents. To accommodate its added burden, emergency services were affected along-with elective surgeries.

Aims

To quantify and analyze the trends of essential surgeries and bellwether procedures during the waxing and waning of the pandemic, across various hospitals in India.

Settings and Design

Multi-centric retrospective study.

Methods and Material

A research consortium led by World Health Organization (WHO) Collaboration Center (WHOCC) for Research in Surgical Care Delivery in Low-and Middle-Income countries, India, conducted this study with 5 centers. All surgeries performed during April 2020 (Wave I), November 2020 (Recovery I), and April 2021 (Wave II) were compared with those performed in April 2019 (pre-pandemic period).

Statistical Analysis Used

Microsoft Excel 2019 and SPSS Version 20.

Results

The total number of surgeries reduced by 77% during Wave I, which improved to a 52% reduction in Recovery I compared to the pre-pandemic period. However, surgeries were reduced again during Wave II to 68%, but the reduction was less compared to Wave I. Emergency and essential surgeries were affected along with the elective ones but to a lesser extent.

Conclusions

The present study has quantified the effects of the pandemic on surgical-care delivery across a timeline and documented a reduction in overall surgical volumes during the peaks of the pandemic (Wave I and II) with minimal improvement as the surge of COVID-19 cases declined (Recovery II). The surgical volumes improved during the second wave compared to the first one which may be attributable to better preparedness. Cesarean sections were affected the least.

Imaging Analytics using Artificial Intelligence in Oncology: A Comprehensive Review

The present era has seen a surge in artificial intelligence-related research in oncology, mainly using deep learning, because of powerful computer hardware, improved algorithms and the availability of large amounts of data from open-source domains and the use of transfer learning. Here we discuss the multifaceted role of deep learning in cancer care, ranging from risk stratification, the screening and diagnosis of cancer, to the prediction of genomic mutations, treatment response and survival outcome prediction, through the use of convolutional neural networks. Another role of artificial intelligence is in the generation of automated radiology reports, which is a boon in high-volume centres to minimise report turnaround time. Although a validated and deployable deep-learning model for clinical use is still in its infancy, there is ongoing research to overcome the barriers for its universal implementation and we also delve into this aspect. We also briefly describe the role of radiomics in oncoimaging. Artificial intelligence can provide answers pertaining to cancer management at baseline imaging, saving cost and time. Imaging biobanks, which are repositories of anonymised images, are also briefly described. We also discuss the commercialisation and ethical issues pertaining to artificial intelligence. The latest generation generalist artificial intelligence model is also briefly described at the end of the article. We believe this article will not only enrich knowledge, but also promote research acumen in the minds of readers to take oncoimaging to another level using artificial intelligence and also work towards clinical translation of such research.

Exploring the cost-effectiveness of high versus low perioperative fraction of inspired oxygen in the prevention of surgical site infections among abdominal surgery patients in three low- and middle-income countries

Background

This study assessed the potential cost-effectiveness of high (80-100%) vs low (21-35%) fraction of inspired oxygen (FiO2) at preventing surgical site infections (SSIs) after abdominal surgery in Nigeria, India, and South Africa.

Methods

Decision-analytic models were constructed using best available evidence sourced from unbundled data of an ongoing pilot trial assessing the effectiveness of high FiO2, published literature, and a cost survey in Nigeria, India, and South Africa. Effectiveness was measured as percentage of SSIs at 30 days after surgery, a healthcare perspective was adopted, and costs were reported in US dollars ($).

Results

High FiO2 may be cost-effective (cheaper and effective). In Nigeria, the average cost for high FiO2 was $216 compared with $222 for low FiO2 leading to a -$6 (95% confidence interval [CI]: -$13 to -$1) difference in costs. In India, the average cost for high FiO2 was $184 compared with $195 for low FiO2 leading to a -$11 (95% CI: -$15 to -$6) difference in costs. In South Africa, the average cost for high FiO2 was $1164 compared with $1257 for low FiO2 leading to a -$93 (95% CI: -$132 to -$65) difference in costs. The high FiO2 arm had few SSIs, 7.33% compared with 8.38% for low FiO2, leading to a -1.05 (95% CI: -1.14 to -0.90) percentage point reduction in SSIs.

Conclusion

High FiO2 could be cost-effective at preventing SSIs in the three countries but further data from large clinical trials are required to confirm this.

Imaging of Neck Nodes in Head and Neck Cancers - a Comprehensive Update

Cervical lymph node metastases from head and neck squamous cell cancers significantly reduce disease-free survival and worsen overall prognosis and, hence, deserve more aggressive management and follow-up. As per the eighth edition of the American Joint Committee on Cancer staging manual, extranodal extension, especially in human papillomavirus-negative cancers, has been incorporated in staging as it is important in deciding management and significantly impacts the outcome of head and neck squamous cell cancer. Lymph node imaging with various radiological modalities, including ultrasound, computed tomography and magnetic resonance imaging, has been widely used, not only to demonstrate nodal involvement but also for guided histopathological evaluation and therapeutic intervention. Computed tomography and magnetic resonance imaging, together with positron emission tomography, are used widely for the follow-up of treated patients. Finally, there is an emerging role for artificial intelligence in neck node imaging that has shown promising results, increasing the accuracy of detection of nodal involvement, especially normal-appearing nodes. The aim of this review is to provide a comprehensive overview of the diagnosis and management of involved neck nodes with a focus on sentinel node anatomy, pathogenesis, imaging correlates (including radiogenomics and artificial intelligence) and the role of image-guided interventions.

Anatomical categorization of isolated non-focal dystonia: novel and existing patterns using a data-driven approach

According to expert consensus, dystonia can be classified as focal, segmental, multifocal, and generalized, based on the affected body distribution. To provide an empirical and data-driven approach to categorizing these distributions, we used a data-driven clustering approach to compare frequency and co-occurrence rates of non-focal dystonia in pre-defined body regions using the Dystonia Coalition (DC) dataset. We analyzed 1,618 participants with isolated non-focal dystonia from the DC database. The analytic approach included construction of frequency tables, variable-wise analysis using hierarchical clustering and independent component analysis (ICA), and case-wise consensus hierarchical clustering to describe associations and clusters for dystonia affecting any combination of eighteen pre-defined body regions. Variable-wise hierarchical clustering demonstrated closest relationships between bilateral upper legs (distance = 0.40), upper and lower face (distance = 0.45), bilateral hands (distance = 0.53), and bilateral feet (distance = 0.53). ICA demonstrated clear grouping for the a) bilateral hands, b) neck, and c) upper and lower face. Case-wise consensus hierarchical clustering at k = 9 identified 3 major clusters. Major clusters consisted primarily of a) cervical dystonia with nearby regions, b) bilateral hand dystonia, and c) cranial dystonia. Our data-driven approach in a large dataset of isolated non-focal dystonia reinforces common segmental patterns in cranial and cervical regions. We observed unexpectedly strong associations between bilateral upper or lower limbs, which suggests that symmetric multifocal patterns may represent a previously underrecognized dystonia subtype.

Comparative Evaluation of Intranasal Dexmedetomidine Spray Versus Intranasal Normal Saline Spray in Patients Undergoing Transalveolar Extractions for Anxiety Reduction: A Randomized Control Study

Background

Dexmedetomidine has dose-dependent selectivity for alpha 2 adrenoceptors. It is a good sedative with analgesic characteristics and good haemodynamic stability. Intranasal sedation is a non-invasive medication delivery method that is both safe and well accepted by both children and adults. One of the most common procedures in maxillofacial surgery is transalveolar extraction. In minor oral surgery, a painless transalveolar extraction with little post-operative pain would be ideal.

Aim

To examine the effectiveness of intranasal dexmedetomidine spray against intranasal normal saline spray in patients undergoing transalveolar extractions for anxiety relief.

Method

We compared sedation effect by Ramsay sedation scale, analgesia by visual analogue scale, monitored BP and pulse rate for anxiety, and spo2 levels for any complication in this prospective double-blinded randomized control study for two groups, A group with intranasal dexmedetomidine spray and the B group of intranasal NS spray for placebo effect at 0 min, 15 min, 30 min, and 45 min until transalveolar extraction.

Result

As a result of the intranasal spray of dexmedetomidine, there were no related problems such as respiratory depression. There was a substantial difference in sedation and analgesia between group A and the placebo group, as well as a significant decrease in pulse rate and hypotension in the dexmedetomidine group to reduce anxiety.

Conclusion

Intranasal injection of atomized dexmedetomidine (1.5 mcg/kg) for patient sedation having transalveolar extractions or other minor surgical operations in oral and maxillofacial surgery is clinically effective, convenient, lowers anxiety, and safe.Clinical Trial Registration: No. CTRI/2021/07/035181.

Role of PET/CT in Oropharyngeal Cancers

Oropharyngeal squamous cell carcinoma (OPSCC) comprises cancers of the tonsils, tongue base, soft palate, and uvula. The staging of oropharyngeal cancers varies depending upon the presence or absence of human papillomavirus (HPV)-directed pathogenesis. The incidence of HPV-associated oropharyngeal cancer (HPV + OPSCC) is expected to continue to rise over the coming decades. PET/CT is a useful modality for the diagnosis, staging, and follow up of patients with oropharyngeal cancers undergoing treatment and surveillance.

Strategies to minimise and monitor biases and imbalances by arm in surgical cluster randomised trials: evidence from ChEETAh, a trial in seven low- and middle-income countries

BACKGROUND

Cluster randomised controlled trials (cRCT) present challenges regarding risks of bias and chance imbalances by arm. This paper reports strategies to minimise and monitor biases and imbalances in the ChEETAh cRCT.

METHODS

ChEETAh was an international cRCT (hospitals as clusters) evaluating whether changing sterile gloves and instruments prior to abdominal wound closure reduces surgical site infection at 30 days postoperative. ChEETAh planned to recruit 12,800 consecutive patients from 64 hospitals in seven low-middle income countries. Eight strategies to minimise and monitor bias were pre-specified: (1) minimum of 4 hospitals per country; (2) pre-randomisation identification of units of exposure (operating theatres, lists, teams or sessions) within clusters; (3) minimisation of randomisation by country and hospital type; (4) site training delivered after randomisation; (5) dedicated 'warm-up week' to train teams; (6) trial specific sticker and patient register to monitor consecutive patient identification; (7) monitoring characteristics of patients and units of exposure; and (8) low-burden outcome-assessment.

RESULTS

This analysis includes 10,686 patients from 70 clusters. The results aligned to the eight strategies were (1) 6 out of 7 countries included ≥ 4 hospitals; (2) 87.1% (61/70) of hospitals maintained their planned operating theatres (82% [27/33] and 92% [34/37] in the intervention and control arms); (3) minimisation maintained balance of key factors in both arms; (4) post-randomisation training was conducted for all hospitals; (5) the 'warm-up week' was conducted at all sites, and feedback used to refine processes; (6) the sticker and trial register were maintained, with an overall inclusion of 98.1% (10,686/10,894) of eligible patients; (7) monitoring allowed swift identification of problems in patient inclusion and key patient characteristics were reported: malignancy (20.3% intervention vs 12.6% control), midline incisions (68.4% vs 58.9%) and elective surgery (52.4% vs 42.6%); and (8) 0.4% (41/9187) of patients refused consent for outcome assessment.

CONCLUSION

cRCTs in surgery have several potential sources of bias that include varying units of exposure and the need for consecutive inclusion of all eligible patients across complex settings. We report a system that monitored and minimised the risks of bias and imbalances by arm, with important lessons for future cRCTs within hospitals.

Abstract 3287: A bedside to bench study of anti-PD-1, anti-CD40, and anti-CSF1R indicates that more is not necessarily better

Stimulating innate immunity can potentially enable us to overcome resistance to PD-(L)1 blockade. We previously conducted a phase 1 trial of cabiralizumab (anti-CSF1R) with sotigalimab (CD40 agonistic antibody) and nivolumab. Our purpose was to determine safety and the effects of this regimen on circulating and tumor-infiltrating immune cells and to determine the activity of this regimen in a phase 1b trial for melanoma patients whose disease had progressed on anti-PD-(L)1. CyTOF analysis on circulating immune cells taken before and during treatment revealed a reduction in non-classical monocytes and an increase in dendritic cells. Patients with prolonged stable disease had less T-regulatory cells and more circulating antigen presenting cells after treatment compared to patients that were treated for a shorter time. In the phase 1b component of the trial in 13 melanoma patients, objective response rates were: 1 confirmed partial response (7.7%), 1 unconfirmed partial response (7.7%), 5 stable disease (38.5%) and 6 disease progression (42.6%). Despite therapy-induced changes in circulating immune cells and previous preclinical studies supporting rationale for this combination, responses in humans were insufficient to proceed to the second stage of the phase 1b trial. Given the challenges with translating doses from mice to humans, we proceeded to study various doses of anti-CSF1R in combination with CD40 agonist and anti-PD-1 in a murine model. Higher dose anti-CSF1R in mice was associated with increased tumor growth, worse survival and by single-cell RNA-sequencing analyses, we identified a more suppressive monocyte/macrophage profile in murine tumors. Our study suggests that more anti-CSF1R might not be better. Further optimization of cabiralizumab dosing is necessary to evaluate the clinical potential in combination with anti-PD-1 and anti-CD40 in a difficult-to treat patient population whose therapeutic options are limited.

Citation Format: Dijana Djureinovic, Sarah A. Weiss, Irina Krykbaeva, Rihao Qu, Ioannis Vathiotis, Myrto Moutafi, Lin Zhang, Ana L. Perdigoto, Wei Wei, Gail Anderson, William Damsky, Michael Hurwitz, Barbara Johnson, Amit Mahajan, Frank Hsu, Kathryn Miller-Jensen, Yuval Kluger, Mario Sznol, Susan M. Kaech, Marcus Bosenberg, Lucia Jilaveanu, Harriet M. Kluger. A bedside to bench study of anti-PD-1, anti-CD40, and anti-CSF1R indicates that more is not necessarily better [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 3287.

Imaging of brain metastasis in non-small-cell lung cancer: indications, protocols, diagnosis, post-therapy imaging, and implications regarding management

Increased survival (due to the use of targeted therapies based on genomic profiling) has resulted in the increased incidence of brain metastasis during the course of disease, and thus, made it essential to have proper imaging guidelines in place for brain metastasis from non-small-cell lung cancer (NSCLC). Brain parenchymal metastases can have varied imaging appearances, and it is pertinent to be aware of the various molecular risk factors for brain metastasis from NSCLC along with their suggestive imaging appearances, so as to identify them early. Leptomeningeal metastasis requires additional imaging of the spine and an early cerebrospinal fluid (CSF) analysis. Differentiation of post-therapy change from recurrence on imaging has a bearing on the management, hence the need for its awareness. This article will provide in-depth literature review of the epidemiology, aetiopathogenesis, screening, detection, diagnosis, post-therapy imaging, and implications regarding the management of brain metastasis from NSCLC. In addition, we will also briefly highlight the role of artificial intelligence (AI) in brain metastasis screening.

Routine sterile glove and instrument change at the time of abdominal wound closure to prevent surgical site infection (ChEETAh): a pragmatic, cluster-randomised trial in seven low-income and middle-income countries

BACKGROUND

Surgical site infection (SSI) remains the most common complication of surgery around the world. WHO does not make recommendations for changing gloves and instruments before wound closure owing to a lack of evidence. This study aimed to test whether a routine change of gloves and instruments before wound closure reduced abdominal SSI.

METHODS

ChEETAh was a multicentre, cluster randomised trial in seven low-income and middle-income countries (Benin, Ghana, India, Mexico, Nigeria, Rwanda, South Africa). Any hospitals (clusters) doing abdominal surgery in participating countries were eligible. Clusters were randomly assigned to current practice (42) versus intervention (39; routine change of gloves and instruments before wound closure for the whole scrub team). Consecutive adults and children undergoing emergency or elective abdominal surgery (excluding caesarean section) for a clean-contaminated, contaminated, or dirty operation within each cluster were identified and included. It was not possible to mask the site investigators, nor the outcome assessors, but patients were masked to the treatment allocation. The primary outcome was SSI within 30 days after surgery (participant-level), assessed by US Centers for Disease Control and Prevention criteria and on the basis of the intention-to-treat principle. The trial has 90% power to detect a minimum reduction in the primary outcome from 16% to 12%, requiring 12 800 participants from at least 64 clusters. The trial was registered with ClinicalTrials.gov, NCT03700749.

FINDINGS

Between June 24, 2020 and March 31, 2022, 81 clusters were randomly assigned, which included a total of 13 301 consecutive patients (7157 to current practice and 6144 to intervention group). Overall, 11 825 (88·9%) of 13 301 patients were adults, 6125 (46·0%) of 13 301 underwent elective surgery, and 8086 (60·8%) of 13 301 underwent surgery that was clean-contaminated or 5215 (39·2%) of 13 301 underwent surgery that was contaminated-dirty. Glove and instrument change took place in 58 (0·8%) of 7157 patients in the current practice group and 6044 (98·3%) of 6144 patients in the intervention group. The SSI rate was 1280 (18·9%) of 6768 in the current practice group versus 931 (16·0%) of 5789 in the intervention group (adjusted risk ratio: 0·87, 95% CI 0·79-0·95; p=0·0032). There was no evidence to suggest heterogeneity of effect across any of the prespecified subgroup analyses. We did not anticipate or collect any specific data on serious adverse events.

INTERPRETATION

This trial showed a robust benefit to routinely changing gloves and instruments before abdominal wound closure. We suggest that it should be widely implemented into surgical practice around the world.

FUNDING

National Institute for Health Research (NIHR) Clinician Scientist Award, NIHR Global Health Research Unit Grant, Mölnlycke Healthcare.

Clinical implementation of artificial intelligence in neuroradiology with development of a novel workflow-efficient picture archiving and communication system-based automated brain tumor segmentation and radiomic feature extraction

Purpose

Personalized interpretation of medical images is critical for optimum patient care, but current tools available to physicians to perform quantitative analysis of patient’s medical images in real time are significantly limited. In this work, we describe a novel platform within PACS for volumetric analysis of images and thus development of large expert annotated datasets in parallel with radiologist performing the reading that are critically needed for development of clinically meaningful AI algorithms. Specifically, we implemented a deep learning-based algorithm for automated brain tumor segmentation and radiomics extraction, and embedded it into PACS to accelerate a supervised, end-to- end workflow for image annotation and radiomic feature extraction.

Materials and methods

An algorithm was trained to segment whole primary brain tumors on FLAIR images from multi-institutional glioma BraTS 2021 dataset. Algorithm was validated using internal dataset from Yale New Haven Health (YHHH) and compared (by Dice similarity coefficient [DSC]) to radiologist manual segmentation. A UNETR deep-learning was embedded into Visage 7 (Visage Imaging, Inc., San Diego, CA, United States) diagnostic workstation. The automatically segmented brain tumor was pliable for manual modification. PyRadiomics (Harvard Medical School, Boston, MA) was natively embedded into Visage 7 for feature extraction from the brain tumor segmentations.

Results

UNETR brain tumor segmentation took on average 4 s and the median DSC was 86%, which is similar to published literature but lower than the RSNA ASNR MICCAI BRATS challenge 2021. Finally, extraction of 106 radiomic features within PACS took on average 5.8 ± 0.01 s. The extracted radiomic features did not vary over time of extraction or whether they were extracted within PACS or outside of PACS. The ability to perform segmentation and feature extraction before radiologist opens the study was made available in the workflow. Opening the study in PACS, allows the radiologists to verify the segmentation and thus annotate the study.

Conclusion

Integration of image processing algorithms for tumor auto-segmentation and feature extraction into PACS allows curation of large datasets of annotated medical images and can accelerate translation of research into development of personalized medicine applications in the clinic. The ability to use familiar clinical tools to revise the AI segmentations and natively embedding the segmentation and radiomic feature extraction tools on the diagnostic workstation accelerates the process to generate ground-truth data.

Major Salivary Gland Cancer With Distant Metastasis Upon Presentation: Patterns, Outcomes, and Imaging Implications

OBJECTIVES

Given limited data availability on distant metastasis (DM) in major salivary gland (MSG) malignancy presentation, we aimed to evaluate the rate, histologic patterns, location, and predictors of DM at first MSG cancer presentation and suggest potential implications on diagnostic workup.

STUDY DESIGN

Retrospective cohort.

SETTING

Commission on Cancer-accredited hospitals.

METHODS

We included patients in the National Cancer Database (2010-2016) with MSG malignancy. Site and rate of DM were stratified by histologic subtype. Factors predictive of DM at presentation were determined by multivariate regression analysis. Survival analyses were conducted via the Kaplan-Meier method, log-rank test, and Cox regression analysis.

RESULTS

Of 5776 patients with MSG carcinoma, 333 (5.8%) presented with DM. The most common DM site was the lung (57.1%), followed by bone (46.8%) and liver (19.5%). DM was most common in adenocarcinoma-not otherwise specified (15.1%, 132/874) and salivary duct carcinoma (10.4%, 30/288). High-grade mucoepidermoid carcinoma had the highest rate of lung metastases (81.6%, 31/38). Conversely, myoepithelial carcinoma had the highest rate of bone metastases (85.7%, 6/7). DM at presentation was independently associated with an increased mortality risk (hazard ratio, 1.62; 95% CI, 1.40-1.90).

CONCLUSION

We identified a DM rate of 5.8% in MSG malignancy at presentation. Overall 43% of patients presented without DM to the lung but with DM to the bones, liver, and/or brain. The most common metastatic sites differed by tumor histology. Staging with computed tomography neck and chest alone may fail to detect sites of DM; this work can be used for patient counseling in the clinical setting.

O108 Central adiposity influences serum calcium concentrations and increases risk of kidney stone disease

Introduction

Serum calcium (SCa) and adiposity are associated with kidney stone disease (KSD). We used conventional and genetic epidemiological approaches to further understanding of these relationships.

Methods

Waist-hip ratio (WHR), a marker of central adiposity, SCa and KSD data were analysed by adjusted linear regression using UK Biobank participants. Univariable, multivariable and mediation Mendelian randomisation (MR) were undertaken using 316 and 246 genetic instruments for WHR and SCa, respectively.

Results

Observational analyses of 3,466 KSD cases and 489,944 controls showed that participants of normal BMI (20–25kg/m2) but in the fifth quintile for WHR have greater risk of incident KSD compared to the first quintile (HR=1.39 (95%CI=1.18–1.63)). After adjustment for sex, age, serum vitamin D, and phosphate, higher WHR was positively associated with SCa (ß=0.04, 95%=CI 0.04–0.05, P&lt;0.001). Univariable MR demonstrated that relative risk of KSD increases with increasing WHR and SCa; 1 standard deviation (SD) increases relative risk by 46% (95%CI=1.27–1.67, P=5.9e-8) and 63% (95%CI=1.37–1.93, P=2.0E-8), respectively. A 1 SD increase in WHR increases SCa by 0.11mmol/L (95%CI=0.07–0.14, P=1.8e-8). Multivariable MR revealed that SCa and WHR independently increase KSD relative risk (OR=1.71, 95%CI=1.49–1.96, P&lt;0.001 and OR=1.41, 95%CI=1.17–1.69, P&lt;0.001 respectively). Mediation MR established that 14% of the effect of WHR on KSD risk is mediated via alterations in SCa.

Conclusion

Central adiposity is causally linked to KSD, partly by raising SCa. Mechanisms by which central adiposity increases KSD risk, independent of and via SCa, remain to be revealed and may identify novel therapeutic methods for KSD.

Take-home message

Central adiposity and serum calcium are independent, causal risk factors for kidney stone disease. One mechanism by which central obesity increases risk of kidney stone disease is by influencing serum calcium concentrations.

Molecular profiling of dedicated lung cancer biopsy tissue sample collected at time of diagnostic bronchoscopy

e20587

Background: The combined use of molecular biomarker testing and targeted precision therapeutics has led to improved survival in lung cancer. Broadening access to national guideline recommended comprehensive molecular testing requires overcoming the challenges of inadequate tissue biopsies, which can lead to the need for additional procedures and ultimately, delays in initiation of care. We show Percepta Genomic Atlas identifies key molecular alterations in transbronchial needle aspirate (TBNA) and transbronchial biopsy (TBB) samples of lung or lymph node collected during the initial diagnostic bronchoscopy. Methods: Percepta Genomic Atlas combines the whole exome TruSeq RNA Exome and targeted AmpliSeq Focus DNA assays (Illumina) for a comprehensive gene panel including ALK, RET, ROS1, NTRK1/3, MET, EGFR, BRAF, KRAS and HER2. TruSight Oncology 500 DNA and AmpliSeq Focus RNA assays (Illumina) were used as reference assays. DNA and RNA were extracted from samples with the AllPrep Micro kit (Qiagen) and analyzed by Percepta Genomic Atlas and reference assays. 94 biopsy samples (73 TBNA and 21 TBB from 71 patients undergoing a diagnostic bronchoscopy for suspected lung cancer were collected into RNAprotect (Qiagen) under an IRB approved protocol. Local molecular testing results from FFPE biopsy samples taken during the same bronchoscopy procedure were collected. Results: RNA and DNA in sufficient amounts to run the Percepta Genomic Atlas and reference assays was obtained from 85 of 94 lung biopsies from 63 of 71 patients. Percepta Genomic Atlas identified pathogenic variants in 29 bronchoscopy biopsy samples from 23 patients including single nucleotide variants in EGFR, KRAS, BRAF and PIK3CA, an EGFR exon 19 deletion/insertion and copy number amplications in AR, EGFR, CDK4, CCND1, MYC, MYCN and PIK3CA. No fusions were identified. This results in a 100% sensitivity for detecting pathogenic alterations when compared to reference assay results. When comparing Percepta Genomic Atlas results to local molecular testing of bronchoscopy samples performed as part of routine clinical care, we found 100% concordance with 7 of 7 alterations detected in 7 patients, including mutations in EGFR, KRAS and BRAF. In a further 4 patients, Percepta Genomic Atlas and local multi-gene NGS testing results agreed, with neither assay identifying guideline recommended alterations. Conclusions: Using a combination of whole exome RNA and targeted DNA sequencing, Percepta Genomic Atlas detects the clinically actionable mutations in patients with non-small cell lung cancer using fresh tissue specimens collected during bronchoscopic tissue sampling, with high concordance to standard of care testing. By initiating broad molecular testing at the time of the bronchoscopy, Percepta Genomic Atlas may provide timelier results for patients with lung cancer.

Immune Checkpoint Inhibitor-Induced Hypophysitis and Patterns of Loss of Pituitary Function

Background

Immune checkpoint inhibitors (ICI) are clinically active across multiple tumor types but the associated immune-related adverse events (irAEs) lead to treatment delays or discontinuation and negatively impact quality-of-life. Hypophysitis is often a permanent irAE that may affect multiple pituitary hormonal axes. Here we comprehensively characterize our institution's clinical experience with ICI-induced hypophysitis and the associated patterns of pituitary function loss.

Methods

Patients with solid tumors, mostly melanoma and renal cell carcinoma (RCC), treated with ICI at Yale Cancer Center were prospectively enrolled from October 2016-May 2021. Demographics and clinical data were obtained from the medical record including type and timing of irAEs. Patients were included in this cohort if hypophysitis was diagnosed by pre-specified biochemical and clinical parameters.

Results

The overall incidence of hypophysitis was 69/490 (14%) in patients with melanoma (n=58, 84%), RCC (n=10,14%), and merkel cell carcinoma (n=1, 1%) who received ipilimumab plus nivolumab (77%; 53/69), anti-PD-(L)1 (17%; 12/69), or ipilimumab monotherapy (6%; 4/69). Of the 69 patients analyzed, median time to hypophysitis on combination ICI versus anti-PD-1 was 2.8 vs. 4.1 months. The incidence of hypophysitis in patients with melanoma was 25% (46/187) with ipilimumab plus nivolumab and 5% (7/129) with anti-PD-(L)1 compared to 9% (7/77) and 8% (3/37), respectively, in patients with RCC. Patients who developed hypophysitis on combination ICI had a higher rate of headache (p=0.05) and co-occurring irAEs (p=0.01) compared anti-PD-(L1)1 monotherapy. At a median follow-up of 2.2 years, 77% of patients were alive. Objective response rates to ICI in melanoma patients were higher than previously reported for unselected populations. Central hypothyroidism and hypogonadism were the most common pituitary axes affected after the adrenal axis. In select cases, there was evidence of spontaneous rebound in free testosterone levels after an initial decline.

Conclusions

We demonstrate a higher rate of ICI-induced hypophysitis than previously reported, which may be reflective of real-world practice due to increased awareness as experience with ICI has grown. In select cases, there was evidence of rebound in free testosterone and/or gonadotropins but not in adrenal axis hormones.

Giant Osteochondroma of the mandibular condyle and temporomandibular joint - A case report

Osteochondroma is one of the common bone tumours but is rarely seen in the head and neck region. Osteochondroma of the mandibular condyle, extending to the temporomandibular joint (TMJ) is an infrequent occurrence. Patients commonly present with restricted mouth opening and malocclusion. Due to the significant overlap in features between chondromas and condylar hyperplasia, it is very likely to be misdiagnosed, resulting in treatment errors. In this report, an interesting case of a large osteochondroma of the mandibular condyle extending into the zygomatic and petrous part of the temporal bone involving the left TMJ in a 35-year-old female patient is described who presented with facial asymmetry and restricted mouth opening. This paper outlines the clinico-radiographic and histopathological features for diagnosis and appropriate treatment of osteochondroma.

Trends in Development of Novel Machine Learning Methods for the Identification of Gliomas in Datasets That Include Non-Glioma Images: A Systematic Review

Purpose

Machine learning has been applied to the diagnostic imaging of gliomas to augment classification, prognostication, segmentation, and treatment planning. A systematic literature review was performed to identify how machine learning has been applied to identify gliomas in datasets which include non-glioma images thereby simulating normal clinical practice.

Materials and Methods

Four databases were searched by a medical librarian and confirmed by a second librarian for all articles published prior to February 1, 2021: Ovid Embase, Ovid MEDLINE, Cochrane trials (CENTRAL), and Web of Science-Core Collection. The search strategy included both keywords and controlled vocabulary combining the terms for: artificial intelligence, machine learning, deep learning, radiomics, magnetic resonance imaging, glioma, as well as related terms. The review was conducted in stepwise fashion with abstract screening, full text screening, and data extraction. Quality of reporting was assessed using TRIPOD criteria.

Results

A total of 11,727 candidate articles were identified, of which 12 articles were included in the final analysis. Studies investigated the differentiation of normal from abnormal images in datasets which include gliomas (7 articles) and the differentiation of glioma images from non-glioma or normal images (5 articles). Single institution datasets were most common (5 articles) followed by BRATS (3 articles). The median sample size was 280 patients. Algorithm testing strategies consisted of five-fold cross validation (5 articles), and the use of exclusive sets of images within the same dataset for training and for testing (7 articles). Neural networks were the most common type of algorithm (10 articles). The accuracy of algorithms ranged from 0.75 to 1.00 (median 0.96, 10 articles). Quality of reporting assessment utilizing TRIPOD criteria yielded a mean individual TRIPOD ratio of 0.50 (standard deviation 0.14, range 0.37 to 0.85).

Conclusion

Systematic review investigating the identification of gliomas in datasets which include non-glioma images demonstrated multiple limitations hindering the application of these algorithms to clinical practice. These included limited datasets, a lack of generalizable algorithm training and testing strategies, and poor quality of reporting. The development of more robust and heterogeneous datasets is needed for algorithm development. Future studies would benefit from using external datasets for algorithm testing as well as placing increased attention on quality of reporting standards.

Systematic Review Registration

www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42020209938, International Prospective Register of Systematic Reviews (PROSPERO 2020 CRD42020209938).

Pilot MRI-based strategies to improve the detection of stroke in patients with dizziness/vertigo

Posterior strokes are frequently misdiagnosed as they present with non-specific complaints such as dizziness/vertigo. Emergency department (ED) practice often relies on CT/CTA to "exclude" infarct in such patients, providing false reassurance due to lower sensitivity of CT (42%) for stroke in the posterior circulation. We describe a pilot at our institution using a specialized MRI protocol with 95% sensitivity for posterior stroke, which may be used in place of CT/CTA or conventional MRI for stroke evaluation. Further development of this approach may help reduce the high rate of missed posterior stroke in patients presenting with dizziness.

Prevalence of growth hormone deficiency in patients with unexplained chronic fatigue after undergoing bone marrow transplantation in adulthood

PURPOSE

Many patients who undergo bone marrow transplantation (BMT) in adulthood experience unexplained chronic fatigue which can have a major impact on their health-related quality of life (QoL). Pre-BMT treatment regimens increase the risk of developing acquired growth hormone deficiency (GHD), which results in a clinical syndrome with decreased energy and has additionally been linked to metabolic syndrome.

METHODS

Using the gold-standard insulin hypoglycemic test (IHT), we evaluated the prevalence of GHD in 18 post-BMT adult patients with unexplained chronic fatigue, as well as the correlation between peak serum GH response and QoL scores, the metabolic syndrome, and insulin resistance. Peak serum GH cut-point less than 3.0 ug/L was used for the diagnosis of severe GHD. The Fatigue Severity Scale and Quality of Life in Adult GHD Assessment questionnaires were used to quantify fatigue symptoms.

RESULTS

The prevalence of severe GHD within this sample of 18 patients was 50%. A trend between lower peak serum GH response and higher fatigue and QoL-AGHDA scores was observed.

CONCLUSIONS

GHD may represent a remediable contributor to post-BMT chronic fatigue in adults, further studies are needed to evaluate the potential role of screening and GH replacement therapy in this vulnerable patient population.

IMPLICATIONS FOR CANCER SURVIVORS

GHD may be a treatable explanation for disabling post-BMT fatigue pending results of intervention studies.

Listening to community concerns in the COVID-19 infodemic: A WHO digital approach

Background

The Infodemic (too much information including false or misleading information in digital and physical environments) during the COVID-19 pandemic has led to confusion, risk-taking and behaviors that can amplify outbreaks, and reduce effectiveness of pandemic response efforts. To address this challenge, the WHO Information Network for Epidemics (EPI-WIN), in collaboration with research partners, developed a public health Infodemic intelligence analysis methodology for weekly analysis of digital media data to identify, categorize, and understand key concerns expressed in online conversations.

Methods

Thirty-five keyword-based searches (per language) using Meltwater Explore and Google Trends were created and grouped according to a set of pandemic public health taxonomy categories developed specifically for this analysis. The taxonomy has five thematic categories of conversation about COVID-19 and public health response: (1) the cause of the illness, (2) the illness, (3) the treatment, (4) the interventions and (5) Information.

Results

The two most recurring topics to attract increasing interest were Vaccines and Asymptomatic transmission followed by Immunity, Cause of the virus, Vulnerable communities and Reduction of movement, and Risk factors based on demographics and risk of misinformation.

Conclusions

The application of this taxonomy to online social listening week-on-week resulted in a better in-time understanding of the evolution and dynamics of high velocity conversations about COVID-19 globally during the pandemic and proposes a quantifiable approach to support planning of risk communication response.

Key messages

Describe widespread innovation in social listening methods for greater accountability to affected populations. Formulate insights into how digital media can be better utilized for more rapidly responding to the evolving needs of communities.