Contouring Analysis on Synthetic Contrast-Enhanced MR from GRMM-GAN and Implications on MR-Guide Radiation Therapy

PURPOSE/OBJECTIVE(S)

MR-guided linear accelerators have been commercialized making MR-only planning and adaptation an appealing alternative circumventing MR-CT registration. However, obtaining daily contrast-enhanced MR images can be prohibitive due to the increased risk of side effects from repeated contrast injections. In this work, we evaluate the quality of contrast-enhanced multi-modal MR image synthesis network GRMM-GAN (gradient regularized multi-modal multi-discrimination sparse-attention fusion generative adversarial network) for MR-guided radiation therapy.

MATERIALS/METHODS

With IRB approval, we trained the GRMM-GAN based on 165 abdominal MR studies from 65 patients. Each study included T2, T1 pre-contrast (T1pre), and T1 contrast enhanced (T1ce) images. The two pre-contrast MR modalities, T2 and T1pre images were adopted as inputs for GRMM-GAN, and the T1ce image at the portal venous phase was used as an output. Ten MR scans containing 21 liver tumors were selected for contouring analysis. A Turing test was first given to six radiation oncologists, in which 100 real T1ce and synthetic T1ce image slices are randomly given to the radiation oncologists to determine the authenticity of the synthesis. We then invited two radiation oncologists (RadOnc 1 and RadOnc2) to manually contour the 21 liver tumors independently on the real T1ce images. RadOnc2 then performed contouring on the respective synthetic T1ce MRs. DICE coefficient (defined as the intersection over the average of two volumes) and Hausdorff distance (HD, measuring how far two volumes are from each other) were used as analysis metrics. The DICE coefficients were calculated from the two radiation oncologists' contours on the real T1ce MR for each tumor. The DICE coefficients were also calculated from RadOnc 2's contours on real and synthetic MRs. Besides, tumor center shifts were extracted. The tumor center of mass coordinates was extracted from real and synthetic volumes. The difference in the coordinates indicated the shifts in the superior-inferior (SI), right-left (RL), and anterior-posterior (AP) directions between real and synthetic tumor volumes.

RESULTS

An average of 52.3% test score was achieved from the six radiation oncologists, which is close to random guessing. RadOnc 1 and RadOnc 2, who had participated in the contouring analysis, achieved an average DICE of 0.91±0.02 from tumor volumes drawn on the real T1ce MRs. This result sets the inter-operator uncertainty baseline in the real clinical setting. RadOnc 2 achieved an average DICE (real vs. synth) of 0.90±0.04 and HD of 4.76±1.82 mm. Only sub-millimeter (SI: 0.67 mm, RL: 0.41 mm, AP: 0.39 mm) tumor center shifts were observed in all three directions.

CONCLUSION

The GRMM-GAN method has the potential for MR-guided liver radiation when contrast agents cannot be administered daily and provide synthetic contrast-enhanced MR for better tumor targeting. The network can produce synthetic MR images with satisfactory contour agreement and geometric integrity.

Global survival trends for brain tumors, by histology: analysis of individual records for 556,237 adults diagnosed in 59 countries during 2000-2014 (CONCORD-3)

BACKGROUND

Survival is a key metric of the effectiveness of a health system in managing cancer. We set out to provide a comprehensive examination of worldwide variation and trends in survival from brain tumors in adults, by histology.

METHODS

We analyzed individual data for adults (15-99 years) diagnosed with a brain tumor (ICD-O-3 topography code C71) during 2000-2014, regardless of tumor behavior. Data underwent a 3-phase quality control as part of CONCORD-3. We estimated net survival for 11 histology groups, using the unbiased nonparametric Pohar Perme estimator.

RESULTS

The study included 556,237 adults. In 2010-2014, the global range in age-standardized 5-year net survival for the most common sub-types was broad: in the range 20%-38% for diffuse and anaplastic astrocytoma, from 4% to 17% for glioblastoma, and between 32% and 69% for oligodendroglioma. For patients with glioblastoma, the largest gains in survival occurred between 2000-2004 and 2005-2009. These improvements were more noticeable among adults diagnosed aged 40-70 years than among younger adults.

CONCLUSIONS

To the best of our knowledge, this study provides the largest account to date of global trends in population-based survival for brain tumors by histology in adults. We have highlighted remarkable gains in 5-year survival from glioblastoma since 2005, providing large-scale empirical evidence on the uptake of chemoradiation at population level. Worldwide, survival improvements have been extensive, but some countries still lag behind. Our findings may help clinicians involved in national and international tumor pathway boards to promote initiatives aimed at more extensive implementation of clinical guidelines.

Resilience from the perspective of diagnostic radiography students

INTRODUCTION

Resilience is a concept associated with the ability to overcome, adapt, and recover from stressors. The radiography profession is known to be stressful, and one can reason that radiographers must be resilient in order to cope with the clinical environment. Research shows there are varied understandings of resilience. However, little is known about the concept of resilience specifically as it relates to the perspectives of diagnostic radiography students within the clinical workplace. This paper reports on one aspect of a comprehensive study of resilience amongst radiography students. The objective of this paper is, therefore, to present the exploration of the concept of resilience drawing from the data gathered from first-year diagnostic radiography students.

METHODS

A qualitative, explorative, descriptive and contextual approach was adopted for this study. Qualitative data was collected through focus group interviews. A purposive sampling method was employed, selecting from first-year diagnostic radiography students at a University of Technology (UoT) in the Western Cape, South Africa. Interviews were audio-recorded transcribed and thematically analysed. Data was collected until saturation was reached.

RESULTS

The meaning of resilience as explained from the perspective of radiography students included three subthemes namely: (1) fundamentals of resilience; (2) external protective factors and (3) internal protective factors.

CONCLUSION

This study demonstrated that radiography students associated resilience with positive attributes. Furthermore, the study identified various resilience enhancement strategies to better support diagnostic radiography students in the clinical environment like supportive radiographers and talking to peers.

IMPLICATIONS FOR PRACTICE

The identification of resilience enhancement strategies is important as it will assist with the introduction of curriculum renewal initiatives tailored to support first-year diagnostic radiography students as they develop their resilience to stressors in the clinical environment.

Epidemiology and impact of frailty in patients with atrial fibrillation in Europe

BACKGROUND

Frailty is a medical syndrome characterised by reduced physiological reserve and increased vulnerability to stressors. Data regarding the relationship between frailty and atrial fibrillation (AF) are still inconsistent.

OBJECTIVES

We aim to perform a comprehensive evaluation of frailty in a large European cohort of AF patients.

METHODS

A 40-item frailty index (FI) was built according to the accumulation of deficits model in the AF patients enrolled in the ESC-EHRA EORP-AF General Long-Term Registry. Association of baseline characteristics, clinical management, quality of life, healthcare resources use and risk of outcomes with frailty was examined.

RESULTS

Among 10,177 patients [mean age (standard deviation) 69.0 (11.4) years, 4,103 (40.3%) females], 6,066 (59.6%) were pre-frail and 2,172 (21.3%) were frail, whereas only 1,939 (19.1%) were considered robust. Baseline thromboembolic and bleeding risks were independently associated with increasing FI. Frail patients with AF were less likely to be treated with oral anticoagulants (OACs) (odds ratio 0.70, 95% confidence interval 0.55-0.89), especially with non-vitamin K antagonist OACs and managed with a rhythm control strategy, compared with robust patients. Increasing frailty was associated with a higher risk for all outcomes examined, with a non-linear exponential relationship. The use of OAC was associated with a lower risk of outcomes, except in patients with very/extremely high frailty.

CONCLUSIONS

In this large cohort of AF patients, there was a high burden of frailty, influencing clinical management and risk of adverse outcomes. The clinical benefit of OAC is maintained in patients with high frailty, but not in very high/extremely frail ones.

Accuracy of AF burden detection with the new Confirm Rx with Sharp-sense technology

Funding Acknowledgements

Type of funding sources: None.

Introduction

Implantable cardiac monitors (ICMs) are increasingly used to monitor atrial fibrillation (AF) burden following catheter ablation. AF burden recorded by the Confirm Rx™ ICM cannot be modified even after adjudication of false-positive (FP) episodes. We sought to investigate accuracy of the AF burden detection in a UK cohort.

Methods

This multicentre retrospective study included patients with Confirm Rx™ and at least one episode >6 minutes across 9 UK hospitals. Each episode had a corresponding 120-second EGM (electrogram) and heart rate scatterplot which was considered representative of the whole episode. One cardiologist adjudicated all EGMs as ‘True AF’ or ‘False positive’ and a random sample of 10% was reviewed to account for intra and interobserver variability. AF burden was computed as the duration of all episodes classified as AF by the Confirm-Rx divided by the total duration of follow-up. ‘True-AF’ burden was calculated by dividing the duration of episodes adjudicated as ‘True-AF’ by the total duration of follow-up. We also investigated the accuracy of AF burden according to implantation indication and episode duration.

Results

A total of 16,230 individual AF episodes were included from 232 consecutive patients. Overall, 26,137 hours of AF were recorded and a total follow-up 315 patient-years which equates to an AF burden of 0.95%. However, only 24,404.7 (93.3%) hours represented time in ‘True-AF’ and a ‘True-AF’ burden for the whole cohort of 0.89% (Table 1). Patients with a Confirm-Rx™ for palpitations and suspected AF had the lowest proportion of ‘True-AF’ burden and had a modest contribution to the overall AF burden (Figure 1). Conversely, patients with known AF had the highest proportion of ‘True-AF’ burden recorded. Most AF (84.5%) episodes lasted less than 1 hour with approximately a quarter adjudicated as false-positive detections, but their contribution towards overall AF burden was very small (Figure 2A-2B). In contrast, AF >3 hours accounted for 76.4% of time in AF and the proportion of ‘True-AF’ burden was 98.5%.

Conclusion

The accuracy of the estimated AF burden for the whole cohort was excellent (93.3%), driven by the high proportion of ‘True-AF’ burden in AF>3 hours.

Diagnostic accuracy of the Confirm-Rx atrial fibrillation detection algorithm in real-world patients

Funding Acknowledgements

Type of funding sources: None.

Introduction

Continuous rhythm monitoring with implantable cardiac monitors (ICMs) is commonly used to detect and characterise atrial fibrillation (AF) episodes. The Confirm Rx™ with SharpSense™ technology offers four new discriminators and second pass analysis aimed at enhancing detection and improving accuracy for cardiac arrhythmias. This study sought to investigate the diagnostic accuracy of the Confirm Rx™ AF detection algorithm in a UK cohort of ‘real-world’ patients.

Methods

This multicentre retrospective study included patients with Confirm Rx™ and at least one episode of AF>6 minutes from August 2018 to August 2021 across 9 UK hospitals. Each episode had a corresponding 120-second electrogram (EGM) and heart rate scatterplot. One cardiologist manually adjudicated all EGMs as ‘True-AF’ or ‘False-positive. To assess for intra and inter-observer variability, 10% of the EGMs were reviewed. Diagnostic accuracy was determined by calculating the raw and patient-averaged positive predictive value (PPV) for AF episode of different durations and implant indications.

Results

During the study 232 patients met inclusion criteria with a total of 315 patient-years of follow-up. 16,320 individual AF episodes were adjudicated; intra- and interobserver variability was excellent (Cohen’s kappa 0.85 and 0.86, respectively). The rate of ‘True-AF’ detection was 3.19 episodes per month corresponding to a raw PPV of 74.5% for the whole cohort. The highest number of episodes per months was observed in patients with a Confirm-Rx for palpitations (5.1) and suspected AF (5.8) but only approximately half of these represented ‘True-AF’ episodes (Figure 1). Patients with known AF had the lowest rate of AF episodes (1.6 episodes per month) but the highest proportion of ‘True-AF’ episodes (PPV of 95.5%). A clear trend of improving diagnostic accuracy was seen with longer AF episodes (Table1). AF>3 hours had a PPV above 94% and all episodes lasting longer than 24 hours were ‘True-AF’. For AF episode of short duration, the PPV varied with the population being monitored; however, for longer AF episodes the PPV increased significantly and irrespective of implant indication (Figure 2).

Conclusion

Overall, the Confirm Rx™ ICM diagnostic accuracy was modest for all AF episodes lasting longer than 6 minutes (74.5%) but improved considerably for longer AF episodes irrespective of implant indication.

Prevalence, predictors and outcomes of thyroid dysfunction in patients with acute myocardial infarction: the ThyrAMI-1 study

PURPOSE

Thyroid dysfunction in patients with cardiac disease is associated with worse outcomes. This study aimed to evaluate the prevalence and analyse predictors and outcomes of thyroid dysfunction in patients presenting with an acute myocardial infarction (AMI).

METHODS

A prospective multicentre observational study of patients recruited from six acute hospitals within the North of England. Consecutive patients without previous thyroid disease presenting with both ST-elevation AMI (STEMI) and non-ST-elevation AMI (NSTEMI) were recruited to the Thyroxine in Acute Myocardial Infarction 1 (ThyrAMI-1) cohort study between December 2014 and 2016. Thyroid profile, standard biochemistry measurements and demographic information were obtained within 12 h of admission to hospital. Multivariable logistic regression analyses were performed to assess the predictors of thyroid dysfunction and Cox proportional hazards analyses were utilised to compare all-cause mortality by categories of thyroid dysfunction up to June 2019.

RESULTS

Of the 1802 participants analysed, 1440 (79.9%) were euthyroid, 312 (17.3%) had subclinical hypothyroidism (SCH), 22 (1.2%) had subclinical hyperthyroidism (SHyper) and 25 (1.3%) had low T3 syndrome (LT3S). Predictors for SCH were increasing age, female sex, higher thyroid peroxidase antibody (TPOAb) levels, higher serum creatinine levels and early morning sampling time (between 00:01-06:00 h). The predictors of SHyper were lower body mass index and afternoon sampling time (between 12:01 and 18:00 h). Predictors of LT3S were increasing age, higher creatinine levels and presence of previous ischaemic heart disease. Compared to the euthyroid group, patients with LT3S had higher all-cause mortality; adjusted hazard ratio (95% CI) of 2.02 (1.03-3.95), p = 0.04, whereas those with SCH and SHyper did not exhibit significantly increased mortality; adjusted hazard ratios (95% CI) of 1.05 (0.74-1.49), p = 0.79 and 0.27 (0.04-1.95), p = 0.19, respectively.

CONCLUSIONS

Thyroid dysfunction is common in AMI patients on admission to hospital and our data provide an understanding regarding which factors might influence thyroid dysfunction in these patients. Furthermore, the negative association between LT3S and increased mortality post-AMI has once again been highlighted by this study. More research is required to assess if treatment of thyroid dysfunction improves clinical outcomes.

High somatostatin receptor expression and efficacy of somatostatin analogues in patients with metastatic Merkel cell carcinoma

BACKGROUND

Merkel cell carcinoma (MCC) is an aggressive, high-grade, cutaneous neuroendocrine tumour (NET). Agents blocking programmed death 1/programmed death ligand 1 have efficacy in metastatic MCC (mMCC), but half of patients do not derive durable benefit. Somatostatin analogues (SSAs) are commonly used to treat low- and moderate-grade NETs that express somatostatin receptors (SSTRs).

OBJECTIVES

To assess SSTR expression and the efficacy of SSAs in mMCC, a high-grade NET. Methods In this retrospective study of 40 patients with mMCC, SSTR expression was assessed radiologically by somatostatin receptor scintigraphy (SRS; n = 39) and/or immunohistochemically when feasible (n = 9). Nineteen patients (18 had SRS uptake in MCC tumours) were treated with SSA. Disease control was defined as progression-free survival (PFS) of ≥ 120 days after initiation of SSA.

RESULTS

Thirty-three of 39 patients (85%) had some degree (low 52%, moderate 23%, high 10%) of SRS uptake. Of 19 patients treated with SSA, seven had a response-evaluable target lesion; three of these seven patients (43%) experienced disease control, with a median PFS of 237 days (range 152-358). Twelve of 19 patients did not have a response-evaluable lesion due to antecedent radiation; five of these 12 (42%) experienced disease control (median PFS of 429 days, range 143-1757). The degree of SSTR expression (determined by SRS and/or immunohistochemistry) did not correlate significantly with the efficacy endpoints.

CONCLUSIONS

In contrast to other high-grade NETs, mMCC tumours appear frequently to express SSTRs. SSAs can lead to clinically meaningful disease control with minimal side-effects. Targeting of SSTRs using SSA or other novel approaches should be explored further for mMCC.

P5252Can functional MR imaging supersede angiography? An audit of stress cardiac MRI outcomes compared those seen in the CE-MARC trials

Background

Recent studies have compared the performance of cardiac MRI (CMR) with coronary angiography. The CE-MARC trial established CMR's high diagnostic accuracy for coronary artery disease (CAD). Following these results, and those of CE-MARC 2, which showed reduced unnecessary angiography rates with CMR-guided care, we increased our adoption of CMR as an investigation of choice for CAD at our centre.

Purpose

In patients who have a CMR for stable angina, what is the outcome after detection of CAD, how do findings compare with angiography, and do those without CAD identified go on to have a major adverse cardiovascular event (MACE)?

Method

We performed a retrospective audit of all stress CMR performed from August 2016 to March 2017 at our hospital in North England. All patients were followed up for a minimum of 12 months.

NICE guideline care was used during the study period. The CE-MARC trial was used for quality standards and to compare results.

Results

91 stress CMRs were performed. 13 were excluded as they were performed on out-of-area patients. Median follow up was 14.5 months.

Of the remaining 78 patients, 34 (43%) had a positive CMR. 20/34 (59%) proceeded to angiogram. In 16/20 of patients, CMR findings correlated with angiogram findings. A PPV of 80%. The PPV in CE-MARC was 77.2% (72.1–81.6).

Of those who did not proceed to angiography, 8/14 had non-viable myocardium, 3 continued with medical management, in two it was unclear. 3/34 (8.8%) with positive CMR had a MACE.

44 patients had a negative CMR. Three had an angiogram during follow up. All were negative. There was a MACE in 1/44 (2.3%).

Conclusion

The audit population has a similar PPV to that of CE-MARC.

MACE rates at 12 months were similar to CE-MARC which suggests that the trial results are reproducible in our setting. The wider use of CMR can therefore improve investigation and management for patients with stable angina.

The audit is limited by the small number of patients proceeding to angiogram and the ability to confirm negative CMR results.

P782The evaluation of a nurse-led Sacubitril/Valsartan initiation and titration clinic

Background

Sacubitril/Valsartan is a new NICE-approved treatment for heart failure patients with NYHA 2–4 symptoms, LVEF<35% and on a stable dose of ACEi/ARB medication. The PARADIGM-HF trial was stopped early after showing an absolute risk reduction of cardiovascular death/hospitalisation of 5%. NICE specify that it should be initiated by a heart failure specialist with access to a multidisciplinary team. We set up a secondary care specialist nurse-led clinic in our trust in North England for Sacubitril/Valsartan initiation and monitoring.

Purpose

To assess compliance to NICE guidelines and establish the number of clinic visits required for dose titration. To compare demographics and treatment outcomes of our patients with the trial population.

Methods

A retrospective analysis of all patients prescribed Sacubitril/Valsartan over two years with a minimum follow up of 6 months. Data was collected from patient records and compared with NICE guidelines and the PARADIGM-HF trial (total population and Western European subset).

Results

159 patients commenced Sacubitril/Valsartan. Table 1 shows demographic and therapy data and demonstrates our cohort is largely similar to the Western Europe cohort of Paradigm-HF. However, our patients had higher rates of MRA and complex device treatments. Prescribing was compliant with NICE guidelines in 97%. Failure to exceed the target 50% ACEi/ARB dose was the main reason for non-compliance in 60% (3/5). These 3 patients all discontinued. Overall 16% discontinued the drug (42% for hypotension) compared to 18% in the trial. No serious adverse reactions occurred. Mean number of clinic visits was 3.7±1.4.

Table 1. Demographic and therapy data Cohort size Age Female % Ischaemic Aetiology % LVEF B-Blocker % MRA % CRT % ICD % North England 159 69.3±11.1 20 59 27 90 73 23 47 PARADIGM-HF full trial 8442 63.8±11.5 21 60 30 93 54 7 15 Western European Subset 1680 68.3±9.9 18 30 95 44 12 33

Conclusion

Our cohort closely reflects the trial and the resultant NICE guidelines. More of our patients are treated with MRA and complex devices compared to PARADIGM-HF. This may be due to the quality of our service or may reflect our patient selection. Similar tolerability in our patients is reassuring as study patients are highly selected. Those receiving suboptimal ACE/ARB doses (therefore not NICE compliant) prior to initiation all failed to tolerate the new drug which cautions against straying from guidance. Our data shows a specialist nurse-led service can be delivered safely and effectively achieving therapeutic doses with a small number of patient visits. This data supports its deliverability in a non-trial setting.

Epidemiological Data on Anaphylaxis in French Emergency Departments

BACKGROUND

Although anaphylaxis has been considered a priority public health issue in the world allergy community, epidemiological data on morbidity and mortality remain suboptimal. We performed the first multicenter epidemiological study in French emergency departments (EDs). The study covered 7 EDs over a period of 1 year. The objectives were to identify areas that are amenable to change and to support ongoing national and international efforts for better diagnosis, management, and prevention of anaphylaxis.

METHODS

Ours was a descriptive study based on data routinely reported to French institutional administrative databases from 7 French public health institutions in the Lorraine region between January and December 2015. Data were collected based on the anaphylaxisrelated codes of the International Classification of Diseases (ICD)-10, and cases were clinically validated as anaphylaxis.

RESULTS

Of the 202 079 admissions to the EDs, 4817 had anaphylaxis-related codes; of these, 323 were clinically validated as anaphylaxis. Although 45.8% were severe, adrenaline was prescribed in only 32.4% of cases. Of the 323 cases, 57.9% were subsequently referred for an allergy work-up or evaluation (after or during hospitalization), and 17.3% were prescribed autoinjectable epinephrine.

CONCLUSION

Our results highlight an urgent need for improved public health initiatives with respect to recognition and treatment of anaphylaxis. We flag key problems that should be managed in the coming years through implementation of national and international actions.

Acquired cancer resistance to combination immunotherapy from transcriptional loss of class I HLA

Understanding mechanisms of late/acquired cancer immunotherapy resistance is critical to improve outcomes; cellular immunotherapy trials offer a means to probe complex tumor-immune interfaces through defined T cell/antigen interactions. We treated two patients with metastatic Merkel cell carcinoma with autologous Merkel cell polyomavirus specific CD8+ T cells and immune-checkpoint inhibitors. In both cases, dramatic remissions were associated with dense infiltration of activated CD8+s into the regressing tumors. However, late relapses developed at 22 and 18 months, respectively. Here we report single cell RNA sequencing identified dynamic transcriptional suppression of the specific HLA genes presenting the targeted viral epitope in the resistant tumor as a consequence of intense CD8-mediated immunologic pressure; this is distinguished from genetic HLA-loss by its reversibility with drugs. Transcriptional suppression of Class I loci may underlie resistance to other immunotherapies, including checkpoint inhibitors, and have implications for the design of improved immunotherapy treatments.

Validation of Memorial Sloan Kettering Cancer Center nomogram to detect non-sentinel lymph node metastases in a United Kingdom cohort

AIM

Axillary lymph node dissection, although associated with long-term morbidity, has been the standard of treatment for all nodepositive breast cancer patients. We assessed the risk prediction ability (validity) of Memorial Sloan Kettering Cancer Center (MSKCC) nomogram for non-sentinel lymph node metastases and analysed the outcome of patients with sentinel node metastases.

PATIENTS AND METHODS

All operable early breast cancer patients with sentinel node macro metastases (size > 2mm) who underwent axillary dissection from April 2009 to March 2015 were considered eligible. The risk of non-sentinel lymph node metastases was calculated using an online MSKCC calculator, and accuracy was determined based on the area under the receiver-operating characteristic curve (AUC-ROC). Tumour characteristics and overall survival were also analysed as secondary end points.

RESULTS

Of 1745 patients who were diagnosed with operable breast cancer during the study period, 114 patients were considered eligible. The AUC-ROC was 0.66 suggestive of lesser accuracy in prediction and not statistically significant (p value = 0.7303). Seventysix (50.7%) of these patients did not have any non-sentinel node metastases. At a mean follow up of four years, the disease-free survival was 86.4% and overall survival rate was 88.4%.

CONCLUSIONS

The MSKCC nomogram was unable to accurately predict the risk in our cohort of patients with more than half of this cohort of patients not requiring axillary dissection. These findings are consistent with other European studies. This study thus highlights the need for modified prediction model for European cohorts.

Proton Therapy for Craniopharyngioma - An Early Report from a Single European Centre

AIMS

Proton beam therapy (PBT) is being increasingly used for craniopharyngioma. We describe our early outcome of patients treated with PBT.

MATERIALS AND METHODS

Between August 2013 and July 2016, 18 patients with craniopharyngiomas were treated with 54 Cobalt Gray Equivalent (CGE) in 30 fractions over 6 weeks at our centre. The early outcome of 16 patients included in a registry study was analysed. Radiological response was assessed by RECIST criteria and the disease- and treatment-related toxicities were scored according to the CTCAE 4.0.

RESULTS

All patients are alive at a median follow-up of 32.6 months (range 9.2-70.6 months) from initial diagnosis. The median age at PBT was 10.2 years (range 5.4-46.9 years). One patient progressed 8.7 months after PBT and subsequently had complete resection of the tumour. At a median follow-up of 18.4 months after PBT, five patients remained in complete remission, four in partial remission and seven with stable disease. The most common adverse effects during PBT were grade 1 (cutaneous in seven patients and fatigue in six patients). There were no treatment-related grade 3 toxicities.

CONCLUSIONS

Our early results are encouraging and comparable with the limited literature on PBT for craniopharyngioma.

Abstract P1-15-03: Management and outcomes of metaplastic breast cancer

Purpose/Objectives: Metaplastic breast cancer (MBC) is a rare malignancy composed of both epithelial and mesenchymal components that accounts for less than 1% of primary breast carcinomas. Knowledge of effective management of the disease remains limited. We retrospectively evaluated the treatment and outcomes of patients with MBC from three academic hospitals.

Materials/Methods: Patients diagnosed with MBC between June 2, 1993 and May 6, 2016 were identified. Demographic and clinical variables were extracted via primary chart review. Descriptive statistics were utilized to summarize the patient cohort's clinical course. The Kaplan-Meier method was used to obtain estimates of local control (LC) and survival.

Results: Seventy-six patients were identified with a median follow-up of 7.6 years (range: 0.18-19.9 years). The median age at diagnosis was 54 (range 28-81). About two-thirds of patients (67%, n=51) presented with a palpable mass while the remaining patients were screen-detected via mammogram (32%, n=24). The majority of patients were AJCC-7 stage I (38%, n=29) or stage II (49%, n=37), while 10% (n=8) were stage III and 3% (n= 2) stage IV. About half of tumors (46%, n=35) were subtyped using WHO histologic classification of MBC. Over half of subtyped cases were spindle cell carcinoma (51%, n=18), 17% were matrix-producing carcinoma (n=6), 23% were adenocarcinoma with squamous differentiation (n=8), 6% were carcinosarcoma (n=2), and 3% were mixed (n=1).The majority of patients had triple negative disease (82%, n=62), while 13% (n=10) had HR+/HER2- disease, and 5% (n=4) had HER2+ disease. Most patients had high grade tumors (84%, n=64) and received breast conserving surgery (61%, n=46) while 39% (n=29) had mastectomies. Seventy-six percent (n=58) of patients received chemotherapy and 61% (n=46) received radiation therapy. All HR+ patients received adjuvant endocrine therapy, and 1 patient received immunotherapy. Of patients who received chemotherapy, 78% (n=45) received adjuvant therapy alone, 17% (n=10) neoadjuvant therapy alone, and 5% (n=3) both. Seventy percent (n=41) of chemotherapy regimens included a taxane. Among 74 patients without metastatic disease at presentation, recurrences were observed in 18% (n=13). Most patients recurred distantly (69%, n=9), while the remainder had isolated local recurrences (n=4). Of 9 distant failures, 3 had MBC subtype information and all 3 were spindle cell carcinoma. Of 4 local recurrences, 3 of 4 were adenocarcinoma with squamous cell differentiation and 1 was spindle cell carcinoma. At a median follow-up of 7.6 years, the local recurrence-free survival was 88%, disease-free survival was 80%, and overall survival was 80%. Kaplan-Meier point estimates for remaining free of local recurrence versus distant recurrence were 99% (95% C.I., 90- 100) versus 96% (95% C.I., 87- 99) at 2 years and 88% (95% C.I., 76-94) versus 87% (95% C.I., 75- 93) at 5 years.

Conclusions: MBC is a rare histologic subtype that commonly presents with high-grade disease and triple-negative receptor status. In contrast to other smaller series, local and distant failure rates in this cohort were consistent with non-MBC triple negative cohorts. Additional molecular based research is warranted to further characterize features associated with local and distant failure.

Citation Format: Thomas H, Horick N, Spring LM, Brachtel EF, Jimenez RB. Management and outcomes of metaplastic breast cancer [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P1-15-03.

Resistance of Arctic phytoplankton to ocean acidification and enhanced irradiance

The Arctic Ocean is a region particularly prone to ongoing ocean acidification (OA) and climate-driven changes. The influence of these changes on Arctic phytoplankton assemblages, however, remains poorly understood. In order to understand how OA and enhanced irradiances (e.g., resulting from sea–ice retreat) will alter the species composition, primary production, and eco-physiology of Arctic phytoplankton, we conducted an incubation experiment with an assemblage from Baffin Bay (71°N, 68°W) under different carbonate chemistry and irradiance regimes. Seawater was collected from just below the deep Chl a maximum, and the resident phytoplankton were exposed to 380 and 1000 µatm pCO₂ at both 15 and 35% incident irradiance. On-deck incubations, in which temperatures were 6 °C above in situ conditions, were monitored for phytoplankton growth, biomass stoichiometry, net primary production, photo-physiology, and taxonomic composition. During the 8-day experiment, taxonomic diversity decreased and the diatom Chaetoceros socialis became increasingly dominant irrespective of light or CO₂ levels. We found no statistically significant effects from either higher CO₂ or light on physiological properties of phytoplankton during the experiment. We did, however, observe an initial 2-day stress response in all treatments, and slight photo-physiological responses to higher CO₂ and light during the first five days of the incubation. Our results thus indicate high resistance of Arctic phytoplankton to OA and enhanced irradiance levels, challenging the commonly predicted stimulatory effects of enhanced CO₂ and light availability for primary production.

Immune responses in the aquatic gastropod Lymnaea stagnalis under short-term exposure to pharmaceuticals of concern for immune systems: Diclofenac, cyclophosphamide and cyclosporine A

This is a pioneering study in the ecotoxicological assessment of immunotoxic effects of the three selected drugs of concern to a freshwater gastropod species. Lymnaea stagnalis was exposed in the laboratory for 3 days to three drugs used for immune systems: diclofenac (nonsteroidal anti-inflammatory drug), cyclophosphamide (anti-cancer immunosuppressive drug) or cyclosporine A (anti-xenograft immunosuppressive drug). Exposure ranges included environmental realistic (1-10μgL^-1) and therapeutic concentrations (100-1000μgL^-1). At the end of exposure times, the immune parameters of individual snails were measured: hemocyte density and viability, hemocyte phagocytosis capacity and hemocyte-related oxidative activities (basal and NADPH-oxidase stimulated with zymosan particles). Diclofenac and cyclosporine A induced immune responses, although the effects were not strong. No immunosuppression was observed. Such subtle immunomodulations bring further interrogations regarding their long-term immunotoxicity and possible resulting tradeoffs with life-history traits. On the other hand, the prodrug cyclophosphamide did not induce significant immune responses. Since metabolism pathways differ greatly between vertebrates and invertebrates, this study also suggests that relevant vertebrate metabolites should be included in the immunotoxicity assessment of pharmaceuticals in non-target invertebrate species. Finally, the possible interactive effects of these pharmaceuticals sharing similar modes of action or effects features should also be explored.

Public health matters: Innovative approaches for engaging medical students

BACKGROUND

Public health faces the paradox of being increasingly emphasized by the key health and social care regulators and stakeholders, while remaining a largely under-represented discipline in the context of medical curricula. Enhancing medical student engagement in public health teaching is one way to address this concern.

METHODS

We discuss four key solutions to the challenges faced by public health educators in medical schools, and present five case studies which demonstrate innovative approaches to engaging medical students in our discipline.

RESULTS

Four different approaches have been piloted by members of the Public Health Educators in Medical Schools (PHEMS) network: (i) ensuring social accountability, (ii) demonstrating clinical relevance, (iii) mapping the core curriculum, and (iv) using technology enhanced learning. Preliminary student feedback suggests that these approaches can be used to position public health as an enabler of modern medical practice, and promote a more holistic understanding of medicine by linking patient-centred care to the population level.

CONCLUSIONS

The zeitgeist in both academia and the healthcare system supports the teaching of public health within the medical curriculum; there is also consensus at the political and pedagogical level. The challenge of ensuring engagement now needs to be met at the student-teacher interface.

Optical analysis of samarium doped sodium bismuth silicate glass

Samarium doped sodium bismuth silicate glass was synthesized using the melt quenching method. Detailed optical spectroscopic studies of the glassy material were carried out in the UV-Vis-NIR spectral range. Using the optical absorption spectra Judd-Ofelt (JO) parameters are derived. The calculated values of the JO parameters are utilized in evaluating the various radiative parameters such as electric dipole line strengths (S_ed), radiative transition probabilities (A_rad), radiative lifetimes (τ_rad), fluorescence branching ratios (β) and the integrated absorption cross- sections (σ_a) for stimulated emission from various excited states of Sm³⁺‡ ion. The principal fluorescence transitions are identified by recording the fluorescence spectrum. Our analysis revealed that the novel glassy system has the optimum values for the key parameters viz. spectroscopic quality factor, optical gain, stimulated emission cross section and quantum efficiency, which are required for a high performance optical amplifier. Calculated chromaticity co-ordinates (0.61, 0.38) also confirm its application potential in display devices.

Recommendations for the Analysis of Hemocyte-related Immunocompetent Oxidative Activity in the Freshwater Snail Activity in the Freshwater Snail Lymnaea Stagnalis

Not available

The Limits of Property-Led Regeneration

In this paper, the role of property development in city revitalization is considered. Case study material is used to analyze the changing organizational nature of property development, especially the interrelationships between property developers and the traditional purveyors of urban policy: Local authorities. It is shown how the property industry is dependent on the development of organizational capacities with public authorities in a manner not anticipated by the rhetoric of central government, a rhetoric which has pushed the property-led approach as an alternative to development by, and through, the public sector. In contrast to this view, illustrative material is presented which indicates how property-led development is highly dependent on the public sector. Also illustrated is how the process of property-led regeneration has the capacity to undermine a range of local, community, interests in areas affected by redevelopment schemes, a situation which has been exacerbated by the prioritization of the shorter-term development goals of the property industry. In conclusion, it is noted that property-led approaches to regeneration, although a necessary component of urban revitalization, are neither a sufficient nor an adequate response to the multiple tasks involved in the revitalization of cities.

Studies on the V2O5-TiO2 System. IV. Oxygen Chemisorption

The chemical adsorption of oxygen on V2O5 and V2O5 -TiO2 over the temperature range 100–450°C and at pressures between 10−2 and 3 Torr has been studied. Assays have been performed using a volumetric method, the isotherms obtained being in accordance with Langmuir's adsorption model.

Isobaric plots at 1.5 Torr of these isotherms exhibit two maxima, at 250 and 400°C, respectively. These maxima have been interpreted in terms of the surface chemisorption of O2− and its diffusion into the bulk solid.

The amount adsorbed at the 250°C maximum depends on the sample composition in the following decreasing adsorption order: VT80, VT50, VT10, VT20 and VT0.

At the 400°C maximum, the same amount of O2 is adsorbed experimentally by all the TiO2-containing samples, this value being quite different from that corresponding to pure V2O5 (VTO). Possible explanations for this observation are based on (i) the relative magnitudes of the V/Ti surface ratios and (ii) the presence of Ti4+ in V2O5 crystals.

Assessing particle kinematics via template matching algorithms

Template matching algorithms represent a viable tool to locate particles in optical images. A crucial factor of the performance of these methods is the choice of the similarity measure. Recently, it was shown in [Gao and Helgeson, Opt. Express 22 (2014)] that the correlation coefficient (CC) leads to good results. Here, we introduce the mutual information (MI) as a nonlinear similarity measure and compare the performance of the MI and the CC for different noise scenarios. It turns out that the mutual information leads to superior results in the case of signal dependent noise. We propose a novel approach to estimate the velocity of particles which is applicable in imaging scenarios where the particles appear elongated due to their movement. By designing a bank of anisotropic templates supposed to fit the elongation of the particles we are able to reliably estimate their velocity and direction of motion out of a single image.

National Healthcare Delivery Systems Influence Lung Transplant Outcomes for Cystic Fibrosis

Successful lung transplantation (LTx) depends on multiple components of healthcare delivery and performance. Therefore, we conducted an international registry analysis to compare post-LTx outcomes for cystic fibrosis (CF) patients using the UNOS registry in the United States and the National Health Service (NHS) Transplant Registry in the United Kingdom. Patients with CF who underwent lung or heart-lung transplantation in the United States or United Kingdom between January 1, 2000 and December 31, 2011 were included. The primary outcome was all-cause mortality. Kaplan-Meier analysis and Cox proportional hazards regression evaluated the effect of healthcare system and insurance on mortality after LTx. 2,307 US LTx recipients and 451 individuals in the United Kingdom were included. 894 (38.8%) US LTx recipients had publically funded Medicare/Medicaid insurance. US private insurance and UK patients had improved median predicted survival compared with US Medicare/Medicaid recipients (p < 0.001). In multivariable Cox regression, US Medicare/Medicaid insurance was associated with worse survival after LTx (US private: HR0.78,0.68-0.90,p = 0.001 and UK: HR0.63,0.41-0.97, p = 0.03). This study in CF patients is the largest comparison of LTx in two unique health systems. Both the United States and United Kingdom have similar early survival outcomes, suggesting important dissemination of best practices internationally. However, the performance of US public insurance is significantly worse and may put patients at risk.

Early cryoprecipitate for major haemorrhage in trauma: a randomised controlled feasibility trial

BACKGROUND

Low fibrinogen (Fg) concentrations in trauma haemorrhage are associated with poorer outcomes. Cryoprecipitate is the standard source for Fg administration in the UK and USA and is often given in the later stages of transfusion therapy. It is not known whether early cryoprecipitate therapy improves clinical outcomes. The primary aim of this feasibility study was to determine whether it was possible to administer cryoprecipitate, within 90 min of admission to hospital. Secondary aims were to evaluate laboratory measures of Fg and clinical outcomes including thrombotic events, organ failure, length of hospital stay and mortality.

METHODS

This was an unblinded RCT, conducted at two civilian UK major trauma centres of adult trauma patients (age ≥16 yrs), with active bleeding and requiring activation of the major haemorrhage protocol. Participants were randomised to standard major haemorrhage therapy (STANDARD) (n=22), or to standard haemorrhage therapy plus two early pools of cryoprecipitate (CRYO) (n=21).

RESULTS

85% (95% CI: 69-100%) CRYO participants received cryoprecipitate within 90 min, median time 60 min (IQR: 57-76) compared with 108 min (67-147), CRYO and STANDARD arms respectively (P=0.002). Fg concentrations were higher in the CRYO arm and were maintained above 1.8 g litre(-1) at all time-points during active haemorrhage. All-cause mortality at 28 days was not significantly different (P=0.14).

CONCLUSIONS

Early Fg supplementation using cryoprecipitate is feasible in trauma patients. This study supports the need for a definitive RCT to determine the effect of early Fg supplementation on mortality and other clinical outcomes.

TRIAL REGISTRY NUMBER

ISRCTN55509212.

A multidisciplinary team approach minimises prophylactic mastectomy rates

BACKGROUND

Prophylactic mastectomy (PM) has become increasingly common but is not without complications especially if accompanied by reconstructive surgery. In patients with sporadic unilateral breast cancer, contralateral PM offers no survival advantage. Multidisciplinary team (MDT) communication and interaction may facilitate shared decision-making and curtail PM rates. The aim of this study was investigate the effect of a regional MDT meeting on PM decision-making.

METHODS

We conducted an observational study involving retrospective review of prospectively recorded MDT meeting records for a 151 patient requests for PM from 2011 to 2014. Final MDT decisions were recorded as PM 'accepted', 'declined' or 'pending'. For MDT sanctioned requests, the factors justifying PM were recorded. Where PM was declined, justification for MDT refusal was sought and recorded.

RESULTS

Approximately half of all requests for PM have been upheld (53.0%) and 1/3 of requests have been declined (32.5%). Of those declined, low risk of contralateral breast cancer versus relatively high risk of systemic relapse were commonly cited as justification for PM refusal (45.7%). A proportion of patients who initiated PM discussion subsequently changed their minds (19.6%), or failed to attend clinic appointments (6.5%). Some patients were deemed medically unfit for complex reconstructive surgery (13%), or were declined on the basis of an apparent cosmetic drive for surgery (6.5%), concerns regarding depression or anxiety (2.2%) and/or if family history could not be substantiated (6.5%).

DISCUSSION

MDT meetings facilitate cross-specialty interrogation of requests for PM, minimise unnecessary surgery and restrict PM to those likely to derive maximum benefit.

Psychotic experiences and psychological distress predict contemporaneous and future non-suicidal self-injury and suicide attempts in a sample of Australian school-based adolescents

BACKGROUND

Recent cross-sectional studies have shown psychotic experiences (PEs) are associated with suicidal ideation and behaviours. We aimed to examine associations between psychotic experiences (including persistent PE), and contemporaneous and incident non-suicidal self-injury (NSSI) and suicide attempts.

METHOD

Participants were from an Australian longitudinal cohort of 1896 adolescents (12-17 years). NSSI and suicide attempts were measured using the Self-Harm Behaviour Questionnaire. Items from the Diagnostic Interview Schedule for Children were used to assess psychotic experiences, and the General Health Questionnaire-12 measured psychological distress.

RESULTS

Adolescents both psychologically distressed and endorsing psychotic experiences had increased odds of contemporaneous and incident NSSI and attempted suicide. Psychotic experiences alone did not predict future risk. Persistent psychotic experiences were associated with increased risk of NSSI and suicide attempts.

CONCLUSIONS

Psychological distress with accompanying psychotic experiences and persistent psychotic experiences are important predictors of NSSI and suicide attempts. Screening these phenotypes in adolescents will assist in discerning those adolescents most at risk, providing opportunities for targeted suicide prevention strategies.