A Deep Learning Approach to Classify Fabry Cardiomyopathy from Hypertrophic Cardiomyopathy Using Cine Imaging on Cardiac Magnetic Resonance

A challenge in accurately identifying and classifying left ventricular hypertrophy (LVH) is distinguishing it from hypertrophic cardiomyopathy (HCM) and Fabry disease. The reliance on imaging techniques often requires the expertise of multiple specialists, including cardiologists, radiologists, and geneticists. This variability in the interpretation and classification of LVH leads to inconsistent diagnoses. LVH, HCM, and Fabry cardiomyopathy can be differentiated using T1 mapping on cardiac magnetic resonance imaging (MRI). However, differentiation between HCM and Fabry cardiomyopathy using echocardiography or MRI cine images is challenging for cardiologists. Our proposed system named the MRI short-axis view left ventricular hypertrophy classifier (MSLVHC) is a high-accuracy standardized imaging classification model developed using AI and trained on MRI short-axis (SAX) view cine images to distinguish between HCM and Fabry disease. The model achieved impressive performance, with an F1-score of 0.846, an accuracy of 0.909, and an AUC of 0.914 when tested on the Taipei Veterans General Hospital (TVGH) dataset. Additionally, a single-blinding study and external testing using data from the Taichung Veterans General Hospital (TCVGH) demonstrated the reliability and effectiveness of the model, achieving an F1-score of 0.727, an accuracy of 0.806, and an AUC of 0.918, demonstrating the model's reliability and usefulness. This AI model holds promise as a valuable tool for assisting specialists in diagnosing LVH diseases.

Beyond the hype: 'acceptable futures' for AI and robotic technologies in healthcare

AI and robotic technologies attract much hype, including utopian and dystopian future visions of technologically driven provision in the health and care sectors. Based on 30 interviews with scientists, clinicians and other stakeholders in the UK, Europe, USA, Australia, and New Zealand, this paper interrogates how those engaged in developing and using AI and robotic applications in health and care characterize their future promise, potential and challenges. We explore the ways in which these professionals articulate and navigate a range of high and low expectations, and promissory and cautionary future visions, around AI and robotic technologies. We argue that, through these articulations and navigations, they construct their own perceptions of socially and ethically 'acceptable futures' framed by an 'ethics of expectations.' This imbues the envisioned futures with a normative character, articulated in relation to the present context. We build on existing work in the sociology of expectations, aiming to contribute towards better understanding of how technoscientific expectations are navigated and managed by professionals. This is particularly timely since the COVID-19 pandemic gave further momentum to these technologies.

Protocol for the Brain Health Support Program Study of the Canadian Therapeutic Platform Trial for Multidomain Interventions to Prevent Dementia (CAN-THUMBS UP): A Prospective 12-Month Intervention Study

BACKGROUND/OBJECTIVES

CAN-THUMBS UP is designed as a comprehensive and innovative fully remote program to 1) develop an interactive and compelling online Brain Health Support Program intervention, with potential to positively influence dementia literacy, self-efficacy and lifestyle risk factors; 2) enroll and retain a community-dwelling Platform Trial Cohort of individuals at risk of dementia who will participate in the intervention; 3) support an open platform trial to test a variety of multidomain interventions that might further benefit individuals at risk of dementia. This manuscript presents the Brain Health Support Program Study protocol.

DESIGN/SETTING

Twelve-month prospective multi-center longitudinal study to evaluate a fully remote web-based educational intervention. Participants will subsequently be part of a Platform Trial Cohort and may be eligible to participate in further dementia prevention clinical trials.

PARTICIPANTS

Three hundred fifty older adults who are cognitively unimpaired or have mild cognitive impairment, with at least 1 well established dementia risk factor.

INTERVENTION

Participants engage in the Brain Health Support Program intervention for 45-weeks and complete pre/post intervention measures. This intervention is designed to convey best available evidence for dementia prevention, consists of 181 chapters within 8 modules that are progressively delivered, and is available online in English and French. The program has been developed as a collaborative effort by investigators with recognized expertise in the program's content areas, along with input from older-adult citizen advisors.

MEASUREMENTS

This study utilizes adapted remote assessments with accessible technologies (e.g. videoconferencing, cognitive testing via computer and mobile phone, wearable devices to track physical activity and sleep, self-administered saliva sample collection). The primary outcome is change in dementia literacy, as measured by the Alzheimer's Disease Knowledge Scale. Secondary outcomes include change in self-efficacy; engagement using the online program; user satisfaction ratings; and evaluation of usability and acceptance. Exploratory outcomes include changes in attitudes toward dementia, modifiable risk factors, performance on the Neuropsychological Test Battery, performance on self-administered online cognitive assessments, and levels of physical activity and sleep; success of the national recruitment plan; and the distribution of age adjusted polygenic hazard scores.

CONCLUSIONS

This fully remote study provides an accessible approach to research with all study activities being completed in the participants' home environment. This approach may reduce barriers to participation, provide an easier and less demanding participant experience, and reach a broader geography with recruitment from all regions of Canada. CAN-THUMBS UP represents a Canadian contribution to the global World-Wide FINGERS program (alz.org/wwfingers).

Clinical outcomes and gestational age based prediction of pneumatosis intestinalis in preterm infants with necrotizing enterocolitis

BACKGROUND

To determine the clinical implications and gestation age-specific diagnostic predictability of pneumatosis in preterm infants with necrotizing enterocolitis (NEC).

METHODS

A retrospective study on abdominal radiographs comparing clinical and radiological information in infants with and without pneumatosis.

RESULT

Our findings disproved our hypothesis. Pneumatosis was seen more frequently in infants with higher gestational age [28.4 (26.1-32.4) vs. 26.4 (24.3-29) weeks; p < 0.001] and birth weight [1110 (762-1768) vs. 770 (645-1022) grams; p < 0.001] and were more likely delivered vaginally (39.1% vs. 21.7%, p = 0.01). Portal venous gas was seen frequently on radiographs (10.3% vs. 0%, p < 0.001), but not pneumoperitoneum (20.7% vs. 36.7%, p = 0.02). Infants with pneumatosis frequently developed acute kidney injury, with higher serum creatinine (16.5% vs. 4.5%, p = 0.02) and frequent oliguria (12.9% vs. 2.7 %; p = 0.043) and had higher C-reactive protein levels at 24 and 96 hours (p < 0.002). Receiver operating curves for pneumatosis showed GA >28 weeks and birth weight > 1000 gm to have a sensitivity of 58.6% and specificity of 72.5%.

CONCLUSION

Contrary to our hypothesis, infants who developed pneumatosis during NEC were more mature with a higher gestational age and birth weight than those who did not.

Virtual cardiac rehabilitation during the COVID-19 pandemic: a tertiary site experience

Funding Acknowledgements

Type of funding sources: Public Institution(s). Main funding source(s): University of British Columbia Clinician Investigator Program

Background

The COVID-19 pandemic resulted in the abrupt suspension of centre-based cardiac rehabilitation (CR). Multidisciplinary virtual CR (VCR) with the use of digital, telephone, and video communication was implemented for continued care access. Exercise therapy was delivered through synchronous video-supervised sessions, pre-recorded sessions, and self-directed physical activity.

Purpose

To describe patient characteristics, completion rates, and safety outcomes in a real-world VCR population.

Methods

Prospective observational study of a tertiary academic CR program. VCR was implemented at pandemic onset (March 2020). Patients who were enrolled in, and either completed or dropped out, during the study period were included. Completers were defined as completing 6 months of virtual enrolment and an exit assessment. Risk was defined by the AACPVR 2020 risk categorization. Adverse cardiovascular events were defined as a patient-initiated event requiring medical assessment and stratified as exercise or non-exercise related. Continuous variables are presented as means and SD or medians and IQR. Student’s t-test was used for between group comparisons. Categorical variables are presented as n (%) and compared using the χ2 test or Fischer’s exact test. A p-value &lt;0.05 was considered significant.

Results

Between March 13th, 2020, and August 31st, 2021, 222 [mean age 61.8 years (SD, 12.6) 77% male], were enrolled and discharged from the VCR program (Table 1). There were 160 completers and 62 non-completers (completion rate 72%). Among the non-completers 26 attended the MD intake assessment only. The remaining 36 completed a median of 85 days (IQR 25-197). This cohort included 21 (9%) high-risk and 35 (16%) moderate risk patients. Those at moderate risk were more likely to be non-completers and those at low risk were more likely to be completers (Table 1). Two exercise and 17 non-exercise adverse events were observed (median clinical surveillance 217 days [IQR 205-240]) (Table 2). Exercise related adverse events included neurally mediated syncope during a synchronous video exercise session in a low risk patient. This was responded to as per centre developed virtual safety protocols. A second syncope related to heart block occurred in a moderate risk patient during independent physical activity and required permanent pacemaker insertion. Both patients completed the program. Three non-exercise adverse cardiac events resulted in cessation of participation included one death and two heart failure hospitalizations (Table 2). One stroke and 13 emergency department visits for cardiac symptoms occurred in completers.

Conclusion

Real world VCR is feasible, including in those at moderate to high risk. Modest completion rates and a low exercise related adverse event rate were observed. Synchronous video exercise sessions with video monitoring and safety protocols may improve response to adverse exercise related events.

The Maturation of the Acoustic Change Complex in Response to Iterated Ripple Noise in 'Normal'-Hearing Infants, Toddlers, and Adults

BACKGROUND

Infants and toddlers are still being evaluated for their hearing sensitivity but not their auditory-processing skills. Iterated rippled noise (IRN) stimuli require the auditory system to utilize the temporal periodicity and autocorrelate the iterations to perceive pitch.

PURPOSE

This study investigated the acoustic change complex (ACC) elicited by IRN in "normal"-hearing infants, toddlers, and adults to determine the maturation of cortical processing of IRN stimuli.

DESIGN

Cortical responses to filtered white noise (onset) concatenated with IRN stimuli (d = 10 milliseconds, gain = 0.7 dB: 4-32 iterations) were recorded in quiet, alert participants.

STUDY SAMPLE

Participants included 25 infants (2.5-15 months), 27 toddlers (22-59 months), and 8 adults (19-25 years) with "normal" hearing sensitivity.

DATA COLLECTION AND ANALYSIS

Cortical auditory-evoked responses were recorded for each participant, including the onset response to the noise and an ACC to the transition from noise to IRN. Group differences were assessed using repeated-measures analyses of variance.

RESULTS

Most infants had a replicable onset (P) response, while only about half had a measurable ACC (P_ACC) response to the high-saliency IRN condition. Most toddlers had onset responses and showed a P-N_ACC response to the IRN16 and IRN32 conditions. Most of the toddler group had responses present to the onset and showed a P-N_ACC response to all IRN conditions. Toddlers and adults showed similar P-N_ACC amplitudes; however, adults showed an increase in N1_ACC amplitude with increase in IRN iterations (i.e., increased salience).

CONCLUSION

While cortical responses to the percept of sound as determined by the onset response (P) to a stimulus are present in most infants, ACC responses to IRN stimuli are not mature in infancy. Most toddlers as young as 22 months, however, exhibited ACC responses to the IRN stimuli even when the pitch saliency was low (e.g., IRN4). The findings of the current study have implications for future research when investigating maturational effects on ACC and the optimal choice of stimuli.

Lichen sclerosus following genital piercing

Male genital lichen sclerosus (MGLSc) is a chronic inflammatory dermatosis that predominantly affects uncircumcised males. Several aetiological factors have been described, with growing evidence supporting chronic urine exposure of susceptible epithelium being crucial to its pathogenesis. We describe a 45-year-old man with a 2-year history of MGLSc at the site of a urethrocutaneous fistula secondary to a penile piercing. To our knowledge, this is the first documented case of MGLSc occurring at the site of a genital piercing.

Automatic Detection and Segmentation of Breast Cancer on MRI Using Mask R-CNN Trained on Non-Fat-Sat Images and Tested on Fat-Sat Images

RATIONALE AND OBJECTIVES

Computer-aided methods have been widely applied to diagnose lesions on breast magnetic resonance imaging (MRI). The first step was to identify abnormal areas. A deep learning Mask Regional Convolutional Neural Network (R-CNN) was implemented to search the entire set of images and detect suspicious lesions.

MATERIALS AND METHODS

Two DCE-MRI datasets were used, 241 patients acquired using non-fat-sat sequence for training, and 98 patients acquired using fat-sat sequence for testing. All patients have confirmed unilateral mass cancers. The tumor was segmented using fuzzy c-means clustering algorithm to serve as the ground truth. Mask R-CNN was implemented with ResNet-101 as the backbone. The neural network output the bounding boxes and the segmented tumor for evaluation using the Dice Similarity Coefficient (DSC). The detection performance, and the trade-off between sensitivity and specificity, was analyzed using free response receiver operating characteristic.

RESULTS

When the precontrast and subtraction image of both breasts were used as input, the false positive from the heart and normal parenchymal enhancements could be minimized. The training set had 1469 positive slices (containing lesion) and 9135 negative slices. In 10-fold cross-validation, the mean accuracy = 0.86 and DSC = 0.82. The testing dataset had 1568 positive and 7264 negative slices, with accuracy = 0.75 and DSC = 0.79. When the obtained per-slice results were combined, 240 of 241 (99.5%) lesions in the training and 98 of 98 (100%) lesions in the testing datasets were identified.

CONCLUSION

Deep learning using Mask R-CNN provided a feasible method to search breast MRI, localize, and segment lesions. This may be integrated with other artificial intelligence algorithms to develop a fully automatic breast MRI diagnostic system.

A Retrospective Review of the Effect of COVID-19 Pandemic on Laboratory Utilization

Introduction/Objective

We performed a retrospective analysis of test volumes in clinical pathology prior to and during the COVID-19 pandemic to better understand the impact of the pandemic on our laboratory utilization.

Methods/Case Report

The laboratory information system was queried for test order volume in 2019 and 2020 using Discern Analytics 2.0. Representative tests including C-reactive protein (CRP), D-dimer, fibrinogen, ferritin, lactate dehydrogenase (LDH), procalcitonin, prothrombin time (PT), point of care iSTAT blood gas analysis, ABO and Rhesus typing (ABORh), antibody screening, flow cytometry, and serum protein electrophoresis (SPEP). Data was analyzed using Microsoft Excel 2013.

Results (if a Case Study enter NA)

The data showed an increase in the number of tests ordered and verified in the in-patient setting. The increase was most substantial for D-dimer, CRP and LDH with a percentage increase of approximately 200% on each test from year 2019 to 2020. An increase of 73% and 57% was noted for ferritin and fibrinogen respectively. A slight decrease in volume was noted for tests ordered in the out-patient setting including SPEPs during the pandemic. There was no significant change in the number of orders verified for point of care ISTAT blood gas testing between 2019 and 2020. Procalcitonin test volume increased steadily from its implementation in May 2020 with a steep rise in test volume in November and December. A total of 75,295 SARS-CoV-2 molecular tests were ordered between March and December 2020 with approximately 80% of the orders being performed as a send- out test.

Conclusion

The COVID-19 pandemic has had a substantial impact on laboratory utilization with significant volume increases in tests that guide the management of hospitalized COVID-19 patients and slight decrease in tests ordered mostly in the outpatient setting. These results may help guide current and future decisions relating to laboratory operations during pandemics.

737 Supporting Surgeons in Their Return to Training

Aim

t any one time, approximately 10% of the junior doctor workforce (∼5000 doctors) take time out of training. Following the Bawa Gaba case, and with trainees shielding during the COVID pandemic, there is greater scrutiny and demand to support trainees returning to the frontline. Supported Return to Training (SuppoRTT) is a Health Education England Program designed to improve the Return-To-Training (RTT) experience. For surgical specialties there are additional challenges of reintroducing trainees to practical skills.

Method

e designed and facilitated the first regional SuppoRTT course for Orthopaedic Specialist Registrars, which consisted of peer and consultant-led clinical updates, forum discussions and externally commissioned professional coaching. A pre-course survey established participants’ concerns and expectations about RTT and formed the basis of discussions. A post-course survey assessed value of the course and impact on participants.

Results

Eight participants (6 female) attended. Grade of training on return ranged from ST3 to ST8. Main areas of concern related to colleague perception, reduced confidence with decision-making, operative skill fade, and frustrations with organisational elements of managing work-life balance. There was an overwhelmingly positive response to the support offered on our course, particularly to the discussions around RTT concerns and returning to on-calls. All respondents strongly agreed that sharing their concerns and hearing about peer experience was valuable.

Conclusions

High numbers of trainees take approved time out of training. RTT is associated with anxiety around performance and safety. Surgical trainees can be supported with a targeted course that offers clinical update, peer support and professional coaching.

Predictors of psychosocial adaptation and mental wellbeing among people with chronic illness and disabilities in a chinese context

Introduction

The process of adjustment to disability and illness among people with chronic illness and disabilities (CID) impacts on motivation for rehabilitation illness self-management, and psychological well-being. It involves a complex interplay of biopsychosocial factors, and was seldom examined in the Chinese context.

Objectives

Identify the predictors of mental well-being of people with from a set of variables including illness and social support, functional abilities, coping strategies, resilience. Examine how these factors interact in determining psychosocial adaptation and mental well-being by structural equations modelling (SEM).

Methods

We conducted a survey of people with CID, who were recruited from community-rehabilitation settings and self-help groups (N = 244). The research questionnaire collected basic demographic information, illness-related variables (e.g. pain, fatigue, functional limitations), and RIDI), social support, measures of resilience, coping, psychosocial ad as predictors, and mental well-being.

Results

Of General Linear Model (GLM) revealed that males have better adaptation than females. Resilience, social coping, & active problem solving are significant predictors of adaptation (Table 1), while age, breathing, pain, resilience, avoidance coping, are predictors of maladaptation (Table 2). A SEM was tested to examine the interaction among the predictors and outcome of adaptation and mental well-being (Figure 1), and the model fit was fair (CFI = 0.89; RMSEA = 0.09)

Conclusions

The results indicated that there are gender differences in adaptation. While all the hypothesized groups of variables contributed to mental well-being of people with CID. Resilience, illness variables, and some forms of coping are closely linked to adaptation and maladaptation.

Disclosure

No significant relationships.

HGG-27. ANTI-CANCER POTENTIAL OF ARGINASE FOR HIGH-GRADE GLIOMA IN VITRO & IN-VIVO

BACKGROUND

High-grade glioma is currently incurable. It was reported that glioma may be auxotrophic to arginine due to the lack of urea cycle genes expressions, suggesting arginase may be a potential agent for high grade glioma. AIM: We investigated the efficacy of pegylated arginase I (pegArg-I) or in combination with other anti-cancer drugs for high-grade glioma in vitro and in vivo.

METHODS

4 high-grade glioma cell lines (U87, U373, U138, D54) were treated with pegArg-I in vitro. The molecular mechanism of pegArg-I-induced cytotoxicity was tested in U87. The ultra-morphological changes of pegArg-I-treated U87 was investigated by both scanning and transmission electron microscopy. Orthotopic glioma xenograft model with luciferase-transfected U87 cell line was tested for anti-cancer efficacy of peg-Arg I in vivo.

RESULTS

We showed that pegArg-I induced significant cell death in all 4 cell lines in vitro. Temozolomide, difluoromethyornithine and chloroquine (CQ) were then tested together with pegArg-I in U87 in vitro. We found that only CQ showed additive effect with pegArg-I against glioma in vitro. Such additive cytotoxic effect may be associated with enhanced autophagy and necrosis as shown in transmission electron microscopy and autophagy markers’ expression by Western blotting. PegArg-I prolonged the survival of glioma mice, suggesting its possible anti-glioma efficacy. However, CQ+pegArg-I didn’t show further significant anti-cancer efficacy in vivo.

CONCLUSION

PegArg-I may be useful in slowing the progression of glioma, but additional drug candidate which works synergistically with pegArg-I remains to be explored.

Immune cell profiling in Gleason 9 prostate cancer patients treated with brachytherapy versus external beam radiotherapy: An exploratory study

This exploratory study evaluates immunological changes in high-risk Gleason 9 prostate cancer patients treated with EBRT+BT compared to EBRT alone. Notably, BT demonstrates the potential to elicit a T cell response which may support further investigation using circulating immune cells as predictive and prognostic biomarkers for radiotherapy response.

1013 Cardiovascular Biomarkers and Pathophysiological Insights into Obstructive Sleep Apnea During Acute Coronary Syndrome

Introduction

Obstructive sleep apnea (OSA) is prevalent and carries prognostic implication in patients with acute coronary syndrome (ACS). The relative contribution of pathophysiological mechanisms in ACS towards OSA is not well-studied. We examined the correlation between severity of OSA and myocardial necrosis, inflammation, wall stress, and fibrosis.

Methods

A total of 89 patients admitted with ACS underwent an overnight sleep study during index admission. Plasma levels of peak troponin I, high-sensitivity C-reactive protein (hs-CRP), N-terminal pro-brain natriuretic peptide (NT-proBNP), and suppression of tumorigenicity 2 (ST2) were prospectively analyzed. Two patients diagnosed with central sleep apnea were excluded.

Results

The recruited patients were divided into no (AHI &lt;5 events/hour, 9.2%), mild (5-&lt;15, 27.6%), moderate (15-&lt;30, 21.8%), and severe (≥30, 41.4%) OSA. The respective Epworth Sleepiness Scale scores were 3.8±3.7, 5.3±4.9, 4.0±2.8, and 5.5±4.5 (p=0.734). Compared to the no, mild and moderate OSA groups, the severe OSA group had a higher body mass index (p=0.005). They were also more likely to present with ST-segment elevation ACS (vs non-ST-segment elevation ACS) (p=0.041), have undergone previous coronary artery bypass grafting (p=0.013), demonstrate complete coronary occlusion during baseline coronary angiography (p=0.049), and have a larger left atrium diameter measured on echocardiography (p=0.029). Likewise, the severe OSA group had higher plasma levels of troponin I (10584±13078, 11699±20130, 19280±30670, 37571±31269 µg/L; p=0.017), hs-CRP (8.1±9.2, 23.1±52.3, 9.3±17.1, 39.4±44.7 mg/L; p=0.004), and NT-proBNP (667±604, 765±856, 636±728, 1395±1220 pg/mL; p=0.004), but not ST2 (p=0.10). After adjusting for the effects of the confounding variables, severe OSA was independently associated with troponin I (i.e., myocardial necrosis; OR 1.00003, 95% CI 1.000013-1.000048; p=0.001) and NT-proBNP (i.e., myocardial wall stress; OR 1.00081, 95% CI 1.00021-1.00141; p=0.008).

Conclusion

Severe OSA during the acute phase of ACS was associated with extensive myocardial necrosis and myocardial wall stress, but not with inflammation and myocardial fibrosis.

Support

Nil

Pre-operative CT localization for patients with subsolid opacities expecting video-assisted thoracoscopic surgery-single center experience of fluorescent iodized emulsion and hook-wire localization technique

OBJECTIVE

To describe our clinical experience of using combination of fluorescent iodized emulsion, indocyanine green & lipiodol, and hook-wire in pre-operative CT localization of patients with subsolid lung lesions prior to video-assisted thoracoscopic surgery (VATS).

METHODS

A retrospective review between June 2018 and July 2019 of consecutive Chinese patients whom underwent VATS for subsolid lung lesions with pre-operative CT localization done with combination of fluorescent iodized emulsion and hook-wire technique in a tertiary hospital (Tuen Mun Hospital, Hong Kong SAR). The duration and complications related to the localization procedure were recorded The clinical records, operative findings and pathology reports were retrieved from the hospital electronic clinical management system.

RESULTS

Combination fluorescent iodized emulsion with hook-wire enabled accurate localization and resection of all subsolid lung lesions in VATS. No major complications were reported.

CONCLUSION

Combination of fluorescent iodized emulsion and hook-wire placement under CT guidance is a simple, safe and cost- effective procedure that enabled accurate localization and resection of subsolid nodule in VATS.

ADVANCES IN KNOWLEDGE

VATS has been the mainstay for indeterminate pulmonary nodules for diagnostic and/or curative purpose. The main problem that surgeons may encounter during operation is the difficulty in locating the target lesion particularly for subsolid lesions. Many pre-operative localization methods have been developed in this regard. With the novel technique that we described, we were able to overcome disadvantages of most described methods.

Adjuvant whole breast radiotherapy with simultaneous integrated boost to tumor bed with intensity modulated radiotherapy technique in elderly breast cancer patients

Background

Adjuvant whole breast radiotherapy is the standard of care for breast cancer patients after partial mastectomy. Intensity-modulated radiation therapy (IMRT) has been reported to reduce acute toxicities compared to conventional radiotherapy. IMRT with simultaneous integrated boost (SIB) technique can deliver higher doses to tumor bed and irradiate whole breast with a lower dose level to shorten overall treatment duration. This study presents the long-term results of adjuvant IMRT with SIB in elderly breast cancer patients who received partial mastectomy.

Methods

From January 2007 to January 2018, 93 elder breast cancer patients (≥65-year-old) who received IMRT with SIB technique after partial mastectomy were reviewed retrospectively. The axillary areas were managed with either sentinel lymph node biopsies or axillary lymph node dissection. The dose to whole breast was 50.4 Gy in 28 fractions in all patients and the dose to tumor bed was 61.6 to 66.4 Gy in 28 fractions. The primary end point is locoregional control. Secondary end points include: overall survival, breast cancer-specific survival, distant-metastases-free survival, disease-free survival, and acute and chronic toxicities.

Results

The median follow-up was 56.1 months. One patient had ipsilateral breast tumor recurrence, 3 patients had regional lymph node recurrence, and 9 patients had distant metastases. Death occurred in 5 patients, including 3 patients died of breast cancer progression. Five-year overall survival is 96.3% and 5-year locoregional recurrence-free survival is 96.4%. The 5-year breast cancer specific survival and 5-year distant metastases-free survival is 97.5% and 87.2%, respectively. Seven patients developed second primary cancer after RT. Eighty-one point seven percent patients had acute grade 1 dermatitis while 18.3% suffered from grade 2 dermatitis. The incidence of grade 1 pneumonitis and grade 1 stomatitis was 4.3% and 8.6%, respectively.

Conclusions

Adjuvant IMRT with SIB technique is a safe and effective treatment strategy for elderly breast cancer patients after partial mastectomy.

Melioidosis in patients with suspected tuberculosis in Cambodia: a single-center cross-sectional study

SETTING

Melioidosis-Burkholderia pseudomallei infection-is increasingly recognized in Cambodia, a country with a high incidence of tuberculosis (TB). Melioidosis and TB can be clinically indistinguishable.

OBJECTIVE

To quantify the proportion of patients with clinically suspected TB who had melioidosis by testing sputum for B. pseudomallei.

DESIGN

This was a prospective, 6-month cross-sectional single-center study at a Cambodian provincial referral hospital among patients with suspicion of TB who provided sputum specimens for testing. TB was diagnosed using sputum Xpert^® MTB/RIF molecular assay or culture; melioidosis was diagnosed using sputum culture for B. pseudomallei.

RESULTS

Of 404 patients evaluated for possible TB, 52 (12.9%, 95%CI 9.8-16.5) had TB. Four patients (1.0%, 95%CI 0.3-2.5) had melioidosis; none had concurrent TB or an existing medical risk factor for melioidosis, although two were farmers, an occupational risk factor.

CONCLUSION

One per cent of patients being evaluated for TB at a Cambodian provincial referral hospital had culture-proven respiratory melioidosis, a highly lethal infection. None had previously recognized medical conditions that would increase their risk of melioidosis. Testing for melioidosis should be considered in patients presenting with suspected TB in Cambodia.

Evaluation of breast stiffness measured by ultrasound and breast density measured by MRI using a prone-supine deformation model

Background

This study evaluated breast tissue stiffness measured by ultrasound elastography and the percent breast density measured by magnetic resonance imaging to understand their relationship.

Methods

Magnetic resonance imaging and whole breast ultrasound were performed in 20 patients with suspicious lesions. Only the contralateral normal breasts were analyzed. Breast tissue stiffness was measured from the echogenic homogeneous fibroglandular tissues in the central breast area underneath the nipple. An automatic, computer algorithm-based, segmentation method was used to segment the whole breast and fibroglandular tissues on three dimensional magnetic resonanceimaging. A finite element model was applied to deform the prone magnetic resonance imaging to match the supine ultrasound images, by using the inversed gravity loaded transformation. After deformation, the tissue level used in ultrasound elastography measurement could be estimated on the deformed supine magnetic resonance imaging to measure the breast density in the corresponding tissue region.

Results

The mean breast tissue stiffness was 2.3 ± 0.8 m/s. The stiffness was not correlated with age (r = 0.29). Overall, there was no positive correlation between breast stiffness and breast volume (r = - 0.14), or the whole breast percent density (r = - 0.09). There was also no correlation between breast stiffness and the local percent density measured from the corresponding region (r = - 0.12).

Conclusions

The lack of correlation between breast stiffness measured by ultrasound and the whole breast or local percent density measured by magnetic resonance imaging suggests that breast stiffness is not solely related to the amount of fibroglandular tissue. Further studies are needed to investigate whether they are dependent or independent cancer risk factors.

ZB transposon and chicken vasa homologue (Cvh) promoter interact to increase transfection efficiency of primordial germ cells in vivo

1. In order to increase the efficiency of generating transgenic chicken, this trial focused on two points: primordial germ cells (PGCs）transfection in vivo and a germline-specific promoter.2. In order to transfect PGCs in vivo, two plasmids (pZB-CAG-GFP, pCMV-ZB）were co-injected into chicken embryos via the subgerminal cavity at Hamburger and Hamilton (HH) stage 2-3 or via blood vessel at HH stage 13-14. Results showed that the percentage of GFP+ embryos, viability and hatching rate of embryos injected at HH stage 13-14 were significantly higher than that at HH stage 2-3.3. Two plasmid transposon systems were used for chicken embryo micro-injections. The donor plasmid, with a green fluorescent protein (GFP) reporter gene, was mediated by the ZB transposon. The helper plasmid was a transposase expression vector driven by the promoter of the chicken vasa homologue (Cvh) gene or Human cytomegalovirus (CMV) promoter. Results showed that 60.98% of gonads in Cvh group expressed GFP, which was 52.50% higher than seen in the CMV group. Only gonad tissue from the Cvh group showed any GFP signal, whereas both gonads and other tissues in the CMV group showed green fluorescence.4. The data suggested that ZB transposon-mediated gene transfer was efficient for transfecting PGCs in vivo; the Cvh promoter drove the transposase gene specifically in the germline and increased the efficiency of germline transmission. Blood vessels injection at HH stage 13-14 may be a more efficient route for PGCs transfection in vivo.

Abstract P3-12-05: Fractionation patterns in adjuvant breast radiotherapy in Ontario, Canada from 2009 to 2015

Purpose: To report the patterns of use of hypofractionated radiotherapy (HFRT) (≤16 fractions)in breast cancer and ductal carcinoma in situ (DCIS) patients in Ontario, Canada from 2009 to 2015 and identify factors related to HFRT use.

Methods: A retrospective cohort study of Ontario women diagnosed with breast cancer or DCIS followed by adjuvant breast or chest wall radiation (RT) from 2009 to 2015 was conducted using data from the Institute for Clinical Evaluative Sciences (ICES). Logistic regression models were used to identify factors associated with HFRT use. Physician was included as a random effect. To calculate the potential amount of time that could be saved if all patients were to receive 16 fractions of HFRT, the number of extra RT treatments after the 16th visit was multiplied by the median amount of time spent to treat one patient at our cancer centre (8.76 minutes). This time was found with Sunnybrook Health Sciences Centre data collected from October 2017 to March 2018 (n=523) and represents the amount of time from when a patient enters the RT unit for treatment setup, until the RT beam is turned off.

Results: A total of 42,072 patients were included. Most patients were aged between 50 and 69 years old (56.7%) with stage I or II breast cancer (74.6%) and had breast conserving surgery (BCS) (76.9%). Half previously received chemotherapy and 7.9% were DCIS patients. Use of sequential boost, simultaneous boost, and regional nodal RT was 17.2%, 3.1%, and 31.7% respectively. Institutional variation in HFRT use ranged from 27.5% to 71.6%. HFRT use has increased in all patient populations over the study period. HFRT use was more common in breast cancer and DCIS patients with BCS than in chest wall and nodal RT. Simultaneous boost (OR=0.09), nodal RT (OR=0.08), previous chemotherapy (OR=0.7), stage 0, II, and III breast cancer (OR=0.06 relative to stage I), were correlated with less HFRT use. Older age, later year of diagnosis, sequential boost (OR=0.09), BCS and no surgery (OR=1.2, 1.5 relative to mastectomy) were correlated with higher HFRT use. Institution was significantly correlated to HFRT use. The variance estimate for the physician random effect was 0.33 (p&lt;0.0001). For breast cancer patients with BCS and breast RT specifically, 62,396 extra visits occurred from 2009 to 2015, corresponding to ˜9100 hours of treatment if all patients received HFRT. For the entire patient population, a total of 190,726 extra visits occurred or ˜27,900 hours.

Trends in the use of HFRT (%) from 2009 to 2015 for DCIS and breast cancer patients in Ontario.YearStage I-IV + BCS + Breast RTStage I-IV + BCS + Breast + Nodal RTStage I-IV + Mastectomy + Breast RTStage I-IV + Mastectomy + Breast + Nodal RTDCIS + BCS200962.610.329.09.545.2201062.06.323.76.951.2201162.24.121.34.752.7201263.79.621.711.452.0201365.112.629.315.057.3201469.37.835.415.164.5201573.711.839.217.573.4BCS: breast conserving surgery, RT: radiation treatment

Conclusions: HFRT use in Ontario has increased over time for all patient populations, and reflects the current evidence supporting HFRT in different patient populations, with lower HFRT use seen in chest wall and nodal RT and higher HFRT use in early-stage breast cancer patients with BCS.

Citation Format: Chow E, Chan S, Yao Z, Sutradhar R, Lee J, Wan BA, Paszat L. Fractionation patterns in adjuvant breast radiotherapy in Ontario, Canada from 2009 to 2015 [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P3-12-05.