Negative Surveillance Research Articles

Solving the imbalanced dataset problem in surveillance image blur classification

Surveillance videos taken in unconstrained environments can be tampered with due to different environmental factors and malicious human activities. They often blur the video content and introduce difficulty in identifying the events in the scene. The problem is particularly acute for smart surveillance systems that need to make real-time decisions based on the video. Automatic detection and classification of the blur anomalies in the video are crucial to these systems. Traditional learning-based classification methods often face imbalance problems in the sample numbers and distributions among the data classes in the dataset that severely affect their training and hence the classification performance. In this paper, a new learning-based approach for surveillance image blur classification is proposed. The imbalanced dataset problem is tackled both at the data and algorithm levels. At the data level, two synthesizers are developed to generate the required negative surveillance images to balance the sample numbers for all classes. At the algorithm level, an attention-based structure making use of the special feature of the minority class is proposed to improve the classification accuracy. Our experiment results show that the proposed approach significantly outperforms state-of-the-art methods for blur classification while keeping the model size small for edge applications.

Abstract PS05-06: Outcomes of Surveillance using Contrast Enhanced Mammography in Women with a Personal History of Breast Cancer

Abstract Background Women with a personal history of breast cancer (PHBC) have a high rate of subsequent breast malignancy. Annual mammography with selective ultrasound has been the standard method of surveillance after breast cancer for many years, aiming for early detection, treatment and improved survival. In surveillance populations, interval cancers, which can account for ~30% of subsequent breast cancers, are more likely to be larger, hormone receptor negative and lymph node positive than cancers detected by surveillance (Lee et al, Radiology 2021). Interval cancer rates of 3.6 per 1000 mammographic screens have been reported previously in women with PHBC (Houssami et al, JAMA 2011). For women with PHBC a more sensitive surveillance approach may be justified, noting mammography has lower program sensitivity in PHBC surveillance than in screening. Magnetic resonance imaging (MRI) is used selectively but with resource and access limitations. Contrast enhanced mammography (CEM) offers a more sensitive modality than conventional mammography with specificity comparable to MRI, but its utility for surveillance is uncertain. Methods Retrospective study of 1,190 women with PHBC who commenced annual CEM surveillance in an Australian hospital setting between June 2016 and December 2022 (Elder et al, Breast Cancer Res Treat 2023) combining outcomes of initial CEM and any subsequent surveillance imaging over that period, including incident surveillance-detected cancers and interval cancers (cancers diagnosed in the year following a negative surveillance episode), recalls for assessment, the contribution of contrast to recall, and pathology and treatment details for cancer diagnoses. Outcomes were reported using descriptive statistics and hazards modelling. Results There were 3,784 episodes for analysis: 1,190 first CEM surveillance episodes, and 2,594 subsequent surveillance episodes of which >90% were contrast based imaging. 79% of women had at least three annual rounds of surveillance imaging. 186 cases from the total 3784 surveillance episodes were recalled for assessment (recall rate 4.9%). 72 (39%) recalled cases identified malignant lesions (true positives (TP)), with 50 invasive cancers and 22 cases of DCIS. 114 (61%) recalled cases were false positives (FP). 51% of cases were only recalled due to contrast and 35% of these were TP. Invasive cancers were predominantly stage 1 (64%) or stage 2 (32%) and most were grade 2 (44%) or grade 3 (47%). The median invasive cancer size was 16mm (IQR 9-25mm). 62% of invasive cancers were hormone receptor positive HER2 negative, and 24% were triple negative. The median DCIS size was 19mm (IQR 10-26mm) with only a single low grade case. 40% of invasive cancers and 59% of DCIS were recalled due to contrast. Comparison of tumour features indicates similarities between contrast-directed recalls and other diagnoses; conclusive findings would require a larger sample. Five interval cancers were identified, of which three were asymptomatic and detected on surveillance imaging scheduled early for other reasons. Thus, the rate of symptomatic interval cancers was 0.8 per 1000 screens (program sensitivity 96.0%). Surveillance-detected cancer rates differed significantly by index cancer subtype (χ2=11.9, p=0.0026), with highest rates for women with triple negative index cancers. Incidence cancer rates were higher among the 6.9% of women with moderate or marked BPE at first CEM surveillance episode (χ2=8.8, p=0.032), but did not differ significantly by age group (χ2=5.2, p=0.39) nor breast density (χ2=4.7, p=0.19). Conclusions Routine use of CEM in annual surveillance of women with PHBC led to 1.85-fold increase in the detection of clinically significant malignant lesions, with lower interval cancer rates than previous published series of women with PHBC. CEM appears to increase the sensitivity of surveillance programs for women with PHBC, improving on imaging without contrast. Citation Format: Julia Matheson, Carolyn Nickson, Kenneth Elder, Allan Park, Allison Rose, Bruce Mann. Outcomes of Surveillance using Contrast Enhanced Mammography in Women with a Personal History of Breast Cancer [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PS05-06.

Predicting five-year interval second breast cancer risk in women with prior breast cancer.

Annual surveillance mammography is recommended for women with a personal history of breast cancer. Risk prediction models that estimate mammography failures such as interval second breast cancers could help to tailor surveillance imaging regimens to women's individual risk profiles. In a cohort of women with a history of breast cancer receiving surveillance mammography in the Breast Cancer Surveillance Consortium in 1996-2019, we used LASSO-penalized regression to estimate the probability of an interval second cancer (invasive cancer or ductal carcinoma in situ) in the one-year following a negative surveillance mammogram. Based on predicted risks from this one-year risk model, we generated cumulative risks of an interval second cancer for the five-year period following each mammogram. Model performance was evaluated using cross-validation in the overall cohort and within race and ethnicity strata. In 173,290 surveillance mammograms, we observed 496 interval cancers. One-year risk models were well-calibrated (expected/observed ratio = 1.00) with good accuracy (area under the receiver operating characteristic curve = 0.64). Model performance was similar across race and ethnicity groups. The median five-year cumulative risk was 1.20% (interquartile range 0.93-1.63%). Median five-year risks were highest in women who were under age 40 or pre- or peri-menopausal at diagnosis and those with estrogen receptor-negative primary breast cancers. Our risk model identified women at high risk of interval second breast cancers who may benefit from additional surveillance imaging modalities. Risk models should be evaluated to determine if risk-guided supplemental surveillance imaging improves early detection and decreases surveillance failures.

Comparison of clinical outcomes of patients with serial negative surveillance cultures according to a subsequent polymerase chain reaction test for carbapenemase-producing Enterobacterales

Carbapenemase-producing Enterobacterales (CPE) are of serious concern worldwide due to high morbidity and mortality. To evaluate the impact of the result of a subsequent polymerase chain reaction (PCR) test for carbapenemase after serial negative surveillance cultures on positive culture conversion in patients with three consecutive negative surveillance cultures for CPE, and to identify risk factors for conversion. A retrospective study of patients with positive CPE cultures on CHROMagar KPC medium was performed in a Korean tertiary hospital from October 2018 to December 2022. PCR for blaKPC, blaNDM, blaIMP, blaVIM, blaGES, and blaOXA-48 was performed after three consecutive negative rectal swab cultures. Clinical characteristics and outcomes of patients were compared according to whether follow-up PCR was positive (CNPP) or negative (CNPN). Of 1075 patients with positive CPE cultures, 150 (14.0%) yielded three consecutive negative rectal swab cultures. Of these, 50 (33.3%) were CNPP, and 100 (66.7%) were CNPN. Risk factors associated with a positive PCR result on multivariate analysis were: age, central venous catheter, and Escherichia coli infection. CNPP patients were more likely to have positive culture conversion for CPE than CNPN patients (39/44 (88.6%) vs 21/50 (42.0%), P<0.001). In multivariate analysis, independent risk factors for culture conversion were: a positive PCR result after surveillance cultures, diabetes mellitus, central venous catheter, and Klebsiella pneumoniae. CNPP patients have higher rates of culture conversion than CNPN patients, and a follow-up PCR test after serial negative surveillance cultures is useful in deciding whether or not to discontinue contact precautions.

Can daily bathing with 4% chlorhexidine + daily chlorhexidine wipe for 1week be effective in decolonizing Candida auris colonization?

Herein, it is aimed to present the decolonizing rates of Candida auris colonized cases after daily bathing with 4% chlorhexidine plus daily cleaning with 4% chlorhexidine wipe for 1week (will be mentioned as DCHX). The study period was from October, 2021, to November, 2022. Inclusion criteria were (i) age > 18, (ii) receiving DCHX, (iii) proven C. auris carrier on auricular, or axillar or inguinal swab surveillance cultures up to 5-day period before DCHX. Cases with three consecutive negative surveillance cultures 3days apart were considered to be decolonized. A total of 38 cases [14 female, aged 61.8 ± 15.5years] fulfilled the inclusion criteria. Six (15.8%), 23 (60.1%), and 22 cases (57.8%) were postauricular, inguinal, and axillary culture positive, respectively. Only three cases (7.9%) were triple culture positive. Nine cases (23.7%) had three consequent negative surveillance cultures after DCHX and were considered to be decolonized.There was no significant difference in decolonization rates of concomitant only antibiotic receiving cohort vs. concomitant antifungal + antibiotic receiving cohort (5/16 vs. 2/8, p = 1) were decolonized similarly. Of the nine C. auris decolonized cases, two developed C. auris infection in 30days follow-up after decolonization. However, 10 (34.5%) of 29 non-decolonized cases developed C. auris infection (p: 0.450) within 30days after surveillance culture positivity. Over all cohorts, day 30 mortality was 23.7% (9/38). In conclusion, based on our observational and relatively small uncontrolled series, it appears that DCHX is not very effective in decolonizing C. auris carriers (especially in cases who are C. auris colonized in > 1 areas), although it is not completely ineffective.

The timing of recurrence after endoscopic papillectomy.

Endoscopic papillectomy (EP) offers a safe and effective method for resection of ampullary adenomas. Data regarding the long-term resolution of adenoma following EP are limited. The aim of this study therefore was to examine the timing of recurrence after EP of ampullary adenomas. This was a single-center retrospective study including patients who received EP for ampullary adenomas from 8/2000 to 1/2018. Patients with confirmed complete eradication of adenoma were included in the recurrence analysis with recurrence defined as finding adenomatous histology after 1 negative surveillance endoscopy. Kaplan-Meier estimates were calculated to determine recurrence rates. Of the 165 patients who underwent EP, 136 patients (mean age 61.9, 51.5% female) had adenomatous histology with a mean lesion size of 21.2mm. A total of 124 (91.2%) achieved complete eradication with a follow-up of 345.8 person-years. Recurrence occurred in 20 (16.1%) patients at a mean of 3.2 (± 3) years (range 0.5-9.75years) for a recurrence rate of 5.8 (95% CI 3.6-8.8) per 100 person-years. Nine (45%) recurrences occurred after the 1st 2years of surveillance. Recurrence rate did not differ by baseline pathology [low-grade dysplasia: 5.2 (95% CI 3.0-9.0), high-grade dysplasia: 6.9 (95% CI 2.3-15.5), adenocarcinoma: 7.7 (95% CI 0.9-25.1)]. Recurrence remains a significant concern after EP. Given the timing of recurrence, long surveillance periods may be necessary. Larger multicenter studies are needed, however, to determine appropriate surveillance intervals.

Association of follow-up imaging frequency with temporal incidence and patterns of distant failure following (chemo) radiotherapy for HPV related oropharyngeal cancer

ObjectivesEmerging data supports radical intent therapy for oligometastatic (OM) relapsed human papilloma virus (HPV+) related oropharyngeal cancer (OPC). We assess the association of follow-up imaging frequency amongst HPV + OPC, with temporal and spatial patterns of distant relapse, to inform rationalisation of routine post-treatment imaging. Materials and methodsA retrospective single centre cohort study was carried out of consecutive HPV + OPC patients treated with radical intent (chemo)radiotherapy ((CT)RT) between 2011 and 2019. OM state was defined as ≤ 5 metastasis, none larger than 3 cm (OMs) or, if interval from last negative surveillance imaging > 6-months, then ≤ 10 metastasis, none larger than 5 cm, (OMp). Patients not meeting OMs / OMp criteria were deemed to have incurable diffuse metastatic disease (DMdiffuse). Results793 HPV-OPC patients were identified with median follow-up 3.15years (range 0.2–8.9). 52 (6.6 %) patients had radiologically identified DM at first failure and were considered for analysis. The median time to recurrence was 15.1 months (range: 2.6–63 months). 87 % of distant metastasis (DM) occurred in the first two years after treatment. Twenty-seven (52 %) patients had OM (OMs or OMp) at time of failure, with 31 % having OMs. The median time from completion of treatment to diagnosis of DMdiffuse vs OM was 22.2 months (range: 2.6–63.1 months) vs 11.6 months (range: 3.5–32.5 months). The probability of being diagnosed with OM vs DMdiffuse increased with reducing interval from last negative surveillance scan to imaging identifying DM (≤6 months 88.9 %, 7–12 months 71.4 %, 13–24 months 35 %, > 24 months 22.2 %). ConclusionWe demonstrate that a reduced interval between last negative imaging and subsequent radiological diagnosis of DM is associated with increased likelihood of identification of OM disease. Consideration of increased frequency of surveillance imaging during the first two years of follow up is supported, particularly for patients at high risk of distant failure.

Protocol of a multicentre randomised controlled trial assessing transperineal prostate biopsy to reduce infectiouscomplications

IntroductionApproximately one million prostate biopsies are performed annually in the USA, and most are performed using a transrectal approach under local anaesthesia. The risk of postbiopsy infection is increasing due...

Abstract 3360: Negative predictive value of circulating tumor tissue modified viral HPV DNA for identifying recurrence among patients treated for HPV-driven oropharyngeal cancer

Abstract Purpose: Despite favorable outcomes, up to 20% of patients with human papillomavirus (HPV)-driven oropharyngeal squamous cell carcinoma (OPSCC) will experience recurrence. Monitoring circulating tumor tissue modified viral (TTMV)-HPV DNA during post-treatment surveillance has emerged as a tool that has demonstrated &amp;gt;95% positive predictive value (PPV) for detecting recurrence. Here we describe a large real-world population with detailed clinical follow-up, permitting determination of the longitudinal negative predictive value (NPV) of the assay. Patients and methods: This IRB-approved, retrospective observational cohort study included 312 patients across five U.S. centers who were ≥3 months post-treatment for HPV-driven OPSCC. Patients had one or more TTMV-HPV DNA results (NavDx®, Naveris Laboratories) obtained during surveillance between February 2020 and January 2021. A baseline TTMV-HPV DNA test was not required. HPV status was assessed by p16 immunohistochemistry or HPV PCR/ISH. Test results were correlated with physician-reported exam and imaging findings to assess disease status in follow-up. Results: The cohort was mostly male (85%), had a median age of 61 (range: 27-81), included smokers (50%), and 282 (90%) had involved nodes (N1: 204, N2: 70, N3: 8) at initial staging. Curative-intent treatment involved surgery with or without another modality in 54% of cases (169/312). Median follow-up time was 23.5 months, and 39 patients (12.5%) had documented recurrence. Most patients had &amp;gt;1 TTMV-HPV DNA test result ≥3 months post-treatment (231, 74%), with 48 (15%) having 5 or more tests. Among patients with multiple negative surveillance tests, the median time between tests was 126 days (4.2 months, range: 0.37-24.2). The first TTMV-HPV DNA surveillance test was most often performed within the first year post-treatment (195, 63%). Across 812 test results, the NPV was 99.5%. There were 4 false negative tests among patients with confirmed p16-positive (3/4) or HPV PCR-positive (1/4) biopsy-proven recurrence. One of these patients had a subsequent positive TTMV-HPV DNA test during salvage immunotherapy. Only one of these patients had baseline TTMV-HPV DNA testing available, which showed a low positive &amp;lt;50 TTMV-HPV16 DNA Score, whereas the other three patients did not have a baseline result available. Conclusion: Our findings further support the clinical potential of monitoring circulating TTMV-HPV DNA during post-treatment surveillance. We demonstrate a very high assay NPV correlated with physician-reported outcomes. TTMV-HPV DNA can be used to assist in surveillance and could inform imaging needs and future practice guidelines for HPV-driven head and neck cancer survivors. Citation Format: Glenn J. Hanna, Scott Roof, James Jabalee, Eleni M. Rettig, Rocco M. Ferrandino, Sida Chen, Marshall Posner, Krzysztof J. Misiukiewicz, Eric M. Genden, Raymond L. Chai, John Sims, Elaine Thrash, Scott J. Stern, Adam Raben, Lydia I. Clements, Abie H. Mendelsohn, Charlotte Kuperwasser, Catherine Del Vecchio Fitz, Barry M. Berger. Negative predictive value of circulating tumor tissue modified viral HPV DNA for identifying recurrence among patients treated for HPV-driven oropharyngeal cancer [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 3360.

The Clinical Utility of MRSA Nasal Surveillance Swabs in Ruling-Out MRSA Infections in Children.

The utility of methicillin-resistant Staphylococcus aureus (MRSA) nasal surveillance swabs has not been well-described in children. This retrospective, cohort study yielded a negative predictive value of 99.4% for an initial negative MRSA nasal surveillance swab in 165 hospitalized children with a suspected infection and clinical cultures obtained from a likely site of infection.

Performance of Statistical and Machine Learning Risk Prediction Models for Surveillance Benefits and Failures in Breast Cancer Survivors.

Machine learning (ML) approaches facilitate risk prediction model development using high-dimensional predictors and higher-order interactions at the cost of model interpretability and transparency. We compared the relative predictive performance of statistical and ML models to guide modeling strategy selection for surveillance mammography outcomes in women with a personal history of breast cancer (PHBC). We cross-validated seven risk prediction models for two surveillance outcomes, failure (breast cancer within 12 months of a negative surveillance mammogram) and benefit (surveillance-detected breast cancer). We included 9,447 mammograms (495 failures, 1,414 benefits, and 7,538 nonevents) from years 1996 to 2017 using a 1:4 matched case-control samples of women with PHBC in the Breast Cancer Surveillance Consortium. We assessed model performance of conventional regression, regularized regressions (LASSO and elastic-net), and ML methods (random forests and gradient boosting machines) by evaluating their calibration and, among well-calibrated models, comparing the area under the receiver operating characteristic curve (AUC) and 95% confidence intervals (CI). LASSO and elastic-net consistently provided well-calibrated predicted risks for surveillance failure and benefit. The AUCs of LASSO and elastic-net were both 0.63 (95% CI, 0.60-0.66) for surveillance failure and 0.66 (95% CI, 0.64-0.68) for surveillance benefit, the highest among well-calibrated models. For predicting breast cancer surveillance mammography outcomes, regularized regression outperformed other modeling approaches and balanced the trade-off between model flexibility and interpretability. Regularized regression may be preferred for developing risk prediction models in other contexts with rare outcomes, similar training sample sizes, and low-dimensional features.

Role of short-dwell daily ethanol-lock therapy in the management of hemodialysis tunneled cuffed catheter-related bloodstream infection.

Catheter-Related Blood Stream Infection (CRBSI) is the major limitation of using Tunneled cuffed catheter (TCC) for long-term Hemodialysis. The standard therapy of CRBSI involves systemic antibiotics with catheter replacement/removal. As antibiotic alone is rarely effective therapy for CRBSI, biofilm eradication using antimicrobial locking solutions is a promising modality for CRBSI treatment, hence catheter salvage. The present study evaluated the efficacy and safety of Ethanol-lock therapy (ELT) in combination with systemic antibiotics for the management of CRBSI associated with hemodialysis TCC. 56 patients with CRBSI were treated with 70% ELT (1 h daily for 5 days) along with systemic antibiotics. Seventeen patients with CRBSI who didn't consent to ELT were treated with antibiotics alone. The effect of ELT was evaluated as clinical cure (fever resolution and negative surveillance cultures), infection-free TCC survival duration and adverse events of ELT among patients with CRBSI. The parameters were compared with 17 patients treated with antibiotics alone. ELT was successful in 50 out of 56 patients (89.28%); compared to 41.17% (seven out of 17) with antibiotics alone (p < 0.001). Mean TCC survival was also significantly higher with ELT combined with systemic antibiotics (126.23 ± 18.67 days) compared to antibiotics alone (38.76 ± 9.91) (p = 0.006). No systemic adverse effects were noted with ELT; two patients receiving ELT had catheter breakage during the study period. We conclude that short-dwell daily ELT with systemic antibiotics is an effective therapy for CRBSI in hemodialysis patients with TCC.

2035. Detecting Vancomycin-resistant Enterococci infection in an immunosuppressed population after screening

Abstract Background Vancomycin-Resistant Enterococci (VRE) are major pathogens for severely immunosuppressed patients. Because VRE are common pathogens in our institution, such patients are often empirically treated to cover VRE, exposing them to broad-spectrum antimicrobials. Analogous to nasal screening for Methicillin-resistant Staphylococcus aureus carriage, targeted VRE surveillance is performed to identify and isolate colonized patients to reduce transmission. To assess risks and benefits of empiric therapy, we evaluated this surveillance procedure. Methods All patients admitted to two inpatient hospital units from 01/01/2019 to 12/31/2021 had routine perirectal VRE surveillance ordered and results retrospectively reviewed. One swab from each Culturette set was tested by vanA PCR, and the other was inoculated on CHROMEID® VRE (Biomerieux) if the PCR was positive. Subsequent clinical cultures of any site within 14 days of surveillance screening were reviewed for VRE. Results 1133 patients were screened; 46 (4.1%) patients had VRE colonization. Within 2 weeks following VRE screening 20 patients had clinical samples that were positive for an Enterococcus species (14 in the first 7 days and 6 in days 8-14). The most common sites of clinical cultures were urine, 8 (40%), wound, 4 (20%), intra-abdominal, 4 (20%), and blood, 2 (10%). No clinical culture sample contained VRE. Conclusion The rate of VRE carriage was low in this population, raising the question of the value of broad-spectrum empiric therapy coverage for VRE. No VRE infections were subsequently detected in any patients irrespective of surveillance. The negative predictive value for clinical VRE infection was 100% with negative surveillance screening in this population. Disclosures All Authors: No reported disclosures.

Peer Appearance Teasing and Restrained Eating Among Chinese Adolescent Girls: A Mediation Model of Fear of Negative Appearance Evaluation and Body Surveillance.

Restrained eating is becoming widespread recently. The present study aimed to examine whether peer appearance teasing was positively associated with restrained eating among Chinese adolescent girls and whether this association was mediated by fear of negative appearance evaluation (FNAE) and body surveillance. A sample of 720 Chinese adolescent girls completed questionnaires on peer appearance teasing, FNAE, body surveillance, and restrained eating. Peer appearance teasing was significantly and positively related to girls' restrained eating. FNAE mediated the relationship between peer appearance teasing and restrained eating. Furthermore, the association between peer appearance teasing and restrained eating was sequentially mediated by FNAE and body surveillance. The findings of this study provide new insights into the development of restrained eating among adolescent girls, and highlight peer appearance teasing and body surveillance as potential targets for intervention programs regarding body image concerns and eating disorders.

S1349 Utility of LAD Score for Treatment Response Assessment and Recurrence Monitoring in Patients With Hepatocellular Carcinoma

Introduction: The GALAD score, which incorporates the biomarkers AFP, AFP-L3% and DCP, has excellent performance for detection of hepatocellular carcinoma (HCC). However, its accuracy in treatment response assessment and recurrence prediction are unknown. We aimed to evaluate the accuracy of these biomarkers in predicting the presence of post-treatment viable tumor and HCC recurrence. Methods: We identified patients with cirrhosis or chronic hepatitis B infection who underwent curative surgical or locoregional treatment (Y-90, TACE, ablation) for HCC between May 2019 to May 2022, with GALAD labs obtained greater than 1 month post-treatment. Because the study cohort already has known HCC, we removed the demographic factors to calculate a score based solely on the biomarkers (the “LAD” score). The LAD score is calculated from the following formula: .04×(AFP-L3) +2.34×log(AFP)+1.33×log(DCP). Evidence of viable tumor was determined by imaging, biopsy, or liver explant pathology after transplant. Patients with non-viable tumor on initial post-treatment imaging were further analyzed for tumor recurrence. The sensitivity and specificity of the LAD score in predicting tumor viability were calculated. The optimal receiver operating characteristic (ROC) curve was used to calculate the cutoff for the LAD score. Results: A total of 78 patients (97 treatments) with surveillance imaging and biomarkers were analyzed. The number of treatments per patient ranged between 1 and 3 (mean 1.2). Mean age at time of HCC detection was 67 years, and a third of patients were female. The most common treatment modality was TACE (48.6%), followed by Y-90 (29.9%), ablation (16.5%), and resection (7.2%). About a third of cases (34.0%) had a viable tumor on initial post treatment images. The optimal LAD cutoff was calculated at 2.23, yielding a sensitivity and specificity of 87.4% and 60.9% for detection of viable tumors, respectively. After median follow up of 21.3 months, 11 cases (17.2%) developed recurrent HCC (mean time to recurrence 3.5 months) among cases with post-treatment non-viable tumor. A total of 7 recurrence cases (64%) had a positive LAD score at negative post-treatment surveillance images. Positive LAD score had a borderline association with recurrence (HR 3.17; 95%CI [0.92, 10.92], p = 0.067). Conclusion: LAD score is increased in most HCC patients with post-treatment viable tumors, suggesting its utility for post treatment response assessment. It might provide risk stratification for HCC recurrence.Figure 1.: Incidence of HCC Recurrence in LAD Positive vs Negative Cases

232.1: Donor-derived Cell-Free DNA Testing in Kidney Transplantation: Do One-month Values Have Any Prognostic Significance?

Introduction: Percutaneous renal allograft biopsy is the current standard for detecting acute rejection after kidney transplantation (KT). Noninvasive tests such as plasma-based donor-derived cell-free DNA (dd-cfDNA) assays have been proposed as an alternative to biopsy. We sought to examine the value of dd-cfDNA testing at one month following KT in different donor and recipient categories. Methods: We performed a single center retrospective review of all adult KT patients (pts) who underwent dd-cfDNA testing between January 2018 and August 2021. The diagnosis of acute rejection was based on histopathology obtained from percutaneous, ultrasound-guided needle biopsies. Our center’s standard practice included dd-cfDNA testing and performing surveillance kidney biopsies at 1 month following KT. The dd-cfDNA test was considered elevated if >1.0%. Results: During the study period, 3157 dd-cfDNA tests were performed in 695 de novo pts. Higher mean 1-month dd-cfDNA levels were noted in the following categories: Retransplants (n=30, 1.8±2.1); highly sensitized pts (PRA 98-100%, n=27, 1.6±2.0; for highly sensitized retransplants, n=18, 2.0±2.3; for highly sensitized primary KTs, n=9, 0.7±0.5); and pts who underwent early reoperations (n=16, 0.85±0.9). In all other KT categories, mean 1-month dd-cfDNA levels were lower and similar: DCD donor KTs (n=53, 0.56±0.4), living donor KTs (n=51, 0.47±0.4); acute kidney injury (AKI) donor KTs (n=23, 0.47±0.6); standard criteria donor (SCD) KTs (n=91, 0.47±0.4); expanded criteria donor (ECD) KTs (n=44, 0.46±0.5); dual KTs (n=16, 0.45±0.4); and pts with delayed graft function (DGF, n=50, 0.46±0.4). In 58 primary KT pts with negative 1-month surveillance biopsies, corresponding mean 1-month dd-cfDNA levels were 0.49±0.4. In 10 pts with positive 1-month surveillance biopsies, corresponding mean 1-month dd-cfDNA levels were 1.5±1.8. In 26 pts with a 1-month dd-cfDNA level >1.0, the subsequent incidence of acute rejection was 27%; in 22 pts with a 1-month dd-cfDNA level ≥2.0, the subsequent incidence of acute rejection was 50% (mean follow-up 14 months). Conclusions: We noted a bimodal distribution of 1-month dd-cfDNA levels. Higher mean 1-month dd-cfDNA levels (range 0.72-2.2) were associated with retransplants, high PRA pts, and pts with early reoperations; 22-44% of these pts had 1-month dd-cfDNA levels >1.0. Conversely, primary KT alone pts (DCD, living donor, AKI donor, SCD, ECD, dual KT, those with DGF) had lower 1-month dd-cfDNA levels (range 0.45-0.56) and only 7-14% had 1-month dd-cfDNA levels >1.0. One-month surveillance biopsy results correlated with corresponding dd-cfDNA levels. Elevated 1-month dd-cfDNA levels occurred in pts at a higher risk for acute rejection, suggesting that these pts need to be monitored more closely.

Porcine cytomegalovirus in xenotransplantation: The new frontier in human transplantation?

Porcine cytomegalovirus in xenotransplantation: The new frontier in human transplantation?

Decision-making and regret in patients with germline CDH1 variants undergoing prophylactic total gastrectomy

IntroductionProphylactic total gastrectomy (PTG) can eliminate gastric cancer risk and is recommended in carriers of a germline CDH1 pathogenic variant. PTG has established risks and potential life-long morbidity. Decision-making regarding...

P333 INFECTIVE ENDOCARDITIS ON TRICUSPID VALVE CAUSED BY S. AUREUS METHICILLIN RESPONSIVE: RESOLUTION AND RECURRENCE OF DISEASE

Abstract Introduction Tricuspid valve endocarditis accounts for 5–10% of endocarditis cases and is more frequent in intravenous drug abusers. Recurrence of endocarditis occurs not infrequently in patients treated with conservative therapy. Clinical Case In June 2021, a 32–year–old man with a history of intravenous drug abuse came to our observation. He had been presenting for about a week high fever with shaking shivering resistant to antipyretic and antibiotic therapy and laboratory tests with neutrophilic leukocytosis with increase in CRP and procalcitonin. Trans–thoracic echocardiogram was performed and it showed mild tricuspid regurgitation with the presence of filamentous mobile isoechoic formations adhering to the valve leaflets compatible with endocarditic vegetations. A trans–esophageal echocardiogram was performed that confirmed the transthoracic finding of endocarditis on the tricuspid valve with evidence of 11 mm mobile oval vegetation adhering to the posterior flap; blood cultures were positive for methicillin susceptible S. Aureus and antibiotic therapy with oxacillin was administered as a continuous infusion for 6 weeks. The cardiac surgery center was consulted and the surgeons did not indicate any intervention because of the normofunction of the tricuspid valve and the absence of embolic phenomena on total body CT. Subsequent laboratory tests showed negative inflammation indices and negative surveillance blood cultures. Control ETE was planned with the confirmation of complete resolution of endocardial lesions. In September the patient affered the emergency room for an accidental fall from a work vehicle: transthoracic and trans–esophageal echocardiograms were repeated for the concomitant finding of hyperpyrexia and cough with an increase in CRP and procalcitonin. They showed the presence of new larger endocarditic lesions on tricuspid valve with moderate regurgitation. Blood cultures were negative. Antibiotic therapy with oxacillin was reintroduced and the patient was transferred to the infectious disease clinic in prevision of cardiac surgery.

Comprehensive Diagnostic Performance of Real-Time Characterization of Colorectal Lesions Using an Artificial Intelligence–Assisted System: A Prospective Study

The “resect-and-discard” and “leave in situ” strategies for colorectal polyps, which were proposed to reduce polypectomy-related costs, are attracting great attention. 1 Rex D.K. et al. Gastrointest Endosc. 2011; 73: 419-422 Abstract Full Text Full Text PDF PubMed Scopus (435) Google Scholar The American Society for Gastrointestinal Endoscopy proposed diagnostic performance thresholds (negative predictive value or surveillance interval agreement ≥90%) for these optical biopsy strategies. 2 Rees C.J. et al. Gut. 2017; 66: 887-895 Crossref PubMed Scopus (120) Google Scholar Artificial intelligence (AI)–assisted computer-aided characterization (CADx) has been investigated as a possible solution for implementing optical biopsy strategies. 3 Chen P.J. et al. Gastroenterology. 2018; 154: 568-575 Abstract Full Text Full Text PDF PubMed Scopus (231) Google Scholar , 4 Byrne M.F. et al. Gut. 2019; 68: 94-100 Crossref PubMed Scopus (338) Google Scholar , 5 Misawa M. et al. Dig Endosc. 2021; 33: 273-284 Crossref PubMed Scopus (16) Google Scholar However, it remains uncertain how endoscopists interpret the output of CADx in clinical practice. We therefore conducted a prospective study to investigate the comprehensive diagnostic performance of endoscopists in relation to CADx predictions.