Positive Yield Research Articles

P0482 Diagnostic yield of Small Bowel Capsule endoscopy and Double Balloon Enteroscopy for Small bowel Crohn’s disease

Abstract Background Small Bowel Capsule Endoscopy (SBCE) a valuable tool in visualizing the small bowel (SB) SBCE paired with Double Balloon Enteroscopy (DBE) can obtain histology to investigate Crohn’s disease (CD). Diagnostic yield was assessed using SBCE & DBE. Methods A retrospective analysis of patients referred to SBCE service with suspected CD. PillCam SB3 was used in this study with one reporting gastroenterologist. Previous colonoscopy, histology, faecal calprotectin (FC) & MR enterography (MRE) analysed. Linear regression statistical analysis performed. Results 94 patients (50% female, median age = 44). No prior diagnosis of CD. 99% completed study rate. Pre-referral, 46 had Colonoscopy, 26 elevated FC (median = 160) & 8 had abnormal MRE. Abnormal MRE findings: mural thickening of SB, strictures and terminal ileitis. Raised FC was not statistically significant for a SBCE finding in keeping with CD p = 0.357 however, an abnormal MRE was p=0.034. 64.8% of SBCE had an abnormal report, 35.1% had findings in keeping with CD i.e. 54% of abnormal findings on SBCE were indicative of CD. Further investigations: repeat SBCE (10.7%), repeat ileocolonoscopy (1.96%) RDBE (16.6%) & ADBE (10.7%). Repeat SBCE was performed to assess healing. No further diagnosis of CD made with DBE. Conclusion SBCE and DBE are useful adjunct diagnostic tools rather than the primary investigations. A positive yield on SBCE did not correlate to diagnosis of CD. FC did not show significant correlation to a positive diagnosis. MRE showed to be significant precursor to SBCE. Similar research including intestinal ultrasound should be conducted.

Is CT pulmonary angiography overutilized in the evaluation of patients with suspected pulmonary embolism? A retrospective study.

Despite the high mortality rate of acute untreated pulmonary embolism (PE) at 30%, diagnosing PE is challenging. While the prevalence of PE has decreased in recent years, the overuse of computed tomography pulmonary angiography (CTPA) remains a concern. The National Institute for Health and Care Excellence (NICE) provides guidelines using the Wells score for PE assessment. The Royal College of Radiologists (RCR) recommends a positive yield of 15.4% - 37% for CTPA tests. This study assesses the positive yield of CTPA for suspected PE patients and evaluates the potential reduction through Wells score/D-dimer assessment as recommended by NICE. All patients who underwent CTPA between September 1, 2019, and January 31, 2020, at Salmaniya Medical Complex were included. Data on patient demographics and pre-CTPA workup were collected from electronic patient records (EPR) and stored in MS Excel 2019 for analysis. Of 188 suspected PE patients (mean age 50 ±12.3 years; 62.8% female), 12.2% were diagnosed with PE. None had documented Wells scores. A low-risk Wells score (≤4) was assigned to 68.6% of patients, with only 26.1% undergoing D-dimer testing. PE was confirmed in 4 patients with low-risk Wells scores and elevated D-dimers. All 10 patients with low-risk Wells scores and negative D-dimers were PE-negative. In total, 5.3% - 47.9% of the CTPAs conducted could have been avoided by following NICE guidelines. We propose integrating an algorithm-based checklist with validated tools like the Wells and Geneva scores into the ePMA system to guide appropriate CTPA referrals, promote evidence-based decision-making, reduce unnecessary imaging, and optimize patient care and resource use.

Usefulness of bronchial sputum aspirate specimens for the diagnosis of Non-tuberculous mycobacterial pulmonary disease.

The usefulness of bronchoscopy for the diagnosis of NTM pulmonary disease (NTM-PD) has been reported. However, performing bronchoscopy for aspirated sputum and airway secretion specimens (sputum aspirate specimens) in the region extending from the trachea down to the orifice of each segmental bronchus has been poorly documented. We evaluated the diagnostic yield of sputum aspirate specimens collected from the central airway using bronchoscopy. We reviewed the medical records of 114 patients with clinically suspected NTM-PD on chest computed tomography (CT) who underwent bronchoscopy. Patients for whom sputum aspirate and bronchial washing specimens were obtained using a thin bronchoscope were included. Positive culture acid-fast bacilli yield was compared between sputum aspirate specimens obtained during bronchial luminal examination and bronchial washing specimens obtained by wedging the tip of the bronchoscope into bronchi with the most affected lung segment. Among the 69 NTM culture-positive patients, culture positivity yield for sputum aspirate and bronchial washing specimens was 94.2% (65/69) and 88.4% (61/69), respectively. While 8 (11.6%) patients were culture-positive for only sputum aspirate specimens, 4 (5.8%) patients were culture-positive for only bronchial washing specimens. Comparison of chest CT findings and bronchoscopy procedure showed no difference between patients with positive cultures from both sputum aspirate and bronchial washing specimens and those with positive cultures on only one of either specimen. In diagnosing NTM-PD using thin bronchoscopy, the diagnostic yield of sputum aspirate specimens from the central airway was comparable to that of bronchial washing specimens obtained from the peripheral airway.

A comprehensive synergistic study of process parameters on co-hydrothermal carbonization of digested sewage sludge and sugarcane bagasse: Hydrochar yield, lead adsorption capacity, and physicochemical properties

The hydrothermal carbonization approach applies to waste management, clean water supply, and the creation of valuable materials. An appropriate adsorbent using bagasse and sewage sludge was synthesized via co-hydrothermal carbonization for efficient lead removal. The effect of process parameters on adsorption capacity, hydrochar yield, and synergistic properties was thoroughly examined. Results showed that sensitive positive adsorption synergy occurred at higher sludge/bagasse ratios, while moderate positive and negative yield synergy was achieved at lower and higher temperatures, respectively. Due to the co-hydrothermal carbonization process, the maximum experimental adsorption capacity increased from 105 to 140 mg/g compared to the predicted value. In addition, during the first 10 min of adsorption, mean adsorption speeds of 108 mg/g and 75 mg/g were achieved for experimental and predicted values, respectively. Moreover, at an equilibrium concentration of 0.5 mg/g, the experimental equilibrium adsorption capacity increased from 42.2 to 98.3 mg/g compared to the expected value. This foundational research provides basic information on the adsorption ability of hydrochar in the co-hydrothermal carbonization process and presents an environmentally friendly approach to waste management and clean water supply.

Transbronchial Needle Aspiration via Ultrathin Bronchoscope Improves Diagnostic Yield for Peripheral Lung Lesions: Randomized Sequencing Trial.

Peripheral pulmonary lesions (PPLs) are frequently identified and require diagnostic sampling. Diagnostic yield of radial endobronchial ultrasound (rEBUS) guided bronchoscopic biopsies is suboptimal, despite ultrasound confirmation of navigation success. Pairing ultrathin bronchoscopy and peripheral transbronchial needle aspiration (pTBNA) may improve yield. We prospectively recruited consecutive patients undergoing Olympus MP190F ultrathin bronchoscopy with rEBUS-guided sampling of PPLs. Cases were randomized to pTBNA (Olympus Periview FLEX) either before or after the usual transbronchial forceps biopsy (TBLBx) and brush. Diagnostic yield from cytology or histopathology, clinical outcomes to a minimum 24 months follow-up and complications were recorded. One hundred one sampled lesions were included (pTBNA first 61, pTBNA last 40). Overall diagnostic yield was 66.3%, with no significant difference between groups (64% vs. 70% P=0.528) or prespecified subgroups according to sampling order. Seventy lesions had an end diagnosis of malignancy, of which 50 were correctly diagnosed (71.4%). TBLBx (49/96, 49%) and pTBNA (48/101, 47.5%) had the highest individual positive yield. For 12 (11.9%) participants, pTBNA was the only positive sample. Lesions <20mm and those with eccentric rEBUS image seemed to benefit most from this approach. Rapid on-site cytologic examination (ROSE) was associated with both positive procedural diagnosis (P=0.019) and pTBNA-positive samples (P=0.004). Pneumothorax occurred in 4% and moderate bleeding in 5%. Thirteen percent had an unplanned admission within 1 month of bronchoscopy. Adding pTBNA to conventional sampling through an ultrathin bronchoscope guided by rEBUS, improved diagnostic yield (11.9% additional diagnoses). The sampling sequence did not affect the yield of pTBNA.

Analysis of Plant Physiological Parameters and Gene Transcriptional Changes Under the Influence of Humic Acid and Humic Acid-Amino Acid Combinations in Maize.

The study investigated the application of humic acids (HAs) and a combination of humic acids and amino acids (HA+AA) in maize under field conditions. Based on preliminary data in the literature, the aim was to investigate the effects of the two plant conditioning compounds on plant physiological parameters. In addition to measuring plant physiological parameters in the field, a complete transcriptome analysis was performed to determine exactly which genes were expressed after the treatments and in which physiological processes they play a role. Maize plants showed significant positive yield changes after two priming treatments. Genome-wide transcriptomic analysis revealed the activation of photosynthetic and cellular respiration processes, as well as protein synthesis pathways, which explains the increased yield even under extreme precipitation conditions. The results show that the HA treatment helped in water management and increased the chlorophyll content, while the HA+AA treatment led to higher protein and dry matter contents. The post-harvest tests also show that the HA+AA treatment resulted in the highest yield parameters. Functional annotation of the maize super transcriptome revealed genes related to translation processes, photosynthesis, and cellular respiration. The combined pathway analysis showed that the HA and combined treatments activated genes related to photosynthesis, carbon fixation, and cellular respiration, providing valuable in-depth insight into the usefulness of the HA and HA+AA treatments in priming. Based on the studies, we believe that the use of natural-based humic acid plant conditioners may provide a beneficial opportunity to promote renewable, regenerative agriculture.

Clinical application of whole-exome sequencing analysis in childhood epilepsy

The swift updates of public databases and advancements in next-generation sequencing (NGS) technologies have enhanced the genetic identification capacities of epilepsy clinics. This study aimed to evaluate the diagnostic efficacy of NGS in pediatric epilepsy patients as a whole and to present the data obtained in the whole exome sequence analysis. We enrolled 40 children with suspected childhood epilepsy in this study. All patients underwent evaluation by a clinical geneticist or pediatric neurologist and the molecular genetic analysis of those children was performed by whole-exome sequencing (WES). Out of the 40 patients, 12 (30%) received a genetic diagnosis, involving 14 mutations across 13 genes. The cumulative positive diagnostic yield was 30%. Twelve of these patients were identified to have 5 variants previously documented as pathogenic, 9 variants classified as likely pathogenic, and 5 novel variants that have not been reported before. The outcomes indicate that whole-exome sequencing offers great benefits in clinical patient diagnosis, particularly in terms of detecting diagnostic variants. This study underscored the significance of whole exome sequencing (WES) studies, where only a broad gene set is examined in epilepsy patients. This approach has the potential to establish gene-specific phenotypic profiles, particularly by uncovering novel candidate genes in epilepsy patients with well-defined phenotypes. Additionally, conducting validation studies on variants of uncertain clinical significance could enhance the outcome yield.

New onset seizures in Octogenarians.

The occurrence of new seizure(s) in older adults is two- to three-fold higher as compared to the younger population, and previous studies have characterized the clinical features of seizures in patients beyond 60 or 65 years. This study, in response to the recent ILAE task force on epilepsy in the elderly (2023), has assessed the clinical characteristics of individuals who are over 85 years old. Data was collected from prospectively maintained electronic medical records, and the participants were divided into seizure-free and seizure-recurrence groups, and their clinical characteristics were compared. Over a 30-year period, a single comprehensive epilepsy care center included a total of 40 patients, with a mean age of 88.7 ± 2.79 years - most common seizure type was generalized tonic-clonic seizures (45%), with a positive neuroimaging yield of 42.5% and an EEG showing specific abnormalities in 50% of cases. Etiology was unidentified in 50%, while stroke was the most common among identified etiologies (27.5%). Over a mean follow-up of 1.4 [0.2-5.8] years, monotherapy effectively controlled 62.5% of patients, but 47.5% experienced recurrence. When compared to the non-recurrence group, these patients showed significant risk factors such as a history of prior stroke [47.3% versus 23.8%, p = 0.031], use of phenytoin [68.4% versus 33.3%, p = 0.056], and clobazam [42.1% vs. 19%, p = 0.049]. This study contributes to better identification and improved characterization of late-onset seizures and adds that appropriate, timely management results in better outcomes.

Agricultural innovation for climate change: limited but positive impacts of commercialized drought-tolerant corn

Abstract The extent to which new technologies can countervail the risks posed by climate change is a critical element for designing adaptation strategies. This study uses new experimental data spanning 17 US states from 2008 to 2023 to examine the potential impact of recently commercialized drought tolerant (DT) traits on both yield and yield resilience in US corn production. We find that there is no yield advantage for DT hybrids under average weather conditions, but they improve yield resilience, particularly with respect to precipitation. These effects are spatially heterogeneous, such that DT has a positive yield impact in the droughty, western US, but a small, or even negative, impact in the central and eastern US. In addition, the presence of DT reduces yield variance and kurtosis, and increases skewness, all of which imply a reduction in yield risk. Using the statistical model estimates, we project the impact of DT on corn yields under future climate conditions obtained from 20 general circulation models with two representative concentration pathways. The projected ensemble means of yield gains are 6.34 bu/acre and 5.39 bu/acre under moderate and extreme warming scenarios, respectively, by the mid-twenty-first century. These gains compensate for 23% and 13.5% of total yield loss due to climate change. Our results indicate that current commercial DT hybrids reduce yield risk, improve resilience with respect to precipitation, and have the potential to offer moderate benefits under climate change warming scenarios.

Diversity Presentation of Pulmonary Tuberculosis in Children: A Case Series of Three Patients

Malaysia, among other developing countries has significant tuberculosis (TB) morbidity and mortality. Variation in presentations with subtle symptoms plays a crucial role in diagnosis challenges. Depending on the stage of the disease, patient may be presented with spectrum of no symptoms up to severe complications of the disease including extensive miliary TB. Diagnosis requires a high index of suspicion. In addition to that, positive yield of the sampling for microbiological investigation is difficult as the pathophysiology involving paucibacillary tuberculous. In this case series, we discuss three cases of diversity in presentation of pulmonary tuberculosis in children.

Boron availability and fertilizer response of maize in soils from sub‐Saharan Africa

AbstractBackground and aimsLow boron (B) availability is associated with strongly weathered, coarse‐textured, and low organic matter soils, widespread in sub‐Saharan Africa (SSA). It is unknown to what extent B fertilization can increase maize yields in SSA. This study aims to understand the soil properties controlling B availability to field‐grown maize.MethodsBoron fertilizer omission trials with maize were executed at 15 sites in Kenya, Zambia, and Zimbabwe. Yield, B uptake, and soil parameters potentially relevant for B availability, including extractable soil B (hot water, 0.01 M CaCl2, and 0.43 M HNO3), were determined.ResultsSoil B pools were strongly intercorrelated and were positively correlated with organic carbon, suggesting the relevance of organic matter for soil B availability. Soil parameters described limited variation in B uptake and the yield response to B fertilization. Boron fertilization did not increase yields in any of the 15 sites but increased uptake in 11 sites. Yields were reduced through B fertilization in five sites, likely because B application induced toxicity. No clear critical soil or plant B concentrations indicating deficiency could be derived, but positive yield responses to B fertilization were absent with hot water B levels above 0.69 mg kg−1.ConclusionAssessing B fertilizer needs in maize grown in tropical soils based on soil or plant tissue concentrations remains challenging. Improving soil organic matter status could potentially alleviate B deficiency in crops when present. Recommendations are given to overcome the identified challenges associated with studying B availability in tropical soils.

The Impact of the COVID-19 Lockdown on Cancer Referrals in Primary Care in the UK: Two Years On

Background: Cancer is common, with most cancer patients presenting initially to a general practitioner. The COVID-19 pandemic led to changes in the delivery of primary care, which could have affected cancer referrals. This observational study looked at two-week cancer referrals (2WRs) made before, during and after the first UK COVID-19 lockdown in 2020, at a GP practice in the Wirral, England. Methods: A search was conducted to find the cancer referrals made between 23rd March 2020 - 1st July 2020, during the first lockdown. Using the same methodology, cancer referral data was collected for the corresponding time periods in 2019 and 2021. The number of 2WRs and positive diagnostic yields were then compared. Results: The number of cancer referrals decreased by 40.4% in 2020, compared to 2019. In 2021, the number of referrals then increased by 225%, compared to 2020. Overall, the number of cancer referrals increased between 2019-2021. The positive diagnostic yield for the 2020 2WRs increased by 251.4%, compared to that of 2019. The calculated yield for the 2021 data then decreased by 10.8% compared to 2020. Overall, the positive diagnostic yield increased between 2019-2021. Conclusion: The numbers and outcomes of cancer referrals at this Wirral GP practice have changed considerably following the first UK COVID-19 lockdown in 2020, and the influence of the pandemic was still affecting cancer referrals in 2021. A greater focus on early cancer detection in primary care could help overcome the ways in which the pandemic has affected primary care delivery.

Risk factors and prediction model for low-birth-weight infants born to women with gestational diabetes mellitus.

To explore the risk factors for low-birth-weight infants born to pregnant women with GDM to develop a prediction model and to construct a prediction nomogram for the risk of low birth weight infants born to pregnant women with GDM. The clinical data of singleton infants diagnosed with gestational diabetes mellitus in Southeast China in 2019 were retrospectively reviewed. Gestational conditions and neonatal weight were assessed. A total of 386 diabetic mothers and infants were enrolled, including 193 in the low birth weight group and 193 in the normal birth weight group. The statistically significant factors were age over 36 years (OR = 1.916, 95% CI 1.048-3.505), junior high school education (OR = 4.454, 95% CI 1.882-10.543), history of fetal distress (OR = 0.120, 95% CI 0.016-0.925), gestational hypertension (OR = 3.681, 95% CI 1.357-9.986), preeclampsia (OR = 24.652, 95% CI 5.956-102.036), threatened preterm birth (OR = 18.393, 95% CI 8.457-39.999), triglycerides (OR = 0.642, 95% CI 0.485-0.850), and inadequate gestational weight gain (OR = 1.997, 95% CI 1.162-3.432). The area under the receiver operating characteristic curve (AUC) was 0.834 (95% CI: 0.794-0.874, p < 0.001), and the sensitivity and specificity were 82.38 and 87.56%, respectively. The goodness-of-fit test likelihood ratio 2 was 2.089 (p = 0.978). The comprehensive nomogram model showed that the discrimination and mean absolute error were 0.834 and 0.015, respectively. The calibration curves showed acceptable agreement between the predictions of the column line plots and the observations. The DCA curves showed good positive net yields in the prediction model. This study established a prediction model and risk score for low birth weight in pregnant women with GDM. It helps pregnancy clinics to identify the risk of low birth weight in newborns promptly, in addition to glycemic control and weight management for pregnant women with GDM, and should improve the appropriate treatment plan for pregnant women with higher risk, to provide personalized and precise treatment for pregnant women with GDM and improve infant outcomes.

Inclusion of Individuals With Lived Experiences in the Development of a Digital Intervention for Co-Occurring Depression and Cannabis Use: Mixed Methods Investigation.

Existing interventions for co-occurring depression and cannabis use often do not treat both disorders simultaneously and can result in higher rates of symptom relapse. Traditional in-person interventions are often difficult to obtain due to financial and time limitations, which may further prevent individuals with co-occurring depression and cannabis use from receiving adequate treatment. Digital interventions can increase the scalability and accessibility for these individuals, but few digital interventions exist to treat both disorders simultaneously. Targeting transdiagnostic processes of these disorders with a digital intervention-specifically positive valence system dysfunction-may yield improved access and outcomes. Recent research has highlighted a need for the inclusion of individuals with lived experiences to assist in the co-design of interventions to enhance scalability and relevance of an intervention. Thus, the purpose of this study is to describe the process of eliciting feedback from individuals with elevated depressed symptoms and cannabis use and co-designing a digital intervention, Amplification of Positivity-Cannabis Use Disorder (AMP-C), focused on improving positive valence system dysfunction in these disorders. Ten individuals who endorsed moderate to severe depressive symptoms and regular cannabis use (2-3×/week) were recruited online via Meta ads. Using a mixed methods approach, participants completed a 1-hour mixed methods interview over Zoom (Zoom Technologies Inc) where they gave their feedback and suggestions for the development of a mental health app, based on an existing treatment targeting positive valence system dysfunction, for depressive symptoms and cannabis use. The qualitative approach allowed for a broader investigation of participants' wants and needs regarding the engagement and scalability of AMP-C, and the quantitative approach allowed for specific ratings of intervention components to be potentially included. Participants perceived the 13 different components of AMP-C as overall helpful (mean 3.9-4.4, SD 0.5-1.1) and interesting (mean 4.0-4.9, SD 0.3-1.1) on a scale from 1 (not at all) to 5 (extremely). They gave qualitative feedback for increasing engagement in the app, including adding a social component, using notifications, and being able to track their symptoms and progress over time. This study highlights the importance of including individuals with lived experiences in the development of interventions, including digital interventions. This inclusion resulted in valuable feedback and suggestions for improving the proposed digital intervention targeting the positive valence system, AMP-C, to better match the wants and needs of individuals with depressive symptoms and cannabis use.

Splenic flexure adenocarcinoma: A national cohort analysis of extent of surgical resection and outcomes.

The optimal extent of resection for splenic flexure adenocarcinoma remains debated. These tumours straddle the left- and right-sided vasculature with lymphatic drainage in a watershed area; current guidelines recommend either segmental or extended colectomy. We analysed surgical management of splenic flexure tumours and compared outcomes between approaches. The Surveillance, Epidemiology and End Results database was searched for adults with Stage I-III splenic flexure adenocarcinoma, 2004-2019. Of 5238 patients, 55% underwent extended colectomy. Compared to segmental colectomy, these patients were more likely to have advanced stage. On multivariable analysis, age ≤ 65 years remained independently associated with extended colectomy. Although fewer nodes were examined in segmental colectomy (median 14 vs. 16, p < 0.001), the number of positive nodes (both, median 0 [interquartile ratio 0-2], p = 0.20) and the lymph node ratio were similar between cohorts. Surgical approach was not significantly associated with increased positive nodal yield in adjusted analyses. Five-year overall and disease-specific survival were 73% and 84% for segmental and 72% and 83% for extended colectomy (p > 0.4); these remained comparable after adjustment. Nationally, we observed similar rates of segmental and extended colectomy for splenic flexure adenocarcinoma. Extended colectomy was not more common in Stage III disease, indicating lack of stage migration, and was not associated with better oncological outcomes. These observations support current practice involving either approach, which should be tailored to patient-related factors and preferences, while considering technical aspects and quality of life.

Peanut cultivar response to residual soil test potassium in North Mississippi

AbstractThe average U.S. peanut (Arachis hypogaea L.) yield has increased by approximately 25% with the adoption of peanut cultivar ‘Georgia‐06G’. Since this adoption, many new high yielding runner cultivars with similar yield potential have been released. However, current nutrient recommendations are based on soil tests that were developed prior to the release of Georgia‐06G. Particularly for potassium, current soil test potassium (STK) critical values were established on soil textures with relatively low cation exchange capacity (CEC) but were not validated on soil textures with high CEC. This study aimed to evaluate the growth and yield response of five recently released peanut cultivars to four STK levels ranging from very low to medium based on Mississippi State University Extension soil testing recommendations. The STK classification levels were also based on two soil series categorized with high CEC—Leeper (∼38.4 meq 100 g−1) and Marietta (∼15.9 meq 100 g−1) soil series. Cultivars Georgia‐06G, ‘Georgia‐16HO’, ‘Georgia‐18RU’, FloRun ‘331’, and ‘AU‐NPL‐17’ were evaluated in this study. No STK × variety interaction occurred, indicating similar K requirements across all varieties evaluated. However, a positive pod yield response occurred in both soil types when the average STK increased from 128 to 167 lbs ac−1 for all cultivars and site years. Critical STK values on both soils were greater than many current Extension recommendations, and the critical STK value of Leeper is greater than the Marietta soil series, likely due to the higher CEC value. These results demonstrate the need to adjust peanut STK sufficiency levels based on soil CEC. Further evaluation of modern peanut cultivar productivity response to STK sufficiency levels is needed for soils with moderate CEC.

Improving Diagnostic Yield and Accuracy of Stereotactic Biopsies through Changes in Practice and Techniques: An 8-Year Single-Center Comparative Study.

Background Stereotactic biopsies are used to aid neurosurgeons in clinching the diagnosis of intracranial lesions that are difficult to access surgically. A published study of stereotactic biopsies in our center demonstrated a diagnostic yield of only 76% for biopsies from the year 2014 to 2019. A set of criteria/prerequisites was applied to increase yield. Objective The aim of the study was to identify the improvement in accuracy and yield after implementation of a set of criteria/prerequisites. Materials and Methods This was a retrospective and prospective analysis of all patients who underwent stereotactic biopsies from the year 2014 to 2022. This study was conducted at Sarawak General Hospital, Malaysia. A set of stereotactic criteria/prerequisites was introduced since 2020, which include preoperative careful, meticulous trajectory planning and target selection, regular checking and maintenance of equipment, larger burr holes, and good sampling techniques. Results A total of 83 patients underwent stereotactic biopsies from the year 2014 to 2022. Frameless and frame-based methods were used for 45 (54%) and 38 (46%) patients, respectively. The overall diagnostic yield of all biopsies was 84%. Fifty patients underwent stereotactic biopsies prior to implementation of good practice guidelines in 2020 with a positive histopathological yield and accuracy of 76 and 88%, respectively. Thirty-three biopsies done postimplementation demonstrated a yield and accuracy of 97% ( p < 0.05). There was also a shift of preference toward frame-based methods after 2019, with 85% of these biopsies being frame based. Conclusion This comparative study shows that adherence to specific stereotactic biopsy guidelines and techniques introduced in our center has successfully improved our biopsy yield and accuracy.

467. DISTRIBUTION OF LYMPH NODE INVOLVEMENT IN PATIENTS WITH GASTRO-ESOPHAGEAL JUNCTION ADENOCARCINOMA

Abstract Background Curative cancer surgery relies on understanding the lymphatic spread of the tumour to guide lymphadenectomy. The lymphatic involvement in patients with esophageal squamous cell carcinoma (SCC) has been evaluated extensively in large cohort studies from the East where SCC predominates, but the pattern of lymph node spread in gastro-esophageal junction (GEJ) adenocarcinoma is less clear. The primary aim of this study was to compare differences in the pattern of lymph node involvement according to the Siewert classification. Methods Consecutive patients who underwent curative resection for GEJ adenocarcinoma between February 2010 and April 2023 were analysed from a prospectively maintained database. Patient demographic data, neo-adjuvant treatment, operation type and histopathological report data were collected and analysed according to the pathological Siewert classification of GEJ cancer. Results 807 patients who underwent curative surgery for GEJ adenocarcinoma were analysed. The median lymph node yield was 26 (5-81). Comparing positive para-esophageal node yields, Type I and II tumours were similar but both significantly higher than Type III. For positive para-gastric nodes, Type 2 and 3 tumours were similar but both significantly higher than type 1. The significance of these comparisons is presented in table 1. There were no differences comparing other specific nodal groups. Evaluating the effect of node involvement on overall survival positive node status and positive hepatic artery nodes were found to be independent factors adversely affecting survival. Conclusion Siewert type I tumours have greater proximal lymph node involvement compared to type III tumours with higher proportions of positive para-esophageal nodes. Type III tumours on the other hand have higher proportions of para-gastric nodes. Type II tumours have similar para-esophageal node involvement to type 1 tumours and similar para-gastric involvement to type III tumours. Involvement of more specific nodal groups does not seem to vary between the sub types.

The Usefulness of FDG PET-CT in the Routine Staging of Gastric Cancer: A Retrospective Analysis from the Lead Cancer Center, Pakistan

Background: Accurate staging of tumors is paramount in the management of cancer patients. Current noninvasive modalities like computed tomography (CT) and fluorodeoxyglucose positron emission tomography (FDG PET) scan offer viable approaches to stage the disease; however, the role of FDG PET-CT in gastric cancer remains unclear, in comparison to esophageal and gastroesophageal junction cancers, where they have proven usefulness. Aim: The primary outcome was to assess the usefulness of FDG PET-CT in staging gastric cancer in our population. The secondary outcome was to compare the positive yield of PET-CT with staging laparoscopy and avidity of FDG PET-CT scan in gastric cancer. Materials and Methods: In our institution, FDG PET-CT is routinely used in staging gastric cancer, where CT scan does not show metastases. We did a retrospective analysis of data of gastric cancer patients, who were not known to have metastatic disease, who underwent pretreatment staging workup at our institute between January 2018 and December 2022. Tumor and lymph node (LN) avidity and their association with Lauren classification was assessed. Multivariate regression analysis for factors associated with metastases on FDG PET-CT scan with tumor size, nodal status, and node avidity was also assessed. Data were analyzed using SPSS version 26 for descriptive and comparative statistics; multivariate regression analysis was performed to identify factors affecting the diagnosis of metastases on PET-CT. P =0.05 was considered statistically significant. Results: Tumor avidity was shown in 181 (89.16%) patients, and LN avidity in 80 (39.4%) patients. This was independent of the Lauren classification. In addition, previously unidentified metastases were highlighted in 16 (8%) patients. Multivariate regression analysis for factors associated with metastases on FDG PET-CT scan showed a significant association with tumor size (P &lt; 0.001), nodal status (P = 0.005), and node avidity (P = 0.024). Conclusions: FDG PET-CT scan can identify an additional 8% of previously unidentified metastases, thereby playing a useful role in the staging workup of advanced gastric cancer patients. Approximately 90% of gastric cancers and 40% of LNs were PET avid in our population.

Integrating the melanoma 31-gene expression profile test with clinical and pathologic features can provide personalized precision estimates for sentinel lymph node positivity: an independent performance cohort.

Up to 88% of sentinel lymph node biopsies (SLNBs) are negative. The 31-gene expression profile (31-GEP) test can help identify patients with a low risk of SLN metastasis who can safely forego SLNB. The 31-GEP classifies patients as low (Class 1A), intermediate (Class 1B/2A), or high risk (Class 2B) for recurrence, metastasis, and SLN positivity. The integrated 31-GEP (i31-GEP) combines the 31-GEP risk score with clinicopathologic features using a neural network algorithm to personalize SLN risk prediction. Patients from a single surgical center with 31-GEP results were included (n = 156). An i31-GEP risk prediction < 5% was considered low risk of SLN positivity. Chi-square was used to compare SLN positivity rates between groups. Patients considered low risk by the i31-GEP had a 0% (0/30) SLN positivity rate compared to a 31.9% (30/94, p < 0.001) positivity rate in those with > 10% risk. Using the i31-GEP to guide SLNB decisions could have significantly reduced the number of unnecessary SLNBs by 19.2% (30/156, p < 0.001) for all patients and 33.0% (30/91, p < 0.001) for T1-T2 tumors. Patients with T1-T2 tumors and an i31-GEP-predicted SLN positivity risk > 10% had a similar SLN positivity rate (33.3%) as patients with T3-T4 tumors (31.3%). The i31-GEP identified patients with < 5% risk of SLN positivity who could safely forego SLNB. Combining the 31-GEP with clinicopathologic features for a precise risk estimate can help guide risk-aligned patient care decisions for SLNB to reduce the number of unnecessary SLNBs and increase the SLNB positivity yield if the procedure is performed.