Prospective Evaluation of Artificial Intelligence Triage of Incidental Pulmonary Emboli on Contrast-Enhanced CT Examinations of the Chest or Abdomen.

Background: Artificial intelligence (AI) algorithms improved detection of incidental pulmonary embolism (IPE) on contrast-enhanced CT (CECT) examinations in retrospective studies; however, prospective validation studies are lacking. Objective: To assess the effect on radiologists' real-world diagnostic performance and report turnaround times of a radiology department's clinical implementation of an AI triage system for detecting IPE on CECT examinations of the chest or abdomen. Methods: This prospective single-center study included consecutive adult patients who underwent CECT of the chest or abdomen for reasons other than PE detection from May 12, 2021 to June 30, 2021 (phase 1) or from July 1, 2021 to September 29, 2021 (phase 2). Before phase 1, the radiology department installed a commercially available AI triage algorithm for IPE detection that automatically processed CT examinations and notified radiologists of positive results through an interactive floating widget. In phase 1, the widget was inactive, and radiologists interpreted examinations without AI assistance. In phase 2, the widget was activated, and radiologists interpreted examinations with AI assistance. A review process involving a panel of radiologists was implemented to establish the reference standard for the presence of IPE. Diagnostic performance and report turnaround times were compared using Pearson Chi-square test and Wilcoxon rank-sum test, respectively. Results: Phase 1 included 1467 examinations in 1434 patients (mean age, 53.8±18.5 years; 753 male, 681 female); phase 2 included 3182 examinations in 2886 patients (mean age, 55.4±18.2 years; 1520 male, 1366 female). The frequency of IPE was 1.4% (20/1467) in phase 1 and 1.6% (52/3182) in phase 2. Radiologists without AI, in comparison with radiologists with AI, showed significantly lower sensitivity (80.0% vs 96.2%, P=.03), without a significant difference in specificity (99.1% vs 99.9%, P=.58), for detection of IPE. The mean report turnaround time for IPE-positive examinations was not significantly different between radiologists without AI and radiologists with AI (78.3 vs 64.6 min, P=.26). Conclusion: An AI triage system improved radiologists' sensitivity for IPE detection on CECT examinations of the chest or abdomen without significant change in report turnaround times. Clinical Impact: This prospective real-world study supports the use of AI assistance for maximizing IPE detection.

Physical and biophysical markers of assessment in medical training: A scoping review of the literature.

PURPOSE: Assessment in medical education has changed over time to measure the evolving skills required of current medical practice. Physical and biophysical markers of assessment attempt to use technology to gain insight into medical trainees' knowledge, skills, and attitudes. The authors conducted a scoping review to map the literature on the use of physical and biophysical markers of assessment in medical training. MATERIALS AND METHODS: The authors searched seven databases on 1 August 2022, for publications that utilized physical or biophysical markers in the assessment of medical trainees (medical students, residents, fellows, and synonymous terms used in other countries). Physical or biophysical markers included: heart rate and heart rate variability, visual tracking and attention, pupillometry, hand motion analysis, skin conductivity, salivary cortisol, functional magnetic resonance imaging (fMRI), and functional near-infrared spectroscopy (fNIRS). The authors mapped the relevant literature using Bloom's taxonomy of knowledge, skills, and attitudes and extracted additional data including study design, study environment, and novice vs. expert differentiation from February to June 2023. RESULTS: Of 6,069 unique articles, 443 met inclusion criteria. The majority of studies assessed trainees using heart rate variability (n = 160, 36%) followed by visual attention (n = 143, 32%), hand motion analysis (n = 67, 15%), salivary cortisol (n = 67, 15%), fMRI (n = 29, 7%), skin conductivity (n = 26, 6%), fNIRs (n = 19, 4%), and pupillometry (n = 16, 4%). The majority of studies (n = 167, 38%) analyzed non-technical skills, followed by studies that analyzed technical skills (n = 155, 35%), knowledge (n = 114, 26%), and attitudinal skills (n = 61, 14%). 169 studies (38%) attempted to use physical or biophysical markers to differentiate between novice and expert. CONCLUSION: This review provides a comprehensive description of the current use of physical and biophysical markers in medical education training, including the current technology and skills assessed. Additionally, while physical and biophysical markers have the potential to augment current assessment in medical education, there remains significant gaps in research surrounding reliability, validity, cost, practicality, and educational impact of implementing these markers of assessment.

Effect of an Evaluation Algorithm on CT Utilization in Identifying Appendicitis in Children.

OBJECTIVE: Our objective was to determine if there was a significant change in computed tomography (CT) utilization or length of stay (LOS) among patients evaluated for acute appendicitis after implementation of an appendicitis evaluation algorithm. METHODS: We conducted a retrospective chart review of patients aged 3-18 years in an urban, tertiary pediatric emergency department with acute abdominal pain, evaluated for appendicitis. Data were collected for 6 months preimplementation and postimplementation of the evaluation algorithm with a 3-month washout period between September 2018 and November 2019. Main outcomes were rate of CT utilization and LOS preimplementation and postimplementation and were analyzed using χ 2 test and Mann-Whitney U test, respectively. Descriptive analysis of demographics was performed, in addition to logistic regression to assess differences between the 2 study periods. RESULTS: A total of 2872 charts were identified with a chief complaint inclusive of "abdominal pain." Of these, 1510 met age requirements but did not meet at least 1 inclusion criteria; 229 more were excluded upon chart review for a final study sample of 1133 patients. Of these, 648 (57.2%) were female, 747 (65.9%) were White, and 988 (87.2%) were non-Hispanic. The majority of patients (770, 68%) were discharged home from the emergency department without a diagnosis of acute appendicitis. Neither CT (25.7% to 24.8%; P = 0.794) nor ultrasound (59.5% to 59.7%; P = 1.000) utilization significantly changed postimplementation. Total ED median LOS increased significantly (333.50 to 362.00 minutes; P = 0.011). Significant factors associated with CT utilization included fever, migration of pain, and right lower quadrant tenderness. Significant factors associated with appendicitis diagnosis included right lower quadrant pain, nausea/vomiting, migration of pain, and peritoneal signs. CONCLUSIONS: Overall, the appendicitis evaluation algorithm did not significantly decrease CT utilization or LOS. Equivocal grade 2 or 3 ultrasound finding rates were high, likely leading to higher rates of CT utilization and increasing LOS.

A general alkene aminoarylation enabled by N-centred radical reactivity of sulfinamides.

Arylethylamines are popular structural elements in bioactive molecules but are often made through a linear series of synthetic steps. A modular protocol to assemble arylethylamines from alkenes in one step would represent a useful advance in discovery chemistry, though current limitations preclude a generally applicable method. In this work we disclose an aminoarylation of alkenes using aryl sulfinamide reagents as bifunctional amine and arene donors. This reaction features excellent regioselectivity and diastereoselectivity on a variety of activated and unactivated substrates. Using a weakly oxidizing photocatalyst, a nitrogen radical is generated under mild conditions and adds to an alkene to form a new C-N bond. A desulfinylative aryl migration event known as a Smiles-Truce rearrangement follows to form a new C-C bond. In this manner, arylethylamines can be rapidly assembled from abundant alkene feedstocks. Moreover, chiral information from the sulfinamide can be transferred via rearrangement to a new carbon stereocentre in the product, thus advancing the development of traceless asymmetric alkene difunctionalization.

General-Purpose Large Language Models Versus a Domain-Specific Natural Language Processing Tool for Label Extraction From Chest Radiograph Reports.

GPT-4 outperformed a radiology domain-specific natural language processing model in classifying imaging findings from chest radiograph reports, both with and without predefined labels. Prompt engineering for context further improved performance. The findings indicate a role for large language models to accelerate artificial intelligence model development in radiology by automating data annotation.

Prospective Evaluation of AI Triage of Pulmonary Emboli on CT Pulmonary Angiograms.

Background Artificial intelligence (AI) algorithms have shown high accuracy for detection of pulmonary embolism (PE) on CT pulmonary angiography (CTPA) studies in academic studies. Purpose To determine whether use of an AI triage system to detect PE on CTPA studies improves radiologist performance or examination and report turnaround times in a clinical setting. Materials and Methods This prospective single-center study included adult participants who underwent CTPA for suspected PE in a clinical practice setting. Consecutive CTPA studies were evaluated in two phases, first by radiologists alone (n = 31) (May 2021 to June 2021) and then by radiologists aided by a commercially available AI triage system (n = 37) (September 2021 to December 2021). Sixty-two percent of radiologists (26 of 42 radiologists) interpreted studies in both phases. The reference standard was determined by an independent re-review of studies by thoracic radiologists and was used to calculate performance metrics. Diagnostic accuracy and turnaround times were compared using Pearson χ2 and Wilcoxon rank sum tests. Results Phases 1 and 2 included 503 studies (participant mean age, 54.0 years ± 17.8 [SD]; 275 female, 228 male) and 1023 studies (participant mean age, 55.1 years ± 17.5; 583 female, 440 male), respectively. In phases 1 and 2, 14.5% (73 of 503) and 15.9% (163 of 1023) of CTPA studies were positive for PE (P = .47). Mean wait time for positive PE studies decreased from 21.5 minutes without AI to 11.3 minutes with AI (P < .001). The accuracy and miss rate, respectively, for radiologist detection of any PE on CTPA studies was 97.6% and 12.3% without AI and 98.6% and 6.1% with AI, which was not significantly different (P = .15 and P = .11, respectively). Conclusion The use of an AI triage system to detect any PE on CTPA studies improved wait times but did not improve radiologist accuracy, miss rate, or examination and report turnaround times. © RSNA, 2023 Supplemental material is available for this article. See also the editorial by Murphy and Tee in this issue.

Limited ability of the renal ablation-specific (MC)2 risk scoring system to predict major adverse events from percutaneous renal microwave ablation.

PURPOSE: To access if the (MC)2 scoring system can identify patients at risk for major adverse events following percutaneous microwave ablation of renal tumors. METHODS: Retrospective review of all adult patients who underwent percutaneous renal microwave ablation at two centers. Patient demographics, medical histories, laboratory work, technical details of the procedure, tumor characteristics, and clinical outcomes were collected. The (MC)2 score was calculated for each patient. Patients were assigned to low-risk (<5), moderate-risk (5-8) and high-risk (>8) groups. Adverse events were graded according to the criteria from the Society of Interventional Radiology guidelines. RESULTS: A total of 116 patients (mean age = 67.8 [95%CI 65.5-69.9], 66 men) were included. 10 (8.6%) and 22 (19.0%) experienced major or minor adverse events, respectively. The mean (MC)2 score for patients with major adverse events (4.6 [95%CI 3.3-5.8]) was not higher than those with either minor adverse events (4.1 [95%CI 3.4-4.8], p = 0.49) or no adverse events (3.7 [95%CI 3.4-4.1], p = 0.25). However, mean tumor size was greater in those with major adverse events (3.1 cm [95%CI 2.0-4.1]) than minor adverse events (2.0 cm [95%CI 1.8-2.3], p = 0.01). Patients with central tumors were also more likely to experience major adverse events compared to those without central tumors (p = 0.02). The area under the receiver operator curve to predict major adverse events was 0.61 (p = 0.15), indicating a poor ability of the (MC)2 score to predict major adverse events. CONCLUSION: The (MC)2 risk scoring system does not accurately identify patients at risk for major adverse events from percutaneous microwave ablation of renal tumors. The mean tumor size and central tumor location may serve as a better indicator for risk assessment of major adverse events.

New strategies for the synthesis of 1- and 2-azetines and their applications as value-added building blocks.

Four-membered nitrogen-containing heterocycles are highly desirable functional groups with synthetic and biological applications. Unsaturated four-membered N-heterocycles, 1- and 2-azetines, are historically underexplored, but have recently been gaining interest due to the development of new synthetic methods to access these compounds, and to their potential as reactive intermediates. This review covers both the synthesis and applications of azetines, with a focus on synthetic methods to access azetines developed since 2018, and a comprehensive review of the reactivity and applications of azetines as starting materials or intermediates to access both other heterocycles and complex products.

Decision support architectures for the recovery of interdependent infrastructure with large-scale damage and socially vulnerable populations.

Infrastructure damage has household-level consequences after a major disaster. Losses are experienced due to factors such as unavailable services and impaired mobility. Socially vulnerable residents, in particular, have few resources with which to adapt. Decision support tools for making justifiable, transparent, repeatable decisions that center the needs of users during recovery are currently nonexistent. In part, this is because infrastructure recovery is a complex process, often involving the coordination of multiple entities. The recovery problem can be rendered more tractable by applying tools suitable for modeling complex systems and processes. System theoretic process analysis (STPA) can be used for goalsetting in a complex, dynamic system such as community civil infrastructure. STPA is used here to devise a decision support tool architecture suitable for coordinated multiagency recovery efforts. The example application is a long-term recovery process with widespread infrastructure damage, population displacement, and other disruptions in system use due to a major disaster. In the example, losses and hazards are defined to reflect recovery challenges commonly faced by vulnerable populations experiencing partial or total displacement. This extension of STPA then reverses these hazards, starting with the most hazardous system states and progressing sequentially to less hazardous states until recovery is complete.

Telescoping screw fixation compared to traditional in situ screw fixation for slipped capital femoral epiphysis: clinical, radiographic and patient-reported outcomes.

This study compares clinical, radiographic and patient-reported outcomes among telescoping and traditional screws for the treatment of slipped capital femoral epiphysis (SCFE). We hypothesized that telescoping screws would prevent slip progression and result in preserved femoral neck growth and improved patient-reported outcomes. Traditional screws were compared to telescoping screws in a 2:1 matched cohort based on age at initial surgery, length of radiographic follow-up and whether or not the hip was pinned prophylactically or as a treatment for SCFE. Neck length and telescoping screw length were measured. The patient-reported outcomes were obtained at routine clinic visits. Total 42 hips were included with a mean follow-up of 24.5 ± 3.3 months. No patients developed avascular necrosis, chondrolysis or needed revision surgical procedures. Telescoping screws increased in length for the entire cohort by a mean of 6.0 ± 4.3 mm. Neck length change was not different in SCFE hips when treated with traditional screws vs. telescoping screws (P = 0.527). However, there was a difference in neck length change between the two groups when comparing prophylactically treated hips (P = 0.001). There were no significant differences in patient-reported outcomes among hips treated with telescoping screws compared to traditional screws. Traditional and telescoping screws are both effective for the treatment of SCFE. Telescoping screws have an advantage when prophylactically treating hips that are at risk of slipping as they don't lead to the coxa breva that is seen with traditional screws. However, both treatment methods had similar patient-reported outcomes.

Improving Discharge Instructions Following a Concussion Diagnosis in the Pediatric Emergency Department: A Pre-post Intervention Study.

INTRODUCTION: Many children are discharged from the pediatric emergency department (PED) with incomplete or inappropriate instructions following a concussion. Our objective was to evaluate the effectiveness of a simple intervention in improving discharge instruction disbursement and completeness following PED diagnosis of concussion. METHODS: A pre/post intervention study of 935 patients (375 preintervention and 560 postintervention) ages 5-19, diagnosed with a concussion and discharged from the PED between July 2016 and November 2019, was performed at a single United States pediatric tertiary-care center. Dedicated provider education sessions were held, and a consensus guideline-based set of discharge instructions were implemented in the electronic health record. Primary outcomes included the presence of return-to-play (RTP) instructions, return-to-learn (RTL) instructions, follow-up recommendations, and "complete" discharge (ie, all 3 components present). Statistical process control charts were generated and tested for special cause variation. RESULTS: More patients received instructions for RTP (87% versus 59%) and RTL (60% versus 3%), and a complete discharge was more frequent (45% versus 2%), following the conclusion of the intervention. Only the improvement in RTP instructions was completely sustained into the following academic year, whereas RTL and complete discharge rates declined to 27% and 20%, respectively. CONCLUSIONS: A simple, low-cost intervention such as peer-to-peer education and consensus guideline-based discharge instruction templates can significantly improve discharge readiness after pediatric concussion. Further work is needed to maintain progress and continue improvements, at our large academic trauma center.

Preferential snake detection in a simulated ecological experiment.

OBJECTIVES: According to Isbell's snake detection theory (SDT), the need to rapidly detect and thus avoid snakes had a major impact on the evolution of the primate visual system, and thus the origin and evolution of the primate lineage, as expansion of the visual sense is a key characteristic of primates. The SDT rests on the assumption that there are both cortical (conscious) and subcortical (unconscious) brain structures and pathways that are responsible for rapid visual detection of and quick avoidance reactions to snakes. Behavioral evidence for the SDT primarily comes from visual search tasks and presentations of images on a computer screen; our aim was to evaluate the SDT under more ecologically valid circumstances. MATERIALS AND METHODS: We asked participants to take a virtual hike in which a realistic model of a snake, rabbit, or bottle had been placed on the trail. Subjects were instructed simply to imagine themselves as the hiker while watching the video. We measured heart rate and skin conductance reactions while the participants viewed the video. After the video, the participants were shown pictures of the three stimuli and asked if they had seen any of them. RESULTS: We found that snakes were detected more often than rabbits or bottles, and that participants showed greater changes in heart rate and greater skin conductance responses in the snake condition than in the other two conditions, even when the participant did not report having seen the snake. DISCUSSION: A critical component of the SDT is that primates must be able to quickly detect snakes even when their attention is directed elsewhere. Using a novel experimental context-a simulated hike-we assessed arousal and detection without directing participants to attend to any particular stimulus or event. Our data support the SDT by providing evidence of enhanced detection and autonomic arousal even in the absence of detection. Replication of these results using additional controls and experimental contexts will help refine our understanding of snake avoidance by primates.

Adolescent Posterior-Superior Glenoid Labral Pathology: Does Involvement of the Biceps Anchor Make a Difference?

BACKGROUND: Adolescent athletes are at risk of sustaining an injury to the posterior and superior labrum of the glenoid. Limited information is available regarding the outcomes of surgical intervention in this specific age cohort. PURPOSE: To compare those patients with pure posterior pathology and those with posterior labral tears that involve the biceps anchor (superior labrum anterior-posterior [SLAP] tears) to determine risks for failure in the surgical management. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: A retrospective review was performed on all patients under the age of 19 years over an 8-year period to identify those treated for superior and posterior labral pathology, followed by chart review, radiographic review, and arthroscopic findings. Patient characteristics and other variables were recorded, including cause (traumatic vs atraumatic), activity/sports (overhead vs nonoverhead), involvement of the biceps anchor-crossing the 12-o'clock position (posterior vs SLAP), associated pathologies, outcome scores (Single Assessment Numerical Evaluation [SANE] and Pediatric/Adolescent Shoulder Survey [PASS] scores), and complications. RESULTS: Forty-eight patients (30 boys, 18 girls) with a mean age at surgery of 16.5 years (range, 13.5-19 years) were identified who met criteria, with a mean follow-up of 4.1 years (range, 1.3-6.9 years). Nineteen patients had SLAP tears and 29 patients had posterior tears. All but 2 regularly participated in sports at the time of their injury; of the athletes, 26 (56.5%) played an overhead sport and 20 (43.5%) played a nonoverhead sport. The cause of the injury was traumatic in 25 cases (52.1%) and atraumatic in 23 cases (47.9%). Outcome scores were not significantly different between cause or type of sports played; SANE scores were not significantly different by tear type (mean SLAP score, 88.4 compared with mean posterior score, 80.9; P = .124); but the mean PASS score in the SLAP group was 88.7, compared with 76.2 in the posterior group (P = .005) at final assessment. Only 1 SLAP patient had failed management (5.3%) compared with 5 patients in the posterior-only cohort (17.2%). CONCLUSION: Posterior SLAP tears have better outcomes and lower failure rates than posterior-only tears in the adolescent population. Posterior-superior labral tears can occur in all sports types with multiple causes, but the only factor that appears to play a role in ultimate outcome is whether the tear crosses under the biceps anchor to the anterior side.

Characterizing the ribosomal tandem repeat and its utility as a DNA barcode in lichen-forming fungi.

BACKGROUND: Regions within the nuclear ribosomal operon are a major tool for inferring evolutionary relationships and investigating diversity in fungi. In spite of the prevalent use of ribosomal markers in fungal research, central features of nuclear ribosomal DNA (nrDNA) evolution are poorly characterized for fungi in general, including lichenized fungi. The internal transcribed spacer (ITS) region of the nrDNA has been adopted as the primary DNA barcode identification marker for fungi. However, little is known about intragenomic variation in the nrDNA in symbiotic fungi. In order to better understand evolution of nrDNA and the utility of the ITS region for barcode identification of lichen-forming fungal species, we generated nearly complete nuclear ribosomal operon sequences from nine species in the Rhizoplaca melanophthalma species complex using short reads from high-throughput sequencing. RESULTS: We estimated copy numbers for the nrDNA operon, ranging from nine to 48 copies for members of this complex, and found low levels of intragenomic variation in the standard barcode region (ITS). Monophyly of currently described species in this complex was supported in phylogenetic inferences based on the ITS, 28S, intergenic spacer region, and some intronic regions, independently; however, a phylogenetic inference based on the 18S provided much lower resolution. Phylogenetic analysis of concatenated ITS and intergenic spacer sequence data generated from 496 specimens collected worldwide revealed previously unrecognized lineages in the nrDNA phylogeny. CONCLUSIONS: The results from our study support the general assumption that the ITS region of the nrDNA is an effective barcoding marker for fungi. For the R. melanophthalma group, the limited amount of potential intragenomic variability in the ITS region did not correspond to fixed diagnostic nucleotide position characters separating taxa within this species complex. Previously unrecognized lineages inferred from ITS sequence data may represent undescribed species-level lineages or reflect uncharacterized aspects of nrDNA evolution in the R. melanophthalma species complex.

Development of an interprofessional clinical learning environment report card.

Multiple factors in the learning environment can encourage or impede student learning. Unanswered questions regarding the shared learning environment for graduate nursing and medical education and the desire for an ongoing improvement process drove creation of an interprofessional collaborative and development of an Interprofessional Clinical Learning Environment Report Card (I-CLERC) at one U.S. academic medical center. The I-CLERC offers a process and a product for institutionalizing a shared assessment tool to inform improvement efforts, track progress and promote accountability. In addition, it enhances interprofessional collaboration, with students and faculty from both nursing and medicine working together to define excellence, monitor performance, and identify areas for improvement in the shared clinical learning environment. The purpose of this manuscript is to describe development and implementation of an interdisciplinary, institutional collaborative for ongoing evaluation of the shared clinical learning environment.

Fractures in the Pediatric Emergency Department: Are We Considering Abuse?

Approximately one fourths of infant fractures are due to abuse. Recognition of abuse is important to avoid further morbidity/mortality. There is limited knowledge regarding how frequently pediatric emergency department clinicians consider abuse in infants with fractures. Our primary objective was to estimate the percentage of infants with fractures for whom abuse was considered, and to examine characteristics associated with abuse consideration. We performed a retrospective review of infants <1 year of age presenting to a pediatric emergency department. Our primary outcome variable was consideration of abuse. Our secondary outcome measures were identification of predictor variables associated with consideration of abuse. We identified 509 infants meeting study criteria. Pediatric emergency physicians considered abuse in approximately two thirds of infants with fractures. Consideration was more likely to occur in younger infants, in the presence of no history or unwitnessed injury mechanism, when evaluated by male physicians, and emergency department encounters from 12 am to 6 am.

Radiology in Medical Education: A Pediatric Radiology Elective as a Template for Other Radiology Courses.

PURPOSE: Traditionally, the pediatric radiology elective for medical students and pediatric residents constituted a morning teaching session focused mainly on radiography and fluoroscopy. A more structured elective was desired to broaden the exposure to more imaging modalities, create a more uniform educational experience, and include assessment tools. METHODS: In 2012, an introductory e-mail and formal syllabus, including required reading assignments, were sent to participants before the start date. A rotating weekly schedule was expanded to include cross-sectional imaging (ultrasound, CT, MR) and nuclear medicine. The schedule could accommodate specific goals of the pediatric resident or medical student, as requested. Starting in 2013, an online pre-test and post-test were developed, as well as an online end-of-rotation survey specific to the pediatric radiology elective. Taking the Image Gently pledge was required. A scavenger hunt tool, cue cards, and electronic modules were added. RESULTS: Pre-test and post-test scores, averaged over 2 years, showed improvement in radiology knowledge, with scores increasing by 27% for medical students and 21% for pediatric residents. Surveys at the end of the elective were overwhelmingly positive, with constructive criticism and complimentary comments. CONCLUSIONS: We have successfully created an elective experience in radiology that dedicates time to education while preserving the workflow of radiologists. We have developed tools to provide a customized experience with many self-directed learning opportunities. Our tools and techniques are easily translatable to a general or adult radiology elective.

The role of sentinel lymph node biopsy in Paget's disease of the breast.

BACKGROUND: Sentinel lymph node (SLN) biopsy has become a standard of care for axillary lymph node staging in breast cancer and appears suitable for virtually all patients with clinically node-negative (cN0) invasive disease. However, its role in Paget's disease of the breast, a condition in which invasion may or may not be present, remains undefined. METHODS: Among 7,083 consecutive SLN biopsy procedures, we retrospectively identified 39 patients with Paget's disease of the breast. Nineteen patients had no associated clinical/radiographic features ("Paget's only"), and 20 patients had associated clinical/radiographic findings ("Paget's with findings"). RESULTS: The mean ages for the Paget's alone and with findings groups were 63.6 and 49.6 years, respectively. The use of breast conservation therapy was 32% in the Paget's alone group and 10% in the Paget's with findings group. Invasive carcinoma was found in 27% of patients in the Paget's alone group and 55% of patients in the Paget's with findings group. The success rate of SLN biopsy was 98%, and the mean number of SLNs removed was 3 in both groups. In the entire cohort of Paget's disease, 28% (11/39) of the patients had positive SLNs (11%, Paget's alone; 45%, Paget's with findings). CONCLUSION: In our "Paget's only" cohort, invasive cancer was found in 27% of cases and positive SLNs in 11%. SLN biopsy should be considered in all patients with Paget's disease of the breast, whether associated clinical/radiographic findings are present.