HER2-Positive Metastatic Colorectal Cancer.

OPINION STATEMENT: Targeted treatment strategies are available for human epidermal growth factor receptor 2 (HER2)-positive (amplified and/or overexpressed) metastatic colorectal cancer (mCRC), and HER2 testing is indicated in patients with mCRC. At present, standard of care first-line treatment for those with HER2-positive mCRC remains chemotherapy in combination with epidermal growth factor receptor (EGFR) inhibitors or bevacizumab, depending on RAS/BRAF mutational status and tumor sidedness. HER2-targeted agents should be considered for those with RAS/BRAF wild-type disease in subsequent-line treatment and in first-line treatment for patients not appropriate for intensive therapy. While the choice of anti-HER2 therapy is empiric given lack of head-to-head comparisons, the combination of trastuzumab plus tucatinib has received FDA accelerated approval for use in this setting and is generally the authors' preference. Trastuzumab plus lapatinib, trastuzumab plus pertuzumab, and trastuzumab deruxtecan (T-DXd) also have evidence of efficacy in this setting. As T-DXd has demonstrated activity following treatment with other HER2-targeted regimens and carries an increased risk of high-grade toxicities, the authors favor reserving it for use after progression on prior anti-HER2 therapy. HER2-targeted therapies that inhibit signal transduction appear to have limited activity in those with RAS mutations, including trastuzumab-containing regimens. However, the antibody drug conjugate T-DXd has some data showing efficacy in this setting, and the authors would consider T-DXd in subsequent-line therapy for HER2-positive, RAS-mutated mCRC. Several areas of uncertainty remain regarding how to best utilize HER2-targeted therapies in mCRC. These include the optimal sequence of anti-HER2 therapies with chemotherapy and anti-EGFR therapies, the optimal combination partners for anti-HER2 therapies, and the incorporation of predictive biomarkers to guide use of anti-HER2 therapies. Results of ongoing studies may thus alter the treatment paradigm above in the coming years.

Safety and utility of indwelling pleural catheters in lung transplant recipients.

INTRODUCTION: The safety and efficacy of indwelling pleural catheters (IPCs) in lung allograft recipients is under-reported. METHODS: We performed a multicenter, retrospective analysis between 1/1/2010 and 6/1/2022 of consecutive IPCs placed in lung transplant recipients. Outcomes included incidence of infectious and non-infectious complications and rate of auto-pleurodesis. RESULTS: Seventy-one IPCs placed in 61 lung transplant patients at eight centers were included. The most common indication for IPC placement was recurrent post-operative effusion. IPCs were placed at a median of 59 days (IQR 40-203) post-transplant and remained for 43 days (IQR 25-88). There was a total of eight (11%) complications. Infection occurred in five patients (7%); four had empyema and one had a catheter tract infection. IPCs did not cause death or critical illness in our cohort. Auto-pleurodesis leading to the removal of the IPC occurred in 63 (89%) instances. None of the patients in this cohort required subsequent surgical decortication. CONCLUSIONS: The use of IPCs in lung transplant patients was associated with an infectious complication rate comparable to other populations previously studied. A high rate of auto-pleurodesis was observed. This work suggests that IPCs may be considered for the management of recurrent pleural effusions in lung allograft recipients.

Sight Unseen: Diagnostic Yield and Safety Outcomes of a Novel Multimodality Navigation Bronchoscopy Platform with Real-Time Target Acquisition.

BACKGROUND: Several advanced bronchoscopy platforms are currently available, but the clinical data supporting their use vary. Electromagnetic navigation bronchoscopy (ENB) remains the dominant technology; it is limited by its reliance on preoperative computed tomography, which only approximates patient anatomy during the procedure. Recently, ENB was enhanced with the (1) addition of digital tomosynthesis-based navigation correction, (2) improvements in planning algorithms, and (3) continuous real-time guidance (Illumisite™; Medtronic, Minneapolis, MN, USA). There are currently no clinical data on the diagnostic yield and safety profile of this system. OBJECTIVES: The primary objective of this study is to describe the diagnostic yield of the first 100 pulmonary parenchymal lesions sampled using the multimodality navigation bronchoscopy (MNB) platform. The secondary objective is to describe safety. METHODS: In this single-center prospective observational study, a database was maintained to track patient, procedural, and outcome data for the first 100 consecutive lesions sampled using the MNB platform at an academic quaternary referral center. Descriptive statistics and univariate and multivariate analyses are reported. RESULTS: The overall diagnostic yield of samples acquired was 79% (79/100). In the cohort where digital tomosynthesis was used, the diagnostic yield was 83% (69/83). Sensitivity for malignancy was 71% (52/73). Overall complication rates were low: pneumothorax (n = 3, 3%) and bleeding requiring intervention (n = 2, 2%). There were no procedural-related hospital admissions. CONCLUSIONS: The MNB system performed favorably. Platform superiority cannot be established without future prospective and comparative studies.

Safety and Feasibility of a Sheath Cryoprobe for Bronchoscopic Transbronchial Biopsy: The FROSTBITE Trial.

BACKGROUND: Bronchoscopic lung biopsy is typically performed using transbronchial forceps. However, this method is limited by small sample size and presence of crush artifact. Cryobiopsy offers the potential to overcome these limitations with larger artifact-free samples but has not been widely adopted due to concerns over increased rates of bleeding and pneumothorax. A new, smaller 1.1-mm cryoprobe has been developed that operates in a similar fashion to forceps, though the safety profile of this cryoprobe has not yet been prospectively studied. OBJECTIVE: The aim of this study was to investigate the safety of transbronchial biopsy using a novel 1.1-mm cryoprobe. METHODS: This prospective, single-arm study enrolled patients referred for transbronchial biopsy. All procedures were performed using the 1.1-mm cryoprobe with oversheath. The primary outcome was the composite of significant complications related to the cryobiopsy procedure (bleeding Grade ≥3, pneumothorax Grade ≥2, and respiratory failure). Bleeding and pneumothorax were graded according to previously published scales. RESULTS: Fifty participants from two academic medical centers underwent transbronchial cryobiopsy. Indications for biopsy included evaluation of lung transplant allograft (50%), diffuse lung disease (44%), and pulmonary parenchymal lesion (6%). There were two pneumothoraces (4%), neither of which required aspiration or chest tube placement. There were no Grade 3 or 4 bleeding events. Mild bleeding (Grade ≤2) was observed in 25 cases (50%). No complications occurred that met the a priori primary outcome of bleeding Grade ≥3, pneumothorax Grade ≥2, and respiratory failure. CONCLUSIONS: Transbronchial cryobiopsy using a 1.1-mm cryoprobe is feasible with an acceptable safety profile.

High Accuracy of Digital Tomosynthesis-Guided Bronchoscopic Biopsy Confirmed by Intraprocedural Computed Tomography.

BACKGROUND: Digital fluoroscopic tomosynthesis-guided electromagnetic navigational bronchoscopy (F-ENB) is a novel adjunct to ENB associated with higher diagnostic yield. The likelihood of F-ENB allowing accurate placement of a biopsy needle within a target remains unclear. OBJECTIVE: This study intends to determine the accuracy of F-ENB as confirmed by cone-beam computed tomography (CBCT) scan. METHODS: Patients undergoing CBCT-assisted ENB for lung nodule biopsy were prospectively enrolled. ENB was performed followed by digital tomosynthesis correction. Once optimal F-ENB alignment was achieved, and a needle was advanced into the expected location of the nodule followed by CBCT. The primary outcome was the percentage of "needle-in-lesion" hits, defined as needle tip within the nodule in 3 planes. Secondary outcomes were diagnostic yield, procedure and room time, complications, radiation, and distance between the needle tip and nodule. RESULTS: Twenty-six patients with a total of 29 nodules were enrolled. Mean nodule size was 13 mm (±4 mm) in maximal axial dimension, 83% (n = 24) were located in the peripheral third of the chest, and 17% (n = 5) had a bronchus sign. F-ENB guidance resulted in needle-in-lesion in 21 of 29 nodules (72%). Mean needle tip-to-nodule distance for nonhits was 1.75 mm (±1.35 mm). There were no complications. CONCLUSION: F-ENB resulted in a needle-in-lesion biopsy in greater than 70% of nodules despite features traditionally associated with poor diagnostic yield (size, absence of bronchus sign). Mean distance between needle tip and target for nonhits was less than 2 mm. These data suggest F-ENB alignment is accurate for small peripheral nodules.

Utilizing left atrial strain to identify patients at risk for atrial fibrillation on ibrutinib.

BACKGROUND: Ibrutinib is associated with atrial fibrillation (AF), though echocardiographic predictors of AF have not been studied in this population. We sought to determine whether left atrial (LA) strain on transthoracic echocardiography could identify patients at risk for developing ibrutinib-related atrial fibrillation (IRAF). METHODS: We performed a retrospective review of 66 patients who had an echocardiogram prior to ibrutinib treatment. LA strain was measured with TOMTEC Imaging Systems, obtaining peak atrial longitudinal strain (PALS) and peak atrial contraction strain (PACS) on 4-chamber and 2-chamber views. Statistical analysis was performed with chi-square analysis, t test, or binomial regression analysis, with a P-value < .05 considered statistically significant. RESULTS: Twenty-two patients developed IRAF (33%). Age at initiation of ibrutinib was significantly associated with IRAF (65.1 years vs 74.1 years, P = .002). Mean ibrutinib dose was lower among patients who developed IRAF (388.2 ± 121.7 vs 448.6 ± 88.4, P = .025). E/e' was significantly higher among patients who developed IRAF (11.5 vs 9.3, P = .04). PALS was significantly lower in patients who developed AF (30.3% vs 36.3%, P = .01). On multivariate regression analysis, age, PALS, and PACS were significantly associated with IRAF. On multivariate regression analysis, only PACS remained significantly associated with IRAF while accounting for age. CONCLUSIONS: Age, ibrutinib dose, E/e', and PALS on pre-treatment echocardiogram were significantly associated with development of IRAF. On multivariate regression analyses, age, PALS, and PACS remained significantly associated with IRAF. Impaired LA mechanics add to the assessment of patients at risk for IRAF.

Improved diagnostic yield for lung nodules with digital tomosynthesis-corrected navigational bronchoscopy: Initial experience with a novel adjunct.

BACKGROUND AND OBJECTIVE: The diagnostic yield of electromagnetic navigation bronchoscopy (ENB) is inferior to that of computed tomography (CT)-guided needle biopsy for pulmonary nodules. One explanation for this is divergence between the nodule location on the pre-procedure CT scan and its actual location during the procedure. Fluoroscopic ENB (F-ENB) consists of digital tomosynthesis using a conventional C-arm to re-register the target lesion based on near real-time imaging. We performed a retrospective review of ENB cases at our institution before and after introduction of F-ENB to assess diagnostic yield. METHODS: All consecutive ENB procedures performed at our institution from 25 December 2017 to 25 August 2018 were reviewed. F-ENB was introduced on 25 April 2018. Two cohorts were analysed: standard ENB (S-ENB) from 25 December 2017 to 24 April 2018 and F-ENB from 25 April 2018 to 25 August 2018. All procedural, demographic and diagnostic data were collected. Descriptive statistics, chi-square, Wilcoxon test and Student's t-test were used where appropriate. A multivariable regression analysis was performed to assess factors associated with diagnostic yield. RESULTS: A total of 101 and 67 nodules were biopsied in the S-ENB and F-ENB groups, respectively. Diagnostic yield was 54% in S-ENB cohort and 79% in the F-ENB group (P = 0.0019). Factors independently associated with a positive diagnosis were F-ENB and a positive radial ultrasound view (odds ratio (OR): 3.57, 95% CI: 1.56-8.18 and OR: 3.74, 95% CI: 1.37-11.05, respectively). Complications were minimal (pneumothorax: 1.5%). CONCLUSION: The use of F-ENB may increase the diagnostic yield of ENB and has a low complication rate.

Financial toxicity in cancer care: Prevalence, causes, consequences, and reduction strategies.

Financial toxicity is the adverse impact of a cancer diagnosis on a patient's financial well-being resulting from direct or indirect costs. Potential consequences of financial toxicity include material loss, psychological distress, and/or maladaptive coping strategies. This review will summarize the prevalence, causes, and consequences of financial toxicity, with an emphasis on strategies to anticipate and reduce its burden. Improvement will require multilevel, coordinated efforts between stakeholders including patients, providers, health systems, payers, manufacturers, and policymakers.

Randomized Trial of Apneic Oxygenation during Endotracheal Intubation of the Critically Ill.

RATIONALE: Hypoxemia is common during endotracheal intubation of critically ill patients and may predispose to cardiac arrest and death. Administration of supplemental oxygen during laryngoscopy (apneic oxygenation) may prevent hypoxemia. OBJECTIVES: To determine if apneic oxygenation increases the lowest arterial oxygen saturation experienced by patients undergoing endotracheal intubation in the intensive care unit. METHODS: This was a randomized, open-label, pragmatic trial in which 150 adults undergoing endotracheal intubation in a medical intensive care unit were randomized to receive 15 L/min of 100% oxygen via high-flow nasal cannula during laryngoscopy (apneic oxygenation) or no supplemental oxygen during laryngoscopy (usual care). The primary outcome was lowest arterial oxygen saturation between induction and 2 minutes after completion of endotracheal intubation. MEASUREMENTS AND MAIN RESULTS: Median lowest arterial oxygen saturation was 92% with apneic oxygenation versus 90% with usual care (95% confidence interval for the difference, -1.6 to 7.4%; P = 0.16). There was no difference between apneic oxygenation and usual care in incidence of oxygen saturation less than 90% (44.7 vs. 47.2%; P = 0.87), oxygen saturation less than 80% (15.8 vs. 25.0%; P = 0.22), or decrease in oxygen saturation greater than 3% (53.9 vs. 55.6%; P = 0.87). Duration of mechanical ventilation, intensive care unit length of stay, and in-hospital mortality were similar between study groups. CONCLUSIONS: Apneic oxygenation does not seem to increase lowest arterial oxygen saturation during endotracheal intubation of critically ill patients compared with usual care. These findings do not support routine use of apneic oxygenation during endotracheal intubation of critically ill adults. Clinical trial registered with www.clinicaltrials.gov (NCT 02051816).

Randomized Trial of Video Laryngoscopy for Endotracheal Intubation of Critically Ill Adults.

OBJECTIVE: To evaluate the effect of video laryngoscopy on the rate of endotracheal intubation on first laryngoscopy attempt among critically ill adults. DESIGN: A randomized, parallel-group, pragmatic trial of video compared with direct laryngoscopy for 150 adults undergoing endotracheal intubation by Pulmonary and Critical Care Medicine fellows. SETTING: Medical ICU in a tertiary, academic medical center. PATIENTS: Critically ill patients 18 years old or older. INTERVENTIONS: Patients were randomized 1:1 to video or direct laryngoscopy for the first attempt at endotracheal intubation. MEASUREMENTS AND MAIN RESULTS: Patients assigned to video (n = 74) and direct (n = 76) laryngoscopy were similar at baseline. Despite better glottic visualization with video laryngoscopy, there was no difference in the primary outcome of intubation on the first laryngoscopy attempt (video 68.9% vs direct 65.8%; p = 0.68) in unadjusted analyses or after adjustment for the operator's previous experience with the assigned device (odds ratio for video laryngoscopy on intubation on first attempt 2.02; 95% CI, 0.82-5.02, p = 0.12). Secondary outcomes of time to intubation, lowest arterial oxygen saturation, complications, and in-hospital mortality were not different between video and direct laryngoscopy. CONCLUSIONS: In critically ill adults undergoing endotracheal intubation, video laryngoscopy improves glottic visualization but does not appear to increase procedural success or decrease complications.

Prolonged Response to Dabrafenib/Trametinib in Grade 3 Metastatic Pancreatic Neuroendocrine Tumor (NET G3) with BRAF V600E Mutation.

PURPOSE: Treatment of metastatic pancreatic neuroendocrine tumors (pancNETs), particularly grade 2 (G2) and grade 3 (G3), often presents a dilemma in choosing from multiple similarly efficacious therapies. Data on targeted therapies for these tumor types is limited, and this report presents BRAF-targeted therapy as a therapeutic option for metastatic pancNET G3. METHODS: This is a case report of a patient with G3 pancNET metastatic to the liver, lung, lymph node, and scalp (soft tissue) treated with dabrafenib/trametinib (D/T) in the presence of a BRAF V600E mutation detected in tumor tissue. RESULTS: This patient has demonstrated an ongoing partial response to therapy at all involved sites for nearly 15 months with minimal side effects attributable to D/T. CONCLUSION: Dabrafenib/trametinib therapy for BRAF-mutated metastatic pancNETs provides a novel treatment option and, especially in the G3 setting, should be considered a first-line option. Tumor testing for actionable mutations should be undertaken at the time of diagnosis and/or progression to identify novel therapeutic avenues in these rare tumors.

Diagnostic Yield vs Diagnostic Accuracy for Peripheral Lung Biopsy Evaluation: Evidence Supporting a Future Pragmatic End Point.

BACKGROUND: Diagnostic yield and accuracy endpoints have been used inconsistently in the evaluation of advanced diagnostic bronchoscopy devices and techniques, limiting between-study comparisons. In addition, diagnostic accuracy can be adjudicated only after prolonged clinical follow-up, which delays reporting on the performance of novel devices. RESEARCH QUESTION: Will a conservative diagnostic yield definition result in few false-negative initial results to closely approximate diagnostic accuracy and represent a useful outcome for future studies of diagnostic utility? METHODS: Commonly used definitions of diagnostic yield were applied to a prospective data set of consecutive peripheral pulmonary lesions sampled by navigational bronchoscopy from 2017 to 2019. All consider malignancy to be diagnostic but differ in their classification of nonmalignant biopsy findings, which were subcategorized as specific benign, nonspecific benign, or normal lung. Diagnostic yield calculations were also compared with diagnostic accuracy, defined as the proportion of biopsy specimens deemed diagnostic by each definition that were confirmed accurate through 2 years of follow-up. RESULTS: A total of 450 biopsy specimens of lesions were analyzed. The prevalence of malignancy was 60.9% (274 of 450). On initial bronchoscopy pathology, there were 227 malignant diagnoses (50.4%), with a single false positive (0.4%). Among 104 biopsy specimens with specific benign findings, only two were false negative for malignancy (1.9%). There were 119 nonspecific benign biopsy specimens, with 46 false negatives for malignancy (38.7%). The discrepancy between diagnostic yield and accuracy was 0.7% for the conservative definition, which only considered malignant or specific benign findings as diagnostic. INTERPRETATION: A conservative diagnostic yield definition excluding nonspecific benign diagnoses closely approximated diagnostic accuracy through 2 years' follow-up, with a less than 1% discrepancy. Using this conservative yield definition may allow for dissemination of reliable diagnostic utility data without protracted delays needed for follow-up data in this era of rapid technological change in advanced diagnostic bronchoscopy.

Robotic versus Electromagnetic bronchoscopy for pulmonary LesIon AssessmeNT: the RELIANT pragmatic randomized trial.

BACKGROUND: Robotic-assisted bronchoscopy has recently emerged as an alternative to electromagnetic navigational bronchoscopy for the evaluation of peripheral pulmonary lesions. While robotic-assisted bronchoscopy is proposed to have several advantages, such as an easier learning curve, it is unclear if it has comparable diagnostic utility as electromagnetic navigational bronchoscopy. METHODS: Robotic versus Electromagnetic bronchoscopy for pulmonary LesIon AssessmeNT (RELIANT) is an investigator-initiated, single-center, open label, noninferiority, cluster randomized controlled trial conducted in two operating rooms at Vanderbilt University Medical Center. Each operating room (OR) is assigned to either robotic-assisted or electromagnetic navigational bronchoscopy each morning, with each OR day considered one cluster. All patients undergoing diagnostic bronchoscopy for evaluation of a peripheral pulmonary lesion in one of the two operating rooms are eligible. Schedulers, patients, and proceduralists are blinded to daily group allocations until randomization is revealed for each operating room each morning. The primary endpoint is the diagnostic yield defined as the proportion of cases yielding lesional tissue. Secondary and safety endpoints include procedure duration and procedural complications. Enrolment began on March 6, 2023, and will continue until 202 clusters have been accrued, with expected enrolment of approximately 400 patients by the time of completion in March of 2024. DISCUSSION: RELIANT is a pragmatic randomized controlled trial that will compare the diagnostic yield of the two most commonly used bronchoscopic approaches for sampling peripheral pulmonary lesions. This will be the first known cluster randomized pragmatic trial in the interventional pulmonology field and the first randomized controlled trial of robotic-assisted bronchoscopy. TRIAL REGISTRATION: ClinicalTrials.gov registration (NCT05705544) on January 30, 2023.

Spray Cryotherapy for Benign Large Airway Stenosis: A Multicenter Retrospective Cohort Study of Safety and Practice Patterns.

BACKGROUND: Benign airway stenosis (BAS) represents a significant burden on patients, providers, and healthcare systems. Spray cryotherapy (SCT) has been proposed as an adjunctive treatment to reduce BAS recurrence. We sought to examine safety and practice variations of the latest SCT system when used for BAS. METHODS: We conducted a retrospective multicenter cohort study in seven academic institutions within the Interventional Pulmonary Outcomes Group. All patients who underwent at least one SCT session with a diagnosis of BAS at the time of procedure at these institutions were included. Demographics, procedure characteristics, and adverse events were captured through each center's procedural database and electronic health record. RESULTS: A total of 102 patients underwent 165 procedures involving SCT from 2013 to 2022. The most frequent etiology of BAS was iatrogenic (n = 36, 35%). In most cases, SCT was used prior to other standard BAS interventions (n = 125; 75%). The most frequent SCT actuation time per cycle was five seconds. Pneumothorax complicated four procedures, requiring tube thoracostomy in two. Significant post-SCT hypoxemia was noted in one case, with recovery by case conclusion and no long-term effects. There were no instances of air embolism, hemodynamic compromise, or procedural or in-hospital mortality. CONCLUSION: SCT as an adjunctive treatment for BAS was associated with a low rate of complications in this retrospective multicenter cohort study. SCT-related procedural aspects varied widely in examined cases, including actuation duration, number of actuations, and timing of actuations relative to other interventions.

Examination of Wnt signaling as a therapeutic target for pancreatic ductal adenocarcinoma (PDAC) using a pancreatic tumor organoid library (PTOL).

Pancreatic ductal adenocarcinoma (PDAC) presents at advanced stages and is refractory to most treatment modalities. Wnt signaling activation plays a critical role in proliferation and chemotherapeutic resistance. Minimal media conditions, growth factor dependency, and Wnt dependency were determined via Wnt inhibition for seven patient derived organoids (PDOs) derived from pancreatic tumor organoid libraries (PTOL). Organoids demonstrating response in vitro were assessed in vivo using patient-derived xenografts. Wnt (in)dependent gene signatures were identified for each organoid. Panc269 demonstrated a trend of reduced organoid growth when treated with ETC-159 in combination with paclitaxel or gemcitabine as compared with chemotherapy or ETC-159 alone. Panc320 demonstrated a more pronounced anti-proliferative effect in the combination of ETC-159 and paclitaxel but not with gemcitabine. Panc269 and Panc320 were implanted into nude mice and treated with ETC-159, paclitaxel, and gemcitabine as single agents and in combination. The combination of ETC-159 and paclitaxel demonstrated an anti-tumor effect greater than ETC-159 alone. Extent of combinatory treatment effect were observed to a lesser extent in the Panc320 xenograft. Wnt (in)dependent gene signatures of Panc269 and 320 were consistent with the phenotypes displayed. Gene expression of several key Wnt genes assessed via RT-PCR demonstrated notable fold change following treatment in vivo. Each pancreatic organoid demonstrated varied niche factor dependencies, providing an avenue for targeted therapy, supported through growth analysis following combinatory treatment of Wnt inhibitor and standard chemotherapy in vitro. The clinical utilization of this combinatory treatment modality in pancreatic cancer PDOs has thus far been supported in our patient-derived xenograft models treated with Wnt inhibitor plus paclitaxel or gemcitabine. Gene expression analysis suggests there are key Wnt genes that contribute to the Wnt (in)dependent phenotypes of pancreatic tumors, providing plausible mechanistic explanation for Wnt (in)dependency and susceptibility or resistance to treatment on the genotypic level.

The Lung Cancer Prediction Model "Stress Test": Assessment of Models' Performance in a High-Risk Prospective Pulmonary Nodule Cohort.

BACKGROUND: Pulmonary nodules represent a growing health care burden because of delayed diagnosis of malignant lesions and overtesting for benign processes. Clinical prediction models were developed to inform physician assessment of pretest probability of nodule malignancy but have not been validated in a high-risk cohort of nodules for which biopsy was ultimately performed. RESEARCH QUESTION: Do guideline-recommended prediction models sufficiently discriminate between benign and malignant nodules when applied to cases referred for biopsy by navigational bronchoscopy? STUDY DESIGN AND METHODS: We assembled a prospective cohort of 322 indeterminate pulmonary nodules in 282 patients referred to a tertiary medical center for diagnostic navigational bronchoscopy between 2017 and 2019. We calculated the probability of malignancy for each nodule using the Brock model, Mayo Clinic model, and Veterans Affairs (VA) model. On a subset of 168 patients who also had PET-CT scans before biopsy, we also calculated the probability of malignancy using the Herder model. The performance of the models was evaluated by calculating the area under the receiver operating characteristic curves (AUCs) for each model. RESULTS: The study cohort contained 185 malignant and 137 benign nodules (57% prevalence of malignancy). The malignant and benign cohorts were similar in terms of size, with a median longest diameter for benign and malignant nodules of 15 and 16 mm, respectively. The Brock model, Mayo Clinic model, and VA model showed similar performance in the entire cohort (Brock AUC, 0.70; 95% CI, 0.64-0.76; Mayo Clinic AUC, 0.70; 95% CI, 0.64-0.76; VA AUC, 0.67; 95% CI, 0.62-0.74). For 168 nodules with available PET-CT scans, the Herder model had an AUC of 0.77 (95% CI, 0.68-0.85). INTERPRETATION: Currently available clinical models provide insufficient discrimination between benign and malignant nodules in the common clinical scenario in which a patient is being referred for biopsy, especially when PET-CT scan information is not available.