Transbronchial real-time lung tumor localization with folate receptor-targeted near-infrared molecular imaging: A proof of concept study in animal models.

OBJECTIVE: The diagnostic yield of bronchoscopy is not satisfactory, even with recent navigation technologies, especially for tumors located outside of the bronchial lumen. Our objective was to perform a preclinical assessment of folate receptor-targeted near-infrared imaging-guided bronchoscopy to detect peribronchial tumors. METHODS: Pafolacianine, a folate receptor-targeted molecular imaging agent, was used as a near-infrared fluorescent imaging agent. An ultra-thin composite optical fiberscope was used for laser irradiation and fluorescence imaging. Subcutaneous xenografts of KB cells in mice were used as folate receptor-positive tumors. Tumor-to-background ratio was calculated by the fluorescence intensity value of muscle tissues acquired by the ultra-thin composite optical fiberscope system and validated using a separate spectral imaging system. Ex vivo swine lungs into which pafolacianine-laden KB tumors were transplanted at various sites were used as a peribronchial tumor model. RESULTS: With the in vivo murine model, tumor-to-background ratio observed by ultra-thin composite optical fiberscope peaked at 24 hours after pafolacianine injection (tumor-to-background ratio: 2.56 at 0.05 mg/kg, 2.03 at 0.025 mg/kg). The fluorescence intensity ratios between KB tumors and normal mouse lung parenchyma postmortem were 6.09 at 0.05 mg/kg and 5.08 at 0.025 mg/kg. In the peribronchial tumor model, the ultra-thin composite optical fiberscope system could successfully detect fluorescence from pafolacianine-laden folate receptor-positive tumors with 0.05 mg/kg at the carina and those with 0.025 mg/kg and 0.05 mg/kg in the peripheral airway. CONCLUSIONS: Transbronchial detection of pafolacianine-laden folate receptor-positive tumors by near-infrared imaging was feasible in ex vivo swine lungs. Further in vivo preclinical assessment is needed to confirm the feasibility of this technology.

Preclinical feasibility of bronchoscopic fluorescence-guided lung sentinel lymph node mapping.

OBJECTIVE: Lung sentinel lymph node mapping, where peritumorally injected material is tracked through the lymphatics, aims to find the first potential sites of nodal metastasis. We sought to evaluate the preclinical feasibility of bronchoscopic fluorescence-guided sentinel lymph node mapping. METHODS: Healthy Yorkshire pigs were used; sentinel lymph node mapping was performed with indocyanine green. The primary fluorescence imaging method was an ultrathin composite fiberscope placed in the bronchoscope working channel. Secondary methods used a fluorescence thoracoscope placed in the trachea (rigid bronchoscopy) and pretracheal fascial plane (mediastinoscopy) to validate ultrathin composite fiberscope settings for sentinel lymph node detection. A tracheostomy was created, and the pig was placed in a lateral decubitus position. Transbronchial intraparenchymal indocyanine green injection was performed primarily in the right lower lobe. Ultrathin composite fiberscope and rigid bronchoscopy were performed with (n = 6) or without (n = 2) mediastinoscopy, with the former group guiding dose and ultrathin composite fiberscope optimization. Fluorescent targets were interrogated by endobronchial ultrasound before ultrathin composite fiberscope-guided transbronchial needle aspiration. Specimen fluorescence was documented before creating cytological smears. Pigs were killed postprocedure for nodal dissection. RESULTS: A total of 100 µL of 10 mg/mL indocyanine green generated strong transbronchial fluorescence with low risk of indocyanine green contamination. Fluorescence was detectable by 10 minutes postinjection. There was concordance among ultrathin composite fiberscope, rigid bronchoscopy, and mediastinoscopy. Except for 1 pig with airway contamination, ultrathin composite fiberscope-guided endobronchial ultrasound transbronchial needle aspiration obtained fluorescent material in all pigs. Specimen fluorescence was associated with specimen adequacy. CONCLUSIONS: Bronchoscopic fluorescence-guided sentinel lymph node mapping was feasible, with specimen fluorescence providing real-time feedback on sentinel lymph node biopsy success. If translated to clinical practice, attention must be paid to minimizing indocyanine green leakage.

Repeated photodynamic therapy mediates the abscopal effect through multiple innate and adaptive immune responses with and without immune checkpoint therapy.

In combination with immune checkpoint inhibitors, photodynamic therapy can induce robust immune responses capable of preventing local tumor recurrence and delaying the growth of distant, untreated disease (ie. the abscopal effect). Previously, we found that repeated photodynamic therapy (R-PDT) using porphyrin lipoprotein (PLP) as a photosensitizer, without the addition of an immune checkpoint inhibitor, can induce the abscopal effect. To understand why PLP mediated R-PDT alone can induce the abscopal effect, and how the addition of an immune checkpoint inhibitor can further strengthen the abscopal effect, we investigated the broader immune mechanisms facilitated by R-PDT and combination R-PDT + anti-PD-1 monoclonal antibody (αPD-1) in a highly aggressive, subcutaneous AE17-OVA mesothelioma dual tumor-bearing C57BL/6 mice. We found a 46.64-fold and 61.33-fold increase in interleukin-6 (IL-6) after R-PDT and combination R-PDT + αPD-1 relative to PBS respectively, suggesting broad innate immune activation. There was a greater propensity for antigen presentation in the spleen and distal, non-irradiated tumor draining lymph nodes, as dendritic cells and macrophages had increased expression of MHC class II, CD80, and CD86, after R-PDT and combination R-PDT + αPD-1. Concurrently, there was a shift in the proportions of CD4+ T cell subsets in the spleen, and an increase in the frequency of CD8+ T cells in the distal, non-irradiated tumor draining lymph nodes. While R-PDT had an acceptable safety profile, combination R-PDT + αPD-1 induced 1.26-fold higher serum potassium and 1.33-fold phosphorus, suggestive of mild laboratory tumor lysis syndrome. Histology revealed an absence of gross inflammation in critical organs after R-PDT and combination R-PDT + αPD-1 relative to PBS-treated mice. Taken together, our findings shed light on how the abscopal effect can be induced by PDT and strengthened by combination R-PDT + αPD-1, and suggests minimal toxicities after R-PDT.

Optimization of thrombolytic dose for treatment of pulmonary emboli using endobronchial ultrasound-guided transbronchial needle injection.

OBJECTIVE: Severe pulmonary embolism is often managed with thrombolysis. We sought to determine whether endobronchial ultrasound (EBUS)-guided transbronchial thrombolysis remained effective at lower alteplase doses, with the goal of minimizing potential bleeding risk. METHODS: Yorkshire pigs were anesthetized and ventilated. Preformed autologous blood clots were administered into bilateral pulmonary arteries via EBUS-guided transbronchial injection. After documenting baseline clot sizes, alteplase was injected into the clots using a 25-gauge transbronchial needle and clot dissolution was monitored over 30 minutes. The study was performed in 2 phases. First, alteplase doses of 5 and 12.5 mg were evaluated. These results informed dose selection for the second phase. Results were compared with 25-mg dose data using EBUS from a previous study. RESULTS: In the first phase, 3 clots were evaluated. Distilled water, 5 mg, and 12.5 mg alteplase were administered. The dissolved clot volume (Vdis) and percentage clot volume loss (Rdis) were -10.9, 111.6, and 160.3 mm3, and -1.6%, 11.0%, and 59.3%, respectively. In the second phase, alteplase doses of 5, 10, and 15 mg were evaluated in 12 clots across 6 pigs. The Vdis were 247.5 mm3 (Rdis, 20.1%), 910.8 mm3 (Rdis, 80.9%), and 798.3 mm3 (Rdis, 76.0%) for 5, 10, and 15 mg alteplase, respectively. Remakably reduced performance was observed with 5 mg alteplase versus 10 mg (Vdis: P < .001, Rdis: P < .001), and 15 mg (Vdis: P = .004; Rdis: P < .001). No complications were observed. CONCLUSIONS: Alteplase doses ≥10 mg were optimal for EBUS-guided transbronchial thrombolysis. This technique might represent an effective alternative therapy for central pulmonary embolism.

Preclinical evaluation of thin convex probe endobronchial ultrasound-guided transbronchial needle aspiration for intrapulmonary lesions.

Background: Conventional flexible bronchoscopy has not achieved the high diagnostic yield for intrapulmonary lesions as seen with image-guided transthoracic biopsy. A thin convex probe endobronchial ultrasound bronchoscope (TCP-EBUS) with a 5.9-mm tip was designed to improve peripheral access over conventional EBUS bronchoscopes to facilitate real-time sampling of intrapulmonary lesions under ultrasound guidance. Methods: TCP-EBUS was inserted into the distal airways of ex-vivo human lungs to assess bronchial accessibility relative to clinically available bronchoscopes. The short- (≤1 h) and medium-term (≤10 d) safety of TCP-EBUS insertion and EBUS-guided transbronchial needle aspiration (TBNA) using a 25-gauge needle were evaluated physiologically and radiologically in live pigs. TCP-EBUS-guided TBNA feasibility was assessed in-vivo with pig intrapulmonary pseudo-tumors and ex-vivo with resected human lung cancer specimens. Results: For bronchial accessibility, TCP-EBUS demonstrated greater reach than the 6.6-mm convex probe endobronchial ultrasound (CP-EBUS) in all bronchi, as well as surpassed a 5.5-mm conventional bronchoscope in 63% (131/209) and a 4.8-mm conventional bronchoscope in 27% (57/209) of assessed bronchi. The median bronchial generation and the mean diameter of bronchi TCP-EBUS reached was 4 (range, 3-7) and 3.3±0.7 mm, respectively. No major complications related to TCP-EBUS-guided TBNA in distal airways were observed in the live pigs. Scattered mucosal erythema of the bronchial walls was observed immediately after TCP-EBUS insertion; this self-resolved by day 10. TCP-EBUS could successfully reach and visualize intrapulmonary targets via ultrasound, with no difficulty in needle deployment or sampling. Conclusions: TCP-EBUS has the potential to facilitate safe real-time transbronchial sampling of intrapulmonary lesions in the central and middle lung fields.

Endobronchial ultrasound-guided bipolar radiofrequency ablation for lung cancer: A first-in-human clinical trial.

OBJECTIVE: Percutaneous radiofrequency ablation (RFA) is a therapeutic option for lung tumors. However, percutaneous approaches have limited access to central lung regions and a relatively high complication rate. To overcome these limitations, a needle-type bipolar RFA device compatible with an endobronchial ultrasound (EBUS) bronchoscope was developed. The aim of this pilot study was to evaluate the immediate-term safety and ablation zone of lung tumor EBUS-guided RFA. METHODS: This was an ablate-and-resect study in patients scheduled for surgical resection of clinical stage I or II lung cancer or metastatic lung lesions ≥1 cm that were accessible using an EBUS bronchoscope. The RFA electrodes were placed within the lung nodule using EBUS guidance followed by ablation. Bronchoscopy and contrast-enhanced computed tomography were performed to evaluate for post-RFA complications. The resected lung underwent pathological assessment to characterize the ablation zone. RESULTS: A total of 5 primary lung cancers were ablated in 5 separate patients; no patients with metastatic lesions were recruited. For a total energy of 4 kJ (n = 3), 6 kJ (n = 1), and 8 kJ (n = 1) delivered, the ablation time was a mean of 13.8 (range, 10.3-16.0) minutes, 8.4 minutes, and 15.6 minutes, respectively, and the maximum ablation diameter was a mean of 1.8 (range, 1.3-2.1) cm, 2.7 cm, and 2.6 cm, respectively. No immediate post-RFA complications were observed. CONCLUSIONS: EBUS-guided bipolar RFA can ablate lung tumors using real-time ultrasound guidance. EBUS-guided RFA might ultimately represent a minimally invasive therapy for lung cancer in patients unable to tolerate surgery. Longer-term safety will need to be evaluated.

Three-dimensionally printed navigational template: a promising guiding approach for lung biopsy.

Background: Percutaneous transthoracic lung biopsy is customarily conducted under computed tomography (CT) guidance, which primarily depends on the conductors' experience and inevitably contributes to long procedural duration and radiation exposure. Novel technique facilitating lung biopsy is currently demanded. Methods: Based on the reconstructed anatomical information of CT scans, a three-dimensionally printed navigational template was customized to guide fine-needle aspiration (FNA). The needle insertion site and angle could be indicated by the template after proper placement according to the reference landmarks. From June 2020 to August 2020, patients with peripheral indeterminate lung lesions ≥30 mm in diameter were enrolled in a pilot trial. Cases were considered successful when the virtual line indicated by the template in the first CT scan was pointing at the target, and the rate of success was recorded. The insertion deviation, procedural duration, radiation exposure, biopsy-related complications, and diagnostic yield were documented as well. Results: A total of 20 patients consented to participate, and 2 withdrew. The remaining 18 participants consisting of 11 men and 7 women with a median age of 63 [inter-quartile range (IQR), 50-68] years and a median body mass index (BMI) of 23.5 (IQR, 20.8-25.8) kg/m2 received template-guided FNA. The median nodule size of the patients was 41.2 (IQR, 36.2-51.9) mm and 17 lesions were successfully targeted (success rate, 94.4%). One lesion was not reached through the designed trajectory due to an unpredictable alteration of the lesion's location resulting from pleural effusion. The median deviation between the actual position of the needle tip and the designed route was 9.4 (IQR, 6.8-11.7) mm. The median procedural duration was 10.7 (IQR, 9.7-11.8) min, and the median radiation exposure was 220.9 (IQR, 198.6-249.5) mGy×cm. No major biopsy-related complication was encountered. Definitive diagnosis of malignancy was reached in 13 of the 17 (76.5%) participants. Conclusions: The feasibility and safety of navigational template-guided FNA were preliminarily validated in lung biopsy cohort. Nonetheless, patients with pleural effusion were not recommended to undergo FNA guided by such technique. Trial Registration: This study was registered with ClinicalTrials.gov (identifier: NCT03325907).

What are the factors affecting the recovery rate of bronchoalveolar lavage fluid?

BACKGROUND: Bronchoalveolar lavage (BAL) is a useful examination for the evaluation of interstitial lung disease. A high BAL fluid (BALF) recovery rate is desirable because low recovery rates lead to inaccurate diagnoses and increased adverse events. Few studies have explored whether BALF recovery rates are influenced by clinical factors. OBJECTIVES: This study aimed to identify the clinical parameters affecting the recovery rates of BALF and the extent of their effects. METHOD: Data from patients who underwent BAL at the Chiba University Hospital between 2013 and 2019 were retrospectively reviewed. BAL was performed with three aliquots of 50-ml physiological saline. The potential association of the BALF recovery rate with clinical parameters such as age, sex, smoking status, underlying disease, bronchus used for the procedure and pulmonary function, was analysed. RESULTS: Eight hundred twenty-six patients had undergone BAL. The average recovery rate was 52.4%. Factors affecting BALF recovery rates included male sex (odds ratio [OR]: 0.32, 95% confidence interval [CI]: 0.20-0.53, p < 0.001); age ≥ 65 years (OR: 0.50, 95% CI: 0.33-0.76, p < 0.001); use of the left bronchus (OR: 0.46, 95% CI: 0.30-0.71, p = 0.001) and bronchi other than the middle lobe bronchus or lingula (OR: 0.41, 95% CI: 0.25-0.65, p < 0.001); and forced expiratory volume in 1 s divided by forced vital capacity <80% (OR: 0.42, 95% CI: 0.40-1.00, p < 0.001). CONCLUSION: Sex, age, bronchus used for the procedure and pulmonary function may be useful as pre-procedural predictors of BALF recovery rates.

Pilot study using virtual 4-D tracking electromagnetic navigation bronchoscopy in the diagnosis of pulmonary nodules: a single center prospective study.

BACKGROUND: Electromagnetic navigation bronchoscopy (ENB) is a navigation technology intended to improve the diagnostic yield of pulmonary nodules. However, nodule displacement due to respiratory motion may compromise the accuracy of the navigation guidance. The Veran SPiNDrive ENB system employs respiratory-gating (4D-tracking) to compensate for this motion. The aim of the present study was to evaluate the diagnostic performance and safety of the Veran SPiNDrive system for biopsy of pulmonary nodules. METHODS: Adult patients with pulmonary nodules of ≥1 cm were enrolled at a single center. Both conventional bronchoscopy and 4D-tracking ENB were performed in one procedure session under general anesthesia, with the procedure order being randomly assigned. Radial probe endobronchial ultrasound and fluoroscopy were used in both groups. The diagnostic performance, safety, total procedure time, and total fluoroscopy time of the ENB phase were compared to the corresponding conventional bronchoscopy phase. RESULTS: The study was terminated due to poor accrual; a total of eleven patients were enrolled. The mean size of pulmonary nodules was 2.1 cm. The sensitivity for malignancy was 67% (6/9) and 56% (5/9) with conventional bronchoscopy and with 4D-tracking ENB, respectively. Two cases developed minor bleeding after conventional bronchoscopy, while no complications were observed after 4D-tracking ENB. The mean procedure time was 16.1 and 21.7 min (P=0.090), and the mean duration time for fluoroscopy use was 77 and 44 sec (P=0.056) for the conventional bronchoscopy and the 4D-tracking ENB phases, respectively. CONCLUSIONS: The diagnostic performance of the Veran SPiNDrive 4D-tracking ENB did not exceed that of conventional bronchoscopy for pulmonary nodules. No complications were seen during 4D-tracking ENB. A study with a larger number of participants is required for further assessment.

Thrombolysis of Pulmonary Emboli via Endobronchial Ultrasound-Guided Transbronchial Needle Injection.

BACKGROUND: Endobronchial ultrasound-guided transbronchial needle injection (EBUS-TBNI) is a novel technique for treating peribronchial targets. The aim of this study was to evaluate preliminary feasibility of thrombolysis of pulmonary emboli via EBUS-TBNI. METHODS: Yorkshire pigs (30-48 kg) were anesthetized and mechanically ventilated. Pre-formed autologous clots were injected sequentially into bilateral lower pulmonary arteries in bilateral models (PE1 and PE2, respectively) or into 1 side in unilateral models using a 21-gauge EBUS-TBNA needle under EBUS guidance. In the bilateral model, 2 hours after clot injection either 25 mL of tissue-plasminogen activator (t-PA; 1mg/mL) or distilled water were administered into each embolus via 25-gauge EBUS-TBNA needle. In the unilateral model, 25 mg t-PA was administered intravenously. Hemodynamic parameters were monitored continuously, and clot dissolved volume was evaluated by EBUS 30 minutes post-treatment administration. RESULTS: All clots (6.1 ± 1.7 mL) were successfully injected as documented by EBUS Doppler imaging. Clot injection in the bilateral model (n = 6) increased pulmonary arterial pressure (mm Hg: Baseline 19.2 ± 5.9 vs PE1: 26.7 ± 9.1, P = .005 vs PE2 29.9 ± 7.1, P = .0007). After t-PA TBNI in the bilateral model (n = 6), pulmonary arterial pressure at 30 minutes post-injection showed improvement (mm Hg: PE2 29.9 ± 7.1 vs post-t-PA 24.4 ± 3.9, P = .0283). Treatment with t-PA TBNI demonstrated superior clot dissolution at 30 minutes post-treatment (dissolved mm3: t-PA TBNI 625.4 ± 156.6 vs t-PA intravenously: 181.6 ± 94.3, P = .0003 vs distilled water TBNI 42.5 ± 33.0, P < .0001). There were no complications. CONCLUSIONS: EBUS-guided transbronchial thrombolysis may be a feasible approach for treating central pulmonary emboli.

Risk factors for acute exacerbation following bronchoalveolar lavage in patients with suspected idiopathic pulmonary fibrosis: A retrospective cohort study.

INTRODUCTION: Bronchoalveolar lavage (BAL) is useful for diagnosing diffuse lung disease and excluding other conditions. However, acute exacerbations (AEs) are recognized as important complications of BAL in patients with idiopathic pulmonary fibrosis (IPF). This study aimed to identify risk factors for BAL-induced AEs in patients with IPF. MATERIAL AND METHODS: We retrospectively analyzed the data of 155 patients with suspected IPF who had undergone BAL between January 2013 and December 2018. BAL-related AE was defined as the development of AE within 30 days after the procedure. We compared clinical features and parameters between patients with AE (AE group) and without AE (non-AE group). We also reviewed the relevant reported literature. RESULTS: Among the 155 patients, 5 (3.2%) developed AE within 30 days after BAL. The average duration from BAL to AE onset was 7.8 days (2-16 days). Results from the univariate analysis revealed PaO2 < 75 mm Hg (p = 0.036), neutrophil content in BAL ≥ 7% (p = 0.0061), %DLCO < 50% (p = 0.019), Gender-Age-Physiology (GAP) stage III (p = 0.034), and BAL recovery rates < 30% (p < 0.001) as significant risk factors for post-BAL AE. All five patients who developed AE recovered and were discharged. CONCLUSIONS: Disease severity, high neutrophil levels in BAL, and poor BAL recovery rates may be risk factors for BAL-induced AEs.

A preclinical research platform to evaluate photosensitizers for transbronchial localization and phototherapy of lung cancer using an orthotopic mouse model.

BACKGROUND: Establishing the efficacy of novel photosensitizers (PSs) for phototherapy of lung cancer requires in vivo study prior to clinical evaluation. However, previously described animal models are not ideal for assessing transbronchial approaches with such PSs. METHODS: An ultra-small parallel-type composite optical fiberscope (COF) with a 0.97 mm outer diameter tip. The integration of illumination and laser irradiation fibers inside the COF allows simultaneous white-light and fluorescence imaging, as well as real-time monitoring of tip position during laser phototherapy. An orthotopic lung cancer mouse model was created with three human lung cancer cell lines transbronchially inoculated into athymic nude mice. The COF was inserted transbronchially into a total of 15 mice for tumor observation. For in vivo fluorescence imaging, an organic nanoparticle, porphysome, was used as a PS. Laser excitation through the COF was performed at 50 mW using a 671 nm source. RESULTS: The overall success rate for creating orthotopic lung tumors was 71%. Transbronchial white light images were successfully captured by COF. Access to the left main bronchus was successful in 87% of mice (13/15), the right main bronchus to the cranial lobe bronchus level in 100% (15/15), and to the right basal trifurcation of the middle lobe, caudal lobe and accessory lobe in 93% (14/15). For transbronchial tumor localization of orthotopic lung cancer tumors, PS-laden tumor with the strong signal was clearly contrasted from the normal bronchial wall. CONCLUSIONS: The ultra-small COF enabled reliable transbronchial access to orthotopic human lung cancer xenografts in vivo. This method could serve as a versatile preclinical research platform for PS evaluation in lung cancer, enabling transbronchial approaches in in vivo survival models inoculated with human lung cancer cells.

Risk factors for skeletal-related events in non-small cell lung cancer patients treated with bone-modifying agents.

PURPOSE: The risk factors for skeletal-related events (SREs) among non-small cell lung cancer (NSCLC) patients during treatment with bone-modifying agents (BMAs) are not yet well-understood. METHODS: The medical records of 238 consecutive NSCLC patients treated with BMAs, including zoledronic acid and denosumab, at the Chiba University Hospital from 2012 to 2016 were reviewed in the present study. SREs were defined as either pathologic fractures, spinal cord compression, the need for bone irradiation or surgery, or hypercalcemia. The risk factors for earlier occurrence of the first SRE from the time of the first bone metastasis diagnosis after the initiation of BMA treatment were identified. RESULTS: Of the 238 included patients, 92% (n = 220) had a performance status (PS) of 0-2 at diagnosis of bone metastasis. Forty-eight (20%) patients developed at least one SRE. The most common first SRE was the need for bone irradiation surgery (n = 27, 56%). Significant risk factors included poor PS (hazard ratio [HR]: 4.36; p = .024), male sex (HR: 2.17; p = .022), and the use of zoledronic acid (HR: 1.91; p = .032). The overall survival (OS) from the first bone metastasis diagnosis was 394 days (95% confidence interval [CI]: 331-465). The OS of patients with PS 3 and 4 at the diagnosis of bone metastasis (median: 36 days; 95% CI: 13-50) was significantly (p < 0.0001) shorter than that of patients with PS 0-2 (median: 411 days; 95% CI: 354-558) (HR: 4.53; 95% CI: 2.62-7.35). CONCLUSIONS: Careful observation is needed for patients with the identified risk factors, which include poor PS and male sex, despite the BMA treatment.

Repeated porphyrin lipoprotein-based photodynamic therapy controls distant disease in mouse mesothelioma via the abscopal effect.

While photodynamic therapy (PDT) can induce acute inflammation in the irradiated tumor site, a sustained systemic, adaptive immune response is desirable, as it may control the growth of nonirradiated distant disease. Previously, we developed porphyrin lipoprotein (PLP), a ∼20 nm nanoparticle photosensitizer, and observed that it not only efficiently eradicated irradiated primary VX2 buccal carcinomas in rabbits, but also induced regression of nonirradiated metastases in a draining lymph node. We hypothesized that PLP-mediated PDT can induce an abscopal effect and we sought to investigate the immune mechanism underlying such a response in a highly aggressive, dual subcutaneous AE17-OVA+ mesothelioma model in C57BL/6 mice. Four cycles of PLP-mediated PDT was sufficient to delay the growth of a distal, nonirradiated tumor four-fold relative to controls. Serum cytokine analysis revealed high interleukin-6 levels, showing a 30-fold increase relative to phosphate-buffered solution (PBS) treated mice. Flow cytometry revealed an increase in CD4+ T cells and effector memory CD8+ T cells in non-irradiated tumors. Notably, PDT in combination with PD-1 antibody therapy prolonged survival compared to monotherapy and PBS. PLP-mediated PDT shows promise in generating a systemic immune response that can complement other treatments, improving prognoses for patients with metastatic cancers.

Risk factors for post-bronchoscopy pneumonia: a case-control study.

The bronchoscopy, though usually safe, is occasionally associated with complications, such as pneumonia. However, the use of prophylactic antibiotics is not recommended by the guidelines of the British Thoracic Society. Thus far there are few reports of the risk factors for post-bronchoscopy pneumonia; the purpose of this study was to evaluate these risk factors. We retrospectively collected data on patients in whom post-bronchoscopy pneumonia developed from the medical records of 2,265 patients who received 2666 diagnostic bronchoscopies at our institution between April 2006 and November 2011. Twice as many patients were enrolled in the control group as in the pneumonia group. The patients were matched for age and sex. In total, 37 patients (1.4%) had post-bronchoscopy pneumonia. Univariate analysis showed that a significantly larger proportion of patients in the pneumonia group had tracheobronchial stenosis (75.7% vs 18.9%, p < 0.01) and a final diagnosis of primary lung cancer (75.7% vs 43.2%, p < 0.01) than in the control group. The pneumonia group tended to have more patients with a history of smoking (83.8% vs 67.1%, p = 0.06) or bronchoalveolar lavage (BAL) (4.3% vs 14.9%, p = 0.14) than the control group. In multivariate analysis, we found that tracheobronchial stenosis remained an independent risk factor for post-bronchoscopy pneumonia (odds ratio: 7.8, 95%CI: 2.5-24.2). In conclusion, tracheobronchial stenosis was identified as an independent risk factor for post-bronchoscopy pneumonia by multivariate analysis in this age- and sex- matched case control study.

Feasibility and accuracy of rapid on-site evaluation of touch imprint cytology during transbronchial biopsy.

BACKGROUND: Rapid on-site evaluation (ROSE) of cytologic material is widely performed because it provides clinicians with instant diagnostic information. However, the utility of ROSE of touch imprint cytology (ROSE-TIC) during transbronchial biopsy (TBB) remains unclear. The aim of this study was to evaluate the feasibility and accuracy of ROSE-TIC for TBB. METHODS: A retrospective study was performed on patients who underwent diagnostic bronchoscopy combined with ROSE-TIC. The results of ROSE-TIC, diagnosed as either positive or negative for malignancy, were compared with the histological findings and final diagnosis. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and diagnostic accuracy were calculated. The success rate of molecular testing on TBB specimens was also assessed. RESULTS: Overall, 460 patients underwent bronchoscopy with ROSE-TIC. Of these, 377 cases (82.0%) were malignant and 83 cases (18.0%) were non-malignant in the final diagnosis. Compared with the histological findings, ROSE-TIC showed sensitivity, specificity, PPV, NPV, and diagnostic accuracy values of 91.1%, 90.4%, 94.8%, 84.0%, and 90.9%, respectively. Compared with the final diagnosis, ROSE-TIC showed sensitivity, specificity, PPV, NPV, and diagnostic accuracy values of 75.3%, 91.6%, 97.6%, 45.0%, and 78.3%, respectively. Seven discordant cases (1.5%) were positive on ROSE-TIC and negative on final diagnosis. The success rates for molecular analysis from TBB samples were 96.6% for EGFR mutation, 87.3% for ALK rearrangement, 93.1% for ROS1 rearrangement, and 96.2% for PD-L1 expression. CONCLUSIONS: The accuracy of ROSE-TIC is high. It can be useful for obtaining instant diagnosis, contributing to a high success rate of molecular analysis for targeted therapy.

Endobronchial Ultrasound-Guided Radiofrequency Ablation of Lung Tumors and Mediastinal Lymph Nodes: A Preclinical Study in Animal Lung Tumor and Mediastinal Adenopathy Models.

Radiofrequency ablation (RFA) can be a therapeutic option in medically inoperable lung cancer patients. In this study, we evaluated a prototype bipolar RFA device applicator that can be deployed from a standard endobronchial ultrasound (EBUS) bronchoscope to determine feasibility and histopathological analysis in animal models. Rabbit lung cancers were created by transbronchial injection of VX2 rabbit cancer cells. Once the tumors were developed, they were ablated transpleurally, under EBUS guidance using the prototype RFA device. The animals were then sacrificed for specimen resection. Pig inflammatory lung pseudo-tumors and lymphadenopathy were created by transbronchial injection of a talc paste and ablated transbronchially under EBUS guidance. Pigs were evaluated at 5 days, 2 weeks, and 4 weeks following ablation by bronchoscopy and cone beam computed tomography before necropsy. Nicotinamide adenine dinucleotide hydrogen diaphorase staining was employed to measure the ablation area. Twenty-four VX2 rabbit tumors were ablated. The total ablated area ranged from 0.6 to 3.0 cm2 (mean: 1.8 cm2), corresponding to a total energy range of 1 to 6 kJ. Six pig lung pseudo-tumors and 5 mediastinal lymph nodes were ablated. Adjacent airway ulceration was observed in 3 ablations of lymph nodes. These airway complications resolved within 4 weeks of RFA without any treatment. There was no hemoptysis, air embolism, respiratory distress, or other serious complication noted. In these 2 animal models, we provide evidence that EBUS-guided bipolar RFA is feasible and histopathology shows that can ablate lung tumors and mediastinal lymph nodes under real-time ultrasound guidance.

Bronchoscopic navigation and tissue diagnosis.

Diagnosis of early-stage lung cancer has become increasingly important as the detection of peripheral pulmonary lesions (PPLs) grows with widespread adoption of CT-based lung cancer screening. Although CT-guided transthoracic needle aspiration has been the standard diagnostic approach for PPLs, transbronchial sampling by bronchoscopy is often performed due to its reduced rate of adverse events. However, the diagnostic yield of conventional bronchoscopy is often poor. Various bronchoscopic technologies have emerged over recent years to address this limitation, including thin/ultrathin bronchoscopes, radial probe endobronchial ultrasound (RP-EBUS), virtual navigation bronchoscopy (VBN), electromagnetic navigation bronchoscopy (ENB), and robotic bronchoscopy. Bronchoscopic transparenchymal nodule access (BTPNA) and transbronchial access tool (TBAT) are novel techniques that leverage navigational bronchoscopic technologies to further improve access to lesions throughout the lung. The devices used for sampling tissue have similarly evolved, such as the introduction of cryobiopsy. These innovative bronchoscopic techniques allows higher diagnostic yield even in small PPLs. Given the complexity of these new techniques and technologies, it is important for physicians to understand their strengths and limitations.

Rabbit VX2 lung tumor models can form early nodal metastases.

BACKGROUND: The rabbit squamous cell cancer line, VX2, has been used to generate various tumor models in rabbits. It is notable for its ability to generate nodal metastases. However, the timing and extent of nodal metastases vary by primary inoculation site and methodology. The development of metastases specifically in lung cancer models has not been well-described. We sought to characterize the generation of nodal metastases in rabbit transbronchial VX2 lung tumor models. METHODS: Rabbit VX2 lung tumor models were created in the right lung via transbronchial injection and serially imaged by computed tomography. Rabbits (n = 15) were sacrificed from between 5 and 24 days post-inoculation for collection of the ipsilateral and contralateral paratracheal lymph nodes. These underwent histopathological evaluation for metastases using hematoxylin and eosin as well as cytokeratin AE1/AE3 immunohistochemical staining. RESULTS: Nodal metastases were detectable as early as 1 week after inoculation but were more prevalent with longer inoculation; all rabbits at > 2 weeks post-inoculation had nodal metastases. Contralateral metastases were in general seen later than ipsilateral metastases. Lymph node volume did not predict the likelihood of nodal metastases (p = 0.4 and p = 0.07 for ipsilateral and contralateral nodal metastases, respectively), but primary tumor volume was significantly associated with the likelihood of nodal metastases (p = 0.001 and p = 0.005 for ipsilateral and contralateral nodal metastases, respectively). Ipsilateral metastases were detectable at a tumor diameter of 1 cm; contralateral metastases were more variable but in general required a tumor diameter of 2 cm. CONCLUSIONS: Rabbit transbronchial VX2 lung tumor models generate nodal metastases relatively early after inoculation. These results suggest such models may be valuable tools in the investigation of novel therapeutic modalities relevant for the treatment of both early-stage and locally advanced lung cancer.