Association between pathological infiltrative tumor growth pattern and prognosis in patients with resected lung squamous cell carcinoma.

INTRODUCTION: Lung squamous cell carcinoma (LUSC) usually shows expansive growth with large tumor nests; few reports on invasive growth patterns (INF) in LUSC have been associated with poor prognosis in gastrointestinal and urothelial cancers. In this study, we examine the association between INF and the prognosis of LUSC. MATERIALS AND METHODS: We analyzed INF as a potential prognostic factor in 254 consecutive patients with LUSC who underwent complete surgical resection at our hospital between 2008 and 2017. INF was classified into 3 categories based on the structure of the tumor other than the large round solid nest of tumor cells. RESULTS: INF was categorized as INFa in 59 patients (23 %) with only well-demarcated large solid tumor cell nests, INFb in 89 patients (35 %) with medium to small, alongside large solid nests, and INFc in 98 patients (39 %) with cord-like/small nests or isolated cells plus large or medium solid nests. No significant lymph node metastasis differences were observed between INFc and INFa/b tumors. However, in patients with p-stage I, INFc had a poorer prognosis with regard to recurrence-free survival (RFS), with a 5-year RFS rate of 53.3 %, compared to 74.9 % for INFa/b (p = 0.010). CONCLUSION: Our study highlights a novel pathological concept of INF in LUSC, and contributed to the proposal that it is a factor indicating an unfavorable prognosis in patients with early-stage LUSC. A prospective multicenter study is warranted for INFc patients, as careful follow-up and adjuvant chemotherapy might lead to the early detection and prevention of recurrence.

Sublobar resection utilizing near-infrared thoracoscopy with intravenous indocyanine green for intralobar pulmonary sequestration: a case report and literature review.

BACKGROUND: Pulmonary sequestration is a rare pulmonary malformation, with intralobar pulmonary sequestration being the most common subtype. Lobectomy has generally been performed for its treatment, owing to unclear boundaries of the lesion. However, recent reports have introduced lung resection using intravenous indocyanine green (ICG) as a treatment for pulmonary sequestrations. CASE DESCRIPTION: A 34-year-old woman presented with chest pain, and enhanced chest computed tomography (CT) displayed a solid mass of 4.5 × 3.1 cm in the right S10 area. An aberrant artery was found running from the celiac artery through the diaphragm to the thoracic cavity. The patient was diagnosed as having pulmonary sequestration Pryce type III, and surgical resection was performed. Intrathoracic findings demonstrated that the precise area of the pulmonary sequestration could not be clearly identified, and a 5-mm aberrant artery was present in the pulmonary ligament. Following the separation of the aberrant artery, intravenous injection of ICG clearly delineated the border between the normal lung tissue and the pulmonary sequestration. Wedge resection was then performed without any postoperative events, and the pathological diagnosis was also pulmonary sequestration. CONCLUSIONS: We herein reported a case of a patient who underwent sublobar resection for intrapulmonary sequestration using intravenous ICG injection, together with a literature review. Our case suggests that a comprehensive understanding of abnormal vessels and pulmonary vasculature in pulmonary resection for intrapulmonary sequestrations, complemented with the use of ICG, might potentially avoid unnecessary pulmonary resection and enable sublobar surgical resection.

The degree of satisfaction and level of learning in male and female surgical residents: a nationwide questionnaire survey of graduating residents in Japan.

PURPOSE: Since 2002, the Japan Surgical Society has established a board certification system for surgeons to be certified for a specialty. Surgery remains a male-dominated field in Japan. This study aimed to clarify if the Japanese surgical residency training system is equally suitable for female and male residents. METHODS: The Japan Surgical Society conducted the first questionnaire survey regarding the system of surgical training for the residents in 2016. The questionnaire included the degree of satisfaction with 7 aspects of the training system, including the number and variety of cases experienced and duration and quality of instruction, and the learning level for 31 procedures. The degree of satisfaction and level of learning were compared between female and male residents. RESULTS: The degree of satisfaction was similar for all items between female and male residents. Female residents chose breast surgery as their subspecialty more frequently than male residents and were more confident in breast surgery procedures than male residents. Conversely, fewer female residents chose gastrointestinal surgery and were less confident in gastrointestinal surgery procedures than male residents. CONCLUSION: Female residents were as satisfied with the current surgical training system as male residents. However, there may be room for improvement in the surgical system, considering that fewer applications for gastrointestinal surgery come from female residents than from males.

Clinical utility of psoas muscle volume in assessment of sarcopenia in patients with early-stage non-small cell lung cancer.

PURPOSE: Sarcopenia influences postoperative outcomes of patients with non-small cell lung cancer (NSCLC). Imaging tools for evaluating and diagnosing sarcopenia have developed, and a novel method of psoas volume index (PVI) obtained by measuring bilateral psoas major muscle volume has been reported. However, the relationship between sarcopenia based on PVI and clinical outcomes has not been fully investigated for patients with early-stage NSCLC. This study aimed to clarify the utility of PVI values in assessing the relationshipe between sarcopenia and clinical outcomes. METHODS: This study included 645 patients with stage I-II NSCLC who underwent curative lung resection between 2012 and 2017. Bilateral psoas major muscle volumes were calculated semi-automatically using a three-dimensional workstation. The cutoff value of PVI for defining sarcopenia was < 60.5 cm3/m3 for men and < 43.6 cm3/m3 for women. RESULTS: The avrage time to obtaine PVI was only 25 s with the 3D system, and interobserver agreements for evauating sarcopenia on PVI was 1. A total of 159 patients (24.7%) were preoperatively diagnosed with sarcopenia. On multivariate analysis, sarcopenia was an independent prognostic factor for overall survival (OS, p < 0.001), recurrence-free survival (RFS, p < 0.001), and lung cancer-specific survival (LCS, p < 0.001). The 5-year OS, RFS, and LCS were significantly worse in sarcopenic patients than non-sarcopenic patients (88.8 vs. 72.4%, p < 0.001; 80.1 vs. 65.0%, p < 0.001; 92.4 vs. 78.9%, p < 0.001, respectively). CONCLUSION: Sarcopenia diagnosed using PVI is an independent prognostic predictor of OS, RFS, and LCS in early-stage NSCLC.

Prognostic impact of artificial intelligence-based volumetric quantification of the solid part of the tumor in clinical stage 0-I adenocarcinoma.

INTRODUCTION: The size of the solid part of a tumor, as measured using thin-section computed tomography, can help predict disease prognosis in patients with early-stage lung cancer. Although three-dimensional volumetric analysis may be more useful than two-dimensional evaluation, measuring the solid part of some lesions is difficult using this methods. We developed an artificial intelligence-based analysis software that can distinguish the solid and non-solid parts (ground-grass opacity). This software calculates the solid part volume in a totally automated and reproducible manner. The predictive performance of the artificial intelligence software was evaluated in terms of survival or recurrence-free survival. METHODS: We analyzed the high-resolution computed tomography images of the primary lesion in 772 consecutive patients with clinical stage 0-I adenocarcinoma. We performed automated measurement of the solid part volume using an artificial intelligence-based algorithm in collaboration with FUJIFILM Corporation. The solid part size, the solid part volume based on traditional three-dimensional volumetric analysis, and the solid part volume based on artificial intelligence were compared. RESULTS: Higher areas under the curve related to the solid part volume were provided by the artificial intelligence-based method (0.752) than by the solid part size (0.722) and traditional three-dimensional volumetric analysis-based method (0.723). Multivariate analysis demonstrated that the solid part volume based on artificial intelligence was independently correlated with overall survival (P = 0.019) and recurrence-free survival (P < 0.001). CONCLUSION: The solid part volume measured by artificial intelligence was superior to conventional methods in predicting the prognosis of clinical stage 0-I adenocarcinoma.

Artificial intelligence analysis of three-dimensional imaging data derives factors associated with postoperative recurrence in patients with radiologically solid-predominant small-sized lung cancers.

OBJECTIVES: Indications of limited resection, such as segmentectomy, have recently been reported for patients with solid-predominant lung cancers ≤2 cm. This study aims to identify unfavourable prognostic factors using three-dimensional imaging analysis with artificial intelligence (AI) technology. METHODS: A total of 157 patients who had clinical N0 non-small cell lung cancer with a radiological size ≤2 cm, and a consolidation tumour ratio > 0.5, who underwent anatomical lung resection between 2011 and 2017 were enrolled. To evaluate the three-dimensional structure, the ground-glass nodule/Solid Automatic Identification AI software Beta Version (AI software; Fujifilm Corporation, Japan) was used. RESULTS: Maximum standardized uptake value (SUVmax) and solid-part volume measured by AI software (AI-SV) showed significant differences between the 139 patients with adenocarcinoma and the 18 patients with non-adenocarcinoma. Among the adenocarcinoma patients, 42 patients (30.2%) were found to be pathological upstaging. Multivariable analysis demonstrated that high SUVmax, high carcinoembryonic antigen level and high AI-SV were significant prognostic factors for recurrence-free survival (RFS; P < 0.05). The 5-year RFS was compared between patients with tumours showing high SUVmax and those showing low SUVmax (67.7% vs 95.4%, respectively, P < 0.001). The 5-year RFS was 91.0% in patients with small AI-SV and 68.1% in those with high AI-SV (P = 0.001). CONCLUSIONS: High AI-SV, high SUVmax and abnormal carcinoembryonic antigen level were unfavourable prognostic factors of patients with solid-predominant lung adenocarcinoma with a radiological size ≤2 cm. Our results suggest that lobectomy should be preferred to segmentectomy for patients with these prognostic factors.

Effect of photodynamic therapy (PDT) on a rat model of bleomycin-induced interstitial pneumonia.

BACKGROUND: Even if lung cancer is detected at an early stage, surgery may be difficult in patients with severe comorbidities, like interstitial pneumonia (IP). Radiation therapy cannot be performed due to the high risk of acute IP exacerbation. Therefore, an effective alternative, such as photodynamic therapy (PDT), is required. To prove that acute exacerbation is not induced after PDT in peripheral lung cancer, we investigated the effects of PDT on IP rat models. METHODS: Bleomycin (BLM) was administered intratracheally. Seven days after administration, left thoracotomy was performed. Talaporfin sodium was injected, and diode laser irradiation (664 nm, 150mW, 100J/cm2) was performed. Seven days after PDT, the whole blood and left lungs were collected. A total of 23 rats, comprising BLM + PDT (n = 4), BLM + non-PDT (n = 10), non-BLM + PDT (n = 2), non-BLM + non-PDT (n = 5), and two rats that died immediately after PDT were observed. Serum levels of Krebs von den Lungen-6, surfactant protein-D, lactate dehydrogenase, and serum C-reactive protein were measured. Fibrosis and macrophage scorings, and the ​​collagen fibers percentage were examined by staining with hematoxylin and eosin, Elastica van Gieson, anti-α smooth muscle antibody, and anti-CD68 antibodies. RESULTS: There was no remarkable difference in the values of each marker in fibrosis and macrophage scores with or without PDT. In case of death, fibrosis was mild, and PDT was not affected. CONCLUSIONS: In IP rat models, PDT did not induce lung fibrosis or acute exacerbation.

Serum-derived exosomal PD-L1 expression to predict anti-PD-1 response and in patients with non-small cell lung cancer.

PD-L1 expression is the most useful predictive biomarker for immunotherapy efficacy on non-small cell lung cancer (NSCLC), and CD8+ tumor-infiltrating lymphocytes (CD8+ TILs) play an essential role in the clinical activity of immunotherapy. PD-L1 is found on the exosome's surface, and PD-L1 expressing exosomes can inhibit antitumor immune responses. This study aimed to analyze tumor PD-L1 expression, serum exosomal PD-L1, and CD8+ TILs to investigate anti-PD-1 response and clinicopathological outcomes in NSCLC. One hundred twenty patients with stage I-III NSCLC were enrolled, and serum samples collected during the initial surgery were pooled. The Human CD274/PD-L1 ELISA kit was used to quantify the exosomal PD-L1. Exosomal PD-L1 levels were significantly correlated with tumor PD-L1 levels (p < 0.001) and the number of CD8+ TILs (p = 0.001). Patients with exosomal PD-L1 ≥ 166 pg/mL tended to have a worse RFS than those with < 166 pg/mL in all stage (p = 0.163) and stage I patients (p = 0.116). Seventeen patients exhibited postoperative recurrences and received anti-PD-1 treatment. The disease control rate of patients with exosomal PD-L1 ≥ 166 pg/mL was 100%. The measurement of serum exosomal PD-L1 as a quantitative factor with tumor PD-L1 status may help predict anti-PD-1 response and clinical outcomes in patients with NSCLC.

Ruptured mediastinal mature teratoma causing severe mediastinitis: report of a surgically resected case and a literature review.

BACKGROUND: Mediastinal teratomas occasionally rupture into the thoracic cavity, which induces mediastinitis or various other severe complications. Surgical treatment is crucial for ruptured teratomas; however, few literature reviews to date have addressed the characteristics of ruptured mediastinal teratomas. CASE PRESENTATION: We report a 29-year-old woman with severe mediastinitis owing to a mediastinal mature teratoma that ruptured into the mediastinum and right pleural cavity. Surgical resection by median sternotomy was performed within 24 hours after emergency admission. Intraoperative findings demonstrated the ruptured wall of the tumor with exposure of its white contents, which appeared similar to skin and fat, and necrotic tissue in the anterior mediastinum. The tumor was adhered to the right upper lobe, the ascending aorta, and pericardium. Owing to the severe adhesion of the tumor caused by inflammation in the surrounding tissues, a small portion of the tumor could not be removed, and hence complete resection with a sufficient surgical margin was not achieved. Pathologically, the tumor consisted of a solid mass and a cystic mass with severe adhesion to the resected portion of the lung, which included skin and lipid tissue. The tumor was concluded to be a mature teratoma as neither an immature component nor malignant transformation was observed. The patient had an uneventful postoperative course. CONCLUSIONS: To our knowledge, this is the report of successful surgical resection of a ruptured mediastinal teratoma causing severe mediastinitis, with the first literature review of ruptured mediastinal teratomas. We also discuss relevant findings from reports in the literature.

Clinical usefulness of the 3-tier classification according to the proportion of morphological patterns for patients with pathological stage I invasive lung adenocarcinoma.

OBJECTIVES: We classified pathological stage I invasive lung adenocarcinomas according to our 3-tier classification, which was based on the proportion of invasive morphological patterns as follows: (1) patients with each predominant subtype, (2) those with a minor histological subtype, even not the predominant subtype and (3) those without each invasive component. We aimed to evaluate the classification's clinical impact in survival, recurrence, malignant grade, and epidermal growth factor receptor (EGFR) mutational status. MATERIALS AND METHODS: A total of 1,269 patients with p-stage I lung adenocarcinoma underwent curative surgical resection between January 2008 and December 2017. Of these, 620 patients (48.9%) met the inclusion criteria of this study. RESULTS: Postoperative recurrence was observed in 81 patients (13.1%). Multivariate analysis showed that vascular invasion (hazard ratio, 2.61; p < 0.001) and p-stage IB (hazard ratio, 2.19; p = 0.001) were significantly associated with an unfavorable RFS, while the presence of acinar component (hazard ratio, 1.64; p = 0.052) or solid component (hazard ratio, 1.60; p = 0.074) were marginally significant. The presence of lepidic or papillary component and the absence of acinar or solid component significantly correlated with an increased proportion of lung adenocarcinomas harboring EGFR mutations. CONCLUSION: In patients with p-stage I invasive lung adenocarcinoma, it is beneficial to use not only the predominant subtype but analyzing the extent of each histological component based on our classification to predict patient prognoses and form appropriate postoperative follow-up methods.

The Correlation Between Fissureless Technique and Prolonged Air Leak for Patients Undergoing Video-Assisted Right Upper Lobectomy.

PURPOSE: We aimed to assess the clinical usefulness of the fissureless technique, which avoided dissection of the lung parenchyma over the pulmonary artery, in preventing prolonged air leak after video-assisted thoracic surgery right upper lobectomy (VATS RUL). METHODS: Perioperative outcomes, including the frequency of prolonged air leak after fissureless technique or traditional fissure dissection technique, which dissected the lung parenchyma through the fissure, were compared in patients who underwent VATS RUL (n = 213) between January 2016 and March 2020. We adopted our fissural grade to evaluate the degree of fused fissure ranging from II (light incomplete fissure) to IV (severe incomplete fissure), which covered all fissural grades in 213 patients. RESULTS: Fifty-four and 159 patients underwent fissureless and traditional techniques, respectively. Significant differences in the incidence of prolonged air leak (p = 0.037), time to air leak cessation (p = 0.047), and duration of chest tube placement (p = 0.017) were observed between fissureless and traditional technique groups. On multivariable analysis, traditional technique (p = 0.005), and greater fissural grade (III vs II, p = 0.020; IV vs II, p = 0.001) were significantly associated with prolonged air leak. CONCLUSIONS: Fissureless technique during VATS RUL can be a superior alternative to the traditional technique to prevent prolonged air leak in treating incomplete fissures.

Powered articulation by the SigniaTM stapling system for stapling position adjustments: optimizing safe surgical margins in thoracoscopic sublobar resection.

Accumulation of experience and advances in techniques and instruments have enabled surgeons to perform video-assisted thoracic surgery (VATS) safely for sublobar resection, including segmentectomy and wedge resection. A key to successful VATS sublobar resection is to have adequate resection margins and the appropriate use of articulated surgical staplers is essential for this purpose. The SigniaTM stapling system (Covidien Japan, Tokyo) has been used extensively in the fields of thoracic surgery. Its features include high maneuverability with fully powered articulation, rotation, clamping, and firing, which the surgeon can control with one hand. We introduce the "sliding technique" using the SigniaTM system, which allows for adjustment of the resection lines of the pulmonary parenchyma to optimize safe surgical margins with minimal stapler movement, and without repetitively moving the stapler in and out of the pleural cavity, during VATS sublobar resection.

Prognostic Significance of Ground-Glass Opacity Components in 5-Year Survivors With Resected Lung Adenocarcinoma.

BACKGROUND: Reports on the prognosis for 5-year survivors with lung adenocarcinoma after resection are sparse. This study aimed to identify factors associated with overall survival (OS) and cancer-specific survival (CSS) for 5-year survivors with completely resected lung adenocarcinoma, and to determine whether preoperative imaging factors, including the presence of ground-glass opacity (GGO) components, affect late recurrence in long-term survivors. METHODS: Complete resection of lung adenocarcinoma was performed for 1681 patients between January 2000 and December 2013. Of these patients, 936 who survived 5 years or longer after surgery were identified, and factors associated with OS and CSS were determined using the Cox proportional hazard model. RESULTS: Multivariable analysis demonstrated that lymph node metastasis (p < 0.01) and absence of GGO components (p < 0.01) were independently associated with OS and CSS for the 5-year survivors. The absence of GGO components was significantly associated with OS (p < 0.01) and CSS (p < 0.01) also for the 5-year survivors with stage 1 disease (n = 782) and for the 5-year survivors without recurrence (n = 809). The incidence of recurrence anytime during the 10-year postoperative follow-up period differed significantly between the 5-year survivors with and without GGO components. CONCLUSIONS: The absence of GGO components was significantly associated with an unfavorable prognosis for the 5-year survivors with completely resected lung adenocarcinoma regardless whether they had recurrences not.

Comparative analysis of the results of video-assisted thoracic surgery lobectomy simulation using the three-dimensional-printed Biotexture wet-lung model and surgeons' experience.

OBJECTIVES: We performed a comparative analysis of the performance of video-assisted thoracic surgery (VATS) lobectomy simulation using three-dimensional-printed Biotexture lung models by surgeons classified according to their level of expertise. The aim of this study was to investigate the association between surgeons' experience and time to complete the VATS lobectomy simulation. METHODS: Participants were divided into 3 groups: group A included those who had no experience of actual VATS lobectomy (n = 11), group B included those who had performed 5-10 VATS lobectomies (n = 12) and group C included those who had performed >100 VATS lobectomies (n = 6). Their performances were assessed based on total procedure time, duration to the exposure of the vessels, ligation of the arteries and stapling of the fissures. After the simulation, a questionnaire survey was performed. RESULTS: The median total procedure time was significantly shorter in the group of surgeons with more experience (A vs B, P < 0.001; B vs C, P = 0.034; A vs C, P < 0.001). Regarding 'the exposure of all the vessels to be resected' and 'ligation of the arteries', group B completed these steps in less time than group A (P = 0.024 and P = 0.012, respectively). In the questionnaire, all groups answered that this simulation was useful for novices to improve their skills. CONCLUSIONS: Although time to complete the VATS lobectomy simulation is only a part of evaluation points for real skills, this model can facilitate basic skill acquisitions for novices.

Is there disparity between regions and facilities in surgical resident training in Japan? Insights from a national survey.

PURPOSE: This study sought to assess the disparity between regions and facilities in surgical resident training in Japan via a national level needs-assessment. METHODS: A survey was sent to all 909 graduating residents of 2016. Residents trained in the six prefectures with a population of 7 million or more were included in the large prefecture (LP) group. Residents trained in the other 41 prefectures were included in the small prefecture (SP) group. Each group was further divided into a university hospital (UH) group and a non-university hospital (NUH) group. RESULTS: The response rate was 56.3% (n = 512). Excluding nine residents who did not report their prefectures and facilities, surveys from 503 residents were analyzed. The UH group received significantly more years of training. In the SP and UH groups, there were significantly fewer residents who had performed 150 procedures or more under general anesthesia in comparison to the LP and NUH groups, respectively. Self-assessed competencies for several procedures were significantly lower in the SP and UH groups. CONCLUSION: Disparity in surgical resident training was found between regions and facilities in Japan. The surgical residency curriculum in Japan could be improved to address this problem.

Are graduating residents sufficiently competent? Results of a national gap analysis survey of program directors and graduating residents in Japan.

PURPOSE: To evaluate the self-assessed competency of graduating residents (GRs) in Japan upon completion of their residency and to identify the gap between their competency and the competency expected by their program directors (PDs). METHOD: A list of 31 essential surgical procedures was compiled according to the consensus of surgical educators from around the country. A survey with this list was sent to all 909 GRs and their 611 PDs in 2016. The GRs rated their competency to perform these procedures and the PDs were asked to evaluate the expected competency of their GRs using the Zwisch Scale. RESULT: The response rate was 56.3% for the GRs and 76.8% for the PDs. Fewer than half of the GRs who responded felt confident performing ten (32%) of the surgical procedures evaluated. For most procedures, the GRs' self-reported competency was lower than the expectation reported by their PDs. This gap was more than 10% for 13 of the procedures. CONCLUSION: More than half of the GRs in Japan lacked the confidence in their skill to perform one-third of the surgical procedures selected for evaluation in this study. These findings should be used to update the surgical education curriculum in Japan.

Significant prognostic determinants in lung cancers of the superior sulcus: comparable analysis of resected and unresected cases.

OBJECTIVE: In this study, we aimed to identify prognostic determinants and to comparably analyze clinical features of patients with both resected and unresected superior sulcus tumors (SSTs). METHODS: The data of 56 patients who underwent any treatment for an SST from 2004 through 2016 in our hospital were reviewed. Overall survival (OS) rates were estimated using the Kaplan-Meier method. Univariate and multivariate analyses were performed to determine independent prognostic factors for patients with resected and unresected SST separately. RESULTS: The number of patients with resected and unresected SSTs was 24 (43%) and 32 (57%), respectively. Of the 24 patients who underwent surgery, 20 received induction therapy, with 32% achieving pathological complete response. Complete resection (R0) was performed in 22 patients (92%). On multivariate survival analysis, preoperative serum carcinoembryonic antigen (CEA) level (median 8.3 ng/ml, p = 0.021) was identified as the independent determinant of OS in surgical patients; whereas, initial treatment response (complete response or partial response, p = 0.032) was the independent OS indicator in non-surgical patients. The 5-year OS of the patient with resected and unresected SST was 68.8% and 29.1% (p = 0.008), respectively. CONCLUSION: Significant prognostic factors differ among patients stratified by the presence of surgical resection for SSTs. Preoperative CEA level in surgical candidates and initial treatment response in non-surgical patients were the independent factors associated with OS. Surgical candidates are expected to have more favorable survival than patients with unresectable SSTs.

Profiles of Lung Adenocarcinoma With Multiple Ground-Glass Opacities and the Fate of Residual Lesions.

BACKGROUND: We aimed to clarify clinical profiles of patients with adenocarcinoma presenting as multifocal ground-glass opacities (MGGOs) to assess their prognosis and the optimal management method for residual satellite lesions. METHODS: We identified 190 patients with cN0 MGGOs (MGGO cohort) and 1426 patients with solitary lung adenocarcinoma (control cohort) who underwent complete resection between 2004 and 2016. Propensity score matching was performed to adjust for differences in baseline characteristics of both cohorts for survival analyses. MGGOs consist of a main tumor and satellite lesions and were subdivided into 3 groups: the PG group, with multifocal pure GGOs; the GD group, in which the main tumor presented as GGO dominant; and the SD group, where the main tumor presented as solid dominant. RESULTS: No significant differences in recurrence-free survival were observed between the 2 cohorts before and after the propensity score matching. For patients with MGGOs, 22 were in the PG group, 47 in the GD group, and 121 in the SD group. Type of MGGOs was a significant factor for recurrence-free survival recurrence-free survival both in the entire population (SD vs PG-GD, P = .008) and in p-stage I cohorts (P = .004) on multivariable analysis. Among 116 patients (61.1%) with residual satellite lesions, 38 patients had progressed lesions and 69 stable lesions. Although the emergence of new lesions during the follow-up period was an independent predictor for satellite lesion progression, neither progressed lesions nor the emergence of new lesions influenced survival. CONCLUSIONS: Patients with MGGOs and solitary adenocarcinoma had a similar prognosis. The biologic behavior of main tumors dominates clinical outcomes in patients with MGGOs.

A combination therapy of photodynamic therapy (PDT) and airway stent placement using a transparent silicone stent.

The aim of this study was to evaluate the feasibility of a combination therapy of photodynamic therapy (PDT) and airway stent placement using a transparent silicone stent (gold studded stent [GSS]). Laser irradiation (664 nm, continuous wave) was performed through the GSS using a straight and cylindrical fiber 1.0 cm away from a power meter. There are two types of GSS: the TD type for the trachea and the BD type for the bronchus. Laser outputs were set to 150 mW, 180 mW, 210 mW, 240 mW, 270 mW, and 300 mW. The laser powers passing through the both types of GSS were measured three times for each outputs and the averages were calculated. Based on the results, animal experiment was performed using two female pigs. Under general anesthesia, a GSS (BD type) was inserted into trachea of pigs, and PDT using NPe6 as a photosensitizer was performed by 100 J/cm2 laser irradiation on parts of the trachea with and without a GSS. Immediately after and 1 week after PDT, pig tracheas were harvested and histological analysis was performed. Histological analysis of areas with or without the stent showed edematous changes between the cartilage and submucosal layer immediately after PDT, and necrotic changes 1 week later. The effectiveness of NPe6-PDT for pigs' trachea covered by the stent was same as trachea without the stent. The use of a GSS may enable PDT to be effective even in the area covered by the stent.