Multimodal modeling with low-dose CT and clinical information for diagnostic artificial intelligence on mediastinal tumors: a preliminary study

BACKGROUND

Diagnosing mediastinal tumours, including incidental lesions, using low-dose CT (LDCT) performed for lung cancer screening, is challenging. It often requires additional invasive and costly tests for proper characterisation and surgical planning. This indicates the need for a more efficient and patient-centred approach, suggesting a gap in the existing diagnostic methods and the potential for artificial intelligence technologies to address this gap. This study aimed to create a multimodal hybrid transformer model using the Vision Transformer that leverages LDCT features and clinical data to improve surgical decision-making for patients with incidentally detected mediastinal tumours.

METHODS

This retrospective study analysed patients with mediastinal tumours between 2010 and 2021. Patients eligible for surgery (n=30) were considered 'positive,' whereas those without tumour enlargement (n=32) were considered 'negative.' We developed a hybrid model combining a convolutional neural network with a transformer to integrate imaging and clinical data. The dataset was split in a 5:3:2 ratio for training, validation and testing. The model's efficacy was evaluated using a receiver operating characteristic (ROC) analysis across 25 iterations of random assignments and compared against conventional radiomics models and models excluding clinical data.

RESULTS

The multimodal hybrid model demonstrated a mean area under the curve (AUC) of 0.90, significantly outperforming the non-clinical data model (AUC=0.86, p=0.04) and radiomics models (random forest AUC=0.81, p=0.008; logistic regression AUC=0.77, p=0.004).

CONCLUSION

Integrating clinical and LDCT data using a hybrid transformer model can improve surgical decision-making for mediastinal tumours, showing superiority over models lacking clinical data integration.

Zero-leak prediction during major lung resection aiming for minimal chest drainage duration: a retrospective analysis

BACKGROUND

Early chest tube removal should be considered to enhance recovery after surgery. The current study aimed to provide a predictive algorithm for air leak episodes (ALE) and to create a knowledge base for early chest tube removal.

METHODS

This retrospective study enrolled patients who underwent thoracoscopic anatomical pulmonary resections in our unit. We defined ALE as any airflow ≥ 10 mL/min recorded in the follow-up charts based on the digital thoracic drainage device. Multivariate regression analysis was used to control for preoperative and intraoperative confounding factors. The ALE prediction algorithm was constructed by combining an additive ALE risk-scoring system using the coefficients of the significant predictive factors with the intraoperative water-sealing test.

RESULTS

In 485 consecutive thoracoscopic major pulmonary resections, ALE developed in 209 (43%) patients. Statistically significant ALE-associated preoperative factors included male sex, lower body mass index, radiologically evident emphysema, lobectomy, and upper lobe surgery. Significant ALE-associated intraoperative factors were incomplete fissure and pleural adhesion. The ALE risk scoring demonstrated an average area under the receiver operating characteristic curve of 0.72 in the fivefold cross-validation test. The ALE prediction algorithm correctly predicted ALE-absent patients at a negative predictive value of 80%.

CONCLUSIONS

The algorithm may promote the optimization of the chest tube-dwelling duration by identifying potential ALE-absent patients for accelerated tube removal.

Successful thoracoscopic operative approach for refractory pneumothorax in interstitial lung disease under local anaesthesia

Refractory pneumothorax associated with interstitial lung disease (ILD) remains a challenging condition due to the patient's tolerability and lung compliance that restrict the feasibility of aggressive interventions. Additionally, many cases recur after improvement with treatment, and reports of successful management for this complicated condition are limited. Herein, we report the case of a 60-year-old man with ILD, utilizing home oxygen therapy, who experienced a successful recovery from a surgical intervention under local anaesthesia for pneumothorax. This case highlights the potential for operative intervention under local anaesthesia as a viable option for patients who do not respond to internal approaches.

Fish Bone Descending in the Mediastinum

Ingested sharp foreign bodies rarely migrate extraluminally into adjacent organs such as the pharynx, lungs, and liver. Herein, we report a case of fish bone ingestion where the foreign body followed a unique migration trajectory. Computed tomography revealed a fish bone extraluminally located in the aortopulmonary space in the left mediastinum and peri-esophageal pneumomediastinum. Endoscopic examination indicated no injury to the esophageal mucosa but showed mucosal lacerations in the left hypopharynx. Accordingly, we reasoned that the fish bone penetrated the laryngopharynx and then descended in the mediastinum.

Impact of avalanche type of transport on internal transport barrier formation in tokamak plasmas

In magnetic fusion plasmas, a transport barrier is essential to improve the plasma confinement. The key physics behind the formation of a transport barrier is the suppression of the micro-scale turbulent transport. On the other hand, long-range transport events, such as avalanches, has been recognized to play significant roles for global profile formations. In this study, we observed the impact of the avalanche-type of transport on the formation of a transport barrier for the first time. The avalanches are found to inhibit the formation of the internal transport barrier (ITB) observed in JT-60U tokamak. We found that (1) ITBs do not form in the presence of avalanches but form under the disappearance of avalanches, (2) the surface integral of avalanche-driven heat fluxe is comparable to the time rate change of stored energy retained at the ITB onset, (3) the mean E × B flow shear is accelerated via the ion temperature gradient that is not sustained under the existence of avalanches, and (4) after the ITB formation, avalanches are damped inside the ITB, while they remain outside the ITB.

Low-Dose CT Screening of Persistent Subsolid Lung Nodules: First-Order Features in Radiomics

BACKGROUND

 Nondisappearing subsolid nodules requiring follow-up are often detected during lung cancer screening, but changes in their invasiveness can be overlooked owing to slow growth. We aimed to develop a method for automatic identification of invasive tumors among subsolid nodules during multiple health checkups using radiomics technology based on low-dose computed tomography (LD-CT) and examine its effectiveness.

METHODS

 We examined patients who underwent LD-CT screening from 2014 to 2019 and had lung adenocarcinomas resected after 5-year follow-ups. They were categorized into the invasive or less-invasive group; the annual growth/change rate (Δ) of the nodule voxel histogram using three-dimensional CT (e.g., tumor volume, solid volume percentage, mean CT value, variance, kurtosis, skewness, and entropy) was assessed. A discriminant model was designed through multivariate regression analysis with internal validation to compare its efficacy with that of a volume doubling time of < 400 days.

RESULTS

 The study included 47 tumors (23 invasive, 24 less invasive), with no significant difference in the initial tumor volumes. Δskewness was identified as an independent predictor of invasiveness (adjusted odds ratio, 0.021; p = 0.043), and when combined with Δvariance, it yielded high accuracy in detecting invasive lesions (88% true-positive, 80% false-positive). The detection model indicated surgery 2 years earlier than the volume doubling time, maintaining accuracy (median 3 years vs.1 year before actual surgery, p = 0.011).

CONCLUSION

 LD-CT radiomics showed promising potential in ensuring timely detection and monitoring of subsolid nodules that warrant follow-up over time.

A case of a thoracic mass negative on thoracentesis diagnosed by cryobiopsy from the visceral pleura

Thoracoscopy under local anaesthesia is recommended for malignant tumours with negative pleural effusion cytology. Cryobiopsy from the visceral pleura by thoracoscopy under local anaesthesia can provide more diagnostic options for patients with thoracentesis‐negative malignant effusions. Here we present the first case in which this technique was used. The patient had a pleural metastasis that could not be diagnosed even with rapid cytology of the parietal pleura biopsy. Indications, technical pitfalls, and safety tips are discussed.

Single-Direction Approach for Thoracoscopic Segmentectomy of the Left Upper Lobe Anterior Segment With Mediastinal Lingular Artery

Thoracoscopic resection of the anterior segment of the left upper lobe (S³) is technically challenging because of the intricate hilar structure and multiple intersegmental planes to be dissected. A single-direction approach for S³ segmentectomy is a technique in which surgeons dissect the hilum structures exclusively from the ventral side without dividing the interlobar fissure. Our consecutive case series and a representative surgical video demonstrated the feasibility of this approach in cases where the lingular artery arises from the first branch of the left pulmonary artery (mediastinal lingular artery).

Morphological differences in skulls and feeding apparatuses between Antarctic (Balaenoptera bonaerensis) and common (Balaenoptera acutorostrata) minke whales, and the implication for their feeding ecology

The differences in rorqual feeding ecology have been linked to the presence of different morphological markers. The Antarctic minke whale (Balaenoptera bonaerensis Burmeister, 1867) and the common minke whale (Balaenoptera acutorostrata Lacépède, 1804) are closely related species, but their morphological differences have not been fully investigated. In this study, we compared 21 skull and 11 feeding apparatus (baleen and mouth-related parts) measurement points between these two species using hundreds of individuals covering a wide range of body lengths in both sexes. Their engulfment capacities were estimated using these measurements. Our results show that Antarctic minke whales have (i) proportionally larger skulls to the body length, (ii) more dorsoventrally and laterally curved rostra, (iii) proportionally larger feeding apparatuses to the condylobasal length, and (iv) significantly larger engulfment capacity than common minke whales. These differences could indicate that Antarctic minke whales have developed a feeding strategy suitable for feeding on krill, which forms large schools. In contrast, common minke whales have adapted to prey on small pelagic fishes that are agile and form small schools.

Efficacy of the Segment-Counting Method in Predicting Lung Function and Volume Following Stapler-Based Thoracoscopic Segmentectomy

Purpose: To investigate the accuracy of a segment-counting method in predicting lung function and volume after stapler-based thoracoscopic segmentectomy in comparison with lobectomy.

Methods: Between 2014 and 2018, patients who underwent these procedures were retrospectively reviewed. Thoracic computed tomography and spirometry data before and 1 year after the surgery were assessed. We evaluated the differences between the predicted values using a segment-counting method and the actual postoperative values for lung function and volume in each group. Sub-analyses were also performed to assess the impact of the number of staples and resected segments in predicting patient outcomes.

Results: We included 116 patients (segmentectomy, 69; lobectomy, 47). Actual postoperative lung function and volume values matched the predicted values in the stapler-based segmentectomy group, and significantly exceeded the predictions in the lobectomy group (P <0.01). Sub-analyses revealed lower postoperative lung function values than predicted existed after single segmentectomy, with an odds ratio of 3.29 (95% confidence interval: 1.02–10.70, P = 0.04) in a multivariable analysis. The degree of predicted error regarding lung function was negligible.

Conclusions: The segment-counting method was useful in predicting lung function after stapler-based thoracoscopic segmentectomy. Segmentectomy rarely yielded lower- than-predicted lung function and volume values.

The advanced lung cancer inflammation index predicts outcomes in patients with Crohn's disease after surgical resection

AIM

Precise biomarkers for predicting prognosis could help to identify high-risk Crohn's disease (CD) patients to facilitate better follow-up during the postoperative course. In this study, the primary aim is the identification of the most reliable nutrition marker that predicts surgical relapse in CD patients.

METHOD

We first evaluated the predictive value of various nutrition markers for postoperative surgical relapse in CD patients and identified the advanced lung cancer inflammation index (ALI) as a promising biomarker. Then, we assessed the clinical significance of preoperative ALI in CD patients using two cohorts.

RESULTS

Preoperative ALI showed the highest correlation with reoperation rate compared with other nutritional parameters in CD patients receiving surgical resection (sensitivity 53%, specificity 86%, area under the curve 0.71). Lower levels of preoperative ALI were significantly correlated with the presence of perianal disease. A lower level of preoperative ALI was an independent prognostic factor for reoperation rate after an intestinal resection (hazard ratio 3.37, 95% CI 1.38-10.12, P = 0.006), and the prognostic impact of preoperative ALI was successfully validated in an independent cohort using the same cut-off value.

CONCLUSION

Preoperative ALI might be useful for postoperative management of CD patients.

Conceptual design of a collimator for the neutron emission profile monitor in JT-60SA using Monte Carlo simulations

Materials and structures of a collimator for a new neutron emission profile monitor in JT-60SA are examined through Monte Carlo simulations using the Monte Carlo N-Particle transport code. First, the shielding properties of various material combinations are compared in order to determine a combination with high shielding performances against both neutrons and gamma-rays. It is found that a collimator consisting of borated polyethylene and lead has a high shielding performance against neutrons. Moreover, a high shielding performance against gamma-rays is obtained when a lead pipe with a radial thickness of 0.01 m is inserted into a collimation tube. Second, we demonstrate that it is possible to improve the spatial resolution to a desired level by installing a thin tubular extension structure that fits into the limited space available between the main collimator block and the tokamak device. Finally, the collimator structures that meet both the targeted spatial resolutions (<10% of the plasma minor radius) and the targeted counting rate (10⁵ cps order) are discussed.

The treatment and survival of patients with postoperative recurrent thymic carcinoma and neuroendocrine carcinoma: a multicenter retrospective study

PURPOSE

There are few data available on the outcomes of postoperative recurrent thymic carcinoma (TC) and thymic neuroendocrine carcinoma (TNEC). The aim of this study is to evaluate the treatment and survival in patients with recurrent TC and TNEC after undergoing surgical resection.

METHODS

A retrospective chart review was performed using our multicenter database to identify patients with a postoperative recurrence of TC and TNEC from 1995 to 2018. The clinicopathological factors were reviewed and the survival outcomes were analyzed.

RESULTS

Sixty patients were identified among 152 patients who underwent resection of TC and TNEC. The median follow-up period from the first recurrence was 14.8 months (range 0-144). The 5-year post-recurrence survival was 23% for the whole cohort. According to a univariable analysis, advanced stage [hazard ratio (HR) 2.81, 95% confidence interval (CI) 1.09-9.54], interval between primary surgery and recurrence (HR 0.97, 95% CI 0.95-0.99), any treatment for recurrence (HR: 0.27, 95% CI 0.13-0.58) and chemotherapy for recurrence (HR: 0.46, 95% CI 0.22-0.95) were significant factors related to post-recurrence survival.

CONCLUSIONS

Chemotherapy rather than surgery appears to be the mainstay treatment for managing patients with postoperative recurrent TC and TNEC and it may also be considered in multidisciplinary management. Further studies with a larger sample size are required to confirm our findings.

Radiomics technology for identifying early-stage lung adenocarcinomas suitable for sublobar resection

OBJECTIVE

Early-stage lung adenocarcinomas that are suitable for limited resection to preserve lung function are difficult to identify. Using a radiomics approach, we investigated the efficiency of voxel-based histogram analysis of 3-dimensional computed tomography images for detecting less-invasive lesions suitable for sublobar resection.

METHODS

We retrospectively reviewed the medical records of 197 patients with pathological stage 0 or IA adenocarcinomas who underwent lung resection for primary lung cancer at our institution between January 2014 and June 2018. The lesions were categorized as either less invasive or invasive. We evaluated tumor volumes, solid volume percentages, mean computed tomography values, and variance, kurtosis, skewness, and entropy levels. We analyzed the relationships between these variables and pathologically less-invasive lesions and designed an optimal model for detecting less-invasive adenocarcinomas.

RESULTS

Univariate analysis revealed seven variables that differed significantly between less invasive (n = 71) and invasive (n = 141) lesions. A multivariate analysis revealed odds ratios for tumor volumes (0.64; 95% confidence interval (CI), 0.46-0.89; P = .008), solid volume percentages (0.96; 95% CI, 0.93-0.99; P = .024), skewness (3.45; 95% CI, 1.38-8.65; P = .008), and entropy levels (0.21; 95% CI, 0.07-0.58; P = .003). The area under the receiver operating characteristic curve was 0.90 (95% CI, 0.85-0.94) for the optimal model containing these 4 variables, with 85% sensitivity and 79% specificity.

CONCLUSIONS

Voxel-based histogram analysis of 3-dimensional computed tomography images accurately detected early-stage lung adenocarcinomas suitable for sublobar resection.

Early postoperative inflammatory response by procedure types: stapler-based segmentectomy versus lobectomy

OBJECTIVE

Perioperative C-reactive protein (CRP) levels have become a contentious topic on the surgical outcome of lung cancer, but the influence of the procedure types has not been precisely investigated. From this viewpoint, we compared two types of thoracoscopic anatomical lung resection: segmentectomy and lobectomy.

METHODS

This was a retrospective study involving patients who underwent standardized anatomical lung resection at a single institute from 2014 to 2017; CRP levels were routinely measured on postoperative days 1, 3, and 5. Changes in the CRP levels from the preoperative period were calculated (ΔCRP), and factors associated with a higher ΔCRP value were analyzed.

RESULTS

Among 186 patients included, 91 (48.9%) patients underwent stapler-based segmentectomy and 95 (51.1%) patients underwent lobectomy. The segmentectomy group showed significantly higher ΔCRP values on every measurement day than the lobectomy group, in spite of shorter operation time, smaller blood loss, shorter drainage periods, shorter dissection time, and limited lymph node dissection. The number of stapler cartridges for the lung parenchyma was significantly larger in the segmentectomy group. Regression analyses indicated that procedure type and smoking history were associated with a higher ΔCRP value, whereas no significant difference was indicated in the smoking history between the groups.

CONCLUSION

In our cohort, stapler-based thoracoscopic segmentectomy was associated with an increase in acute inflammatory response despite favorable perioperative outcome compared to lobectomy. Local surgical stress and damage in the remaining segments might play a key role and warrants further investigation.

[Thoracic Incisions for Open Chest Surgery;Posterolateral Thoracotomy, Anterolateral Thoracotomy, Axillary Thoracotomy, and Muscle Sparing Thoracotomy]

Lung disease requiring surgical treatment has shifted from pulmonary tuberculosis that was prevalent in the 1940s during wartime to lung cancer in the last half century. The surgical approach for pulmonary tuberculosis was open chest surgery. Likewise for lung cancer, a thoracotomy approach had initially been used for a while. Thoracoscopic minimally invasive surgery became more widely used around 1990 and was shown to improve the patient's quality of life (QOL). Currently, thoracoscopic surgery and robotic surgery are the mainstream procedures for patients with lung cancer, and thoracotomy procedures have fallen out of favor. However, in some cases of unexpected bleeding from the pulmonary artery or tumor infiltration into the pulmonary artery, appropriate thoracotomy must be performed. In this volume, 4 representative methods of performing thoracotomy are described with some tips in Japanese.

Primary Synovial Sarcoma of the Mediastinum with Long-term Follow-up

Chest radiography showed a right posterior mass on the mediastinum of an 84-year-old woman. The mass had been growing gradually for four years. Surgical excision was performed, and a pathological examination found the mass to be consistent with primary synovial sarcoma (SS) of the mediastinum. To our knowledge, this is a rare case in which follow-up imaging was able to be performed over a period of four years. This disease is aggressive, and its early diagnosis is key to achieving a cure. It is important to consider primary SS in the differential diagnosis of a primary intra-thoracic tumor, even if the tumor grows slowly.

Lifesaving surgery for a ruptured invasive thymoma using the hemi-clamshell approach: a case report

Background

Among anterior mediastinal tumors, a teratoma is known to rupture with growth, but there have been few previous reports about thymoma rupture. We here report a rare case of an invasive thymoma with intrapulmonary and intrathoracic rupture requiring emergency life-saving surgery. To our knowledge, this is the first such case in the literature.

Case presentation

A 56-year-old woman suddenly experienced right precordial pain and hemoptysis. Enhanced computed tomography revealed a large mediastinal tumor pressing against the pulmonary hilar vascularity, with extravasation of blood into the right lung. Tumor rupture into the lungs was suspected. Given the deterioration of her respiratory status and hemodynamics, thymomectomy with removal of the involved tissues was urgently performed using the hemi-clamshell approach and intrapericardial dissection, with veno-arterial extracorporeal membrane oxygenation on standby. She survived, and no recurrence has been noted for 2 years postoperatively.

Conclusions

A large thymoma can suddenly rupture into the thorax, similar to the rupture of a teratoma. Additionally, in cases with hemoptysis, an appropriate procedure should be selected to reach both the pulmonary hilum and thorax for complete resection, as hemoptysis might suggest tumor invasion into the lungs.

Experimental examination of a method to estimate temporal effect by neutrons and γ-rays on scintillation light in scintillator-based soft x-ray diagnostic of experimental advanced superconducting tokamak and large helical device

Scintillators, which are more tolerant of neutrons or γ-rays than semiconductors, are a promising candidate for soft X-ray (SX) diagnostics in high neutron flux environments such as JT-60SA or ITER. Although scintillators are tolerant of radiations, neutrons and γ-rays can cause scintillation light and become noise on SX signals. Therefore, a method to estimate the temporal effect by the radiations on SX signals and an appropriate design of the radiation shield based on the estimation are required. In previous studies, it has been proposed for estimating the effect by the radiations to calculate the absorption powers due to SXs, neutrons, and γ-rays in scintillators assuming that amplitudes of scintillation light are proportional to the absorption powers. In this study, an experimental examination of this proposal is conducted in the Experimental Advanced Superconducting Tokamak (EAST). It is shown that the proposal may be valid in the examination of EAST. In addition to results in EAST, initial results of a multi-channel scintillator-based SX diagnostic in the Large Helical Device (LHD) are introduced. Although a scintillator-based SX diagnostic in LHD observes oscillations of SXs by magnetohydrodynamic (MHD) phenomena successfully, the observed temporal effect on SX signals by neutrons or γ-rays is more significant than the expected effect, which is estimated by calculating the absorption powers. One of the possible reasons for the contradiction between the results in EAST and LHD is unexpected γ-rays around the scintillators in LHD. Although the temporal effect by the radiations is significant in the current system of LHD, the degradation of amplitudes of SX signals after the deuterium plasma experiments is not observed with the current level of the fluence. The scintillator-based SX diagnostic in LHD may work as a diagnostic to research MHD instabilities in deuterium plasma experiments without additional maintenance during an experimental campaign by making the pinhole larger or setting an additional radiation shield.

Hepatic cytochrome P450 metabolism suppressed by mast cells in type 1 allergic mice

Mast cells and Kupffer cells secrete interleukin (IL)-1β, interferon (IFN)-γ, and tumor necrosis factor (TNF)-α, which stimulate excess nitric oxide (NO) producing-inducible NO synthase (iNOS). Unlike Kupffer cells, immunoglobulin E-sensitized mast cells elicit sustained NO production. We investigated the participation of mast cell-released NO and cytokine-derived iNOS activation in type 1 allergy-suppressed hepatic cytochrome P450 (CYP) metabolism. Aminoguanidine, a selective iNOS inhibitor, completely suppressed serum nitrate plus nitrite (NOx) concentrations after primary and secondary sensitization of ICR mice and markedly attenuated allergy-suppressed hepatic CYP1A2, CYP2C, CYP2E1, and CYP3A activities. In the liver, primary and secondary sensitization enhanced iNOS-stimulating IFN-γ (5-15-fold) and TNF-α (3-5-fold) mRNA levels more than IL-1β (2-fold) and F4/80-positive Kupffer cell (2-fold) mRNA levels. When mast cell-deficient (-/-) mice were sensitized, hepatic CYP activities were not suppressed. Serum NOx levels in the sensitized -/- mice were similar with those in saline-treated ICR and -/- mice. In the liver of -/- mice, secondary sensitization markedly enhanced mRNA expression of iNOS (20-fold), IFN-γ (15-fold), and TNF-α (3-fold). However, hepatic total NOS activities in -/- mice were not significantly different between saline treatment and sensitization. Similarly, primary and secondary ICR mice did not significantly enhance total NOS activities in the liver and hepatocytes. The total NOS activities observed did not relate to the high levels of iNOS, IFN-γ, and TNF-α mRNA in the liver. Hepatic c-kit-positive mast cells in sensitized ICR mice were maintained at control levels. Therefore, our data suggest that mast cell-released NO participates in type 1 allergy-suppressed CYP1A2, CYP2C, CYP2E1, and CYP3A metabolism.

Ostomy creation with fewer sutures using tissue adhesives (cyanoacrylates) in inflammatory bowel disease: a pilot study

Introduction Fistula formation around the ostomy site is a stoma-related complication often requiring surgical intervention. This complication may be caused by sutures or may develop as a complication of inflammatory bowel disease. Before conducting a clinical trial, we set out to investigate the safety of ostomy creation with fewer sutures using tissue adhesives in this pilot study. Methods Patients with inflammatory bowel disease who required surgery with ostomy creation at the Hyogo College of Medicine between January 2014 and December 2015 were enrolled. Safety was assessed by evaluating the incidence of stoma-related complications. Ostomy was restricted to loop ileostomy and was created with two sutures and tissue adhesives. Results A total of 14 patients were enrolled. Mean body mass index was 18.9 ± 2.0 kg/m². There were no cases of ostomy retraction and no severe adverse events were observed. Conclusions This pilot study demonstrates that ostomy creation using tissue adhesives is safe. Although retraction and adverse events were not observed, even in patients with inflammatory bowel disease who generally exhibit delayed wound healing, the body mass index was extremely low in this series. This study does not strongly recommend ostomy creation with tissue adhesives; further studies are needed to clarify the efficacy and safety of the procedure.