An analysis of residual lung volume changes after segmentectomy based on three-dimensional computed tomography.

Background: Based on the results of JCOG0802 and CALGB studies, segmentectomy has considered to be a standard procedure for early-stage non-small cell lung cancer (NSCLC). After lobectomy, the residual cavity is filled with mediastinal and diaphragmatic deviations, and compensatory volume changes are present in the residual lungs. In this study, we examined the efficacy of segmentectomy, a surgical procedure, by focusing on its impact on postoperative lung volume and function. Methods: We enrolled 77 patients who underwent segmentectomy as their initial surgical procedure, excluding those with additional lung resections and those who lacked postoperative computed tomography imaging. The predicted residual volume (mL) was defined as the total lung volume before surgery minus the volume of the resected area. Using the predicted residual volume (mL) and postoperative total lung volume (mL), we calculated the rate of postoperative lung volume increase [(postoperative total lung volume/predicted residual volume) × 100] (%). We also classified 52 cases with a rate of postoperative lung volume increase of ≥100% into a compensatory group, while those with a rate of <100% were classified into a non-compensatory group. Results: The average postoperative lung volume increase was 104.6% among 77 cases. Age ≥65 years, pack year index ≥27.5, ≥3 resected segments, and use of electrocautery for intersegmental plane division were significantly associated with compensatory group classification. In 20 compensatory cases with preoperative and postoperative pulmonary function tests, postoperative vital capacity and forced expiratory volume in one second values exceeded the preoperative predictions. This study further examined the areas responsible for postoperative compensatory lung volume increase. In the compensatory group, significant expansion was observed in the ipsilateral lobes, excluding the resected segment and contralateral lung, while no significant changes were noted in the volume of the lobe, including the resected segment. Conversely, the non-compensatory group showed a significant volume decrease in the resected lobe, but no significant increase in other areas. Conclusions: This study emphasizes the importance of preserving lung segments in segmentectomy. The study demonstrates extensive compensatory volume changes in the ipsilateral lung and contralateral lung. There was no significant volume decrease in any residual segment. This underlines the potential of segmentectomy to maintain lung function and expand treatment options post-surgery. In addition, the compensated group included patients with a lower pack-year index and younger patients. These results suggest that postoperative compensatory lung expansion includes not only hyperinflation of the remaining lung, but also an increase in the functional lung parenchyma.

The Clinical Role of Adjuvant Chemotherapy after Sublobar Resection for Non-Small-Cell Lung Cancer ≤ 20 mm with Lymph Node Metastases: A Propensity-Matched Analysis of the National Cancer Database.

Sublobar resection is a standard surgical procedure for small-sized non-small-cell lung cancer (NSCLC). However, the clinical role of adjuvant chemotherapy for small-sized NSCLC with pathological lymph node (LN) metastasis after sublobar resection is unknown. The National Cancer Database was queried for NSCLC patients between 2004 and 2018. Eligibility included sublobar resection with pathological LN metastasis, R0 resection, Charlson comorbidity score = 0, clinical stage T1a-b, and tumor size ≤ 20 mm. The Kaplan-Meier method with a log-rank test and multivariable Cox proportional hazards analyses were used for assessing survival. The samples were evaluated before and after propensity score matching (PSM) with respect to age, sex, histologic type, and pathological LN status. Of 810 patients who met the eligibility criteria, 567 (70.0%) underwent adjuvant chemotherapy. After PSM, patients with adjuvant chemotherapy had a significantly longer survival than those without (median survival: 64.3 vs. 34.0 months, hazard ratio for death: 0.61, p < 0.0001). Multivariate analyses after PSM showed that younger age (p = 0.0206), female (p = 0.0005), and adjuvant chemotherapy (p < 0.0001) were independent prognostic factors for longer survival. Adjuvant chemotherapy has a prognostic impact in patients with small-sized NSCLC and pathological lymph node metastasis who undergo sublobar resection.

Quantification of Resection Margin following Sublobar Resection in Lung Cancer Patients through Pre- and Post-Operative CT Image Comparison: Utilizing a CT-Based 3D Reconstruction Algorithm.

Sublobar resection has emerged as a standard treatment option for early-stage peripheral non-small cell lung cancer. Achieving an adequate resection margin is crucial to prevent local tumor recurrence. However, gross measurement of the resection margin may lack accuracy due to the elasticity of lung tissue and interobserver variability. Therefore, this study aimed to develop an objective measurement method, the CT-based 3D reconstruction algorithm, to quantify the resection margin following sublobar resection in lung cancer patients through pre- and post-operative CT image comparison. An automated subvascular matching technique was first developed to ensure accuracy and reproducibility in the matching process. Following the extraction of matched feature points, another key technique involves calculating the displacement field within the image. This is particularly important for mapping discontinuous deformation fields around the surgical resection area. A transformation based on thin-plate spline is used for medical image registration. Upon completing the final step of image registration, the distance at the resection margin was measured. After developing the CT-based 3D reconstruction algorithm, we included 12 cases for resection margin distance measurement, comprising 4 right middle lobectomies, 6 segmentectomies, and 2 wedge resections. The outcomes obtained with our method revealed that the target registration error for all cases was less than 2.5 mm. Our method demonstrated the feasibility of measuring the resection margin following sublobar resection in lung cancer patients through pre- and post-operative CT image comparison. Further validation with a multicenter, large cohort, and analysis of clinical outcome correlation is necessary in future studies.

Real-world outcomes of lobectomy, segmentectomy and wedge resection for the treatment of stage c-IA lung carcinoma.

OBJECTIVES: To determine safety and survival outcomes associated with lobectomy, segmentectomy and wedge resection for early-stage lung cancer by quiring the French population-based registry EPIdemiology in THORacic surgery (EPITHOR). METHODS: Retrospective analysis of 19 452 patients with stage c IA lung carcinoma who underwent lobectomy, segmentectomy or wedge resection between 2016 and 2022 with curative-intent. Main outcome measures were 90-day mortality and 5-year overall survival estimates. Proportional hazards regression and propensity score matching were used to adjust outcomes for key patient, tumour and practice environment factors. RESULTS: The treatment distribution was 72.2% for lobectomy, 21.5% for segmentectomy and 6.3% for wedge. Unadjusted 90-day mortality rates were 1.6%, 1.2% and 1.1%, respectively (P = 0.10). Unadjusted 5-year overall survival estimates were 80%, 78% and 70%, with significant inter-group survival curves differences (P < 0.0001). Multivariable proportional hazards regression showed that wedge was associated with worse overall survival [adjusted hazard ratio (AHR), 1.23 (95% confidence interval 1.03-1.47); P = 0.021] compared with lobectomy, while no significant difference was disclosed when comparing segmentectomy to lobectomy (1.08 [0.97-1.20]; P = 0.162). The three-way propensity score analyses confirmed similar 90-day mortality rate for wedge resection and segmentectomy compared with lobectomy (hazard ratio: 0.43; 95% confidence interval 0.16-1.11; P = 0.081 and 0.99; 0.48-2.10; P = 0.998, respectively), but poorer overall survival (1.45; 1.13-1.86; P = 0.003 and 1.31; 1-1.71; P = 0.048, respectively). CONCLUSIONS: Wedge resection was associated with comparable 90-day mortality but lower overall survival when compared to lobectomy. Overall, all types of sublobar resections may not offer equivalent oncologic effectiveness in real-world settings.

AI-driven Characterization of Solid Pulmonary Nodules on CT Imaging for Enhanced Malignancy Prediction in Small-sized Lung Adenocarcinoma.

OBJECTIVES: Distinguishing solid nodules from nodules with ground-glass lesions in lung cancer is a critical diagnostic challenge, especially for tumors ≤2 cm. Human assessment of these nodules is associated with high inter-observer variability, which is why an objective and reliable diagnostic tool is necessary. This study focuses on artificial intelligence (AI) to automatically analyze such tumors and to develop prospective AI systems that can independently differentiate highly malignant nodules. MATERIALS AND METHODS: Our retrospective study analyzed 246 patients who were diagnosed with negative clinical lymph node metastases (cN0) using positron emission tomography-computed tomography (PET/CT) imaging and underwent surgical resection for lung adenocarcinoma. AI detected tumor sizes ≤2 cm in these patients. By utilizing AI to classify these nodules as solid (AI_solid) or non-solid (non-AI_solid) based on confidence scores, we aim to correlate AI determinations with pathological findings, thereby advancing the precision of preoperative assessments. RESULTS: Solid nodules identified by AI with a confidence score ≥0.87 showed significantly higher solid component volumes and proportions in patients with AI_solid than in those with non-AI_solid, with no differences in overall diameter or total volume of the tumors. Among patients with AI_solid, 16% demonstrated lymph node metastasis, and a significant 94% harbored invasive adenocarcinoma. Additionally, 44% were upstaging postoperatively. These AI_solid nodules represented high-grade malignancies. CONCLUSION: In small-sized lung cancer diagnosed as cN0, AI automatically identifies tumors as solid nodules ≤2 cm and evaluates their malignancy preoperatively. The AI classification can inform lymph node assessment necessity in sublobar resections, reflecting metastatic potential.

Simply designed robotic combined subsegmentectomy for a lesion in the left S10 via a posterior approach.

Segmentectomies involving the posterior basal segment (S10) of the lower lobe present a challenging surgical procedure due to anatomical complexities, especially when lesions extend towards the lateral basal segment (S9). We introduce a combined subsegmentectomy technique via a posterior approach for a lesion situated between S9b and S10b, which preserves subsegmental branches that do not affect the resection margin of the tumour and facilitates intersegmental division without extending dissection into the interlobar region. This technique, the goal of which is to reduce the extent of dissection and complex stapling, is expected to minimize pulmonary complications and intrathoracic adhesions without compromising oncological outcomes. By potentially mitigating challenges in an ipsilateral reoperation, this approach offers a valuable alternative for managing second lung cancers.

Preoperative evaluation of visceral pleural invasion in peripheral lung cancer utilizing deep learning technology.

PURPOSE: This study aimed to assess the efficiency of artificial intelligence (AI) in the detection of visceral pleural invasion (VPI) of lung cancer using high-resolution computed tomography (HRCT) images, which is challenging for experts because of its significance in T-classification and lymph node metastasis prediction. METHODS: This retrospective analysis was conducted on preoperative HRCT images of 472 patients with stage I non-small cell lung cancer (NSCLC), focusing on lesions adjacent to the pleura to predict VPI. YOLOv4.0 was utilized for tumor localization, and EfficientNetv2 was applied for VPI prediction with HRCT images meticulously annotated for AI model training and validation. RESULTS: Of the 472 lung cancer cases (500 CT images) studied, the AI algorithm successfully identified tumors, with YOLOv4.0 accurately localizing tumors in 98% of the test images. In the EfficientNet v2-M analysis, the receiver operating characteristic curve exhibited an area under the curve of 0.78. It demonstrated powerful diagnostic performance with a sensitivity, specificity, and precision of 76.4% in VPI prediction. CONCLUSION: AI is a promising tool for improving the diagnostic accuracy of VPI for NSCLC. Furthermore, incorporating AI into the diagnostic workflow is advocated because of its potential to improve the accuracy of preoperative diagnosis and patient outcomes in NSCLC.

[Impact of the Size and Depth of Pulmonary Nodules on the Surgical Approach 
for Lung Resection in the Treatment of Early-stage Lung Cancer ≤2 cm].

BACKGROUND: Current studies suggest that for early-stage lung cancers with a component of ground-glass opacity measuring ≤2 cm, sublobar resection is suitable if it ensures adequate margins. However, lobectomy may be necessary for some cases to achieve this. The aim of this study was to explore the impact of size and depth on surgical techniques for wedge resection, segmentectomy, and lobectomy in early-stage lung cancer ≤2 cm, and to determine methods for ensuring a safe resection margin during sublobar resections. METHODS: Clinical data from 385 patients with early-stage lung cancer ≤2 cm, who underwent lung resection in 2022, were subject to a retrospective analysis, covering three types of procedures: wedge resection, segmentectomy and lobectomy. The depth indicator as the OA value, which is the shortest distance from the inner edge of a pulmonary nodule to the opening of the corresponding bronchus, and the AB value, which is the distance from the inner edge of the nodule to the pleura, were measured. For cases undergoing lobectomy and segmentectomy, three-dimensional computed tomography bronchography and angiography (3D-CTBA) was performed to statistically determine the number of subsegments required for segmentectomy. The cutting margin width for wedge resection and segmentectomy was recorded, as well as the specific subsegments and their quantities removed during lung segmentectomy were documented. RESULTS: In wedge resection, segmentectomy, and lobectomy, the sizes of pulmonary nodules were (1.08±0.29) cm, (1.31±0.34) cm and (1.50±0.35) cm, respectively, while the depth of the nodules (OA values) was 6.05 (5.26, 6.85) cm, 4.43 (3.27, 5.43) cm and 3.04 (1.80, 4.18) cm for each procedure, showing a progressive increasing trend (P<0.001). The median resection margin width obtained from segmentectomy was 2.50 (1.50, 3.00) cm, significantly greater than the 1.50 (1.15, 2.00) cm from wedge resection (P<0.001). In wedge resections, cases where AB value >2 cm demonstrated a higher proportion of cases with resection margins less than 2 cm compared to those with margins greater than 2 cm (29.03% vs 12.90%, P=0.019). When utilizing the size of the nodule as the criterion for resection margin, the instances with AB value >2 cm continued to show a higher proportion in the ratio of margin distance to tumor size less than 1 (37.50% vs 17.39%, P=0.009). The median number of subsegments for segmentectomy was three, whereas lobectomy cases requiring segmentectomy involved five subsegments (P<0.001). CONCLUSIONS: The selection of the surgical approach for lung resection is influenced by both the size and depth of pulmonary nodules. This study first confirms that larger portions of lung tissue must be removed for nodules that are deeper and larger to achieve a safe margin. A distance of ≤2 cm from the inner edge of the pulmonary nodule to the nearest pleura may be the ideal indication for performing wedge resection.

NUF2 Expression in Cancer Tissues and Lymph Nodes Suggests Post-Surgery Recurrence of Non-Small Cell Lung Cancer.

In non-small cell lung cancer (NSCLC) cases, detecting potential lymph node metastases is essential to determine the indications for sublobar resection or adjuvant therapy. NUF2 is a tumor-specific antigen that is highly expressed in lung cancer tissues. However, the significance of analyzing NUF2 expression in dissected lymph nodes has not yet been studied. Thus, we investigated the association between NUF2 expression in lung cancer tissues and dissected lymph nodes and early recurrence of NSCLC to determine its usefulness as a marker of lymph node micrometastasis. This retrospective study quantified NUF2 expression in the cancer tissues of 88 patients with NSCLC who underwent complete resection using real-time polymerase chain reaction and investigated its relationship with clinicopathological features and prognosis. We also quantified NUF2 RNA expression in mediastinal lymph nodes from 255 patients with pN0 NSCLC who underwent complete resection with lymph node dissection and analyzed its association with prognosis. NUF2 expression in primary tumors was correlated with lymph node metastasis and unfavorable outcomes in terms of poor recurrence-free and cancer-specific survival. In N0 NSCLC cases, high NUF2 expression in mediastinal lymph nodes indicated poor prognosis, especially in lymph node recurrence. NUF2 emerges as a promising marker for predicting lymph node metastatic recurrence, offering potential utility in guiding post-surgical adjuvant therapy for lung cancer or assisting in intraoperative decisions for sublobar resection.

Sublobar resection or lobectomy and postoperative respiratory complications in emphysematous lungs.

OBJECTIVES: Pulmonary resection in patients with severe emphysema may impact postoperative respiratory complications. Low-attenuation areas evaluated using three-dimensional computed tomography to assess emphysematous changes are strongly associated with postoperative respiratory complications. Herein, we investigated the relationship between low-attenuation area, the surgical procedure and resected lung volume, which has not been explored in previous studies. METHODS: We retrospectively evaluated patients with primary or metastatic lung cancer who underwent surgical resection. The low-attenuation area percentage (low-attenuation area/total lung area × 100) and resected lung volume were calculated using three-dimensional computed tomography software, and the relationship with postoperative respiratory complications was analysed. RESULTS: Postoperative respiratory complications occurred in 66 patients (17%) in the total cohort (n = 383). We set the median value of 1.1% as the cut-off value for low-attenuation area percentage to predict postoperative respiratory complications, which occurred in 24% and 10% of patients with low-attenuation area >1.1% and <1.1%, respectively (P < 0.001). Postoperative respiratory complications occurred in approximately one-third of the patients with low-attenuation area >1.1%, whose resected lung volume was ≥15.8% or ≥5 resected subsegments. Multivariable analysis revealed that sublobar resection was associated with a significantly lower risk of postoperative respiratory complications in patients with low-attenuation area >1.1% (odds ratio 0.4, 95% confidence interval 0.183-0.875). CONCLUSIONS: Emphysema is a risk factor for postoperative respiratory complications, and lobectomy is an independent predictive risk factor. Preserving more lung parenchyma may yield better short-term prognoses in patients with emphysematous lungs.

Optimal therapeutic strategy for non-small cell lung cancer with thoracic extrathoracic metastasis: a study based on SEER database.

Background: Non-small cell lung cancer (NSCLC) patients with extrathoracic metastasis (EM) are a highly heterogeneous cohort. Some of these patients could benefit from primary tumor surgery. This study aimed to identify potential NSCLC patients with EM suitable for primary tumor resection and to determine the optimal therapeutic strategy. Methods: NSCLC patients with EM were extracted from the Surveillance, Epidemiology and End Results database between 2010 and 2015. They were stratified into subgroups with single and multi-EMs. Cox regression analysis was adopted to identify prognostic factors for overall survival (OS). The Kaplan-Meier method was used to compare the OS among patients who received different treatment modalities. Results: The univariate Cox regression analysis demonstrated that advanced age, male sex, race (black), married status, squamous cell carcinoma, higher histological grade, advanced T or N stage, contralateral lung metastasis, multi-EMs, tumor size >2 cm, and lack of treatment were associated with poorer OS in patients with NSCLC (P<0.05). Multivariate Cox regression analysis revealed that the number of EM and treatment modalities were independent prognostic factors affecting OS (P<0.001). For patients with single EM, those who did not receive treatment and those who underwent single-agent chemotherapy, single-agent surgery, surgery combined with chemotherapy, surgery combined with radiotherapy, or surgery combined with chemoradiotherapy had median OS times of 3.0, 11.0, 12.0, 26.0, 11.0, and 25.0 months, respectively. Compared to monotherapy, combination therapy showed significant benefits for patients with single EM in NSCLC. Furthermore, patients with single EM who underwent lobectomy, bilobectomy, or pneumonectomy had significantly longer survival than those who underwent sublobar resection, even when the primary tumor size was ≤2 cm (P=0.04). Conclusions: Primary tumor surgery could benefit NSCLC patients with single EM; lobectomy was at least warranted to improve survival even for primary tumors with size ≤2 cm.

Saving Lives in Thoracic Surgery: Balancing Oncological Radicality and Functional Preservation, Transitioning from Standard Pneumonectomy to Targeted Sublobar Resection.

This review chronicles the evolution of thoracic surgical interventions, from the standardized pneumonectomy to the precise approach of sublobar resections. It discusses the emergence and acceptance of minimally invasive and robot-assisted surgical techniques, highlighting their impact on improving outcomes beyond cancer and their influence on the surgical management of early-stage lung cancer. Evaluating historical developments alongside present methodologies, this review underscores the critical need for meticulous surgical planning and execution to optimize both oncological radicality and functional preservation. This evolution portrayed not only technical advancements but also a shift in the clinical approach towards tailored, organ-preserving methodologies, culminating in a contemporary framework promoting sublobar resections as the standard for specific patient profiles, signifying a new era of precision in thoracic surgery.

Precision Oncology in Lung Cancer Surgery.

Precision in lung cancer surgery is our ability to use the most cutting edge and up to date information to provide personalized and targeted surgical care to our patients. It aims to tailor patient care to patient and tumor characteristics and susceptibilities as well as to optimize the ways treatments are administered. This may include specific perioperative medical treatment, changing operative techniques to more minimally invasive ones if the situation permits, performing sub-anatomical surgeries when possible, and using innovative tumor visualization methods to enhance detection of previously occult disease to ultimately decrease the extent of the planned resection.