Predictive accuracy of lepidic growth subtypes in early-stage adenocarcinoma of the lung by quantitative CT histogram and FDG-PET

OBJECTIVES

The aim of this study was to analyze the accuracy of computed tomography (CT) and F-18 fluorodeoxyglucose-positron emission tomography/CT (FDG-PET/CT) to distinguish lepidic growth adenocarcinoma (LGA), including adenocarcinoma in situ (AIS), minimally invasive adenocarcinoma (MIA), and lepidic-predominant adenocarcinoma, all of which have favorable survival outcomes, from the more aggressive and invasive non-LGA subtypes.

MATERIALS AND METHODS

We identified 225 patients with c-0/I adenocarcinoma of the lung who underwent PET/CT and 3DCT followed by complete resection. Maximum standardized uptake values (SUVmax) of FDG and several histogram parameters were analyzed. Histological grades were classified according to the predominant subtype (G1: lepidic; G3: micropapillary or solid; and G2: subtypes other than G1/G3).

RESULTS

The proportion of pathological invasive factors (lymphatic vessel involvement/blood vessel invasion/pleural invasion/lymph node metastasis) of patients with preinvasive adenocarcinoma, G1, G2, and G3 tumors were 0%, 3.6%, 48.0%, and 100%, respectively; p <  0.001). Multivariate analysis with CT-related parameters demonstrated that 75^th percentile CT attenuation value (75^th%, p <  0.001) and maximum CT attenuation value (maxCT, p =  0.009) were associated with incidence of non-LGA, whereas the value of SUVmax demonstrated a significant correlation (p <  0.001). When all patients were dichotomized according to ground-glass opacities (GGO)/solid-dominancy for CT maximum diameter, a significant correlation with non-LGA was shown in patients with solid-dominant tumor on SUVmax (p <  0.001) and with GGO-dominant tumor on 75^th% (p =  0.006) and maxCT (p =  0.007). The combination of one of the two significant histogram parameters and SUVmax revealed higher predictive performance for pathological high malignant features (positive pathological invasive factors, non-LGA, and the highly malignant subtype covering G2 with moderately or poorly-differentiated carcinoma and G3) than the individual use of either factor.

CONCLUSION

The 75^th%, maxCT, and SUVmax were highly useful in distinguishing LGA from non-LGA in c-0/I adenocarcinoma.

Transition Rate from EGFR-TKI to Cytotoxic Chemotherapy Patients with EGFR Mutation-positive Lung Adenocarcinoma

BACKGROUND/AIM

The transition rate from first-line epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) to cytotoxic chemotherapy (Ct) is poor. The prognosis according to treatment sequence and the reasons patients could not shift from first-line EGFR-TKIs to Ct were herein analyzed.

PATIENTS AND METHODS

Overall, 159 epidermal growth factor receptor mutation-positive adenocarcinoma patients were enrolled in this study.

RESULTS

The median survival times of EGFR-TKIs combined with Ct and EGFR-TKIs were 59.8 months and 22.5 months, respectively (p<0.001) and of patients who received EGFR-TKIs first and Ct first were 38.8 months and 66.4 months, respectively (p=0.016). The main reasons patients could not make the transition to Ct was worsening of performance status and patient's preference.

CONCLUSION

EGFR-TKIs and Ct lead to a good prognosis in EGFR mutation-positive adenocarcinoma patients. It is necessary to consider the timing when changing the treatment strategy before treatment options are limited.

Cost-Benefit Performance Simulation of Robot-Assisted Thoracic Surgery As Required for Financial Viability under the 2016 Revised Reimbursement Paradigm of the Japanese National Health Insurance System

PURPOSE

To discuss the cost-benefit performance (CBP) and establish a medical fee system for robotic-assisted thoracic surgery (RATS) under the Japanese National Health Insurance System (JNHIS), which is a system not yet firmly established.

METHODS

All management steps for RATS are identical, such as preoperative and postoperative management. This study examines the CBP based on medical fees of RATS under the JNHIS introduced in 2016.

RESULTS

Robotic-assisted laparoscopic prostatectomy (RALP) and robotic-assisted partial nephrectomy (RAPN) now receive insurance reimbursement under the category of use of support devices for endoscopic surgery ($5420 and $3485, respectively). If the same standard amount were to be applied to RATS, institutions would need to perform at least 150 or 300 procedures thoracic operation per year to show a positive CBP ($317 per procedure as same of RALP and $130 per procedure as same of RAPN, respectively).

CONCLUSION

Robotic surgery in some areas receives insurance reimbursement for its "supportive" use for endoscopic surgery as for RALP and RAPN. However, at present, it is necessary to perform da Vinci Surgical System Si (dVSi) surgery at least 150-300 times in a year in a given institution to prevent a deficit in income.

Prognostic factors for surgically resected non-small cell lung cancer with cavity formation

Background

Small pulmonary nodules have been detected frequently by computed tomography (CT). Lung cancers with cavity formation are also easily detected. There are a few reports focused on the cavity wall, although cancer cells exist along the cavity wall, not inside. We evaluated the impact of cavity wall thickness on prognosis and assessed the clinicopathological features in non-small cell lung cancer (NSCLC) with cavity formation.

Methods

Between 2005 and 2011, 1,313 patients underwent complete resection for NSCLC. Of these cases, we reviewed 65 patients (5.0%) diagnosed with NSCLC with cavity formation by chest CT. We classified the patients into three groups based on the maximum cavity wall thickness, namely, ≤4 mm (Group 1, 8 patients), >4 and ≤15 mm (Group 2, 33 patients), and >15 mm (Group 3, 24 patients).

Results

The number of patients with pathological whole tumor size >3 cm was 2 (25%) in Group 1, 17 (52%) in Group 2, and 23 (96%) in Group 3 (P<0.001). Cases with lymph node metastasis were 0 (0%) in Group 1, 5 (15%) in Group 2, and 10 (42%) in Group 3 (P=0.016). The 5-year overall survival (OS) rates were 100% in Group 1, 84.0% in Group 2, and 52.0% in Group 3, with significant differences between Group 1 and Group 3 (P=0.044) and between Group 2 and Group 3 (P=0.034). In univariate analysis, neither whole tumor size nor lymph node metastasis was a prognostic factor for OS (P=0.51, P=0.27). Only cavity wall thickness was a significant prognostic factor by multivariate analysis (P=0.009).

Conclusions

Maximum cavity wall thickness was an important prognostic factor in NSCLCs with cavity formation, comparable with other established prognostic factors.

Clinical applications of virtual navigation bronchial intervention

Background

In patients with bronchial tumors, we frequently consider endoscopic treatment as the first treatment of choice. All computed tomography (CT) must satisfy several conditions necessary to analyze images by Synapse Vincent. To select safer and more precise approaches for patients with bronchial tumors, we determined the indications and efficacy of virtual navigation intervention for the treatment of bronchial tumors.

Methods

We examined the efficacy of virtual navigation bronchial intervention for the treatment of bronchial tumors located at a variety of sites in the tracheobronchial tree using a high-speed 3-dimensional (3D) image analysis system, Synapse Vincent. Constructed images can be utilized to decide on the simulation and interventional strategy as well as for navigation during interventional manipulation in two cases.

Results

Synapse Vincent was used to determine the optimal planning of virtual navigation bronchial intervention. Moreover, this system can detect tumor location and alsodepict surrounding tissues, quickly, accurately, and safely. The feasibility and safety of Synapse Vincent in performing useful preoperative simulation and navigation of surgical procedures can lead to safer, more precise, and less invasion for the patient, and makes it easy to construct an image, depending on the purpose, in 5-10 minutes using Synapse Vincent. Moreover, if the lesion is in the parenchyma or sub-bronchial lumen, it helps to perform simulation with virtual skeletal subtraction to estimate potential lesion movement. By using virtual navigation system for simulation, bronchial intervention was performed with no complications safely and precisely.

Conclusions

Preoperative simulation using virtual navigation bronchial intervention reduces the surgeon's stress levels, particularly when highly skilled techniques are needed to operate on lesions. This task, including both preoperative simulation and intraoperative navigation, leads to greater safety and precision. These technological instruments are helpful for bronchial intervention procedures, and are also excellent devices for educational training.

Successful adjustment for self-expanding metallic stent migration using a flexible bronchoscope with two biopsy forceps technique

Although tracheobronchial stents are widely used for tracheal obstruction due to malignant or benign stenosis, stent migration has been reported as a major postoperative complication. A self-expandable metallic stent (SEMS) is more easily introduced compared with silicone stents. However, it is also difficult to remove or replace without complications. We report a new technique for successful SEMS adjustment using a flexible bronchoscope with two biopsy forceps.

Tumor volume determines the feasibility of cell-free DNA sequencing for mutation detection in non-small cell lung cancer

Next‐generation sequencing (NGS) and digital PCR technologies allow analysis of the mutational profile of circulating cell‐free DNA (cfDNA) in individuals with advanced lung cancer. We have now evaluated the feasibility of cfDNA sequencing for mutation detection in patients with non‐small cell lung cancer at earlier stages. A total of 150 matched tumor and serum samples were collected from non‐small cell lung cancer patients at stages IA–IIIA. Amplicon sequencing with DNA extracted from tumor tissue detected frequent mutations in EGFR (37% of patients), TP53 (39%), and KRAS (10%), consistent with previous findings. In contrast, NGS of cfDNA identified only EGFR,TP53, and PIK3CA mutations in three, five, and one patient, respectively, even though adequate amounts of cfDNA were extracted (median of 4936 copies/mL serum). Next‐generation sequencing showed a high accuracy (98.8%) compared with droplet digital PCR for cfDNA mutation detection, suggesting that the low frequency of mutations in cfDNA was not due to a low assay sensitivity. Whereas the yield of cfDNA did not differ among tumor stages, the cfDNA mutations were detected in seven patients at stages IIA–IIIA and at T2b or T3. Tumor volume was significantly higher in the cfDNA mutation‐positive patients than in the negative patients at stages T2b–T4 (159.1 ± 58.0 vs. 52.5 ± 9.9 cm³, P = 0.014). Our results thus suggest that tumor volume is a determinant of the feasibility of mutation detection with cfDNA as the analyte.

Correlation between whole tumor size and solid component size on high-resolution computed tomography in the prediction of the degree of pathologic malignancy and the prognostic outcome in primary lung adenocarcinoma

BACKGROUND

The presence of ground glass opacity (GGO) on high-resolution computed tomography (HRCT) is well known to be pathologically closely associated with adenocarcinoma in situ.

PURPOSE

To determine whether it is more useful to evaluate the whole tumor size or only the solid component size to predict the pathologic high-grade malignancy and the prognostic outcome in lung adenocarcinoma.

MATERIAL AND METHODS

Using HRCT data of 232 patients with adenocarcinoma who underwent curative resection, we retrospectively measured the whole tumor and solid component sizes with lung window setting (WTLW and SCLW) and whole tumor sizes with a mediastinal window setting (WTMW).

RESULTS

There was significant correlation between the WTLW and the measurements of pathological whole tumor (pWT) (r = 0.792, P < 0.0001). The SCLW and WTLW values significantly correlated with the area of pathological invasive component (pIVS) (r = 0.762, P < 0.0001 and r = 0.771, P < 0.0001, respectively). The receiver operating characteristics area under the curve for WTLW, SCLW, and WTMW used to identify lymph node metastasis or lymphatic or vascular invasion were 0.693, 0.817, and 0.824, respectively. Kaplan-Meier curves of disease-free survival (DFS) and overall survival (OS) were better divided according to SCLW and WTMW, compared with WTLW. Multivariate analysis of DFS and OS revealed that WTMW was an independent prognostic factor (HR = 0.72, 95% confidence interval [CI] = 0.58-0.90, P = 0.004 and HR = 0.74, 95% CI = 0.57-0.96, P = 0.022, respectively).

CONCLUSION

The predictive values of the solid tumor size visualized on HRCT especially in the mediastinal window for pathologic high-grade malignancy and prognosis in lung adenocarcinoma were greater than those of whole tumor size.

Association between high-resolution computed tomography findings and the IASLC/ATS/ERS classification of small lung adenocarcinomas in Japanese patients

OBJECTIVES

The detection rate of small pulmonary nodules has recently increased and new techniques have been developed to improve diagnostic yield. The IASLC/ATS/ERS classification demonstrated a difference in prognosis depending on the histological subtypes of lung adenocarcinoma. We evaluated the association between high-resolution computed tomography (HRCT) findings and the classification of these tumors.

METHODS

We reviewed the data of 220 lung adenocarcinoma (≤3 cm) patients who received complete resection with lymph node dissection in our hospital. From the HRCT findings, the tumors were classified into the following 3 categories: pure-solid nodules, part-solid nodules, or pure ground-glass opacity (GGO) nodules. Pathological invasion factor (PIF) was evaluated by the degree of blood vessel invasion, lymphatic permeation, and visceral pleural invasion.

RESULTS

The tumors were classified as pure GGO nodules in 16 patients, part-solid nodules in 91, and pure-solid nodules in 113 from the HRCT findings. Tumors were diagnosed as noninvasive or minimally invasive adenocarcinomas (NMIADs) in 44 patients, and invasive adenocarcinomas (IADs) in 176. Lymph node metastasis was present in 31 patients (14.1%) and PIF in 101 (45.9%). All pure-solid nodules were IADs with a high PIF frequency (75.2%) or with lymph node metastasis (26.5%). All pure GGO nodules were NMIADs or lepidic-predominant adenocarcinomas. Among the part-solid nodules, IAD was detected in 67.0% of the patients and PIF in 16.5%. The consolidation/tumor (C/T) ratio and consolidation size were associated with IAD (optimal cut-off values: 0.4 and 8mm, respectively) and PIF (0.8 and 15 mm, respectively).

CONCLUSIONS

The HRCT findings correlated with the IASLC/ATS/ERS classification and were useful for evaluating the histological nature of the tumors. Most pure-solid tumors had the potential for high-grade malignancy, including PIF and lymph node metastasis. For part-solid tumors, the C/T ratio and consolidation size were important for predicting PIF and for diagnosing IAD according to this classification.