Pathologic N0 status in pulmonary adenocarcinoma is predictable by combining serum carcinoembryonic antigen level and computed tomographic findings

Ten-year follow-up outcomes of limited resection trial for radiologically less-invasive lung cancer

BACKGROUND

The JCOG0804/WJOG4507L single-arm confirmatory trial indicated a satisfactory 10-year prognosis for patients who underwent limited resection for radiologically less-invasive lung cancer. However, only one prospective trial has reported a 10-year prognosis.

METHODS

We conducted a multicenter prospective study coordinated by the National Cancer Center Hospital East and Kanagawa Cancer Center. We analyzed the long-term prognosis of 100 patients who underwent limited resection of a radiologically less-invasive lung cancer in the peripheral lung field. We defined radiologically less-invasive lung cancer as lung adenocarcinoma with a maximum tumor diameter of ≤2 cm, tumor disappearance ratio of ≥0.5 and cN0. The primary endpoint was the 10-year local recurrence-free survival.

RESULTS

Our patients, with a median age of 62 years, included 39 males. A total of 58 patients were non-smokers; 87 had undergone wide wedge resection and 9 underwent segmentectomy. A total of four cases were converted to lobectomy because of the presence of poorly differentiated components in the frozen specimen or insufficient margin with segmentectomy. The median follow-up duration was 120.9 months. The 10-year recurrence-free survival and overall survival rates of patients with lung cancer were both 96.0%. Following the 10-year long-term follow-up, two patients experienced recurrences at resection ends after wedge resection.

CONCLUSIONS

Limited resection imparted a satisfactory prognosis for patients with radiologically less-invasive lung cancer, except two cases of local recurrence >5 years after surgery. These findings suggest that patients with this condition who underwent limited resection may require continued follow-up >5 years after surgery.

A problem with clinical T factor in the 8th TNM edition: Prognosis and EGFR mutation status of small sized lung cancers with difficulty to measure the diameter of solid component in part-solid tumor

OBJECTIVE

Clinical T factors in the 8th TNM classification of lung cancer have a practical problem. In some cases, it is difficult to measure the size of the solid components in part-solid tumors, and the classification of these tumors is controversial.

METHODS

We evaluated 590 resected cT1N0M0 stage IA non-small-cell lung cancers based on the 7th edition between 2009 and 2012. Tumor and solid component diameters were measured using thin-section computed tomography (CT). We defined tumors with difficulty in measuring the size of the solid components as lung cancers with scattered or mixed consolidation (LCSMCs). LCSMCs were observed in 79 (13.4%) patients. Other tumors were classified as cTis, cT1mi, cT1a, cT1b, and cT1c, according to the 8th edition. We compared prognosis and epidermal growth factor receptor mutations (EGFRm) status of LCSMCs with those of cT1a, cT1b, and cT1c.

RESULTS

The difference in overall survival (OS) among cT1a, cT1b, and cT1c was significant (5-year-OS: 96.9% vs. 76.8% vs. 65.0%). There was no significant difference in prognosis between LCSCs and cT1a (5-year-OS: 92.4% vs. 96.9%). A significant difference was observed in the frequency of EGFRm between cT1a, cT1b, and cT1c (52.4%, 42.4%, and 29.8%). The incidence of EGFRm in LCSMCs was 54.8% and there was no significant difference between LCSMCs and cT1a.

CONCLUSIONS

The prognosis and frequency of EGFRm in LCSMCs were close to those in cT1a. As we cannot measure the diameter of the solid component in subsolid lung cancers, it may be appropriate to classify these tumors as cT1a tumors.

Combined procedure with radial probe and convex probe endobronchial ultrasound

Background

Concurrent bronchoscopy using radial probe and convex endobronchial ultrasound (RP‐ and CP‐EBUS) is used to simultaneously evaluate both peripheral lung lesions for the histological diagnosis of the primary tumor and mediastinal lymph nodes for mediastinal staging. So far, little is known about the combined procedure with RP‐ and CP‐EBUS.

Methods

Between January 2020 and March 2021, the bronchoscopy database was reviewed to identify the clinical outcomes of the combined procedure with RP‐ and CP‐EBUS. Patients who underwent transbronchial biopsy using RP‐EBUS alone were classified as the RP‐EBUS group, while those who underwent a combined procedure with RP‐ and CP‐EBUS were classified as the combination group.

Results

The overall diagnostic yield of the bronchoscopic procedure in the combination group was significantly higher than the RP‐EBUS group (90.7% vs. 70.0%, p < 0.001). CP‐EBUS increased the diagnostic yield of the bronchoscopic procedure in the combination group by 9.3%. Although the mean procedure time was significantly longer, and the mean doses of midazolam and fentanyl were significantly higher in the combination group (p < 0.001), there were no differences in the overall complication rates between the two study groups (1.4% and 1.0% for the RP‐EBUS and combination groups, respectively, p = 0.766).

Conclusions

Combined bronchoscopy using RP‐ and CP‐EBUS is feasible and safe. In addition to mediastinal staging, CP‐EBUS increased the overall diagnostic yield of the bronchoscopic procedure by 9.3%.

Precise characterization of a solitary pulmonary nodule using tumor shadow disappearance rate-corrected F-18 FDG PET and enhanced CT

We aimed to characterize solitary pulmonary nodule (SPN) using imaging parameters for F-18 fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) or enhanced CT corrected by tumor shadow disappearance rate (TDR) to reflect the tissue density.We enrolled 51 patients with an SPN who underwent PET/CT and chest CT with enhancement. The FDG uptake of SPN was evaluated using maximum standardized uptake value (SUVmax) on PET/CT. The mean Hounsfield unit (HU) for each SPN was evaluated over the region of interest on nonenhanced and enhanced CT images. The change in mean HU (HUpeak-pre) was quantified by subtracting the mean HU of the preenhanced CT from that of the post-enhanced CT. TDR was defined as the ratio of the tumor area, which disappears at a mediastinal window, to the tumor area of the lung window. We investigated which parameters (SUVmax or HUpeak-pre) could contribute to the characterization of SPN classified by TDR value and whether diagnostic performance could be improved using TDR-corrected imaging parameters.For SPN with higher tissue density (TDR <42%, n = 22), high value of SUVmax (≥3.1) was a significant factor to predict malignancy (P = .006). High value of HUpeak-pre (≥38) was a significant factor to characterize SPN (P = .002) with lower tissue density (TDR ≥42%, n = 29). The combined approach using TDR-corrected parameters had better predictive performance to characterize SPN than SUVmax only (P = .031).Applying imaging parameters such as SUVmax or HUpeak-pre in consideration of tissue density calculated with TDR could contribute to accurate characterization of SPN.

Unexpected exposure to Mycobacterium tuberculosis during bronchoscopy using radial probe endobronchial ultrasound

BACKGROUND

Bronchoscopy using radial probe endobronchial ultrasound (EBUS) is performed when a peripheral lung lesion (PLL) is suspected to be malignant. However, pulmonary tuberculosis is diagnosed in some patients, and healthcare workers could therefore be exposed to tuberculosis if sufficient precautions are not taken. In this study, we examined the proportion of and factors associated with unexpected exposure to Mycobacterium tuberculosis during bronchoscopy using radial probe EBUS.

METHODS

This retrospective study included 970 patients who received bronchoscopy using radial probe EBUS between December 2015 and November 2018. Clinical, histological, radiological, and microbiological data were reviewed.

RESULTS

Pulmonary tuberculosis was diagnosed in 31 patients (3.2%) during bronchoscopy using radial probe EBUS. Patients with a lower age were significantly more likely to be diagnosed with tuberculosis than elderly patients (odds ratio [OR], 0.951; 95% confidence interval [CI], 0.924-0.978; P = 0.001). Among the various CT findings, a low HUs difference between pre- and post-enhanced CT (OR, 0.976; 95% CI, 0.955-0.996; P = 0.022), the presence of concentric cavitation (OR, 5.211; 95% CI, 1.447-18.759; P = 0.012), and the presence of satellite centrilobular nodules (OR, 22.925; 95% CI, 10.556-49.785; P < 0.001) were independently associated with diagnosis of tuberculosis.

CONCLUSIONS

The proportion of unexpected exposure to Mycobacterium tuberculosis during bronchoscopy using radial probe EBUS was 3.2%. A higher risk was independently associated with a younger age and CT findings of a small difference in HUs between pre- and post-enhancement images, concentric cavitation, and the presence of a satellite centrilobular nodule.

A single-arm study of sublobar resection for ground-glass opacity dominant peripheral lung cancer

BACKGROUND

The optimal mode of surgery for ground-glass opacity dominant peripheral lung cancer defined with thoracic thin-section computed tomography remains unknown.

METHODS

We conducted a single-arm confirmatory trial to evaluate the efficacy and safety of sublobar resection for ground-glass opacity dominant peripheral lung cancer. Lung cancer with maximum tumor diameter 2.0 cm or less and with consolidation tumor ratio 0.25 or less based on thin-section computed tomography were registered. The primary end point was 5-year relapse-free survival. The planned sample size was 330 with the expected 5-year relapse-free survival of 98%, threshold of 95%, 1-sided α of 5%, and power of 90%. The trial is registered with University Hospital Medical Information Network Clinical Trials Registry, number University Hospital Medical Information Network 000002008.

RESULTS

Between May 2009 and April 2011, 333 patients were enrolled from 51 institutions. Median age was 62 years (interquartile range, 56-68), and 109 were smokers. Median maximum tumor diameter was 1.20 cm (1.00-1.54). Median maximum tumor diameter of consolidation was 0 (0.00-0.20). The primary end point, 5-year relapse-free survival, was estimated on 314 patients who underwent sublobar resection. Operative modes were 258 wide wedge resections and 56 segmentectomies. Median pathological surgical margin was 15 mm (0-55). The 5-year relapse-free survival was 99.7% (90% confidence interval, 98.3-99.9), which met the primary end point. There was no local relapse. Grade 3 or higher postoperative complications based on Common Terminology Criteria for Adverse Effect v3.0 were observed in 17 patients (5.4%), without any grade 4 or 5.

CONCLUSIONS

Sublobar resection with enough surgical margin offered sufficient local control and relapse-free survival for lung cancer clinically resectable N0 staged by computed tomography with 3 or fewer peripheral lesions 2.0 cm or less amenable to sublobar resection and with a consolidation tumor ratio of 0.25 or less.

Approach to the Subsolid Nodule

Most focal persistent ground glass nodules (GGNs) do not progress over 10 years. Research suggests that GGNs that do not progress, those that do, and solid lung cancers are fundamentally different diseases, although histologically they seem similar. Surveillance of GGNs to identify those that gradually progress is safe and does not risk losing a window. GGNs with 5 mm solid component or less than 10 mm consolidation (mediastinal and lung windows, respectively, on thin slice CT) are highly curable with resection. The optimal type of resection is unclear; sublobar resection is reasonable but an adequate margin is critically important.

CT features associated with EGFR mutations and ALK positivity in patients with multiple primary lung adenocarcinomas

Background

In multiple primary lung adenocarcinomas (MPLAs), the relationship between imaging and gene mutations remains unclear. This retrospective study aimed to identify the correlation of epidermal growth factor receptor (EGFR) mutations and anaplastic lymphoma kinase (ALK) status with CT characteristics in MPLA patients.

Methods

Sixty-seven patients (135 lesions) with MPLAs confirmed by pathology were selected from our institution. All subjects were tested for EGFR mutations and ALK status and underwent chest CT prior to any treatment. The criteria for MPLA definitions closely adhered to the comprehensive histologic assessment (CHA).

Results

Among MPLA patients, EGFR mutations were more common in females (p = 0.002), in those who had never smoked (p = 0.010), and in those with less lymph node metastasis (p < 0.001), and the tumours typically presented with ground-glass opacity (GGO) (p = 0.003), especially mixed GGO (p < 0.001), and with air bronchograms (p = 0.012). Logistics regression analysis showed that GGO (OR = 6.550, p = 0.010) was correlated with EGFR mutation, while air bronchograms were not correlated with EGFR mutation (OR = 3.527, p = 0.060). A receiver operating characteristic (ROC) curve yielded area under the curve (AUC) values of 0.647 and 0.712 for clinical-only or combined CT features, respectively, for prediction of EGFR mutations, and a significant difference was found between them (p = 0.0344). ALK-positive status was found most frequently in MPLA patients who were younger (p = 0.002) and had never smoked (p = 0.010). ALK positivity was associated with solid nodules or masses in MPLAs (p < 0.004) on CT scans. Logistics regression analysis showed that solid nodules (OR = 6.550, p = 0.010) were an independent factor predicting ALK positivity in MPLAs. For prediction of ALK positivity, the ROC curve yielded AUC values of 0.767 and 0.804 for clinical-only or combined CT features, respectively, but no significant difference was found between them (p = 0.2267).

Conclusion

Among MPLA patients, nonsmoking women with less lymph node metastasis and patients with lesions presenting GGO or mixed GGO and air bronchograms on CT were more likely to exhibit EGFR mutations. In nonsmoking patients, young patients with solid lesions on CT are recommended to undergo an ALK status test.

Quantitative volumetric assessment of the solid portion percentage on CT images to predict ROS1/ALK rearrangements in lung adenocarcinomas

In the present study, the predictive role of the percentage of the solid portion volume (PSV) in patients with lung adenocarcinoma was investigated. The PSV was obtained through quantitative volumetric assessments based on reconstructed CT images of lung adenocarcinoma by comparing the index among tumors with c-ros oncogene 1 (ROS1) rearrangement, epidermal growth factor receptor (EGFR) mutations, echinoderm anaplastic lymphoma kinase (ALK) rearrangements or wild-type (WT) status for the three genes. Among 1,120 patients with lung adenocarcinoma, 28 patients with ROS1 rearrangement lung adenocarcinoma, 71 with ALK rearrangement and 578 with EGFR mutations were diagnosed. PSV was quantitatively measured by semi-automated nodule assessment software and compared in patients with different mutation statuses. The PSV (presented as the median with interquartile range) in the ROS1 rearrangement group [87.9 (82.7-92.3)%] was higher than that in the EGFR mutation group [70.4 (51.4-83.4%)] and the WT group [63.0 (50.9-83.2)%; P<0.001], but was similar to that in the ALK rearrangement group [84.0 (70.3-90.0)%; P=0.251]. The area under the receiver operating characteristic curve (AUC) for the PSV to predict ROS1 or ALK rearrangement combined was 0.702 (95% CI: 0.631-0.773; P<0.001); at a cut-off value of 0.805 (when the Youden index was maximal), the predictive sensitivity was 0.697 and the specificity was 0.702. Younger age and higher PSV values were independent predictors of ROS1/ALK rearrangements. The AUC for the predictive model combined with age and PSV was 0.785. In conclusion, the PSV in the lung adenocarcinomas with ROS1 rearrangement was significantly higher compared with that in the EGFR-mutated and WT lung adenocarcinoma, but was similar to that in lung adenocarcinoma with ALK rearrangement. Younger age and higher PSV values on CT in patients with lung adenocarcinomas were predictive factors for ROS1/ALK rearrangement.

Preoperative predictors of lymph node metastasis in clinical T1 adenocarcinoma

Background

The subcategory “solid component of tumor” is a new criterion of tumor categories in the updated eighth edition of the TNM classification. Nevertheless, the predictors of lymph node metastasis among patients with clinical T1 adenocarcinoma, based on the TNM classification 8^th edition, remain unclear. This study aimed to identify the preoperative predictors of lymph node metastasis in clinical T1 adenocarcinoma by comparing clinicopathological characteristics between the groups with and without lymph node metastasis.

Methods

We performed a retrospective observational single-center study at the Sendai Kousei Hospital. From January 2012 to September 2019, we included 515 patients who underwent curative lobectomy or segmentectomy and mediastinal lymph node dissection among those with clinical T1 adenocarcinoma according to the UICC-TNM staging 8^th edition. They were divided into two groups: those with lymph node metastasis (positive group) and those without (negative group). The clinicopathological factors were retrospectively analyzed and compared between the groups.

Results

In univariate analysis, carcinoembryonic antigen (>5.0 ng/mL) (P=0.0007), maximum standardized uptake (>3.5) (P<0.0001), clinical T factor (T1c) (P<0.0001), and consolidation tumor ratio (>0.85) (P<0.0001) were significant predictors of lymph node metastasis. Multivariate analysis revealed that maximum standardized uptake SUVmax (>3.5) (odds ratio =10.4, P<0.0001) was independently associated with lymph node metastasis. In univariate analysis, carcinoembryonic antigen (>5.0) (P=0.048) was the only predictor of lymph node metastasis among patients of cT1b, while no parameters were identified as significant predictors among patients of cT1c.

Conclusions

SUVmax and CEA are useful preoperative predictors of lymph node metastases in patients with clinical T1 adenocarcinoma, stratified to T1b and T1c, based on the 8^th TNM classification.

Preoperative biopsy and tumor recurrence of stage I adenocarcinoma of the lung

PURPOSE

To evaluate whether preoperative biopsy affects the outcomes of patients undergoing at least lobectomy for stage I lung adenocarcinoma.

METHODS

We reviewed the medical records of patients who underwent surgery for stage I lung adenocarcinoma between 2006 and 2013. Tumor recurrence and survival were compared between patients who underwent preoperative biopsy, including computed tomographic-guided needle biopsy and transbronchial biopsy, and those who underwent intraoperative frozen section.

RESULTS

Among 509 patients, 229 patients (44.9%) underwent preoperative biopsy and 280 patients had lung adenocarcinoma diagnosed by intraoperative frozen section (reference group). Recurrence developed in 65 (12.8%) patients within a median follow-up period of 54.4 months. Multivariate analysis demonstrated that preoperative biopsy (OR 1.97, p = 0.045), radiological solid appearance (OR 5.43, p < 0.001), and angiolymphatic invasion (OR 2.48, p = 0.010) were independent predictors of recurrence. In the overall cohort, preoperative biopsy appeared to worsen 5-year disease-free and overall survival significantly (76.6% vs. 93.0%, p < 0.001; and 83.8% vs. 94.5%, p = 0.002, respectively) compared with the reference group. After propensity matching, multivariable logistic regression still identified preoperative biopsy as an independent predictor of overall recurrence (OR 2.21, p = 0.048) after adjusting for tumor characteristics.

CONCLUSION

Preoperative biopsy might be considered a prognosticator of recurrence of stage I adenocarcinoma of the lungs in patients who undergo at least anatomic lobectomy without postoperative adjuvant chemotherapy.

Clinical outcomes of radial probe endobronchial ultrasound using a guide sheath for diagnosis of peripheral lung lesions in patients with pulmonary emphysema

BACKGROUND

Generally, structural destruction of lung parenchyma, such as pulmonary emphysema, is considered to be related to the low diagnostic yields and high complication rates of lung biopsies of peripheral lung lesions. Currently, little is known about the clinical outcomes of using endobronchial ultrasound with a guide sheath (EBUS-GS) to diagnose peripheral lesions in patients with emphysema.

METHODS

This retrospective study was performed to identify the clinical outcomes of EBUS-GS in patients with pulmonary emphysema. This study included 393 consecutive patients who received EBUS-GS between February 2017 and April 2018. The patients were classified according to the severity of their emphysema, and factors possibly contributing to a successful EBUS-GS procedure were evaluated.

RESULTS

The overall diagnostic yield of EBUS-GS in patients with no or mild emphysema was significantly higher than in those with moderate or severe pulmonary emphysema (78% vs. 61%, P = 0.007). There were no procedure-related complications. The presence of a bronchus sign on CT (P <  0.001) and a "within the lesion" status on EBUS (P = 0.009) were independently associated with a successful EBUS-GS procedure. Although the diagnostic yield of EBUS-GS in patients with moderate-to-severe emphysema was relatively low, a bronchus sign and "within the lesion" status on EBUS were contributing factors for a successful EBUS-GS.

CONCLUSIONS

EBUS-GS is a safe procedure with an acceptable diagnostic yield, even when performed in patients with pulmonary emphysema. The presence of a bronchus sign and "within the lesion" status on EBUS were predictors of a successful procedure.

Surgical Outcomes of Radiographically Noninvasive Lung Adenocarcinoma according to Surgical Strategy: Wedge Resection, Segmentectomy, and Lobectomy

Background

The aim of this study was to evaluate the outcomes of surgical resection in patients with radiographically noninvasive lung adenocarcinoma according to the surgical strategy.

Methods

A retrospective study was conducted of 128 patients who underwent pulmonary resection for ground-glass opacity (GGO)–dominant nodules measuring ≤2 cm with a consolidation/tumor ratio ≤0.25 based on computed tomography between 2008 and 2015. The 5-year disease-free survival (DFS) rate and 5-year overall survival (OS) rate were analyzed.

Results

Among the 128 patients, wedge resection, segmentectomy, and lobectomy were performed in 40 (31.2%), 22 (17.2%), and 66 patients (51.6%), respectively. No significant differences were found among the groups in the mean size of tumors (p=0.119), the rate of pure-GGO nodules (p=0.814), the consolidation/tumor ratio (p=0.695), or the rate of invasive adenocarcinoma (p=0.378). Centrally located tumors were more common in the lobectomy group (21.2%) than in the wedge resection (0%) or segmentectomy (0%) groups (p=0.001). There were no significant differences in the 5-year DFS rate (100%, 100%, 92.7%, respectively; p=0.76) or 5-year OS rate (100%, 100%, 100%; p=0.223) among the wedge resection, segmentectomy, and lobectomy groups.

Conclusion

For radiographically noninvasive lung adenocarcinoma measuring ≤2 cm with a consolidation/tumor ratio ≤0.25, wedge resection and segmentectomy could be comparable surgical options to lobectomy.

EGFR-TKI-sensitive mutations in lung carcinomas: are they related to clinical features and CT findings?

Background

Epidermal growth factor receptor (EGFR) mutation testing is restricted to several limitations. In this study, we examined the relationship between EGFR mutation status and clinicoradiological characteristics in a Chinese cohort of patients.

Materials and methods

The data of patients who were diagnosed with lung carcinoma and underwent both EGFR testing and chest computed tomography (CT) at our hospital between January 1, 2011, and November 31, 2015, were retrospectively analyzed. The age, sex, and smoking index of the patients, the size, margin, and density of the tumor, and the presence of specific signs visible on the CT images were assessed.

Results

The results showed a higher rate of EGFR-tyrosine kinase inhibitor (TKI)-sensitive group than nonsensitive group in female patients and patients with a low smoking index (P<0.001, both). In logistic regression analyses, tumor size (P<0.001), smooth margins (P=0.015), and angular margins (P<0.001) were independent negative predictors of EGFR-TKI-sensitive group. Pleural indentation (P<0.001) and air bronchogram (P=0.025) were independent positive predictors of EGFR-TKI-sensitive group. Patients with squamous cell carcinoma had fewer sensitive mutations than those with either adenocarcinoma (P<0.001) or adenosquamous carcinoma (P<0.001).

Conclusion

Clinical and CT characteristics differed significantly between EGFR-TKI-sensitive and nonsensitive groups. Our findings may be useful in deciding therapeutic strategies for patients in whom EGFR testing is not possible.

Radial probe endobronchial ultrasound using a guide sheath for peripheral lung lesions in beginners

Background

The diagnostic yields and safety profiles of transbronchial lung biopsy have not been evaluated in inexperienced physicians using the combined modality of radial probe endobronchial ultrasound and a guide sheath (EBUS-GS). This study assessed the utility and safety of EBUS-GS during the learning phase by referring to a database of performed EBUS-GS procedures.

Methods

From December 2015 to January 2017, all of the consecutive patients who underwent EBUS-GS were registered. During the study period, two physicians with no previous experience performed the procedure. To assess the diagnostic yields, learning curve, and safety profile of EBUS-GS performed by these inexperienced physicians, the first 100 consecutive EBUS-GS procedures were included in the evaluation.

Results

The overall diagnostic yield of EBUS-GS performed by two physicans in 200 patients with a peripheral lung lesion was 73.0%. Learning curve analyses showed that the diagnostic yields were stable, even when the procedure was performed by beginners. Complications related to EBUS-GS occurred in three patients (1.5%): pneumothorax developed in two patients (1%) and resolved spontaneously without chest tube drainage; another patient (0.5%) developed a pulmonary infection after EBUS-GS. There were no cases of pneumothorax requiring chest tube drainage, severe hemorrhage, respiratory failure, premature termination of the procedure, or procedure-related mortality.

Conclusions

EBUS-GS is a safe and stable procedure with an acceptable diagnostic yield, even when performed by physicians with no previous experience.

Electronic supplementary material

The online version of this article (10.1186/s12890-018-0704-7) contains supplementary material, which is available to authorized users.

Prediction of pathological nodal involvement by CT-based Radiomic features of the primary tumor in patients with clinically node-negative peripheral lung adenocarcinomas

PURPOSE

The purpose of this study was to investigate the potential of computed tomography (CT) based radiomic features of primary tumors to predict pathological nodal involvement in clinically node-negative (N0) peripheral lung adenocarcinomas.

METHODS

A total of 187 patients with clinical N0 peripheral lung adenocarcinomas who underwent preoperative CT scan and subsequently received systematic lymph node dissection were retrospectively reviewed. 219 quantitative 3D radiomic features of primary lung tumor were extracted; meanwhile, nine radiological semantic features were evaluated. Univariate and multivariate logistic regression analysis were used to explore the role of these features in predicting pathological nodal involvement. The areas under the ROC curves (AUCs) were compared between multivariate logistic regression models.

RESULTS

A total of 153 patients had pathological N0 status and 34 had pathological lymph node metastasis. On univariate analysis, fissure attachment and 17 radiomic features were significantly associated with pathological nodal involvement. Multivariate analysis revealed that semantic features of pleural retraction (P = 0.048) and fissure attachment (P = 0.023) were significant predictors of pathological nodal involvement (AUC = 0.659); and the radiomic feature F185 (Histogram SD Layer 1) (P = 0.0001) was an independent prognostic factor of pathological nodal involvement (AUC = 0.73). A logistic regression model produced from combining radiomic feature and semantic feature showed the highest AUC of 0.758 (95% CI: 0.685-0.831), and the AUC value computed by fivefold cross-validation method was 0.737 (95% CI: 0.73-0.744).

CONCLUSIONS

Features derived on primary lung tumor described by semantic and radiomic could provide information of pathological nodal involvement in clinical N0 peripheral lung adenocarcinomas.

New simple radiological criteria proposed for multiple primary lung cancers

Background

Controversies remain as to the differential diagnosis between multiple primary lung cancer (MPLC) and intrapulmonary metastasis (IM) in lung cancers. We have investigated the clinical criteria for MPLC and here propose a set of new and simple criteria from the stand point of prognosis.

Methods

A retrospective study was conducted on 588 consecutive patients with resected lung cancer of clinical Stage IA between 2009 and 2012. Multiple lung cancers (MLCs) were observed in 103 (17.5%) of the 588 patients. All main and other tumors were divided into solid tumor (ST) and non-solid tumor (non-ST). We defined Group A as MLCs having at least one non-ST and Group B as all tumors being ST. Cox's proportional hazard model was used for the multivariate analyses to investigate the preoperative prognostic factors. We divided the MLCs into MPLC and IM based on the preoperative prognostic factors, and survival was estimated by the Kaplan-Meier method.

Results

A multivariate analysis with Cox's proportional hazards model revealed that Group A independently predicted good overall survival (HR = 0.165, 95% CI: 0.041-0.672).Differences in the 3- and 5-year overall survivals between Groups A and B were statistically significant (96.3%/92.2% vs. 70.0%/60.0%, Pvalue = 0.0002).

Conclusions

We suggest that Group A, defined as the presence of at least one tumor with a ground glass opacity component and clinical N0, should be excluded from the conventional concept of multiple lung cancers based on the criteria of Martini and Melamed as it has a very good prognosis. This group would be considered to be radiological MPLC.

CT-guided Hookwire localization before video-assisted thoracoscopic surgery for solitary ground-glass opacity dominant pulmonary nodules: radiologic-pathologic analysis

The optimal screening or treatment strategies of solitary pulmonary nodules especially ground-glass opacities (GGOs) remain controversial. With CT-guided Hookwire localization, it is accurate to find the small lesions during video-assisted thoracoscopic surgery (VATS). In this study, we evaluate the efficiency and safety of CT-guided Hookwire localization of GGO-dominant (GGO component > 50%) pulmonary nodules before VATS and investigate the correlation between the radiologic features and pathology. From April 2008 to April 2014, a total of 273 patients with solitary GGO-dominant pulmonary nodules were included. Tumor size was 12.4 ± 5.7 mm in diameter, including 208 pulmonary adenocarcinomas and 65 benign nodules. Dislodgement occurred in six patients (2.20%) during surgery. Postoperative complications included asymptomatic needle track hemorrhage (27.1%), minimal pneumothorax (5.9%) and hemoptysis (0.4%). In 208 (76.2%) pulmonary adenocarcinomas, 82 nodules showed ≥90% GGO and 126 showed 50%≤GGO<90%, while 84 nodules staged as T_1aN0M0, 96 staged as T_1bN₀M_0, and 28 staged as T_1cN₀M₀. The multivariable analysis demonstrated that 50%≤GGO<90% (HR=2.459, 95% CI: 1.246-4.853, P=0.010), speculation (HR=3.911, 95% CI: 1.966-7.663, P<0.001), lobulation (HR=4.582, 95% CI: 2.149-9.767, P<0.001) and vascular convergence (HR=4.096, 95% CI: 1.132-14.824, P=0.032) were the independent risk factors to identification of the malignant GGO-dominant pulmonary nodules. In conclusions,CT-guided Hookwire localizati for GGO-dominant pulmonary nodules before VATS is a safe and effective procedure for accurate diagnosis and resection of indeterminate solitary pulmonary nodules.

What is the radiological definition of part-solid tumour in lung cancer?†

OBJECTIVES

The method of evaluating ground glass opacity (GGO) on thin-section computed tomographic (CT) scans is an issue of debate in early lung cancer. The term 'part-solid tumour' is frequently misused, and there is no consensus for its definition.

METHODS

A retrospective study was conducted on 775 consecutive patients with resected lung adenocarcinoma of clinical stage IA between 2008 and 2013. Part-solid tumours (PSTs) having a ground glass component and consolidation were divided into two categories using the radiological criterion of a consolidation-to-tumour (C/T) ratio of 0.5. Lung cancers were classified into four groups: (i) pure ground glass nodule (pGGN) (C/T ratio = 0); (ii) ground glass-predominant PST (GP-PST) (0< C/T ratio < 0.5); (iii) consolidation-predominant PST (CP-PST) (0.5 ≤ C/T ratio < 1) and (iv) solid tumour (ST) (C/T ratio = 1). We investigated the clinicopathological features and prognoses of patients with GP-PST and CP-PST.

RESULTS

The incidence of lymphatic invasion was 0% in pGGN, 0.8% in GP-PST, 16.8% in CP-PST and 46.2% in ST ( P  < 0.001). Among the PST lung cancers, predictors for lymphatic invasion were C/T ratio (OR 20.631, 2.755-154.508, P  = 0.003) and tumour size (OR 3.228, 1.413-7.375, P  = 0.005) in a multivariable analysis. The difference in recurrence-free survival between GP-PST and CP-PST was statistically significant [98.9 vs. 91.3% (5 years), P -value = 0.044].

CONCLUSIONS

PST comprised two categories in terms of invasiveness and prognosis based on the radiological criteria of a C/T ratio of 0.5. Ground glass-predominant PST and consolidation-predominant PST should be distinguished, and strategies specific to each determined using these terminologies.

Risk factors of lymph node metastasis in lung squamous cell carcinoma of 3 cm or less in diameter

Through literature review we cannot find an efficient risk factor of lymph node metastasis in lung squamous cell carcinoma (SCC). This study aimed to investigate the risk factors of pathological lymph node status in patients with lung SCC of 3 cm or less in diameter, to provide some reference for the fellow surgeons in the decision of operative option.In total, we analyzed 154 patients with lung SCC of 3 cm or less in diameter who underwent lobectomy or bilobectomy or pneumonectomy with systematic lymph node dissection. The relationship between lymph node status and clinical characteristics were examined.Lymph node metastases were present in 48 patients (31.2%) of the study subjects. Multivariate analysis indicated that, age <60 years old (P = .007), tumor location of central-type (P = .003), tumor long axis >2 cm but ≤3 cm (P = .047) were associated with lymph node metastasis, and their odd ratios (OR) were 3.120, 3.359, and 5.196, respectively. Group analysis of the 74 peripheral lung SCC showed that those with the tumor long axis ≤2 cm had a lower rate of lymph node metastasis (7.9% vs 27.8%, P = .025).Age <60 years old, tumor location of central-type, and tumor long axis >2 cm but ≤3 cm are risk factors of lymph node metastasis in lung SCC. Systematic lymph node dissection or sampling is recommended when tumor central-type location and/or long axis >2 cm in lung SCC are present.

[Threshold Segmentation of Pulmonary Subsolid Nodules on CT Images: Detection and Quantification of the Solid Component]

BACKGROUND

The detection and quantification of solid components in pulmonary subsolid nodules (SSN) are of vital importance on differential diagnosis, pathological speculation and prognosis prediction. However, no objective and wide-accepted criterion has been built up to now. The purpose of this study is to explore the optimal threshold that can be used for the detection and quantification of solid components in SSNs by using threshold segmentation method on computed tomography (CT) images.

METHODS

CT images of 102 SSNs were retrospectively analyzed. To establish a reference standard, the observers made judgments on whether the solid component existed in every SSN and did manual measurements of the volume of solid component with the help of software. Threshold segmentations of every nodule were then performed using different threshold settings and all of the measured volumes were assumed to be solid volumes, then solid-to-total volume ratios were calculated. The results were compared with the reference standards using the receiver operating characteristic curve and Wilcoxon test.

RESULTS

The application of thresholds as -250 HU or -300 HU resulted in high diagnostic value on the detection of solid component, with area under curve values as 0.982 and 0.977, respectively; the cut-off values of solid-to-total volume ratio were 1.10% and 6.14%, respectively; the median volumes of solid components were 202.7 mm3 (598.2 mm3), 247.1 mm3(696.0 mm3), which were not significantly different from the reference standard[199.5 mm3 (743.1 mm3)](P=0.125,1, 0.061,3).

CONCLUSIONS

Threshold segmentation on chest CT images is valuable to detect and quantify the solid component on SSNs, the thresholds as -250 HU and -300 HU are recommended.
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Dynamic prognostication using conditional survival analysis for patients with operable lung adenocarcinoma

PURPOSE

To evaluate conditional survival among patients with surgically resected stage I-IIIa lung adenocarcinoma and identify changes in prognostic contributions for various prognostic factors over time.

PATIENTS AND METHODS

We performed conditional survival analysis at each t0 (=0, 1, 2, 3, 4, 5 years) for 723 consecutive patients who underwent surgical resection for lung adenocarcinoma, stratified by various clinico-demographic features, as well as pathologic and imaging (tumor-shadow disappearance ratio [TDR] on CT and maximum standardized uptake value [SUVmax] on PET) characteristics. Uni- and multivariableCox regression analyses were performed to evaluate relationships between those variables and conditional survival.

RESULTS

Three-year conditional overall survival (OS) and disease-free survival (DFS) were 92.12% and 75.51% at baseline, but improved steadily up to 98.33% and 95.95% at 5 years after surgery. In contrast to demographic factors, pathologic (stage, subtype, pathologic grade and differentiation) and radiologic factors (TDR and SUVmax) maintained a statistically significant association with subseqeunt 3-year OS until 3 years after surgery. According to the multivariableanalysis, high SUVmax and low TDR value were independent predictors of subsequent 3-year OS and DFS at baseline, 1 and 2 years after surgery, respectively.

CONCLUSION

Our findings based on CS provide theoretical background for clinicians to plan longer period of surveillance following lung adenocarcinoma resection in survivors with preoperatively high SUVmax and low TDR on PET-CT and chest CT, respectively.

Mean Computed Tomography Value to Predict the Tumor Invasiveness in Clinical Stage IA Lung Cancer

BACKGROUND

The purpose of this study was to validate the ability of the mean computed tomography (m-CT) value to predict tumor invasiveness and recurrence, and further, to compare with other measurements such as consolidation/tumor ratio and solid tumor size.

METHODS

A retrospective study was conducted of 494 patients with clinical stage IA lung cancer who had peripherally located lung adenocarcinoma. Receiver operating characteristic curve analysis was used to compare the ability to predict tumor invasiveness and recurrence between m-CT value, consolidation/tumor ratio, and tumor size. Multiple logistic regression analyses were performed to determine the independent variables for the prediction of pathologic, less invasive lung cancer. Disease-free survival was measured from the date of the operation until any recurrence.

RESULTS

The m-CT values were 643.6 ± 9.4 Hounsfield units in the noninvasive cancer group and 365.9 ± 11.4 Hounsfield units in the invasive cancer group (p < 0.0001). The invasive cancer group was strongly associated with a high CT attenuation value, high consolidation/tumor ratio, large solid tumor size, large tumor size, and high standardized uptake value. Multiple logistic analyses, including the preoperatively determined variables, revealed that standardized uptake value and m-CT are independent predictive factors of less invasive lung cancer. In addition, the hazard ratio of the m-CT value was higher than that of the standardized uptake value value.

CONCLUSIONS

The evaluation of m-CT value is useful in predicting less invasive lung cancer. The m-CT value can potentially determine operative procedure, particularly limited resection for peripheral lung adenocarcinoma.

Whack-a-mole strategy for multifocal ground glass opacities of the lung

Ground glass opacity (GGO) is a good prognostic indicator for lung cancer and is useful for physicians to predict prognosis. Due to recent advances in computed tomography (CT), the chance to encounter GGO is rapidly increasing in clinical practice. Based on the studies on radiological pathological correlation, GGO represents pathological lepidic growth and consolidation on CT represents pathologically invasive components. Thus, consolidation tumor ratio 0.5 or less means pathological less invasiveness for lung cancer. Not a few studies have shown that sublobar resection is equivalent to lobectomy for radiological early lung cancers. Additionally, observation of GGO is one of the options for physicians. Indication of surgical intervention remains unclear. Physician observing GGO in practice should know the natural history of GGO to reach an optimal treatment decision. For multifocal GGO lesions clinical management is surely challenging. Whack-a-mole strategy, which means sublobar resection for radiological invasive cancer is one of the most promising strategies for such lesions.

Assessment of Relationship Between CT Features and Serum Tumor Marker Index in Early-stage Lung Adenocarcinoma

RATIONALE AND OBJECTIVES

The study aimed to assess the relationship between tumor marker index (TMI) and high-resolution computed tomography features in early-stage lung adenocarcinoma.

MATERIALS AND METHODS

Seventy-four stage IA lung adenocarcinomas confirmed pathologically were retrospectively evaluated. Lung nodules were divided into two types: solid nodule (SN) and subsolid nodule (SSN). The maximum diameters on mediastinal window in axial imaging (D_m) and tumor shadow disappearance rate (TDR) were measured. Meanwhile, other computed tomography features of lung nodules were also recorded. TMI represents the geometric mean of normalized CEA and CYFRA 21-1 values, and the discriminatory value of TMI in this study was set at 1.0. The evaluation of discriminatory values for D_m and the TMI between SNs and SSNs was done with Mann-Whitney U-test. The relationship between TDR and TMI in SSNs was evaluated by Pearson correlation analysis.

RESULTS

Of 74 cases, 40 cases (54.05%) showed SNs and 34 cases (45.95%) showed SSNs. D_m and TMI were higher in SNs than in SSNs (z = -4.782, P < 0.001; z = -2.647, P = 0.008). TDR demonstrated negative relationship with TMI in SSNs (r = -0.448, P = 0.008). Spiculation (odds ratio [OR] = 14.685; 95% confidence interval [CI]: 2.739-78.729; P = 0.002), nodule type (OR = 6.215; 95% CI: 1.531-25.228; P = 0.011), and gender (OR = 0.227; 95% CI: 0.062-0.833; P = 0.025) were independent factors associated with TMI.

CONCLUSIONS

Early-stage lung adenocarcinoma with lower TDR coexisting with spiculation was associated with higher TMI, especially in patients with solid nodule, which tended to have poor prognosis.

Thin-section computed tomography findings of lung adenocarcinoma with inherent metastatic potential

PURPOSE

The solid component of lung ground-glass nodules on thin-section computed tomography (TSCT) reflects cancer cell progression and invasiveness. The purpose of this study was to clarify the cut-off value of preoperative TSCT findings in treating a lesion suspected of being adenocarcinoma and to recognize the timing of surgical resection for lung nodules.

METHODS

We reevaluated the TSCT findings in 392 patients with clinical stage IA lung adenocarcinoma who underwent surgical resection between 2003 and 2007. We identified the clinical parameters that were most useful for predicting recurrence and identified a cut-off level for each parameter.

RESULTS

Recurrence was observed in 75 (19 %) of 392 patients (median follow-up: 7 years). The size of internal consolidation of a lung nodule (SCL) and the ratio of the SCL to the maximum tumor diameter (C/T ratio) were extracted as independent factors that predicted recurrence. Only 1 (0.3 %) patient each with a lung nodule C/T ratio ≤0.5 and SCL ≤10 mm recurred. These conditions were associated with a significantly better overall survival and recurrence-free survival.

CONCLUSION

In patients with clinical stage I lung adenocarcinoma with a C/T ratio ≤0.5 and/or SCL ≤10 mm on TSCT, surgery is extremely likely to achieve a cure.

Three-Dimensional Ground Glass Opacity Ratio in CT Images Can Predict Tumor Invasiveness of Stage IA Lung Cancer

PURPOSE

We investigated the relationship between various parameters, including volumetric parameters, and tumor invasiveness according to the International Association for the Study of Lung Cancer (IASLC)/American Thoracic Society (ATS)/European Respiratory Society (ERS) classification.

MATERIALS AND METHODS

We retrospectively reviewed 99 patients with completely resected stage IA lung adenocarcinoma. The correlation between several parameters [one-dimensional ground glass opacity (1D GGO) ratio, two-dimensional (2D) GGO ratio, three-dimensional (3D) GGO ratio, 1D solid size, 2D solid size, and 3D solid size] and tumor invasiveness according to IASLC/ATS/ERS classification was investigated using receiver operating characteristic (ROC) analysis. Adenocarcinoma in situ and minimally invasive adenocarcinoma were referred to as noninvasive adenocarcinoma.

RESULTS

The areas under the curve (AUC) to predict invasive adenocarcinoma for the 1D, 2D, and 3D GGO ratios were 0.962, 0.967, and 0.971, respectively. The optimal cut-off values for the 1D, 2D, and 3D GGO ratios were 38%, 62%, and 74%, respectively. The AUC values for 1D, 2D, and 3D solid sizes to predict invasive adenocarcinoma were 0.933, 0.944, and 0.903, respectively. The optimal cut-off values for 1D, 2D, and 3D solid sizes were 1.2 cm, 1.5 cm², and 0.7 cm³, respectively. The difference in the ROC curves for 3D GGO ratio and 3D solid size was significant (p=0.01).

CONCLUSION

Computed tomography image-related parameters based on GGO were well correlated with and predictive of invasiveness according to IASLC/ATS/ERS classification. 3D GGO ratio was more strongly correlated with pathologic invasiveness than 3D solid size.

Long-Term Follow-up of Small Pulmonary Ground-Glass Nodules Stable for 3 Years: Implications of the Proper Follow-up Period and Risk Factors for Subsequent Growth

INTRODUCTION

How long persistent and stable ground-glass nodules (GGNs) should be followed is uncertain, although a minimum of 3 years is suggested. Here, we evaluated a group of GGNs that had remained stable for an initial period of 3 years with the aim of determining the proportion of GGNs showing subsequent growth after the initial 3 years and identifying the clinical and radiologic factors associated with subsequent growth.

METHODS

We retrospectively analyzed patients who underwent further computed tomography (CT) after the initial 3-year follow-up period showing a persistent and stable GGN (at least 5 years of follow-up from the initial CT).

RESULTS

Between May 2003 and June 2015, 453 GGNs (438 pure GGNs and 15 part-solid GGNs) were found in 218 patients. Of the 218 patients, 14 had 15 GGNs showing subsequent growth after the initial 3 years during the median follow-up period of 6.4 years. For the person-based analysis, the frequency of subsequent growth of GGNs that had been stable during the initial 3 years was 6.7% (14 of 218). For the nodule-based analysis, the frequency was 3.3% (15 of 453). In a multivariate analysis, age 65 years or older (OR = 5.51, p = 0.012), history of lung cancer (OR = 6.44, p = 0.006), initial size 8 mm or larger (OR = 5.74, p = 0.008), presence of a solid component (OR = 16.58, p = 0.009), and air bronchogram (OR = 5.83, p = 0.015) were independent risk factors for subsequent GGN growth.

CONCLUSIONS

For the individuals with GGNs having the aforementioned risk factors, the longer follow-up period is required to confirm subsequent GGN growth.

The prognostic value of tumor shadow disappearance rate on integrated PET/CT evaluation of solitary pulmonary nodules with low glucose metabolism

OBJECTIVE

This study aimed to determine the prognostic value of the tumor shadow disappearance rate (TDR) on integrated PET/computed tomography (PET/CT) evaluation of solitary pulmonary nodules (SPNs) with low glucose uptake.

MATERIALS AND METHODS

From January 2008 to September 2010, 99 patients who underwent fluorine-18 fluorodeoxyglucose PET (F-FDG-PET)/CT scanning for the evaluation of SPNs with a maximum standardized uptake value (SUVmax) below 2.75 (2.5+10%) were retrospectively reviewed. Among the 99 SPNs from these patients, 67 were malignant and 32 were benign, based on surgical pathology. Differences in baseline characteristics between the two groups were examined by means of the independent t-test, the Mann-Whitney U-test, and the χ-test. To test the efficacy of TDR for determining malignancy, the sensitivity, specificity, positive predictive value, negative predictive value, accuracy, and positive and negative likelihood ratios (LR+ and LR-, respectively) with 95% confidence intervals were calculated using the pathological test as the gold standard.

RESULTS

Patients with malignant nodules were older than those with benign nodules (64.5 vs. 55.1 years, respectively, P<0.001) and had higher TDRs (0.8 vs. 0.3, respectively, P<0.001). The optimal cutoff point for the TDR was 0.4886 where the sensitivity, specificity, positive predictive value, and negative predictive value were 0.851, 0.844, 0.919, and 0.730, respectively, and the LR+ and LR- were 5.443 and 0177, respectively. A significant negative correlation between TDR and SUVmax was found only in the malignant group.

CONCLUSION

The diagnostic value of TDR complements the PET/CT evaluation of SPNs with a low F-FDG uptake.

Modified inflammation-based score as an independent malignant predictor in patients with pulmonary focal ground-glass opacity: a propensity score matching analysis

Pulmonary focal Ground-glass Opacities (fGGOs) would frequently be identified after widely implementation of low-dose computed tomography (LDCT) screening. Because of the high false-positive rate of LDCT, antibiotics should be regarded as advocates in clinical management for detected fGGOs. Retrospectively review consecutive patients with fGGOs between August 2006 and August 2012. Then, relative Glasgow prognostic score (GPS) were constructed in three different systems, traditional GPS system (tGPS), modified GPS system 1 (m1GPS), and modified GPS system 2 (m2GPS). Moreover, propensity score matching (PSM) was employed in balancing baseline covariates. After PSM, patients were matched and included in benign and malignant groups as 1:1 ratio. All reported parameters were balanced in both groups and no statistical differences could be detected. Finally, m1GPS exhibited remarkable different distribution between benign and malignant fGGOs. In detail, m1GPS 1 was more frequently observed in benign fGGOs nodules, while m1GPS 2 in malignant fGGOs nodules. Modified inflammation-based score was identified as an independent predictor of malignancies in patients with pulmonary fGGOs. Patients with m1GPS 1 were more likely to be benign fGGOs, while victims with m1GPS 2 more likely to be malignant.

Computer-Aided Nodule Assessment and Risk Yield Risk Management of Adenocarcinoma: The Future of Imaging?

Increased clinical use of chest high-resolution computed tomography results in increased identification of lung adenocarcinomas and persistent subsolid opacities. However, these lesions range from very indolent to extremely aggressive tumors. Clinically relevant diagnostic tools to noninvasively risk stratify and guide individualized management of these lesions are lacking. Research efforts investigating semiquantitative measures to decrease interrater and intrarater variability are emerging, and in some cases steps have been taken to automate this process. However, many such methods currently are still suboptimal, require validation and are not yet clinically applicable. The computer-aided nodule assessment and risk yield software application represents a validated tool for the automated, quantitative, and noninvasive tool for risk stratification of adenocarcinoma lung nodules. Computer-aided nodule assessment and risk yield correlates well with consensus histology and postsurgical patient outcomes, and therefore may help to guide individualized patient management, for example, in identification of nodules amenable to radiological surveillance, or in need of adjunctive therapy.

Surgical treatment of early-stage non-small-cell lung cancer

Surgical resection remains the standard of care for functionally operable early-stage non-small-cell lung cancer (NSCLC) and resectable stage IIIA disease. The role of invasive staging and restaging techniques is currently being debated, but they provide the largest biopsy samples which allow for precise mediastinal staging. Different types of operative procedures are currently available to the thoracic surgeon, and some of these interventions can be performed by video-assisted thoracic surgery (VATS) with the same oncological results as those by open thoracotomy. The principal aim of surgical treatment for NSCLC is to obtain a complete resection which has been precisely defined by a working group of the International Association for the Study of Lung Cancer (IASLC). Intraoperative staging of lung cancer is of utmost importance to decide on the extent of resection according to the intraoperative tumour (T) and nodal (N) status. Systematic nodal dissection is generally advocated to evaluate the hilar and mediastinal lymph nodes which are subdivided into seven zones according to the most recent 7th tumour-node-metastasis (TNM) classification. Lymph-node involvement not only determines prognosis but also the administration of adjuvant therapy.

In 2011, a new multidisciplinary adenocarcinoma classification was published introducing the concepts of adenocarcinoma in situ and minimally invasive adenocarcinoma. This classification has profound surgical implications. The role of limited or sublobar resection, comprising anatomical segmentectomy and wide wedge resection, is reconsidered for early-stage lesions which are more frequently encountered with the recently introduced large screening programmes. Numerous retrospective non-randomised studies suggest that sublobar resection may be an acceptable surgical treatment for early lung cancers, also when performed by VATS.

More tailored, personalised therapy has recently been introduced. Quality-of-life parameters and surgical quality indicators become increasingly important to determine the short-term and long-term impact of a surgical procedure. International databases currently collect extensive surgical data, allowing more precise calculation of mortality and morbidity according to predefined risk factors. Centralisation of care has been shown to improve results. Evidence-based guidelines should be further developed to provide optimal staging and therapeutic algorithms.

Observer Variability for Classification of Pulmonary Nodules on Low-Dose CT Images and Its Effect on Nodule Management

PURPOSE

To examine the factors that affect inter- and intraobserver agreement for pulmonary nodule type classification on low-radiation-dose computed tomographic (CT) images, and their potential effect on patient management.

MATERIALS AND METHODS

Nodules (n = 160) were randomly selected from the Dutch-Belgian Lung Cancer Screening Trial cohort, with equal numbers of nodule types and similar sizes. Nodules were scored by eight radiologists by using morphologic categories proposed by the Fleischner Society guidelines for management of pulmonary nodules as solid, part solid with a solid component smaller than 5 mm, part solid with a solid component 5 mm or larger, or pure ground glass. Inter- and intraobserver agreement was analyzed by using Cohen κ statistics. Multivariate analysis of variance was performed to assess the effect of nodule characteristics and image quality on observer disagreement. Effect on nodule management was estimated by differentiating CT follow-up for ground-glass nodules, solid nodules 8 mm or smaller, and part-solid nodules smaller than 5 mm from immediate diagnostic work-up for solid nodules larger than 8 mm and part-solid nodules 5 mm or greater.

RESULTS

Pair-wise inter- and intraobserver agreement was moderate (mean κ, 0.51 [95% confidence interval, 0.30, 0.68] and 0.57 [95% confidence interval, 0.47, 0.71]). Categorization as part-solid nodules and location in the upper lobe significantly reduced observer agreement (P = .012 and P < .001, respectively). By considering all possible reading pairs (28 possible combinations of observer pairs × 160 nodules = 4480 possible agreements or disagreements), a discordant nodule classification was found in 36.4% (1630 of 4480), related to presence or size of a solid component in 88.7% (1446 of 1630). Two-thirds of these discrepant readings (1061 of 1630) would have potentially resulted in different nodule management.

CONCLUSION

There is moderate inter- and intraobserver agreement for nodule classification by using current recommendations for low-radiation-dose CT examinations of the chest. Discrepancies in nodule categorization were mainly caused by disagreement on the size and presence of a solid component, which may lead to different management in the majority of cases with such discrepancies. (©) RSNA, 2015.

Preoperative flexible bronchoscopy in patients with persistent ground-glass nodule

There are no accurate data on the diagnostic value of preoperative flexible bronchoscopy (FB) for persistent ground-glass nodule (GGN) of the lung. We evaluated the value of preoperative FB in patients with suspected GGN-type lung cancer. We retrospectively searched a database for subjects who had ‘ground-glass opacity’, ‘non-solid nodule’, ‘part-solid nodule’, or ‘sub-solid nodule’ on chest computed tomography reports between February 2004 and March 2012. Patients who had infiltrative ground-glass opacity lesions, mediastinal lymphadenopathy, or pleural effusion, focal ground-glass opacity lesions >3 cm, and were lost to follow-up were excluded. We assessed the diagnostic value of preoperative FB in patients with persistent GGNs who underwent surgical resection. In total, 296 GGNs were evaluated by FB in 264 patients with persistent GGNs who underwent preoperative FB and surgical resection. The median size of the GGNs was 18 mm; 135 (46%) were pure GGN and 161 (54%) were part-solid GGN. No visible tumor or unsuspected endobronchial metastasis was identified by preoperative FB. Only 3 (1%, 3/208) GGNs were identified preoperatively as malignant by bronchial washing cytology; all were part-solid GGNs. No other etiology was identified by FB. Of the GGNs, 271 (91%) were subsequently confirmed as malignant and 25 (9%) were confirmed as benign at surgical resection. Consequently, the overall diagnostic sensitivity and negative predictive value of preoperative FB on a per-nodule basis was 1% (3/271) and 8% (25/293), respectively. The preoperative FB did not change the surgical strategy. Preoperative FB did not add much to the evaluation of persistent GGNs of the lung. Routine preoperative FB may have limited value in surgical candidates with small persistent pure GGNs.

Is lower zone mediastinal nodal dissection always mandatory for lung cancer in the lower lobe?

PURPOSE

Dissection of the lower zone mediastinal nodes is mandatory during systematic nodal dissection for lung cancer. However, the significance of lower zone lymph node metastasis (LZM) in lung cancer remains unclear. Therefore, we aimed to identify the predictive factors for LZM in patients with lower lobe lung cancer.

METHODS

A retrospective study was conducted on 257 patients with lower lobe lung cancer, in whom pulmonary resection and mediastinal nodal dissection were performed between 2009 and 2013. The radiological factors on thin-section computed tomography scans (TSCT) and several conventional clinical factors were evaluated as possible predictors of LZM.

RESULTS

Twenty (7.8 %) patients exhibited LZM. The majority of the tumors were especially located in segment 10 (50 %). All patients showed a solid appearance on TSCT. In a univariate analysis, the tumor location, a solid appearance and the clinical T factor significantly predicted LZM (p = 0.011, 0.005, 0.018). Furthermore, based on a multivariate analysis, the tumor location in segment 10 significantly predicted LZM in patients with lower lobe solid lung cancer (p = 0.031).

CONCLUSION

The appropriate surgical strategy for lower zone lymph node dissection should be selected based on the tumor location and the findings of TSCT, due to the high frequency of LZM (19.6 %), especially in patients with pure solid lung cancer in segment 10.

Comparative analysis of clinicoradiologic characteristics of lung adenocarcinomas with ALK rearrangements or EGFR mutations

OBJECTIVE

To compare the clinicoradiologic features of tumours with echinoderm anaplastic lymphoma kinase (ALK) rearrangements, epidermal growth factor receptor (EGFR) mutations, or wild type (WT) for both genes in a cohort of patients with lung adenocarcinoma to identify useful characteristics of different gene statuses.

METHODS

In 346 lung adenocarcinoma patients, ALK rearrangements were confirmed with fluorescence in situ hybridisation, and EGFR mutations were determined by pyrosequencing assay. Patients were divided into three groups: ALK rearrangement (ALK+ group, n = 48), EGFR mutation (EGFR+ group, n = 166), and WT for both genes (WT group, n = 132). Chest computed tomography (CT) examinations were performed in all patients. The percentages of ground-glass opacity volume (pGGO) and tumour shadow disappearance rate (TDR) were measured using semi-automated nodule assessment software.

RESULTS

The pGGO was significantly lower in the ALK+ group (25.1 % ± 24.3) than in the EGFR+ group (37.2 % ± 25.7, p < 0.001) and the WT group (36.1 % ± 24.6, p = 0.001). The TDR in the ALK+ group (17.3 % ± 25.1) was significantly lower than in the EGFR+ group (26.8 % ± 24.9, p = 0.002) and the WT group (25.7 % ± 24.6, p = 0.003).

CONCLUSIONS

Solid pattern with lower incidence of lobulated border, finely spiculated margins, pleural retraction, and bubble-like lucency on CT imaging are the main characteristics of ALK rearrangement tumours.

KEY POINTS

• EGFR/ALK testing is recommended for lung adenocarcinoma patients for EGFR/ALK-targeted TKI therapy. • EGFR /ALK testing is restricted by limited tissue samples and cost pressures. • Lower pGGO and TDR are the main clinicoradiological characteristics of ALK+ tumours. • pGGO and TDR are predictive factors for selecting patients for ALK/EGFR testing.

The lung adenocarcinoma guidelines: what to be considered by surgeons

In 2011 the International Association for the Study of Lung Cancer (IASLC), the American Thoracic Society (ATS), and the European Respiratory Society (ERS), have proposed a new subclassification of lung adenocarcinomas. This new classification was founded on an evidence-based approach to a systematic review of 11,368 citations from the related literature. Validation has involved projects relating to histologic and cytologic analysis of small biopsy specimens, histologic subtyping, grading, and observer variation among expert pathologists. As enormous resources are being spent on trials involving molecular and therapeutic aspects of adenocarcinoma of the lung, the development of standardized criteria is of great importance and should help advance the field, increasing the impact of research, and improving patient care. This classification is needed to assist in determining patient therapy and predicting outcome. The 2011 IASLC/ATS/ERS adenocarcinoma classification can have an impact on TNM staging. It may help in comparing histologic characteristics of multiple lung adenocarcinomas to determine whether they are intrapulmonary metastases versus separate primaries. Use of comprehensive histologic subtyping along with other histologic characteristics has been shown to have good correlation with molecular analyses and clinical behavior. Also, it may be more meaningful clinically to measure tumor size in lung adenocarcinomas that have a lepidic component by using invasive size rather than total size to determine the size T factor.

Can image analysis on high-resolution computed tomography predict non-invasive growth in adenocarcinoma of the lung?

PURPOSE

Preoperative radiological predictions of pathological invasiveness must be objective and reproducible in addition to being accurate when considering limited surgery for early lung cancer.

METHODS

Two cohorts were used for the analysis. Two independent observers traced lesion edges and measured areas and proportions of solid component on tumor images with the largest diameter by high resolution computed tomography images and "Image J" software.

RESULTS

The value of the intraclass correlation was 0.997 (95% confidence interval [CI], 0.996-0.998) for the area of solid component and 0.979 (95%CI, 0.958-0.986) for the proportion of solid component, suggesting such parameters were reliable in terms of reproducibility. Az value was 0.898 (95%CI, 0.842-0.953) for the area of solid component and 0.882 (95%CI, 0.816-0.949) for the proportion of solid component, demonstrating 2 parameters were both highly predictive of non-invasive adenocarcinoma. The optimal prediction of non-invasive adenocarcinoma with a cut-off value of 7.5 mm(2) for the area of solid component resulted in a sensitivity of 85.3% and specificity of 86.2% in Cohort 1 and a sensitivity of 66.7% and specificity of 88.5% in Cohort 2.

CONCLUSION

Image analysis using "Image J" software was promising for predicting non-invasive adenocarcinoma with its limited inter-observer variability and high predictive performance.

Density features of screened lung tumors in low-dose computed tomography

RATIONALE AND OBJECTIVES

Using low-dose computed tomography (LDCT), small and heterogeneous lung tumors are detected in screening. The criteria for assessing detected tumors are crucial for determining follow-up or resection strategies. The purpose of this study was to investigate the capacity of density features in differentiating lung tumors.

MATERIALS AND METHODS

From July 2008 to December 2011, 48 surgically confirmed tumors (29 malignancies, comprising 17 cases of adenocarcinoma and 12 cases of adenocarcinoma in situ [AdIs], and 19 benignancies, comprising 11 cases of atypical adenomatous hyperplasia [AAH] and eight cases of benign non-AAH) in 38 patients were retrospectively evaluated, indicating that the positive predictive value (PPV) of physicians is 60.4% (29/48). Three types of density features, tumor disappearance rate (TDR), mean, and entropy, were obtained from the CT values of detected tumors.

RESULTS

Entropy is capable of differentiating malignancy from benignancy but is limited in differentiating AdIs from benign non-AAH. The combination of entropy and TDR is effective for predicting malignancy with an accuracy of 87.5% (42/48) and a PPV of 89.7% (26/29), improving the PPV of physicians by 29.3%. The combination of entropy and mean adequately clarifies the four pathology groups with an accuracy of 72.9% (35/48). For tumors with a mean below -400 Hounsfield units, the criterion of an entropy larger than 5.4 might be appropriate for diagnosing malignancy. For others, the pathology is either benign non-AAH or adenocarcinoma; adenocarcinoma has a higher entropy than benign non-AAH, with the exception of tuberculoma.

CONCLUSIONS

Combining density features enables differentiating heterogeneous lung tumors in LDCT.

Clinical model to estimate the pretest probability of malignancy in patients with pulmonary focal Ground-glass Opacity

BACKGROUND

Effective strategies for managing patients with pulmonary focal Ground-glass Opacity (fGGO) depend on the pretest probability of malignancy. Estimating a clinical probability of malignancy in patients with fGGOs can facilitate the selection and interpretation of subsequent diagnostic tests. METHODS : Data from patients with pulmonary fGGO lesions, who were diagnosed at Sun Yat-sen University Cancer Center, was retrospectively collected. Multiple logistic regression analysis was used to identify independent clinical predictors for malignancy and to develop a clinical predictive model to estimate the pretest probability of malignancy in patients with fGGOs.

RESULTS

 One hundred and sixty-five pulmonary fGGO nodules were detected in 128 patients. Independent predictors for malignant fGGOs included a history of other cancers (odds ratio [OR], 0.264; 95% confidence interval [CI], 0.072 to 0.970), pleural indentation (OR, 8.766; 95% CI, 3.033-25.390), vessel-convergence sign (OR, 23.626; 95% CI, 6.200 to 90.027) and air bronchogram (OR, 7.41; 95% CI, 2.037 to 26.961). Model accuracy was satisfactory (area under the curve of the receiver operating characteristic, 0.934; 95% CI, 0.894 to 0.975), and there was excellent agreement between the predicted probability and the observed frequency of malignant fGGOs.

CONCLUSIONS

We have developed a predictive model, which could be used to generate pretest probabilities of malignant fGGOs, and the equation could be incorporated into a formal decision analysis.

Use of high-resolution computed tomography and positron emission tomography/computed tomography in the management of stage IA adenocarcinoma

Preoperative determination of malignant behavior is critical in choosing suitable therapeutic strategies such as sublobar resection for patients with small lung cancers. The aim of present review was to evaluate high-resolution computed tomography and fluorodeoxyglucose-positron emission tomography/computed tomography as tools for management of clinical stage IA adenocarcinoma.