Search

Worldwide, lung cancer is the leading cause of cancer-related deaths. To manage lung nodules, radiologists observe computed tomography images, review various imaging findings, and record these in radiology reports. The report contents should be of high quality and uniform regardless of the radiologist. Here, we propose an artificial intelligence system that automatically generates descriptions related to lung nodules in computed tomography images. Our system consists of an image recognition method for extracting contents-namely, bronchopulmonary segments and nodule characteristics from images-and a natural language processing method to generate fluent descriptions. To verify our system's clinical usefulness, we conducted an experiment in which two radiologists created nodule descriptions of findings using our system. Through our system, the similarity of the described contents between the two radiologists (p = 0.001) and the comprehensiveness of the contents (p = 0.025) improved, while the accuracy did not significantly deteriorate (p = 0.484)., Competing Interests: I have read the journal’s policy and the authors of this manuscript have the following competing interests: This research is a cooperative study between FUJIFILM Corporation and Nagoya University Graduate School of Medicine. This does not alter our adherence to PLOS ONE policies on sharing data and materials., (Copyright: © 2024 Momoki et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

An artificial intelligence (AI) system that reconstructs virtual 3D thin-section CT (TSCT) images from conventional CT images by applying deep learning was developed. The aim of this study was to investigate whether virtual and real TSCT could measure the solid size of early-stage lung adenocarcinoma. The pair of original thin-CT and simulated thick-CT from the training data with TSCT images (thickness, 0.5-1.0 mm) of 2700 pulmonary nodules were used to train the thin-CT generator in the generative adversarial network (GAN) framework and develop a virtual TSCT AI system. For validation, CT images of 93 stage 0-I lung adenocarcinomas were collected, and virtual TSCTs were reconstructed from conventional 5-mm thick-CT images using the AI system. Two radiologists measured and compared the solid size of tumors on conventional CT and virtual and real TSCT. The agreement between the two observers showed an almost perfect agreement on the virtual TSCT for solid size measurements (intraclass correlation coefficient = 0.967, P < 0.001, respectively). The virtual TSCT had a significantly stronger correlation than that of conventional CT (P = 0.003 and P = 0.001, respectively). The degree of agreement between the clinical T stage determined by virtual TSCT and the clinical T stage determined by real TSCT was excellent in both observers (k = 0.882 and k = 0.881, respectively). The AI system developed in this study was able to measure the solid size of early-stage lung adenocarcinoma on virtual TSCT as well as on real TSCT., (© 2023. The Author(s).)

The prognosis and prognostic factors of patients receiving whole-brain radiotherapy (WBRT) for leptomeningeal metastasis (LM) from lung adenocarcinoma have not been established. Particularly, the impact of EGFR mutations and ALK rearrangements on survival remains unclear. This retrospective study evaluated the prognosis and prognostic factors of patients receiving WBRT for LM. We evaluated overall survival (OS) from WBRT initiation and clinical variables in 80 consecutive patients receiving WBRT for LM from lung adenocarcinoma at our institution between June 2013 and June 2021. After a median follow-up of 5.2 (range 0.5-56.5) months, the median OS was 6.2 months (95% CI 4.4-12.4). Of the 80 patients, 51 were classified as EGFR/ALK mutant (EGFR: 44; ALK: 6; both: 1) and 29 as wild-type. The median OS was 10.4 (95% CI 5.9-20.9) versus 3.8 (95% CI 2.5-7.7) months in the EGFR/ALK-mutant versus wild-type patients (HR = 0.49, P = 0.0063). Multivariate analysis indicated that EGFR/ALK alterations (HR = 0.54, P = 0.021) and Eastern Cooperative Oncology Group performance status (ECOG PS) of 0-1 (HR = 0.25, P < 0.001) were independent factors associated with favorable OS. Among the patients who underwent brain MRI before and after WBRT, intracranial progression-free survival was longer in the 26 EGFR/ALK-mutant than 13 wild-type patients (HR = 0.31, P = 0.0039). Although the prognosis of patients receiving WBRT for LM remains poor, EGFR/ALK alterations and good ECOG PS may positively impact OS in those eligible for WBRT., (© 2023. The Author(s), under exclusive licence to Springer Nature B.V.)

Background: To investigate the correlation between iodine-related attenuation in contrast-enhanced dual-energy computed tomography (DE-CT) and the postoperative prognosis of surgically resected solid-type small-sized lung cancers., Methods: We retrospectively reviewed the DE-CT findings and postoperative course of solid-type lung cancers ≤3 cm in diameter. After injection of iodinated contrast media, arterial phases were scanned using 140-kVp and 80-kVp tube voltages. Three-dimensional iodine-related attenuation (3D-IRA) of primary tumors at the arterial phase was computed using the "lung nodule" application software. The corrected 3D-IRA normalized to the patient's body weight and contrast medium concentration was then calculated., Results: A total of 120 resected solid-type lung cancers ≤3 cm in diameter were selected for analysis (82 males and 38 females; mean age, 67 years). During the observation period (median, 47 months), 32 patients showed postoperative recurrence. Recurrent tumors had significantly lower 3D-IRA and corrected 3D-IRA at early phase compared to non-recurrent tumors (p = 0.046 and p = 0.027, respectively). The area under the receiver operating characteristic curve for postoperative recurrence was 0.624 for the corrected 3D-IRA at early phase (p = 0.025), and the cutoff value was 5.88. Kaplan-Meier curves for disease-free survival indicated that patients showing tumors with 3D-IRA > 5.88 had a significantly better prognosis than those with tumors showing 3D-IRA < 5.88 (p = 0.017)., Conclusions: The 3D-IRA of small-sized solid-type lung cancers on contrast-enhanced DE-CT was significantly associated with postoperative prognosis, and low 3D-IRA tumors showed a higher TNM stage and a significantly poorer prognosis.

We retrospectively evaluated the frequency of unexpected accumulation of radioactive iodine on the post-therapy whole-body scan (Rx-WBS) after radioactive iodine (RAI) ablation therapy in patients with differentiated thyroid cancer (DTC). We searched our institutional database for Rx-WBSs of DTC patients who underwent RAI ablation or adjuvant therapy between 2012 and 2019. Patients with distant metastasis diagnosed by CT or PET/CT before therapy, and those had previously received RAI therapy were excluded. In total, 293 patients (201 female and 92 male, median age 54 years) were selected. Two nuclear medicine physicians interpreted the Rx-WBS images by determining the visual intensity of radioiodine uptake by the thyroid bed, cervical and mediastinal lymph nodes, lungs, and bone. Clinical features of the patients with and without the metastatic accumulation were compared by chi-square test and median test. Logistic regression analyses were performed to compare the association between the presence of metastatic accumulation and these clinical factors. Eighty-four of 293 patients (28.7%) showed metastatic accumulation. Patients with metastatic RAI accumulation showed a significantly higher frequency of pathological N1 (pN1) and serum thyroglobulin (Tg) > 1.5 ng/ml under TSH stimulation (p = 0.035 and p = 0.031, respectively). Logistic regression analysis indicated that a serum Tg > 1.5 ng/ml was significantly correlated with the presence of metastatic accumulation (odds ratio = 1.985; p = 0.033). In conclusion, Patients with Tg > 1.5 ng/ml were more likely to show metastatic accumulation. In addition, the presence of lymph node metastasis at the initial thyroid surgery was also associated with this unexpected metastatic accumulation., Competing Interests: No potential conflicts of interest were disclosed. The authors thank Editage (www.editage.jp) for English language editing

Purpose: This paper aims to explore the role of a metabolic parameter on F-FDG-PET/CT for clinical T-classification in early-stage adenocarcinoma., Patients and Methods: One hundred six surgically resected pathological TNM stage (p-stage) 0/I lung adenocarcinomas were retrospectively reviewed. The solid size (SS) measured on thin-section CT and the pathological invasive size (IS) of tumors were recorded. The SUVmax and metabolic tumor volume with SUV ≥1.0 (MTV1.0) derived from PET/CT data were measured on a workstation, and the metabolic tumor diameter with SUV ≥1.0 (MTD1.0) was calculated automatically from MTV1.0. For the correlations between the IS and the SS, MTD1.0, or SUVmax, Pearson's correlation coefficients were compared using the Meng-Rosenthal-Rubin method. Additionally, the reproducibility between the clinical TNM stage (c-stage), based on the SS or MTD1.0, and the p-stage was analyzed using the kappa coefficient (k)., Results: For the correlations between the IS and the other parameters, Pearson correlation coefficient was 0.630 for the SS, 0.600 for the SUVmax, and 0.725 for MTD1.0. MTD1.0 correlated significantly and more strongly with the IS than the SS and the SUVmax did (P = 0.040, and P = 0.008, respectively). The reproducibility between p-stage and c-stage based on the SS was moderate (k = 0.529, P < 0.001), whereas that between p-stage and c-stage based on MTD1.0 was substantial (k = 0.676, P < 0.001)., Conclusions: MTD1.0 on FDG-PET/CT was correlated significantly and more strongly with the pathological IS in lung adenocarcinomas than with the SS on thin-section CT. FDG-PET/CT could classify more precisely early-stage lung adenocarcinoma than the presently used T-classification based on thin-section CT findings.

Background: For subsolid non-small cell lung cancers (NSCLCs), solid size (SS), which is the maximal diameter of the solid component, correlates more accurately with tumor prognosis than the total size, which is the maximal diameter of the entire tumor, including ground-glass opacity. We reviewed the propriety of the TNM staging based on the SS for early-stage NSCLCs., Methods: We retrospectively reviewed the preoperative radiological reports, clinical records, and pathological reports of NSCLC cases in our hospital between 2010 and 2013, and clinical stage (c-Stage) 0 and I tumors were selected. Disease-free survival (DFS), based on survival analysis, was used to assess the tumor characteristics that predicted the prognosis., Results: A total of 247 NSCLC diagnoses in 231 patients (88 women and 143 men; age, 67 ± 7 years) were included in our cohort. They were classified into solid (n = 131) and subsolid (n = 116) nodules. The DFS curves indicated that prognosis was significantly worse in the following order: c-Stage 0, c-Stage IA, and c-Stage IB tumors (p = 0.016). Patients with solid nodules showed a significantly worse prognosis than patients with subsolid nodules (p < 0.001). A multivariate Cox proportional hazards model showed that the significant predictive factors for DFS were c-Stage (hazard ratio, 1.600; p = 0.020) and solid nodules (hazard ratio, 3.077; p = 0.031)., Conclusions: For early-stage NSCLCs, the c-Stage based on the SS in subsolid nodules was useful for predicting postoperative DFS. In addition, whether nodules were solid or subsolid was another independent prognostic factor.

Purpose To investigate the relationship between the postoperative prognosis of patients with part-solid non-small cell lung cancer and the solid component size acquired by using three-dimensional (3D) volumetry software on multidetector computed tomographic (CT) images. Materials and Methods A retrospective study by using preoperative multidetector CT data with 0.5-mm section thickness, clinical records, and pathologic reports of 96 patients with primary subsolid non-small cell lung cancer (47 men and 49 women; mean age ± standard deviation, 66 years ± 8) were reviewed. Two radiologists measured the two-dimensional (2D) maximal solid size of each nodule on an axial image (hereafter, 2D MSSA), the 3D maximal solid size on multiplanar reconstructed images (hereafter, 3D MSSMPR), and the 3D solid volume of greater than 0 HU (hereafter, 3D SV 0HU ) within each nodule. The correlations between the postoperative recurrence and the effects of clinical and pathologic characteristics, 2D MSSA, 3D MSSMPR, and 3D SV 0HU as prognostic imaging biomarkers were assessed by using a Cox proportional hazards model. Results For the prediction of postoperative recurrence, the area under the receiver operating characteristics curve was 0.796 (95% confidence interval: 0.692, 0.900) for 2D MSSA, 0.776 (95% confidence interval: 0.667, 0.886) for 3D MSSMPR, and 0.835 (95% confidence interval: 0.749, 0.922) for 3D SV 0HU . The optimal cutoff value for 3D SV 0HU for predicting tumor recurrence was 0.54 cm 3 , with a sensitivity of 0.933 (95% confidence interval: 0.679, 0.998) and a specificity of 0.716 (95% confidence interval: 0.605, 0.811) for the recurrence. Significant predictive factors for disease-free survival were 3D SV 0HU greater than or equal to 0.54 cm 3 (hazard ratio, 6.61; P = .001) and lymphatic and/or vascular invasion derived from histopathologic analysis (hazard ratio, 2.96; P = .040). Conclusion The measurement of 3D SV 0HU predicted the postoperative prognosis of patients with part-solid lung cancer more accurately than did 2D MSSA and 3D MSSMPR. © RSNA, 2018.

Introduction: We aimed to determine the concordance between the clinical stage (c-stage) and pathologic stage (p-stage) for patients with small-size lung cancer. Additionally we searched for prognostic factors other than the TNM stage., Patients and Methods: We retrospectively reviewed the preoperative multidetector computed tomography (CT) and positron emission tomography/CT reports, surgical records, and pathologic reports of patients with primary lung cancer ≤ 3 cm. The Union for International Cancer Control TNM seventh edition classification of c-stage and p-stage were compared. The tumors were classified into multiple subgroups by concordance or discordance between the c-stage and p-stage. Disease-free survival (DFS) was assessed using survival analysis to assess the tumor characteristics that were predictive of prognosis., Results: A total of 289 surgically resected primary lung cancers were evaluated. The concordance between c-stage and p-stage was 65.4%, with moderate reproducibility (kappa coefficient, 0.467). The upstaging rate from c-stage I to p-stage II-IV was 9.4%, and these patients had significantly worse DFS than those with a concordant stage I classification (P < .001). The main reason for upstaging was an underestimation of metastases to the hilar lymph nodes (n = 7) or mediastinal lymph nodes (n = 11). A multivariate Cox proportional hazards model showed that the significant predictive factors for DFS were p-stage (hazard ratio, 1.342; P = .003) and maximum standardized uptake value on positron emission tomography/CT (hazard ratio, 12.162; P = .001)., Conclusion: The concordance rate between c-stage and p-stage for small primary lung cancers had moderate reproducibility. Discordance between c-stage I and p-stage II-IV significantly affected DFS. The maximum standardized uptake value of the primary lesion was an independent prognostic factor, and combining it with c-stage might improve the prediction of therapeutic outcomes., (Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.)

Purpose: To compare dual-phase dual-energy CT (DE-CT) with FDG-PET/CT for predicting histopathological locoregional invasiveness of non-small cell lung cancers (NSCLCs)., Materials and Methods: We selected 63 consecutive patients with NSCLC lesions (37 males, 26 females; age range, 44-85 years; mean age, 69 years) who were evaluated preoperatively by both DE-CT and PET/CT at our institution. Postoperative microscopic invasiveness (lymphatic permeation, vascular invasion, and/or pleural involvement) was reviewed, and we defined locoregionally invasive tumors as those that had at least one positive finding of microscopic invasiveness. DE-CT scanning in the arterial and delayed phases was performed after injection of iodinated contrast media using 140-kVp and 80-kVp tube voltages. Three-dimensional iodine-related attenuation of primary tumors in the arterial and delayed phases was quantified automatically using "syngo Dual Energy Lung Nodules" application software, and the ratio of arterial phase to delayed phase enhancement (A/D ratio) was calculated. The A/D ratio and SUVmax on PET/CT were evaluated with respect to postoperative invasiveness by univariate logistic regression analysis., Results: The A/D ratio was significantly correlated with lymphatic permeation, vascular invasion, and pleural involvement (p=0.011, p=0.021, and p=0.010, respectively). In contrast, the SUVmax was significantly correlated with pleural involvement (p=0.020) but not with lymphatic permeation or vascular invasion (p=0.088 and p=0.100, respectively). In the subgroup of patients with lesion diameters ≤2cm, the A/D ratio was significantly correlated with locoregional invasiveness (p=0.040), while the SUVmax was not (p=0.121)., Conclusion: For the prediction of microscopic invasiveness of NSCLCs, the diagnostic performance of dual-phase DE-CT may be comparable to that of FDG-PET/CT., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Objectives: We investigated a possible correlation between the maximum standardized uptake value (SUV max ), which is assessed by pretreatment 18 F-fluorodeoxyglucose positron emission tomography with computed tomography, and the overall survival (OS) in patients with hypopharyngeal squamous cell carcinoma from two institutions on long-term follow-up, and examined whether SUV max is correlated with several survival outcomes, including lung metastasis-free survival., Methods: A total of 81 patients were enrolled. The survival rate was calculated by the Kaplan-Meier method. Both univariate and multivariate survival analyses were assessed by a Cox proportional hazards model., Results: SUV max ≥15.2 in institution A (p = 0.0306) or SUV max ≥8 in institution B (p = 0.0132) was significantly predictor of a lower OS. We disaggregated the data by high SUV max (SUV max ≥15.2 from institution A and SUV max ≥8 from institution B) and low SUV max (SUV max <15.2 from institution A and SUV max <8 from institution B). Patients with a high SUV max exhibited a significantly lower OS in both univariate (p = 0.001) and multivariate (p = 0.0046) analyses for adjusted for the clinical stage and treatment group. The patients with a high SUV max exhibited significantly shorter disease-specific (p = 0.0068), distant metastasis-free (p = 0.0428), and lung metastasis-free (p = 0.0328) survivals., Conclusions: High SUV max was significantly correlated with a lower OS, disease-specific survival, distant metastasis-free survival, and lung metastasis-free survival in a multi-institutional retrospective study.

Purpose: We developed an original, computer-aided diagnosis (CAD) software that subtracts the initial thoracic vertebral three-dimensional computed tomography (3D-CT) image from the follow-up 3D-CT image. The aim of this study was to investigate the efficacy of this CAD software during screening for vertebral metastases on follow-up CT images of primary lung cancer patients., Materials and Methods: The interpretation experiment included 30 sets of follow-up CT scans in primary lung cancer patients and was performed by two readers (readers A and B), who each had 2.5 years' experience reading CT images. In 395 vertebrae from C6 to L3, 46 vertebral metastases were identified as follows: osteolytic metastases (n = 17), osteoblastic metastases (n = 14), combined osteolytic and osteoblastic metastases (n = 6), and pathological fractures (n = 9). Thirty-six lesions were in the anterior component (vertebral body), and 10 lesions were in the posterior component (vertebral arch, transverse process, and spinous process). The area under the curve (AUC) by receiver operating characteristic (ROC) curve analysis and the sensitivity and specificity for detecting vertebral metastases were compared with and without CAD for each observer., Results: Reader A detected 47 abnormalities on CT images without CAD, and 33 of them were true-positive metastatic lesions. Using CAD, reader A detected 57 abnormalities, and 38 were true positives. The sensitivity increased from 0.717 to 0.826, and on ROC curve analysis, AUC with CAD was significantly higher than that without CAD (0.849 vs. 0.902, p = 0.021). Reader B detected 40 abnormalities on CT images without CAD, and 36 of them were true-positive metastatic lesions. Using CAD, reader B detected 44 abnormalities, and 39 were true positives. The sensitivity increased from 0.783 to 0.848, and AUC with CAD was nonsignificantly higher than that without CAD (0.889 vs. 0.910, p = 0.341). Both readers detected more osteolytic and osteoblastic metastases with CAD than without CAD., Conclusion: Our temporal 3D-CT subtraction CAD software easily detected vertebral metastases on the follow-up CT images of lung cancer patients regardless of the osteolytic or osteoblastic nature of the lesions., Competing Interests: I have read the journal's policy and the authors of this manuscript have the following competing interests: This study was funded by Fujifilm corporation. TK, TI, and YL are employees of Fujifilm corporation. However, Fujifilm corporation had no control over the interpretation, writing, or publication of this work. This does not alter our adherence to PLOS ONE policies on sharing data and materials.

Background: To investigate the correlation between iodine-related attenuation of dual-energy computed tomography (DE-CT) and the histopathological invasiveness of surgically resected primary non-small cell lung cancers (NSCLCs) ≤ 3 cm in diameter., Methods: We selected 63 consecutive NSCLC lesions from 60 patients (32 males, 28 females; age range, 39-85 years; mean age, 68 years). After injection of iodinated contrast media, arterial phases were scanned using 140-kVp and 80-kVp tube voltages. Three-dimensional iodine-related attenuation (3D-IRA) of primary tumors at the arterial phase was computed using "lung nodule" application software. The corrected 3D-IRA normalized to the patient's body weight and contrast medium concentration was then calculated. Single-factor analysis of variance (ANOVA) was used for comparison among tumor differentiation grade groups. Univariate and multivariate logistic regression analysis was used for the correlation between locoregional invasive tumor and clinical factors., Results: Resected tumors were histopathologically classified into well-differentiated (G1; n = 24), moderately-differentiated (G2; n = 28), and poorly-differentiated (G3; n = 11) groups by degree of tumor differentiation. The mean ± standard deviation of the 3D-IRA was 56.1 ± 22.6 HU in G1 tumours, 48.5 ± 23.9 HU in G2 tumours, and 28.4 ± 15.8 HU in G3 tumours; significant differences were observed between groups by ANOVA. (p = 0.005). Univariate logistic analysis showed that the 3D-IRA and corrected 3D-IRAs were significantly correlated with locoregional invasive tumors (p = 0.002 and p < 0.001, respectively). Multivariate logistic analysis revealed that only the corrected 3D-IRA was significantly correlated with tumor invasiveness (p = 0.003), while gender, clinical size, and solid/subsolid type were not (p = 0.950, p = 0.057 and p = 0.456, respectively)., Conclusions: The 3D-IRA of small-sized NSCLCs was significantly associated with and invasiveness. Low 3D-IRA tumors tended to have greater invasiveness than high 3D-IRA tumors.

Objectives: The maximum standardized uptake value (SUVmax) of FDG-PET/CT is commonly used as an indicator to evaluate the invasiveness and prognosis of non-small-cell lung cancers (NSCLC). We investigated the correlation between SUVmax and tumor invasiveness or postoperative recurrence of solid type NSCLC and compared squamous cell carcinoma (SCC)/adenosquamous carcinoma (ASC) to adenocarcinoma (AC)., Methods: A retrospective review of preoperative PET/CT, thin-section CT, and postoperative pathological records obtained over a 5-year period was conducted. Solid type NSCLC tumors on thin-section CT with confirmed diagnosis from surgical resection (diameter ≤3 cm) were included. Multivariate logistic regression was used to evaluate the correlation between tumor characteristics and pathological prognostic factors or postoperative recurrence., Results: 150 patients (111 males, 39 females; mean age 67 years; 106 cases of AC, 36 cases of SCC, and 8 cases of ASC) were included. SUVmax was significantly correlated with pleural involvement (p = 0.047), lymphatic permeation (p = 0.003), lymph node metastasis (p = 0.027), and tumor invasiveness (p < 0.001). Receiver operating characteristic analysis indicated an optimal SUVmax threshold of 5.0 for tumor invasiveness. Histopathological type was significantly correlated with pleural involvement (p = 0.042), but not with other types of invasiveness. Twenty-nine patients experienced postoperative recurrence. SUVmax was significantly correlated with tumor recurrence (p = 0.004), but size and histopathological type were not (p = 0.502 and p = 0.351, respectively)., Conclusion: SUVmax of the primary lesion in solid type NSCLC was significantly correlated with tumor invasiveness and postoperative recurrence. No differences in tumor invasiveness were observed between solid type AC and SCC/ASC. However, in solid type AC, SUVmax of the primary lesion was more significantly correlated with recurrence.

Objective: To investigate the correlation between iodine concentration of dual-energy CT (DECT) and histopathology of surgically resected primary lung cancers., Methods: We reviewed the medical records, post-operative pathological records and pre-operative DECT images of patients who underwent surgical lung resection for primary lung cancer. After injection of iodinated contrast media, arterial and delayed phases were scanned using 140- and 80-kV tube voltages. Three-dimensional iodine concentration (iodine volume) of primary tumours was calculated using lung nodule application software., Results: A total of 60 patients (37 males and 23 females; age range, 39-84 years; mean age, 69 years) with 62 lung cancers were analysed. The resected tumours were histopathologically classified into well-differentiated (G1; n = 20), moderately differentiated (G2; n = 29), poorly differentiated (G3; n = 9) and undifferentiated (G4; n = 4) groups by degree of tumour differentiation (DTD). The mean ± standard deviation of iodine volume at the delayed phase was 59.6 ± 18.6 HU in G1 tumours, 46.5 ± 11.3 HU in G2 tumours, 34.3 ± 15.0 HU in G3 tumours and 28.8 ± 6.4 HU in G4 tumours; significant differences were observed between groups (p < 0.001). Univariate logistic regression analysis showed that iodine volumes both at the early and delayed phases were significantly correlated with DTD (p = 0.006 and p = 0.001, respectively), whereas gender, body weight and tumour size were not (p = 0.084, p = 0.062 and p = 0.391, respectively)., Conclusion: The iodine volume of lung cancers was significantly associated with their DTD. High-grade tumours tended to have lower iodine volumes than low-grade tumours., Advances in Knowledge: Iodine volume measured by DECT could be a valuable functional imaging method to estimate differentiation of primary lung cancer.

Purpose: Primary lung cancers have varying prognoses, even for tumors ≤3cm in diameter. Thus, a thorough evaluation is necessary for therapeutic planning. Two imaging biomarkers have been shown to be useful for predicting primary lung cancer prognosis: maximum standardized uptake values (SUVmax) on fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT) and the consolidation/tumor (C/T) ratio defined as the maximum diameter of consolidation within a tumor to the maximum tumor diameter on thin-section computed tomography (TSCT). We compared these biomarkers for predicting post-surgical recurrence in patients with small lung cancers., Materials and Methods: Clinical records, post-operative pathologic findings, and pre-operative PET/CT and TSCT images were reviewed. Solitary primary lung cancers of ≤3cm in diameter after surgical resection were selected for analysis. SUVmax and C/T ratios were recorded. Kaplan-Meier survival curves and Cox hazards ratios were used to identify independent predictors of lung cancer recurrence from among age, gender, surgical procedure, lesion size, C/T ratio, and SUVmax., Results: A total of 169 patients (114 males and 55 females; age range: 34-87 years) with solitary lung cancers were evaluated. The median post-operative follow-up period was 42 months. Twenty-eight patients had cancer recurrence with significantly higher SUVmax (p<0.001) and C/T ratios (p<0.001) than patients without recurrence. Disease-free survival was significantly reduced for SUVmax of ≥2.5 vs. SUVmax of <2.5 (p<0.001) or for a C/T ratio of ≥50% vs. a C/T ratio of <50% (p=0.030). For 19 patients with C/T ratios of <50%, none had a post-operative recurrence. A Cox hazards ratio model showed that only SUVmax was an independent predictor of recurrence (hazards ratio=1.324; p<0.001)., Conclusion: SUVmax on FDG-PET/CT was a significant imaging biomarker relevant to the prognosis of patients with lung cancers, and was superior to the C/T ratio on TSCT for predicting postoperative recurrence, particularly for solid type lung cancer., (Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.)

Objective: To determine the prevalence and clinical features of pathologically proven incidental cancer (IC) detected by whole-body fluorine-18 fludeoxyglucose ((18)F-FDG) positron emission tomography (PET)/CT, as well as the incidence of false-positive and false-negative results., Methods: We retrospectively reviewed reports derived from (18)F-FDG PET/CT images of 3079 consecutive patients with known or suspected malignancies for 3 years. Discrete focal uptake indicating IC was identified from reports as well as pathological or clinical diagnoses, and the clinical courses were investigated. The false-positive result was defined as uptake indicating IC but not pathologically confirmed as malignant during follow-up. The false-negative result was defined as pathologically proven IC detected by another modality at initial clinical work-up or diagnosed during the follow-up period., Results: We found (18)F-FDG uptake indicating IC in 6.7% of all patients, and IC was pathologically proven in 2.2% of all patients. The most common sites were the colon, lung and stomach. The median survival duration of patients with IC was 42 months. The results were false positive in 4.5% of all patients, and the results were false negative in 2.3% of all patients., Conclusion: (18)F-FDG PET/CT is a valuable tool for detecting IC. The rates of false-positive and false-negative results are within acceptable range., Advances in Knowledge: This is the first report to describe the survival of patients with IC, and the detailed features of false-negative results at actual clinical settings.

Background: The ratio of the maximum diameter of consolidation to the maximum tumor diameter (C/T ratio) on thin-section computed tomography (TSCT) and the maximum standardized uptake value (SUVmax) on 18 F-fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT) are often used as preoperative independent variables to evaluate the invasiveness of lung adenocarcinoma. We investigated the associations between these independent variables and pathologic invasiveness in pulmonary adenocarcinomas., Methods: We selected patients with peripheral lung adenocarcinomas, definitively diagnosed by surgical resection, with diameters of ≤ 30 mm over a 4-year period ending in December 2010. The association between 3 independent variables (tumor size, SUVmax, and C/T ratio) and pathologic prognostic factors was evaluated using logistic analysis., Results: We evaluated a total of 163 primary lung adenocarcinomas in 148 patients (93 males and 55 females; age range: 34 to 84 years). Using multivariate logistic regression analysis, SUVmax and the C/T ratio were significantly associated with tumor invasiveness (odds ratio [OR] = 1.227; p = 0.025 and OR = 1.019; p = 0.008, respectively). Tumor size was not associated with invasiveness (OR = 1.003; p = 0.925). For solid type adenocarcinomas, only SUVmax was significantly associated with invasiveness (OR = 1.558; p = 0.003). For subsolid type adenocarcinomas, only the C/T ratio was significantly associated with invasiveness (OR = 1.030; p = 0.009)., Conclusions: Both the C/T ratio and the SUVmax are significantly correlated with pathologic invasiveness in patients with small lung adenocarcinomas, while there was a difference between the 2 evaluations. Solid type adenocarcinomas with SUVmax values of ≥ 4.4 and subsolid type adenocarcinomas with C/T ratio ≥ 53% were so highly invasive.

Introduction: The purpose of this study was to investigate doubling time (DT) differences among solid, part-solid (PS) and non-solid (NS) types of lung cancers. We also compared inter-observer differences in size measurements between diameter and three-dimensional (3D) volume measurements of lung cancers, including PS- and NS-type nodules, using 3D computer-aided volumetry (3D-CAV)., Methods: The long-axis diameters and 3D volumes of lung tumours were measured using CAV by two chest radiologists for 71 consecutive patients with peripheral lung cancer who underwent at least two CT examinations before surgical resection. We evaluated the inter-observer variability for the ratio of diameter change (RCdiameter) and volume change (RCvolume), which were based on two CT images obtained at different times prior to resection. Inter-observer agreement was evaluated by Bland-Altman plots. Based on the volumes obtained from 3D-CAV, we calculated the DTs and compared DT differences between solid, PS and NS types of lung tumours., Results: The inter-observer Spearman's rank correlation coefficients were 0.87 for RCvolume and 0.64 for RCdiameter (p < 0.001). For all internal appearance types, the rs values for RCvolume were greater than those for RCdiameter. The median DT values for solid, PS and NS were 278, 347 and 584 days, respectively. NS- and PS-type tumours had significantly longer DTs (p = 0.024; by Spearman's rank correlation coefficient)., Conclusions: DT determinations using 3D-CAV had good correlations with the internal appearances of lung cancers. Lung tumour volume measurements by 3D-CAV exhibited better inter-observer correlations than did diameter measurements., (© 2013 The Authors. Journal of Medical Imaging and Radiation Oncology published by Wiley Publishing Asia Pty Ltd on behalf of Royal Australian and New Zealand College of Radiologists.)

Objectives: In preoperative segmentectomy simulation for primary lung cancer, it is important to identify the intersegmental pulmonary veins and the relationship between them and the surgical safety margin. We have adopted a method that incorporates a virtual safety margin into three-dimensional computed tomography angiography images in order to plan adequate segmentectomy for lung cancer patients. In this study, we describe the new preoperative planning technique and review cases in which we performed segmentectomy based on its results., Methods: We reviewed clinical, radiological, and pathological records and selected patients who underwent segmentectomy for a primary lung cancer lesion with a diameter of 2 cm or less. These segmentectomies were planned using preoperative three-dimensional computed tomography angiography with a virtual safety margin., Results: A total of 17 primary lung cancers in 16 patients (11 male and 5 female, aged 52-82 years) were removed by segmentectomy, planned using the new technique. In 6 of 17 tumors (35%) were non-solid type adenocarcinomas, 3 tumors (18%) were partly solid type adenocarcinomas, 6 tumors (35%) were solid type adenocarcinomas and 2 tumors (12%) were squamous cell carcinomas. Pathological examination revealed no positive surgical margins and no lymph node metastases in any patients., Conclusions: Three-dimensional computed tomography angiography with a virtual safety margin was able to non-invasively visualize the three-dimensional distances and the relationships between the primary tumor and intersegmental pulmonary veins. It was able to aid in the preoperative planning of a suitable segmentectomy procedure for patients with a primary lung cancer lesion of 2 cm or less in diameter., (Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.)

Objectives: To compare the accuracy of pulmonary lobar volumetry using the conventional number of segments method and novel volumetric computer-aided diagnosis using 3D computed tomography images., Methods: We acquired 50 consecutive preoperative 3D computed tomography examinations for lung tumours reconstructed at 1-mm slice thicknesses. We calculated the lobar volume and the emphysematous lobar volume < -950 HU of each lobe using (i) the slice-by-slice method (reference standard), (ii) number of segments method, and (iii) semi-automatic and (iv) automatic computer-aided diagnosis. We determined Pearson correlation coefficients between the reference standard and the three other methods for lobar volumes and emphysematous lobar volumes. We also compared the relative errors among the three measurement methods., Results: Both semi-automatic and automatic computer-aided diagnosis results were more strongly correlated with the reference standard than the number of segments method. The correlation coefficients for automatic computer-aided diagnosis were slightly lower than those for semi-automatic computer-aided diagnosis because there was one outlier among 50 cases (2%) in the right upper lobe and two outliers among 50 cases (4%) in the other lobes. The number of segments method relative error was significantly greater than those for semi-automatic and automatic computer-aided diagnosis (P < 0.001). The computational time for automatic computer-aided diagnosis was 1/2 to 2/3 than that of semi-automatic computer-aided diagnosis., Conclusions: A novel lobar volumetry computer-aided diagnosis system could more precisely measure lobar volumes than the conventional number of segments method. Because semi-automatic computer-aided diagnosis and automatic computer-aided diagnosis were complementary, in clinical use, it would be more practical to first measure volumes by automatic computer-aided diagnosis, and then use semi-automatic measurements if automatic computer-aided diagnosis failed.

Background: To investigate possible causes for false-negative findings on PET scans for solid-type lung cancers, we retrospectively compared PET findings to clinical and pathological features using multivariate analysis., Methods: We reviewed PET/CT records, clinical records, preoperative thin-section CT images, and postoperative pathological records and selected only solid-type primary lung cancers with lesions ≤ 40 mm in diameter that had been definitively diagnosed by surgical resection. PET images with SUVmax of ≥ 2.5 were considered PET-positive. Logistic regression analysis was used to identify independent predictors of PET-positive or negative among five factors: body weight, blood glucose level, lesion size, location, and histological classification., Results: A total of 187 solid-type primary lung cancers were selected. Forty lesions (21.4%) were judged as PET-negative and 147 lesions (78.6%) were judged as PET-positive. Multivariate logistic analysis for the 187 lesions revealed that lesion size (p<0.001) and histological tumour type (p<0.001) were significant factors for determining whether PET findings were negative., Conclusions: Among solid-type lung cancers, lesion size and histopathological findings were significantly associated with FDG uptake. In particular, it warrants attention that lesions ≤ 2 cm and bronchioloalveolar carcinoma and well-differentiated adenocarcinoma have a tendency for negative PET findings., (Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.)

Purpose: To compare pathological prognostic factors of small lung adenocarcinomas with findings of contrast-enhanced dynamic computed tomography (CT) scans., Materials and Methods: We evaluated 108 patients with lung adenocarcinomas ≤ 30 mm in diameter who underwent dynamic CT scans (80-96 ml of contrast material, 2.5-3 ml/s injection) and tumor resections. Attenuation values of both the early phase (20-36 s after injection) and delayed phase (91-95 s) of enhanced CT minus baseline plain CT attenuation were defined as ΔEarly and ΔDelay. The early enhancement ratio was defined as ΔEarly/ΔDelay×100 (%). We statistically compared the early enhancement ratios between the presence and absence of each pathological finding (lymph node metastasis, lymphatic permeation, vascular invasion, and pleural involvement). Patients were divided into 2 groups based on early enhancement ratios: ratio ≥50% (n = 41) and ratio <50% (n = 67) and we statistically compared these 2 groups., Results: The early enhancement ratios in the group with lymph node metastasis, lymphatic permeation, and vascular invasion were significantly lower than in the group without these findings (24.9% vs 48.6%; P < 0.001, 30.0% vs 47.5%; P = 0.002, and 26.5% vs 47.0%; P = 0.002, respectively). Lymph node metastasis, lymphatic permeation, and vascular invasion were significantly more frequent in tumors with a ratio <50% than in tumors with ratio ≥50% (P < 0.001, P = 0.008, and P = 0.005, respectively)., Conclusions: There was a significant correlation between the early enhancement ratio of enhanced dynamic CT and the pathological prognostic factors in small lung adenocarcinomas.

Purpose: We sought to determine the volume of each anatomic lung lobe reconstructed using 3-dimensional computed tomography (3D-CT) imaging from multidetector CT images and to compare these with pulmonary function test results., Materials and Methods: We reviewed preoperative 3D-CT images and spirometry results of 111 patients (86 men and 25 women) with pulmonary neoplasms who were considered candidates for lung resections. On a 3D-CT image, the entire lung was semiautomatically separated into 5 anatomic lobes: right upper lobe, right middle lobe, right lower lobe, left upper lobe, and left lower lobe. For each lobe, total lobar volume, emphysematous lobar volume with low attenuation values of less than -950 HU, and normal lobar volume (NLV=total lobar volume-emphysematous lobar volume) were calculated. Vital capacity, forced expiratory volume in 1 second, and diffusing capacity for carbon monoxide (DLCO) were measured by spirometry. Relationships between NLV values of each lobe and pulmonary function results were determined by the Pearson correlation coefficients and multiple regression analysis., Results: The NLV values for both lower lobes (right lower lobe and left lower lobe) and the other lobes (right upper lobe, right middle lobe, and left upper lobe) were significantly correlated with vital capacity and forced expiratory volume in 1 second; lower lobes showed a stronger tendency toward these correlations. The NLV values of the lower lobes were significantly correlated with DLCO (P<0.001), although the NLV values of the other lobes were not correlated with DLCO (P=0.112)., Conclusions: Pulmonary function results, particularly DLCO, were primarily affected by the NLVs of the lower lobes.

Three-dimensional computed tomography angiography (3D-CTA) is valuable for preoperative simulations for lung cancer. However, when using 3D-CTA alone, it is difficult to identify tumor safety margins, especially for a segmentectomy. We report 2 cases of primary lung cancer for which we performed segmentectomy based on preoperative simulations by 3D-CTA with virtual 3D safety margins. We found this technique easy to use for simulations and useful for safely performing segmentectomy for small tumors in lung cancer., (Copyright © 2012 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.)

Objective: We focused on fibrosis within lung adenocarcinoma tumors in order to retrospectively analyze correlations with dual-phase contrast enhanced dynamic CT findings., Materials and Methods: We evaluated 89 patients with stage I lung adenocarcinoma who underwent dynamic CT scans (80-96 mL of contrast material, 2.5-3 mL/s injection) and tumor resections. Attenuation values of both the early phase (21-37 s after injection) and the delay phase (91-95 s) of enhanced CT minus the baseline plain CT attenuation were calculated as ΔEarly and ΔDelay. An early enhancement ratio was defined as ΔEarly/ΔDelay×100. These enhancement patterns were compared with patient and tumor characteristics, including scar grades that were the degrees of fibrosis within tumors evaluated semi-quantitatively by pathologists., Results: From multivariate analysis, only the tumor scar grade showed significant correlations with ΔEarly (p<0.001) and the early enhancement ratio (p<0.001). For ΔEarly and the early enhancement ratio, there were significant differences among 4 groups based on tumor scar grades (p=0.003 and p=0.006, respectively); a higher scar grade tumor tended to show lower enhancement at the early phase., Conclusions: There was a significant negative correlation between the amount of fibrosis and the enhancement grade at the early phase of contrast enhanced dynamic CT in stage I lung adenocarcinoma. Dynamic CT findings could be modified by the degree of fibrosis within a lung tumor., (Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.)

Objective: The aim of this study was to evaluate the clinical value of virtual bronchoscopy (VB) in aiding diagnosis of peripheral lung cancer by transbronchial biopsy (TBB). In addition, we sought to systematically analyze the factors that affect the diagnostic sensitivity of VB-guided TBB for the evaluation of peripheral lung cancers., Materials and Methods: A hundred and twenty-two peripheral lung cancers from 122 patients (82 men and 40 women, 38-84 years; median 68.5 years) who were performed VB-guided TBB were evaluated retrospectively. VB was reconstructed from 1- or 0.5-mm slice thickness images of multi-detector CT (MDCT). Experienced pulmonologists inserted the conventional and ultrathin bronchoscopes into the target bronchus under direct vision following the VB image., Results: A definitive diagnosis was established by VB-guided TBB in 96 lesions (79%). The diagnostic sensitivity of small pulmonary lesions ≤30 mm in maximal diameter (71%) was significantly lower than that of lesions >30 mm (91%, p=0.008). For small pulmonary lesions ≤30 mm (n=76), internal opacity of the lesion was the independent predictor of diagnostic sensitivity by VB-guided TBB, and the non-solid type lung cancers were significantly lower than the solid type and part-solid type lung cancers for diagnostic sensitivity (odds ratio=0.161; 95% confidence interval=0.033-0.780; p=0.023)., Conclusion: Use of an ultrathin bronchoscope and simulation with VB reconstructed by high quality MDCT images is thought to improve pathological diagnosis of peripheral lung cancers, especially for solid and partly solid types. For small pulmonary lesions ≤30 mm, the lesion internal opacity is a significant factor for predicting the diagnostic sensitivity, and the sensitivity was low for small non-solid type of lung cancers., (Copyright © 2009 Elsevier Ireland Ltd. All rights reserved.)

Rationale and Objectives: The aim of this study was to evaluate the accuracy of measurements of lung volumes reconstructed using three-dimensional computed tomographic (CT) imaging from thin-section multidetector-row CT images compared to standard pulmonary function testing., Materials and Methods: Preoperative three-dimensional CT images and pulmonary function test results of 64 patients with solitary pulmonary nodules who were considered candidates for lung resection were reviewed. On the three-dimensional CT images, total lung capacity (TLC(CTV)), emphysematous lung capacity (ELC(CTV)), and normal lung capacity (NLC(CTV)) were calculated. Total lung capacity (TLC), vital capacity, and forced expiratory volume in 1 second were measured using spirometry., Results: There was a strong positive correlation between estimated TLC(CTV) and measured TLC values (r = 0.87, P < .001). Estimated ELC(CTV) at the threshold value of -900 Hounsfield units was negatively correlated with forced expiratory volume in 1 second (r = -0.56, P < .001). NLC(CTV) values were more strongly correlated with vital capacity values than TLC(CTV) values (r = 0.74, P < .001)., Conclusions: Lung volume calculated using three-dimensional CT volumetry was well correlated with lung volume measured using spirometry. Three-dimensional CT volumetry can be used to evaluate pulmonary function.

Purpose: The ground-glass opacity (GGO) of lung cancer is identified only subjectively on computed tomography (CT) images as no quantitative characteristic has been defined for GGOs. We sought to define GGOs quantitatively and to differentiate between GGOs and solid-type lung cancers semiautomatically with a computer-aided diagnosis (CAD)., Methods and Materials: High-resolution CT images of 100 pulmonary nodules (all peripheral lung cancers) were collected from our clinical records. Two radiologists traced the contours of nodules and distinguished GGOs from solid areas. The CT attenuation value of each area was measured. Differentiation between cancer types was assessed by a receiver-operating characteristic (ROC) analysis., Results: The mean CT attenuation of the GGO areas was -618.4 +/- 212.2 HU, whereas that of solid areas was -68.1 +/- 230.3 HU. CAD differentiated between solidand GGO-type lung cancers with a sensitivity of 86.0% and specificity of 96.5% when the threshold value was -370 HU. Four nodules of mixed GGOs were incorrectly classified as the solid type. CAD detected 96.3% of GGO areas when the threshold between GGO and solid areas was 194 HU., Conclusion: Objective definition of GGO area by CT attenuation is feasible. This method is useful for semiautomatic differentiation between GGOs and solid types of lung cancer.

Rationale: Radioiodine therapy improves the survival of patients with pulmonary metastases of differentiated thyroid cancer (DTC). It is controversial whether the diagnostic whole-body I-131 scan (DWS) before therapy is essential. We determined whether DWS could predict the efficacy of I-131 therapy for pulmonary metastases., Methods: We undertook a retrospective review of records of 42 patients (28 women and 14 men, mean age 52.7 years). The patients had received 62 rounds of I-131 therapy for lung metastases of DTC at our institution between June 2002 and June 2006. On the same day that the DWS (dose of 185 MBq) (5 mCi) was completed, the patient received I-131 therapy (dose of 3700-7400 MBq) (100-200 mCi). Post-therapy whole-body scans (PWS) were performed after 3 to 4 days and 7 to 8 days. For all therapies, chest CT images were obtained before I-131 therapy, and 3 and 6 months after therapy for evaluation of therapeutic effectiveness. In addition, serum thyroglobulin (Tg) values were measured before and after the radioiodine therapy for all treatments., Results: In the group demonstrating I-131 accumulation for pulmonary metastases on DWS, 72% of patients showed a reduction of pulmonary metastases on follow-up CT. On the other hand, in the group that failed to accumulate I-131 on DWS, only 5% of patients showed a reduction of pulmonary metastases. After therapy, serum Tg levels decreased significantly in the group that initially showed accumulation of I-131 in DWS (P = 0.045). In contrast, no remarkable changes between pre- and post-therapy Tg levels were observed in patients who failed to accumulate I-131 in DWS., Conclusion: A whole-body I-131 diagnostic scan before I-131 therapy has a predictive value for the efficacy of therapeutic radioiodine treatment for pulmonary metastases of differentiated thyroid cancer.

The BLADE and PROPELLER (periodically rotated overlapping parallel lines with enhanced reconstruction) techniques have been proposed to reduce the effect of head motion. Preliminary results have shown that BLADE also reduces pulsation artifacts from venous sinuses. The purpose of this study was to compare T1-weighted FLAIR acquired with BLADE (T1W-FLAIR BLADE) and T1-weighted spin-echo (T1W-SE) for the detection of contrast enhancement in a phantom and in patients with suspected brain lesions and to compare the degree of flow-related artifacts in the patients. A phantom filled with diluted Gd-DTPA was scanned in addition to 27 patients. In the phantom study, the peak contrast-to-noise ratio of T1W-FLAIR BLADE was larger than that of T1W-SE, and the position of the peak was shifted to a lower concentration. In patients, the degree of flow-related artifacts was significantly higher in T1W-SE. Among the 27 patients, 9 had metastatic tumor, and 18 did not. On a patient-by-patient basis, the sensitivity and specificity for the detection of metastatic lesions on axial T1W-SE were 100% and 55.6% respectively, while on axial T1W-FLAIR BLADE they were 100% and 100%. T1W-FLAIR BLADE seems to be capable of replacing T1W-SE, at least for axial post-contrast imaging to detect brain metastases.

Purpose: To investigate the usefulness of helical CT with low-dose and single-breath-hold scanning for lung cancer screening., Materials and Methods: Twenty-four helical CT scans of the lung were performed using various parameters in 10 healthy volunteers. The effects of tube current and pitch were evaluated by assessment of image quality and detection of simulated nodules. Screening helical CT was performed at 120 kVp, 50 mA, 1 sec/rotation, 10 mm collimation, and a pitch of 2.0 in 110 patients. The ability of this method to detect nodules and masses, focal parenchymal opacities, and diffuse fibrotic changes was evaluated using conventional CT as the gold standard., Results: A reduction in tube current to 50 mA did not significantly change the assessment of image quality or detection of simulated nodules. Although these factors were degraded by increasing the pitch, there was no significant difference between 1.5 and 2.0. Screening helical CT permitted the entire lung to be scanned with ease during a single-breath-hold in all patients. This method detected 177 of 196 nodules and masses (87 of 91 lesions greater than 5 mm in diameter), 54 of 57 focal parenchymal opacities, and 15 of 15 cases with fibrotic changes., Conclusion: Screening helical CT with low-dose and single-breath-hold scanning shows promise for lung cancer screening.