Texture Features of 18F-Fluorodeoxyglucose Positron Emission Tomography for Predicting Programmed Death-Ligand-1 Levels in Non-Small Cell Lung Cancer.

Background: Identifying programmed death-ligand-1 (PD-L1) expression is crucial for optimizing treatment strategies involving immune checkpoint inhibitors. However, the role of intratumoral metabolic heterogeneity specifically derived from 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET) images in predicting PD-L1 expression in patients with newly diagnosed non-small cell lung cancer (NSCLC) remains unexplored. Here, we investigated the association between FDG PET texture features and PD-L1 expression by retrospectively analyzing the data of patients newly diagnosed with NSCLC who underwent FDG PET/CT scans and PD-L1 immunohistochemical staining before treatment. Methods: Patients were categorized based on their tumor proportion scores (TPSs) into negative-, low-, and high-PD-L1 expression groups. We computed the maximum standardized uptake value and 31 texture features for the primary tumor from PET images and compared differences in parameters among the groups. Results: Of the 83 patients, 12, 45, and 26 were assigned to the negative-, low-, and high-PD-L1 expression groups, respectively. Six specific texture features (low gray-level run emphasis, short-run low gray-level emphasis, long-run high gray-level emphasis, low gray-level zone emphasis, high gray-level zone emphasis, and short-zone low gray-level emphasis) helped distinguish among all possible combinations. Conclusions: Our findings revealed that FDG PET texture features are potential imaging biomarkers for predicting PD-L1 expression in patients newly diagnosed with NSCLC.

FDG PET texture indices as imaging biomarkers for epidermal growth factor receptor mutation status in lung adenocarcinoma.

Identifying the epidermal growth factor receptor (EGFR) mutation status is important for the optimal treatment of patients with EGFR mutations. We investigated the relationship between 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET) texture indices and EGFR mutation status in patients with newly diagnosed lung adenocarcinoma. We retrospectively analyzed data of patients with newly diagnosed lung adenocarcinoma who underwent pretreatment FDG PET/computed tomography and EGFR mutation testing between August 2014 and November 2020. Patients were divided into mutated EGFR and wild-type EGFR groups. The maximum standardized uptake value (SUVmax) and 31 texture indices for the primary tumor were calculated from PET images and compared between the two groups. Of the 66 patients included, 22 had mutated EGFR and 44 had wild-type EGFR. The SUVmax did not significantly differ between the two groups. Among the 31 evaluated texture indices, the following five showed a statistically significant difference between the groups: correlation (P = 0.003), gray-level nonuniformity for run (P = 0.042), run length nonuniformity (P = 0.02), coarseness (P = 0.006), and gray-level nonuniformity for zone (P = 0.04). Based on the preliminary results of this study in a small patient population, FDG PET texture indices may be potential imaging biomarkers for the EGFR mutation status in patients with newly diagnosed lung adenocarcinoma.

An analysis of the left top pulmonary vein and comparison with the right top pulmonary vein for lung resection by three-dimensional CT angiography and thin-section images.

PURPOSE: The right top pulmonary vein (RTPV) is defined as an anomalous branch of the right superior PV (SPV) draining into the PV or left atrium (LA). Several previous reports have described the RTPV, but only a few have mentioned the left top PV (LTPV). The present study aimed to evaluate the branching patterns of the RTPV and LTPV using thin-section CT images and three-dimensional CT angiography (3D-CTA). MATERIALS AND METHODS: This study included 1437 consecutive patients for evaluation of the right side and 1454 consecutive patients for the left side who were suspected of lung cancer and underwent CTA. We assessed the presence of each RTPV and LTPV and their branching patterns on the CTA images. When the RTPV or LTPV was identified, the maximum short-axis diameter was measured. RESULTS: RTPV was found in 9.1% (131/1437), whereas LTPV was found in 2.9% (42/1454) of the patients. RTPV was also observed in 17.1% (7/41) of LTPV cases, except for one case in which the right side could not be evaluated. The most common RTPV inflow site was the right inferior PV (IPV) in 64.9% (85/131) of the patients, whereas that of the LTPV was the left IPV in 100.0% (42/42) of the patients. The mean diameter of the RTPV and LTPV was 3.3 mm (range, 1.3-7.5 mm) and 2.4 mm (range, 0.9-6.3 mm), respectively (P < 0.01). CONCLUSION: The top PV branching pattern variations can be evaluated using thin-section CT and 3D-CTA images. RTPV is not a rare finding, and LTPV should also be identified in lung cancer cases scheduled for resection.

Correlation of epidermal growth factor receptor mutation status and PD-L1 expression with [18F]FDG PET using volume-based parameters in non-small cell lung cancer.

OBJECTIVE: We investigated the relationship between 2-deoxy-2-[18F]fluoro-D-glucose (FDG) PET using volume-based parameters and epidermal growth factor receptor (EGFR) mutation status, programmed death-ligand-1 (PD-L1) expression level, and their combination, in pretreated non-small cell lung cancer (NSCLC). METHODS: FDG PET findings and EGFR mutation status and PD-L1 expression level were investigated retrospectively in 93 patients with newly diagnosed NSCLC (77 adenocarcinomas, 16 squamous cell carcinomas). Tumors were divided into six groups: EGFR mutant/negative PD-L1, EGFR mutant/low PD-L1, EGFR mutant/high PD-L1, EGFR wild/negative PD-L1, EGFR wild/low PD-L1, and EGFR wild/high PD-L1. The maximum standardized uptake value (SUVmax), metabolic tumor volume (MTV), and total lesion glycolysis (TLG) for primary tumor were measured from PET images. The EGFR mutation status and PD-L1 expression level were estimated in tumor tissue specimens and compared with the PET parameters. RESULTS: None of the PET parameters differed significantly between EGFR-mutated and wild-type EGFR. According to the PD-L1 level, significant differences were detected in SUVmax (P = 0.001) and TLG (P = 0.016), but not MTV. Comparing all six groups, significant difference was detected in only SUVmax (P = 0.011). CONCLUSION: Based on the preliminary results of this study, FDG PET may help in the prediction of PD-L1 expression level, but not EGFR mutation status, in patients with newly diagnosed NSCLC. The SUVmax rather than MTV or TLG, may be of value in predicting the six groups according to the combination of EGFR mutation status and PD-L1 expression level.

Computed tomography findings of current nonspecific interstitial pneumonia based on the 2013 updated classification of idiopathic interstitial pneumonias: What is a characteristic of previously diagnosed nonspecific interstitial pneumonia excluded from the updated classification.

PURPOSE: To evaluate computed tomography (CT) findings of nonspecific interstitial pneumonia (NSIP) based on the current classification of idiopathic interstitial pneumonias (IIPs) and elucidate a characteristic of previously diagnosed NSIP excluded from the current classification. MATERIALS AND METHODS: The study included 74 patients with biopsy-proven NSIP (idiopathic NSIP [I-NSIP], 39 patients; NSIP associated with connective tissue disease [CTD-NSIP], 35 patients). Among patients who were compatible with the current classification of IIPs, 29 and 21 were categorized as having current I-NSIP and current CTD-NSIP, respectively. The remaining 24 patients were categorized as having previous I-NSIP or previous CTD-NSIP due to the primary pathologic diagnosis of cellular NSIP or associated findings of acute inflammatory changes. CT findings were evaluated and compared among the four groups. RESULTS: Current I-NSIP was indicated by ground-glass attenuation and reticulation with traction bronchiectasis/bronchiolectasis in predominantly peribronchovascular areas of the lower lung zone. The previous I-NSIP group tended to show broader airspace consolidation than the current I-NSIP group (p = 0.068). The previous CTD-NSIP group showed significantly broader airspace consolidation than the current I-NSIP group (p = 0.035). CONCLUSION: Broad airspace consolidation is a characteristic of previously diagnosed CTD-NSIP excluded from the current classification of IIPs.

Influenza H1N1 virus-associated pneumonia often resembles rapidly progressive interstitial lung disease seen in collagen vascular diseases and COVID-19 pneumonia; CT-pathologic correlation in 24 patients.

PURPOSE: To describe computed tomography (CT) findings of influenza H1N1 virus-associated pneumonia (IH1N1VAP), and to correlate CT findings to pathological ones. METHODS: The study included 24 patients with IH1N1VAP. Two observers independently evaluated the presence, distribution, and extent of CT findings. CT features were divided into either classical form (C-form) or non-classical form (NC-form). C-form included: A.) broncho-bronchiolitis and bronchopneumonia type, whereas NC-forms included: B.) diffuse peribronchovascular type, simulating subacute rheumatoid arthritis-associated (RA) interstitial lung disease (ILD) and C.) lower peripheral and/or peribronchovascular type, resembling dermatomyositis-associated ILD and COVID-19 pneumonia. In 10 cases with IH1N1VAP where lung biopsy was performed, CT and pathology findings were correlated. RESULTS: The most common CT findings were ground-glass opacities (24/24, 100 %) and airspace consolidation (23/24, 96 %). C-form was found in 11 (46 %) patients while NC-form in 13 (54 %). Types A, B, and C were seen in 11(46 %), 4 (17 %), and 9 (38 %) patients, respectively. The lung biopsy revealed organizing pneumonia in all patients and 6 patients (60 %) showed incorporated type organizing pneumonia that was common histological findings of rapidly progressive ILD. CONCLUSION: In almost half of patients of IH1N1VAP, CT images show NC-form pneumonia pattern resembling either acute or subacute RA or dermatomyositis-associated ILD and COVID-19 pneumonia.

An analysis of anatomical variations of the left pulmonary artery of the interlobar portion for lung resection by three-dimensional CT pulmonary angiography and thin-section images.

PURPOSE: The purpose of the present study was to analyze the left pulmonary artery (LPA) branching pattern of the interlobar portion using three-dimensional CT pulmonary angiography (3D-CTPA) and thin-section CT images, and to attempt to diagrammatize these patterns. MATERIALS AND METHODS: The study included 320 patients suspected of having lung cancer of the left upper/lower lobe who underwent CTPA. The number and origin of the LPA branches of the interlobar portion, A1 + 2c, A6, and lingular artery from pars interlobaris (PI), were identified meticulously using 3D-CTPA and thin-section images. We then diagrammatized the identified LPA branching patterns of the interlobar portion. RESULTS: The diagrammatized LPA branching patterns of the interlobar portion were broadly classified into seven types in the order of bifurcation from proximal to distal. Type 1 was the most frequent (120/320, 37.5%). PI originated from the lower portion, that is, from A8 or the common trunk of A8 and A9 in 95 cases (29.7%). We could also precisely diagrammatize the LPA branching patterns of the interlobar portion into 85 types in all 320 patients. CONCLUSION: 3D-CTPA and thin-section images provided precise preoperative information regarding the LPA branching patterns of the interlobar portion.

Pulmonary Multiloculated 'Lotus Torus-like' Sarcoidosis Mimicking Lung Adenocarcinoma.

A 34-year-old Japanese woman exhibited a 35×25-mm solitary multiloculated mass shadow in the left lower lobe mimicking lung adenocarcinoma. On computed tomography, the mass resembled a lotus torus. A transbronchial lung biopsy and mediastinal lymph node biopsy led to the diagnosis of sarcoidosis. This lotus torus-like mass regressed spontaneously. This is the second reported case of pulmonary cavitary sarcoidosis with a 'lotus torus-like' appearance. We propose several findings regarding the lotus torus-like appearance by comparing the findings to those of lung adenocarcinoma. Knowledge of this unique sign may be helpful for the differential diagnosis of pulmonary sarcoidosis from lung adenocarcinoma.

Impact of idiopathic pulmonary fibrosis on advanced non-small cell lung cancer survival.

PURPOSE: The clinical features of patients with advanced non-small cell lung cancer (NSCLC) and interstitial lung disease (ILD) have not fully been elucidated. This study aimed to investigate the clinical features of these patients, particularly with idiopathic pulmonary fibrosis (IPF). METHODS: Data on 218 patients with pathologically confirmed diagnoses of NSCLC who had been treated with chemotherapy and/or molecular targeted therapy were retrospectively analyzed for progression-free survival (PFS), overall survival (OS), responses to first-line therapy, and incidence of acute exacerbations (AEs). RESULTS: Fifty-three of the 218 patients were diagnosed with ILD, and 34 of them with IPF. The frequency of epidermal growth factor receptor (EGFR) mutation was significantly lower in ILD and IPF patients than in non-ILD patients (2 or 0 vs. 32 %, respectively). Median PFS and OS were significantly shorter in both ILD and IPF patients than in non-ILD patients (118, 92, and 196 days for PFS, and 267, 223, and 539 days for OS, respectively). Multivariate analysis showed that poor performance status, absence of EGFR mutation, and presence of IPF were poor prognostic factors for PFS and OS. Disease control rate (DCR) was significantly lower in ILD and IPF patients than in non-ILD patients regardless of the presence of EGFR mutation (67 or 53 vs. 85 %, respectively). The incidence of AEs of ILD was significantly higher during chemotherapy with docetaxel-containing regimens (seven of 38; 18.4 %). CONCLUSIONS: Both IPF and ILD were associated with lower EGFR positivity, lower DCR, and shorter PFS and OS in advanced NSCLC patients.

Preoperative Evaluation of the Right Upper Lobe Pulmonary Artery by 3D-CT Pulmonary Angiography vs. Thin-Section Multiplanar Reconstruction Images Obtained by Contrast-Enhanced Multidetector-Row CT.

We compared the effectiveness of 3-dimensional computed tomography pulmonary angiography (3D-CTPA) and thin-section multiplanar reconstruction (MPR) images obtained using contrast-enhanced multidetector row CT (MDCT), in the evaluation of pulmonary artery (PA) branches of the right upper lobe. We studied 127 patients suspected of having lung cancer of the right upper lobe who underwent contrast-enhanced MDCT scans and a right upper lobectomy. We compared the intraoperative findings of the PA branches of the right upper lobe obtained with 3D-CTPA and thin-section MPR images. In 125 (97.7%) patients, one or more PA branches arose from arteries other than the superior trunk. Among 10 (7.9%) patients, a PA branch arose from the middle lobe in one patient and from the superior segment of the lower lobe in the other 9 patients. According to the intraoperative findings, 97.2% and 99.7% of the PA branches were identified by 3D-CTPA and thin-section MPR images, respectively (p ＜ 0.03). The single branch missed by both imaging modalities was 1.0mm in dia. The 8 branches missed only by 3D-CTPA were ＜ 1.4mm in dia. Both the 3D-CTPA and thin-section MPR images provided precise preoperative information regarding PA branches of the right upper lobe. However, the thin-section MPR images appeared to contribute more to the evaluation of smaller PA branches.

(18)F-FDG PET/CT Imaging of Primary Hepatic Neuroendocrine Tumor.

Primary hepatic neuroendocrine tumors (PHNETs) are extremely rare neoplasms. Herein, we report a case of a 70- year-old man with a hepatic mass. The non-contrast computed tomography (CT) image showed a low-density mass, and dynamic CT images indicated the enhancement of the mass in the arterial phase and early washout in the late phase. F-18 fluorodeoxyglucose ((18)F-FDG) positron emission tomography (PET) and fused PET/CT images showed increased uptake in the hepatic mass. Whole-body (18)F-FDG PET images showed no abnormal activity except for the liver lesion. Presence of an extrahepatic tumor was also ruled out by performing upper gastrointestinal endoscopy, total colonoscopy, and chest and abdominal CT. A posterior segmentectomy was performed, and histologic examination confirmed a neuroendocrine tumor (grade 1). The patient was followed up for about 2 years after the resection, and no extrahepatic lesions were radiologically found. Therefore, the patient was diagnosed with PHNET. To the best of our knowledge, no previous case of PHNET have been detected by (18)F-FDG PET imaging.

CT assessment of subtypes of pulmonary emphysema in females.

We performed a retrospective study examining the prevalence and subtypes of pulmonary emphysema (PE) identified by computed tomography (CT) in females. We reviewed the records of 1,687 female subjects who had undergone CT. They were divided into the following 2 age groups:group A (＜50 years) and group B (≥50 years). PE was diagnosed by the presence of low-attenuation areas using visual assessment (grades 0-3) on CT images. Two subtypes of PE were observed:centrilobular emphysema (CLE) and paraseptal emphysema (PSE). PE was divided into the following 3 categories:I (CLE or CLE-predominant);II (CLE and PSE of equal extent);and III (PSE or PSE-predominant). PE was found in 64 of 274 smokers (23.3%) and 54 of 1,413 non-smokers (3.8%). In smoking subjects, when grades 1 and 2 were grouped together as mild PE, the mean age for CT grade 3 (severe PE) was significantly higher than that for mild PE. In group A, category III predominated, whereas category I was more prevalent in group B, in both smoking and non-smoking subjects. A high incidence of PE was found in smoking subjects as compared with non-smoking subjects. PSE predominated in younger subjects, whereas CLE predominated in older subjects.

A case of pulmonary sclerosing hemangioma surrounded by giant cystic change on high-resolution computed tomography.

Pulmonary sclerosing hemangioma is a rare benign neoplasm, usually presenting as a well-defined round or oval mass. We report a case of pulmonary sclerosing hemangioma surrounded by an unusual giant cystic change on high-resolution computed tomography, which led to the suspicion of this tumor.

[Informational approach to radiology department by end user computing].

In recent years, due to the advanced computerization of medical institutions, systems such as radiology information system (RIS) and reporting have been used extensively also at radiology departments. However, the introduction of these systems will need a great amount of money, and the systems are not yet introduced in our hospital. On the contrary, thanks to the sophistication and price reduction of personal computers (PCs), there is now found a rapid expansion of end user computing (EUC) in which users of a system actively build and manage the system of their duties. Under these circumstances, in order to assist the duties at low costs, we worked the computerization of duties done at our Radiology Department by using the EUC. Specifically, we used software of general-purpose database to build the system with functions dealing with records on implementing medical examinations and treatments, examination booking and diagnostic imaging report. This system which has been developed according to details of conventional duties and requests from medical personnel makes it possible to alleviate the duties which were done manually.

Evaluation of subsubsegmental pulmonary arteries of the posterior and anterior segments of the right upper lobe using multidetector row computed tomography with multiplanar reconstruction images.

PURPOSE: We evaluated the patterns of subsubsegmental pulmonary arteries of the right upper lobe (posterior segment: S2; anterior segment: S3) with multiplanar reconstruction (MPR) images by multidetector row computed tomography (MDCT). MATERIALS AND METHODS: A total of 64 patients who had undergone MDCT scans were included in the study. The subsubsegmental arteries were named by adding "i" or "ii" as the superior or the inferior branch, respectively, of the subsegmental arteries. The subsubsegmental arteries of S2 (A2ai, A2aii, A2bi, A2bii) and S3 (A3ai, A3aii, A3bi, A3bii) were evaluated as arising from either the recurrent artery (RA) or the ascending artery (AA). RESULTS: A2ai originated from the RA and AA in 43 and 21 patients, respectively. The corresponding numbers were 32 each for A2aii; 28 and 36 for A2bi; 23 and 41 for A2bii; 60 and 4 for A3ai; 43 and 21 for A3aii; 59 and 5 for A3bi; and 54 and 10 for A3bii. CONCLUSION: The branching pattern of the subsubsegmental pulmonary arteries in the right upper lobe (S2 and S3) could be visualized using MDCT with MPR images.

Detection of gastric cancer using 18F-FLT PET: comparison with 18F-FDG PET.

PURPOSE: We prospectively investigated the feasibility of 3'-deoxy-3'-(18)F-fluorothymidine (FLT) positron emission tomography (PET) for the detection of gastric cancer, in comparison with 2-deoxy-2-(18)F-fluoro-D-glucose (FDG) PET, and determined the degree of correlation between the two radiotracers and proliferative activity as indicated by Ki-67 index. METHODS: A total of 21 patients with newly diagnosed advanced gastric cancer were examined with FLT PET and FDG PET. Tumour lesions were identified as areas of focally increased uptake, exceeding that of surrounding normal tissue. For semiquantitative analysis, the maximal standardized uptake value (SUV) was calculated. RESULTS: For detection of advanced gastric cancer, the sensitivities of FLT PET and FDG PET were 95.2% and 95.0%, respectively. The mean (+/-SD) SUV for FLT (7.0 +/- 3.3) was significantly lower than that for FDG (9.4 +/- 6.3 p < 0.05). The mean FLT SUV and FDG SUV in nonintestinal tumours were higher than in intestinal tumours, although the difference was not statistically significant. The mean (+/-SD) FLT SUV in poorly differentiated tumours (8.5 +/- 3.5) was significantly higher than that in well and moderately differentiated tumours (5.3 +/- 2.1; p < 0.04). The mean FDG SUV in poorly differentiated tumours was higher than in well and moderately differentiated tumours, although the difference was not statistically significant. There was no significant correlation between Ki-67 index and either FLT SUV or FDG SUV. CONCLUSION: FLT PET showed as high a sensitivity as FDG PET for the detection of gastric cancer, although uptake of FLT in gastric cancer was significantly lower than that of FDG.