Implications of false negative and false positive diagnosis in lymph node staging of NSCLC by means of ¹⁸F-FDG PET/CT

Radioiodinated Nanobody immunoPET probe for in vivo detection of CD147 in pan-cancer

BACKGROUND

To develop the extracellular matrix metalloproteinase inducer (CD147)-targeting therapeutic strategies, accurate detection of CD147 expression in tumors is crucial. Owing to their relatively low molecular weights and high affinities, nanobodies (Nbs) may be powerful candidates for cancer diagnosis and therapy. In this study, we developed a novel CD147-targeted nanobody radiotracer, [124I]I-NB147, which provides guidance for the noninvasive detection of CD147-overexpressing cancers.

METHODS

CD147 expression in human cancers was detected via immunohistochemistry (IHC) on tissue microarrays (TMAs). Western blot (WB) and flow cytometry were used to screen CD147-positive malignant melanoma (MM), triple-negative breast cancer (TNBC), and pancreatic cancer (PCA) cell lines. The CD147 nanobody (NB147) was labeled with [124I]INa using Iodogen as the oxidizing agent and was purified by the PD-10 column. The physicochemical properties, affinity, metabolic characteristics, biodistribution, and immunoPET imaging of [124I]I-NB147 were evaluated Moreover, [18F]F-FDG was used as a control. Finally, CD147 expression analysis was performed via multiplex immunofluorescence (MxIF) and autoradiography on human cancer specimens and tumor-bearing mice tissues.

RESULTS

TMAs results revealed that CD147 is highly expressed in MM, TNBC, and PCA. A CD147-specific nanobody, NB147, was successfully generated with excellent in vitro binding characteristics. [124I]I-NB147 was obtained with high radiochemical yield and purity, and was stable for at least 4 h in vitro. WB and FCM revealed that CD147 was positive in A375, MDA-MB-435 and ASPC1 cells, whereas SK-MEL-28, 4T1 and BXPC3 cells presented low expression levels. The radio-ELISA results indicated that [124I]I-NB147 had a high binding affinity to CD147. The uptake of [124I]I-NB147 was significantly different between CD147 high-expression cells and CD147 low-expression cells (P < 0.001). The biological half-life of the distribution and clearance phases were 0.05 h and 1.58 h, respectively. In CD147-positive tumor models, the [124I]I-NB147 accumulated in A375, MDA-MB-435, and ASPC1 tumors, and the uptake value was significantly higher than that of [18F]F-FDG. Uptake in SK-MEL-28, BXPC3, and 4T1 tumors was not clearly observed. Finally, through autoradiography and histological studies, the correlation analysis between tumor uptake and CD147 expression level was determined.

CONCLUSIONS

The high expression of CD147 in MM, TNBC, and PCA tissuesand in tumor cells was verified. The CD147 nanobody, NB147 was produced and radiolabeled to obtain the immunoPET probe, [124I]I-NB147, which showed high affinity to CD147 and precise visualization for accurate diagnosis of CD147-expressing lesions in different cancers. These results provide insight into the imaging and binding properties of nanobody NB147 over extended periods of time, reinforcing its potential in developing radionuclide therapies for CD147-positive cancer patients.

Comparison of Al[18F]-NOTA-FAPI-04 PET/CT and [18F]-FDG PET/CT in a patient with lung cancer and pulmonary tuberculosis: a case report and literature review

Background

The coexistence of lung cancer and pulmonary tuberculosis (TB) makes differential diagnosis even more complicated. The purpose of the study is to explore superiority of [18F]-NOTA-FAPI-04 PET/CT in distinguishing TB from malignant lesions and accurately detecting inflammatory lymph nodes than [18F]-FDG PET/CT.

Case summary

Herein, we described a case report of a patient with both lung cancer and tuberculosis underwent [18F]-FDG and Al[18F]-NOTA-FAPI-04 positron emission tomography/computed tomography (PET/CT) to determine staging. Additionally, a literature review was conducted to discuss the potential clinical applications of FAPI PET/CT. We reported a 70-year-old man with newly diagnosed lung squamous cell carcinoma underwent [18F]-FDG and Al[18F]-NOTA-FAPI-04 PET/CT to determine staging. The avid uptake of [18F]-FDG in old pulmonary TB and the right hilar inflammatory lymph nodes (<1 cm) were not found on Al [18F]-NOTA-FAPI-04 PET/CT. After 2 months of follow-up, the small lymph node was finally confirmed to be inflammatory.

Conclusion

Al[18F]-NOTA-FAPI-04 PET/CT may perform better in distinguishing TB from malignancy and may offer greater specificity than [18F]-FDG PET/CT for the diagnosis inflammatory lymph nodes.

Lymph node metastasis in early invasive lung adenocarcinoma: Prediction model establishment and validation based on genomic profiling and clinicopathologic characteristics

BACKGROUND

The presence of lymph node (LN) metastasis directly affects the treatment strategy for lung adenocarcinoma (LUAD). Next-generation sequencing (NGS) has been widely used in patients with advanced LUAD to identify targeted genes, while early detection of pathologic LN metastasis using NGS has not been assessed.

METHODS

Clinicopathologic features and molecular characteristics of 224 patients from Ruijin Hospital were analyzed to detect factors associated with LN metastases. Another 140 patients from Huashan Hospital were set as a test cohort.

RESULTS

Twenty-four out of 224 patients were found to have lymph node metastases (10.7%). Pathologic LN-positive tumors showed higher mutant allele tumor heterogeneity (p < 0.05), higher tumor mutation burden (p < 0.001), as well as more frequent KEAP1 (p = 0.001), STK11 (p = 0.004), KRAS (p = 0.007), CTNNB1 (p = 0.017), TP53, and ARID2 mutations (both p = 0.02); whereas low frequency of EGFR mutation (p = 0.005). A predictive nomogram involving male sex, solid tumor morphology, higher T stage, EGFR wild-type, and TP53, STK11, CDKN2A, KEAP1, ARID2, KRAS, SDHA, SPEN, CTNNB1, DICER1 mutations showed outstanding efficiency in both the training cohort (AUC = 0.819) and the test cohort (AUC = 0.780).

CONCLUSION

This study suggests that the integration of genomic profiling and clinical features identifies early-invasive LUAD patients at higher risk of LN metastasis. Improved identification of LN metastasis is beneficial for the optimization of the patient's therapy decisions.

124I-labeled anti-CD147 antibody for noninvasive detection of CD147-positive pan-cancers: construction and preclinical studies

Extracellular matrix metalloproteinase inducer CD147 is a glycoprotein on the cell surface. There is minimal expression of CD147 in normal epithelial and fetal tissues, but it is highly expressed in a number of aggressive tumors. CD147 has been implicated in pan-cancer immunity and progression. With the development of CD147-targeting therapeutic strategy, accurate detection of CD147 expression in tumors and its changes during the therapy is necessary. In this study we constructed a novel radiotracer by labeling the anti-CD147 mAb with radionuclide 124/125I (124/125I-anti-CD147) for noninvasive detection of CD147 expression in pan-cancers, and characterized its physicochemical properties, affinity, metabolic characteristics, biodistribution and immunoPET imaging with 124I-IgG and 18F-FDG as controls. By examining the expression of CD147 in cancer cell lines, we found high CD147 expression in colon cancer cells LS174T, FADU human pharyngeal squamous cancer cells and 22RV1 human prostate cancer cells, and low expression of CD147 in human pancreatic cancer cells ASPC1 and human gastric cancer cells BGC823. 124/125I-anti-CD147 was prepared using N-bromine succinimide (NBS) as oxidant and purified by PD-10 column. Its radiochemical purity (RCP) was over 99% and maintained over 85% in saline or 5% human serum albumin (HSA) for more than 7 d; the RCP of 125I-anti-CD147 in blood was over 90% at 3 h post injection (p.i.) in healthy mice. The Kd value of 125I-anti-CD147 to CD147 protein was 6.344 nM, while that of 125I-IgG was over 100 nM. 125I-anti-CD147 showed much greater uptake in CD147 high-expression cancer cells compared to CD147 low-expression cancer cells. After intravenous injection in healthy mice, 125I-anti-CD147 showed high initial uptake in blood pool and liver, the uptake was decreased with time. The biological half-life of distribution and clearance phases in healthy mice were 0.63 h and 19.60 h, respectively. The effective dose of 124I-anti-CD147 was estimated as 0.104 mSv/MBq. We conducted immunoPET imaging in tumor-bearing mice, and demonstrated a significantly higher tumor-to-muscle ratio of 124I-anti-CD147 compared to that of 124I-IgG and 18F-FDG in CD147 (+) tumors. The expression levels of CD147 in cells and tumors were positively correlated with the maximum standardized uptake value (SUVmax) (P < 0.01). In conclusion, 124/125I-anti-CD147 displays high affinity to CD147, and represents potential for the imaging of CD147-positive tumors. The development of 124I-anti-CD147 may provide new insights into the regulation of tumor microenvironment and formulation of precision diagnosis and treatment programs for tumors.

Canadian Consensus Recommendations for the Management of Operable Stage II/III Non-Small-Cell Lung Cancer: Results of a Modified Delphi Process

The treatment paradigm for patients with stage II/III non-small-cell lung cancer (NSCLC) is rapidly evolving. We performed a modified Delphi process culminating at the Early-stage Lung cancer International eXpert Retreat (ELIXR23) meeting held in Montreal, Canada, in June 2023. Participants included medical and radiation oncologists, thoracic surgeons and pathologists from across Quebec. Statements relating to diagnosis and treatment paradigms in the preoperative, operative and postoperative time periods were generated and modified until all held a high level of consensus. These statements are aimed to help guide clinicians involved in the treatment of patients with stage II/III NSCLC.

Mediastinal Staging in Non-Small-Cell Lung Cancer: Saying Goodbye to Mediastinoscopy

The Oncology Grand Rounds series is designed to place original reports published in the Journal into clinical context. A case presentation is followed by a description of diagnostic and management challenges, a review of the relevant literature, and a summary of the authors' suggested management approaches. The goal of this series is to help readers better understand how to apply the results of key studies, including those published in Journal of Clinical Oncology, to patients seen in their own clinical practice.Accurate staging of the mediastinal lymph nodes in resectable non-small-cell lung cancer (NSCLC) is critically important to determine the overall stage of the tumor and guide subsequent management. The staging process typically begins with positron emission tomography (PET) or computed tomography imaging; however, imaging alone is inadequate, and tissue acquisition is required for confirmation of nodal disease. Mediastinoscopy was long considered the gold standard for staging of mediastinal lymph nodes, but, recently, endobronchial ultrasound-guided (EBUS) fine-needle aspiration (FNA) has become the standard of care. EBUS-FNA, in combination with supplementary technologies, such as intranodal forceps biopsy and esophageal ultrasonography, has a high sensitivity and specificity for the diagnosis of nodal metastases. EBUS-FNA is also capable of assessing N1 disease and obtaining adequate tissue for tumor genomic analysis to help guide treatment. In the case of negative findings on EBUS, a confirmatory video mediastinoscopy is still recommended by the European Society of Thoracic Surgeons guidelines. However, whether confirmatory mediastinoscopy is necessary is a matter of debate, and it is not commonly performed in North America. To address this question, Bousema and colleagues performed a randomized noninferiority trial to determine rates of unforeseen nodal metastases after EBUS alone versus EBUS with confirmatory mediastinoscopy in patients with resectable NSCLC. The authors concluded that EBUS alone is noninferior to EBUS with confirmatory mediastinoscopy. These findings affirm our current practice to forgo confirmatory mediastinoscopy after negative findings on EBUS.

Preclinical Lymph Node Model for Intraoperative Molecular Imaging of Cancer

Purpose

Lymph node(LN) dissection is part of most oncologic resections. Intraoperatively identifying a positive LN(+ LN), that harbors malignant cells, can be challenging. We hypothesized that intraoperative molecular imaging(IMI) using a cancer-targeted fluorescent prober can identify + LNs. This study aimed to develop a preclinical model of a + LN and test it using an activatable cathepsin-based enzymatic probe, VGT-309.

Procedures

In the first model, we used peripheral blood mononuclear cells (PBMC), representing the lymphocytic composition of the LN, mixed with different concentrations of human lung adenocarcinoma cell line A549. Then, they were embedded in a Matrigel® matrix. A black dye was added to mimic LN anthracosis. Model two was created using a murine spleen, the largest lymphoid organ, injected with various concentrations of A549. To test these models, we co-cultured A549 cells with VGT-309. Mean fluorescence intensity(MFI) was. An independent sample t-test was used to compare the average MFI of each A549:negative control ratio.

Results

A significant difference in MFI from our PBMC control was noted when A549 cells were 25% of the LN (p = 0.046) in both 3D cell aggregate models-where the LNs native parenchyma is replaced and the one where the tumor grows over the native parenchyma. For the anthracitic equivalents of these models, the first significant MFI compared to the control was when A549 cells were 9% of the LN (p = 0.002) in the former model, and 16.7% of the LN (p = 0.033) in the latter. In our spleen model, we first noted significance in MFI when A549 cells were 16.67% of the cellular composition.(p = 0.02).

Conclusions

A + LN model allows for a granular evaluation of different cellular burdens in + LN that can be assessed using IMI. This first exvivo + LN model can be used in preclinical testing of several existing dyes and in creating more sensitive cameras for IMI-guided LN detection.

Histology of the Primary Tumor Correlates with False Positivity of Integrated 18F-FDG-PET/CT Lymph Node Staging in Resectable Lung Cancer Patients

This study aimed to evaluate the diagnostic accuracy and false positivity rate of lymph node (LN) staging assessed by integrated 18F-fluorodeoxyglucose positron emission computed tomography (18F-FDG-PET/CT) in patients with operable lung cancer to the tumor histology. In total, 129 consecutive patients with non-small-cell lung cancer (NSCLC) undergoing anatomical lung resections were included. Preoperative LN staging was evaluated in the relationship to the histology of the resected specimens (group 1: lung adenocarcinoma/LUAD; group 2: squamous cell carcinoma/SQCA). Statistical analysis was performed by the Mann-Whitney U-test, the chi² test, and binary logistic regression analysis. To establish an easy-to-use algorithm for the identification of LN false positivity, a decision tree including clinically meaningful parameters was generated. In total, 77 (59.7%) and 52 (40.3%) patients were included in the LUAD and SQCA groups, respectively. SQCA histology, non-G1 tumors, and tumor SUVmax > 12.65 were identified as independent predictors of LN false positivity in the preoperative staging. The corresponding ORs and their 95% CIs were 3.35 [1.10-10.22], p = 0.0339; 4.60 [1.06-19.94], p = 0.0412; and 2.76 [1.01-7.55], and p = 0.0483. The preoperative identification of false-positive LNs is an important aspect of the treatment regimen for patients with operable lung cancer; thus, these preliminary findings should be further evaluated in larger patient cohorts.

Preoperative Hilar and Mediastinal Lymph Node Staging in Patients with Suspected or Diagnosed Lung Cancer: Accuracy of 18F-FDG-PET/CT:A Retrospective Cohort Study of 138 Patients

The aim of this study was to evaluate the diagnostic accuracy of integrated 18F-fluorodeoxyglucose positron emission computed tomography (18F-FDG-PET/CT) in hilar and mediastinal lymph node (HMLN) staging of suspected or proven lung cancer, and to investigate potential risk factors for false negative and false positive HMLN metastases. We retrospectively analyzed 162 consecutive patients with suspected or pathologically proven non-small cell lung cancer (NSCLC). The receiver operating characteristic (ROC) curve was generated to determine the diagnostic efficacy of 18F-FDG-PET/CT. Univariate and multivariate analyses were conducted to detect risk factors of false positives and false negatives. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of integrated 18F-FDG-PET/CT in detecting HMLN metastases were 59.1% (26/44), 69.1% (65/94), 47.3% (26/55), 78.3% (65/83), and 65.9% (91/138), respectively. The ROC curve showed an area under the curve (AUC) of 0.625 (95%-CI 0.468-0.782). The incidence of false negative and false positive HMLN metastases was 21.7% (18/83) and 52.7% (29/55), respectively. Our data shows that integrated 18F-FDG-PET/CT staging provides lower specificity and sensitivity. This confirms the ESTS guideline on lymph node staging for PET-positive HMLN. Yet it advocates more invasive staging even for PET-negative HMLN.

Prediction of malignant lymph nodes in NSCLC by machine-learning classifiers using EBUS-TBNA and PET/CT

Accurate determination of lymph-node (LN) metastases is a prerequisite for high precision radiotherapy. The primary aim is to characterise the performance of PET/CT-based machine-learning classifiers to predict LN-involvement by endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) in stage-III NSCLC. Prediction models for LN-positivity based on [¹⁸F]FDG-PET/CT features were built using logistic regression and machine-learning models random forest (RF) and multilayer perceptron neural network (MLP) for stage-III NSCLC before radiochemotherapy. A total of 675 LN-stations were sampled in 180 patients. The logistic and RF models identified SUV_max, the short-axis LN-diameter and the echelon of the considered LN among the most important parameters for EBUS-positivity. Adjusting the sensitivity of machine-learning classifiers to that of the expert-rater of 94.5%, MLP (P = 0.0061) and RF models (P = 0.038) showed lower misclassification rates (MCR) than the standard-report, weighting false positives and false negatives equally. Increasing the sensitivity of classifiers from 94.5 to 99.3% resulted in increase of MCR from 13.3/14.5 to 29.8/34.2% for MLP/RF, respectively. PET/CT-based machine-learning classifiers can achieve a high sensitivity (94.5%) to detect EBUS-positive LNs at a low misclassification rate. As the specificity decreases rapidly above that level, a combined test of a PET/CT-based MLP/RF classifier and EBUS-TBNA is recommended for radiation target volume definition.

Positron emission tomography imaging of lung cancer: An overview of alternative positron emission tomography tracers beyond F18 fluorodeoxyglucose

Lung cancer has been the leading cause of cancer-related mortality in China in recent decades. Positron emission tomography-computer tomography (PET/CT) has been established in the diagnosis of lung cancer. ¹⁸F-FDG is the most widely used PET tracer in foci diagnosis, tumor staging, treatment planning, and prognosis assessment by monitoring abnormally exuberant glucose metabolism in tumors. However, with the increasing knowledge on tumor heterogeneity and biological characteristics in lung cancer, a variety of novel radiotracers beyond ¹⁸F-FDG for PET imaging have been developed. For example, PET tracers that target cellular proliferation, amino acid metabolism and transportation, tumor hypoxia, angiogenesis, pulmonary NETs and other targets, such as tyrosine kinases and cancer-associated fibroblasts, have been reported, evaluated in animal models or under clinical investigations in recent years and play increasing roles in lung cancer diagnosis. Thus, we perform a comprehensive literature review of the radiopharmaceuticals and recent progress in PET tracers for the study of lung cancer biological characteristics beyond glucose metabolism.

Role of 18F-FDG PET/CT in the postoperative follow-up in patients with stage I-III NSCLC: A retrospective single-institution study

BACKGROUND

The optimal surveillance strategy in patients with resected non-small cell lung cancer (NSCLC) is unknown. Early detection of recurrences by follow-up imaging might improve survival and whole-body 18F-FDG-PET/CT might be the optimal imaging modality given its high accuracy in preoperative staging.

MATERIAL AND METHODS

Data from a single-center cohort of 205 patients with resected stage I-III NSCLC and FDG-PET/CT surveillance was retrospectively collected. Patients had preoperative FDG-positive tumors and FDG-PET/CT at 6, 12, 24 months, chest CT at 18 months. Thereafter, annual chest CT was performed for stage I-II, annual FDG-PET/CT for stage III.

RESULTS

With a median follow-up of 26.3 months (range, 4.1-60.6), the rate for recurrence and secondary primary lung cancer (SPLC) was 22 % and 8 %, respectively. Associated symptoms were present in 48 % (recurrence) and 18 % (SPLC) of patients. Overall, 83 % of recurrences, and 65 % of SPLC were detected on FDG-PET/CT. 82 % of recurrences were detected in one of the first two follow-up PET/CT scans. Second curatively intended treatment (SCIT) was possible in 37 % of patients with recurrence and 100 % with SPLC. The 2-year recurrence-free survival rate after SCIT for recurrence was 53 % [95 %CI; 31-91 %]. Non-malignant FDG-positive findings occurred in 25 % of patients (71 % possible infections).

CONCLUSION

In our cohort of patients, more than 80% of all recurrences were identified in one of the three FDG-PET/CTs performed as part of our imaging protocol during the first two years after resection. Nearly all patients with non-distant recurrence qualified for a SCIT. Further studies are needed to identify patients who might benefit from an even more intensive surveillance strategy.

Comparison of recurrence risk between patients with clinically node-positive and -negative stage I non-small cell lung cancer following surgery: A propensity score matching analysis

Background

Identifying patients with stage I non‐small cell lung cancer (NSCLC) at increased risk of tumor recurrence following surgery remains a major challenge. The current study aimed to compare disease‐free survival (DFS) rates after surgery between patients with clinically node‐positive (cN+) and ‐negative (cN0) stage I NSCLC.

Methods

Patients with pathological stage I resected NSCLC were identified from the lung cancer database of Changhua Christian Hospital in Taiwan. Patients with clinical N status 1 or 2 and pathological N status 0 were identified as the cN+/pN0 cohort, whereas others were identified as the cN0/pN0 cohort. Propensity score matching (PSM) was used to balance the baseline characteristics between both cohorts. Kaplan–Meier method and Cox proportional hazards model were used to evaluate DFS.

Results

From January 2010 to July 2019, 754 eligible patients were enrolled into the study, among whom 41 (5.4%) were cN+/pN0. The median follow‐up time was 43.4 months. Before PSM, the 5‐year DFS rate was 79.0% and 90.3% in cN+/pN0 and cN0/pN0 cohorts (log‐rank test, p = 0.009), respectively. After a 1:4 PSM, multivariate analysis showed that the cN+/pN0 cohort still had a poorer DFS compared to the cN0/pN0 cohort in (hazard ratio, 3.17; p = 0.040).

Conclusion

Among patients with stage I resected NSCLC, cN+ patients had a worse DFS compared to cN0 patients. Surgeons should therefore consider more aggressive adjuvant therapy or frequent follow‐up in patients with surgically resected stage I NSCLC with cN+ status.

Linear Endobronchial Ultrasound in the Era of Personalized Lung Cancer Diagnostics-A Technical Review

Major advances in molecular profiling for available targeted treatments and immunotherapy for lung cancer have significantly increased the complexity of tissue-based diagnostics. Endobronchial ultrasound-guided transbronchial needle aspirations (EBUS-TBNA) are commonly performed for diagnostic biopsies and lymph node staging. EBUS-TBNA has increasingly become one of the main sources of tumor cells for molecular analyses. As a result, there is a growing need for high quality EBUS-TBNA samples with adequate cellularity. This has increased the technical demands of the procedure and has created additional challenges, many of which are not addressed in the current EBUS guidelines. This review provides an overview of current evidence on the technical aspects of EBUS-TBNA in light of comprehensive sample processing for personalized lung cancer management. These include sonographic lymph node characterization, optimal needle choice, suction biopsy technique, and the role of rapid on-site evaluation. Attention to these technical details will be important to maximize the throughput of EBUS-TBNA biopsies for molecular testing.

Assessment of intrathoracic lymph nodes by FDG PET/CT in patients with asbestos-related lung cancer

Background

This study explored the assessment of intrathoracic lymph node metastasis by 18F-fluoro-2-deoxy-D-glucose (FDG) positron emission tomography computed tomography (PET/CT) in patients with asbestos-related lung cancer (ARLC).

Methods

We retrospectively reviewed the data on 35 patients with ARLC who underwent preoperative FDG-PET/CT and surgical resection between January 2012 and December 2018. We collected medical information from medical records and imaging systems and examined the FDG uptake in each lymph nodal region resected by surgery and the presence or absence of pathological lymph node metastasis.

Results

Pathological lymph node metastases were detected in 14 (8.70%) of 161 nodal stations. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of FDG-PET/CT were 71.4% (10/14), 87.8% (129/147), 35.7% (10/28), 97.0% (129/133), and 86.3% (139/161), respectively. Six of the eight false-positive patients had bilateral accumulations, whereas all six true-positive patients had unilateral accumulation (P=0.006). On histopathological examination, the false-positive nodes showed disruption of lymphoid follicles in the cortex, infiltration of histiocyte-like cells in the medulla, fibrous micronodules, and severe anthracosis.

Conclusions

PET/CT scans of patients with ARLC showed comparable sensitivity and specificity to those of PET/CT scans of patients with conventional lung cancer reported in the literature. Many false-positive cases also showed bilateral symmetric accumulation. This method can be used to evaluate lymph node involvement in lung cancer.

Pre-surgical assessment of mediastinal lymph node metastases in patients having ≥ 30 mm non-small-cell lung cancers

INTRODUCTION

Computed tomography (CT) and fluorodeoxyglucose-positron-emission-tomography (FDG-PET) measurements of mediastinal lymph nodes (MLNs) of patients with non-small-cell-lung-cancers (NSCLCs) ≤ 30 mm in maximum diameter are recommended for pre-surgical prediction of MLN metastases.

METHODS

We reviewed all patients at Mount Sinai Health System enrolled in the Initiative for Early Lung Cancer Research on Treatment (IELCART), prospective cohort between 2016 and 2020, who had pre-surgical FDG-PET and underwent surgery with MLN resection and/or pre-operative endobronchial ultrasound (EBUS) for a first primary NSCLC ≤ 30 mm in maximum diameter on pre-surgical CT.

RESULTS

Among 470 patients, none with part-solid (n = 63) or nonsolid (n = 23) NSCLCs had MLN metastases. Solid NSCLCs were identified in 384 patients, none in typical carcinoid (n = 48) or NSCLC ≤ 10 mm in maximum diameter (n = 47, including 8 typical carcinoids) had MLN metastases. Among the remaining 297 patients with solid NSCLCs 10.1-30.0 mm, 7 (2.4%) had MLN metastases. Area-under-the-curve (AUC) for predicting MLN metastases in solid NSCLCs 10.1-30.0 mm, using the CT maximum short-axis MLN diameter was 0.62 (95% CI:0.44-0.81, p = 0.18) and using the highest SUVmax of any MLN, AUC was 0.58 (95% CI:0.39-0.78,p = 0.41). Neither AUCs were significantly different from chance alone. Optimal cutoff for prediction of MLN metastases was ≥ 18.9 mm for CT maximum short-axis diameter [sensitivity 14.3% (95%CI:0.0%-57.9%); specificity 100.0% (95%CI:98.9%-100.0%)] and for highest SUVmax was ≥ 11.7 [sensitivity 14.3% (95%CI:0.0%-57.9%) and specificity 99.7% (95%CI:98.3%-100.0%)].

CONCLUSIONS

CT and SUVmax had low sensitivity but high specificity for predicting MLN metastases in solid NSCLCs 10.1-30.0 mm. Clinical Stage IA NSCLCs ≤ 30 mm should be based on CT maximum tumor diameter and MLN maximum short-axis diameter ≤ 20 mm.

Impact of 18F-FDG PET/CT, CT and EBUS/TBNA on preoperative mediastinal nodal staging of NSCLC

BACKGROUND

Staging of non-small-cell lung cancer (NSCLC) is a multidisciplinary process involving imaging, endoscopic and surgical techniques. This study aims at investigating the diagnostic accuracy of ¹⁸F-FDG PET/CT, CT scan, and endobronchial ultrasound/transbronchial needle aspirate (EBUS/TBNA) in preoperative mediastinal lymph nodes (MLNs) staging of NSCLC.

METHODS

We identified all patients who were diagnosed with NSCLC at the King Hussein Cancer Center in Amman, Jordan, between July 2011 and December 2017. We collected their relevant clinical, radiological, and histopathological findings. The per-patient analysis was performed on all patients (N = 101) and then on those with histopathological confirmation (N = 57), followed by a per-lymph-node-station basis overall, and then according to distinct N-stage categories.

RESULTS

¹⁸F-FDG PET/CT, in comparison to CT, had a better sensitivity (90.5% vs. 75%, p = 0.04) overall and in patients with histopathological confirmation (83.3% vs. 54.6%), and better specificity (60.5% vs. 43.6%, p = 0.01) overall and in patients with histopathological confirmation in MLN staging (60.6% vs. 38.2%). Negative predictive value of mediastinoscopy, EBUS/TBNA, and ¹⁸F-FDG PET/CT were (87.1%), (90.91%), and (83.33%) respectively. The overall accuracy was highest for mediastinoscopy (88.6%) and EBUS/TBNA (88.2%), followed by ¹⁸F-FDG PET/CT (70.2%). Dividing patients into N1 disease vs. those with N2/N3 disease yielded similar findings. Comparison between ¹⁸F-FDG PET/CT and EBUS/TBNA in patients with histopathological confirmation shows 28 correlated true positive and true negative findings with final N-staging. In four patients, ¹⁸F-FDG PET/CT detected metastatic MLNs that would have otherwise remained undiscovered by EBUS/TBNA alone. Lymph nodes with a maximal standardized uptake value (SUVmax) more than 3 were significantly more likely to be true-positive.

CONCLUSION

Multimodality staging of the MLNs in NSCLC is essential to provide accurate staging and the appropriate treatment. ¹⁸F-FDG PET/CT has better overall diagnostic utility when compared to the CT scan. The NPV of ¹⁸F-FDG PET/CT in MLNs is reliable and comparable to the NPV of EBUS/TBNA. SUVmax of MLNs can help in predicting metastases, but nevertheless, a positive ¹⁸F-FDG PET/CT MLNs particularly if such a result would change the treatment plan, should be verified histopathologically.

Impact of EBUS-TBNA in addition to [18F]FDG-PET/CT imaging on target volume definition for radiochemotherapy in stage III NSCLC

Purpose/introduction

[¹⁸F]FDG-PET/CT is the standard imaging-technique for radiation treatment (RT) planning in locally advanced non-small cell lung cancer (NSCLC). The purpose of this study was to examine the additional value of endobronchial-ultrasound transbronchial needle aspiration (EBUS-TBNA) to standard PET/CT for mediastinal lymph-node (LN) staging and its impact on clinical target volume (CTV).

Materials and methods

All consecutive patients with primary stage III NSCLC who underwent [¹⁸F]FDG-PET/CT and EBUS-TBNA prior to RT were analyzed from 12/2011 to 06/2018. LN-stations were assessed by an expert-radiologist and a nuclear medicine-physician. CTV was evaluated by two independent radiation oncologists. LNs were grouped with increasing distance along the lymphatic chains from primary tumor into echelon-1 (ipsilateral hilum), echelon-2 (LN-station 7 and ipsilateral 4), and echelon-3 (remaining mediastinum and contralateral hilum).

Results

A total of 675 LN-stations of which 291 were positive for tumor-cells, were sampled by EBUS-TBNA in 180 patients. The rate of EBUS-positive LNs was 43% among all sampled LNs. EBUS-positivity in EBUS-probed LNs decreased from 85.8% in echelon-1 LNs to 42.4%/ 9.6% in echelon-2/ -3 LNs, respectively (p < 0.0001, Fisher’s exact test). The false discovery rate of PET in comparison with EBUS results rose from 5.3% in echelon-1 to 32.9%/ 69.1% in echelon-2/ -3 LNs, respectively (p < 0.0001, Fisher’s exact test). Sensitivity and specificity of FDG-PET/CT ranged from 85 to 99% and 67 to 80% for the different echelons. In 22.2% patients, EBUS-TBNA finding triggered changes of the treated CTV, compared with contouring algorithms based on FDG-avidity as the sole criterion for inclusion. CTV was enlarged in 6.7% patients due to EBUS-positivity in PET-negative LN-station and reduced in 15.5% by exclusion of an EBUS-negative but PET-positive LN-station.

Conclusion

The false discovery rate of [¹⁸F]FDG-PET/CT increased markedly with distance from the primary tumor. Inclusion of systematic mediastinal LN mapping by EBUS-TBNA in addition to PET/CT has the potential to increase accuracy of target volume definition, particularly in echelon-3 LNs. EBUS-TBNA is recommended as integral part of staging for radiochemotherapy in stage III NSCLC.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00259-021-05204-7.

Amino Acid Transporters on the Guard of Cell Genome and Epigenome

Tumorigenesis is driven by metabolic reprogramming. Oncogenic mutations and epigenetic alterations that cause metabolic rewiring may also upregulate the reactive oxygen species (ROS). Precise regulation of the intracellular ROS levels is critical for tumor cell growth and survival. High ROS production leads to the damage of vital macromolecules, such as DNA, proteins, and lipids, causing genomic instability and further tumor evolution. One of the hallmarks of cancer metabolism is deregulated amino acid uptake. In fast-growing tumors, amino acids are not only the source of energy and building intermediates but also critical regulators of redox homeostasis. Amino acid uptake regulates the intracellular glutathione (GSH) levels, endoplasmic reticulum stress, unfolded protein response signaling, mTOR-mediated antioxidant defense, and epigenetic adaptations of tumor cells to oxidative stress. This review summarizes the role of amino acid transporters as the defender of tumor antioxidant system and genome integrity and discusses them as promising therapeutic targets and tumor imaging tools.

Machine learning-based diagnostic method of pre-therapeutic 18F-FDG PET/CT for evaluating mediastinal lymph nodes in non-small cell lung cancer

OBJECTIVES

We aimed to find the best machine learning (ML) model using ¹⁸F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) for evaluating metastatic mediastinal lymph nodes (MedLNs) in non-small cell lung cancer, and compare the diagnostic results with those of nuclear medicine physicians.

METHODS

A total of 1329 MedLNs were reviewed. Boosted decision tree, logistic regression, support vector machine, neural network, and decision forest models were compared. The diagnostic performance of the best ML model was compared with that of physicians. The ML method was divided into ML with quantitative variables only (MLq) and adding clinical information (MLc). We performed an analysis based on the ¹⁸F-FDG-avidity of the MedLNs.

RESULTS

The boosted decision tree model obtained higher sensitivity and negative predictive values but lower specificity and positive predictive values than the physicians. There was no significant difference between the accuracy of the physicians and MLq (79.8% vs. 76.8%, p = 0.067). The accuracy of MLc was significantly higher than that of the physicians (81.0% vs. 76.8%, p = 0.009). In MedLNs with low ¹⁸F-FDG-avidity, ML had significantly higher accuracy than the physicians (70.0% vs. 63.3%, p = 0.018).

CONCLUSION

Although there was no significant difference in accuracy between the MLq and physicians, the diagnostic performance of MLc was better than that of MLq or of the physicians. The ML method appeared to be useful for evaluating low metabolic MedLNs. Therefore, adding clinical information to the quantitative variables from ¹⁸F-FDG PET/CT can improve the diagnostic results of ML.

KEY POINTS

• Machine learning using two-class boosted decision tree model revealed the highest value of area under curve, and it showed higher sensitivity and negative predictive values but lower specificity and positive predictive values than nuclear medicine physicians. • The diagnostic results from machine learning method after adding clinical information to the quantitative variables improved accuracy significantly than nuclear medicine physicians. • Machine learning could improve the diagnostic significance of metastatic mediastinal lymph nodes, especially in mediastinal lymph nodes with low 18F-FDG-avidity.

Radiomics: an overview in lung cancer management-a narrative review

Radiomics is a novel approach for optimizing the analysis massive data from medical images to provide auxiliary guidance in clinical issues. Quantitative feature extraction is one of the critical steps of radiomics. The association between radiomics features and the clinicopathological information of diseases can be identified by several statistics methods. For instance, although significant progress has been made in the field of lung cancer, too many questions remain, especially for the individualized decisions. Radiomics offers a new tool to encode the characteristics of lung cancer which is the leading cause of cancer-related deaths worldwide. Here, we reviewed the workflow and clinical utility of radiomics in lung cancer management, including pulmonary nodules detection, classification, histopathology and genetics evaluation, clinical staging, therapy response, and prognosis prediction. Most of these studies showed positive results, indicating the potential value of radiomics in clinical practice. The implementation of radiomics is both feasible and invaluable, and has aided clinicians in ascertaining the nature of a disease with greater precision. However, it should be noted that radiomics in its current state cannot completely replace the work of therapists or tissue examination. The potential future trends of this modality were also remarked. More efforts are needed to overcome the limitations identified above in order to facilitate the widespread application of radiomics in the reasonably near future.

Recent and Current Advances in FDG-PET Imaging within the Field of Clinical Oncology in NSCLC: A Review of the Literature

Lung cancer is the leading cause of cancer-related deaths around the world, the most common type of which is non-small-cell lung cancer (NSCLC). Computed tomography (CT) is required for patients with NSCLC, but often involves diagnostic issues and large intra- and interobserver variability. The anatomic data obtained using CT can be supplemented by the metabolic data obtained using fluorodeoxyglucose F 18 (FDG) positron emission tomography (PET); therefore, the use of FDG-PET/CT for staging NSCLC is recommended, as it provides more accuracy than either modality alone. Furthermore, FDG-PET/magnetic resonance imaging (MRI) provides useful information on metabolic activity and tumor cellularity, and has become increasingly popular. A number of studies have described FDG-PET/MRI as having a high diagnostic performance in NSCLC staging. Therefore, multidimensional functional imaging using FDG-PET/MRI is promising for evaluating the activity of the intratumoral environment. Radiomics is the quantitative extraction of imaging features from medical scans. The chief advantages of FDG-PET/CT radiomics are the ability to capture information beyond the capabilities of the human eye, non-invasiveness, the (virtually) real-time response, and full-field analysis of the lesion. This review summarizes the recent advances in FDG-PET imaging within the field of clinical oncology in NSCLC, with a focus on surgery and prognostication, and investigates the site-specific strengths and limitations of FDG-PET/CT. Overall, the goal of treatment for NSCLC is to provide the best opportunity for long-term survival; therefore, FDG-PET/CT is expected to play an increasingly important role in deciding the appropriate treatment for such patients.

Pre-surgical assessment of mediastinal lymph node metastases in Stage IA non-small-cell lung cancers

OBJECTIVE

Evaluation of sensitivity and specificity of CT and fluorodeoxyglucose-positron emission tomography for pre-surgical staging of mediastinal lymph node metastases (N2/N3) of non-small-cell-lung-cancers ≤30 mm.

METHODS

We reviewed a total of 263 patients from a prospective cohort study, who underwent resection including mediastinal lymph nodes, for first primary non-small-cell-lung-cancer ≤30 mm in maximum diameter on pre-surgical CT. Cutoff criteria for short-axis diameter on CT of the largest N2/N3 node of 10, 15, and 20 mm and positron emission uptake of 2.5, 3.0, and 4.0 were evaluated using Area-Under-the-Curve (AUC) assessment. Accuracy criterion was used to determine the optimal cutoffs.

RESULTS

Of 263 patients, 9 had nonsolid, 42 part-solid, and 212 solid non-small-cell-lung-cancers. Post-surgically, none of the 51 patients with nonsolid or part-solid cancers had mediastinal lymph node metastases. Among the 212 patients with solid cancers, 23 had N2 node metastases. For the 212 patients with solid cancers, the AUC for CT lymph node measurements was 0.67 (95% CI: 0.57-0.77), significantly higher (p = 0.001) than chance alone, while the AUC for SUVmax measurements, 0.56 (95% CI: 0.48-0.65), was not (p = 0.13). Optimal CT cutoff was >20 mm had low sensitivity of 30.4% (95% CI: 11.6%-49.2%) but high specificity of 99.5% (95% CI: 98.4%-100.0%).

CONCLUSION

Based on these results, clinical Stage IA for non-small-cell-lung-cancers with nonsolid, part-solid, or solid consistency should be based on pre-surgical CT maximum tumor diameter and lymph node short-axis measurements on CT ≤20 mm. Further prospective evaluation of these clinical Stage IA staging criteria is needed.

Lung cancer staging: State of the art in the era of ablative therapies and surgical segmentectomy

Implementation of lung cancer screening and improvements in imaging are expected to increase the proportion of lung cancer diagnosed at an early stage. The standard of care has historically been anatomic lobectomy; however, there is now an array of surgical and non-surgical approaches for management of local disease either in active use or under investigation. By their nature, these new modalities offer a theoretical trade-off of reduced morbidity in exchange for reduced efficacy in the setting of advanced disease. It is therefore critical that patients being considered for these approaches (e.g. surgical segmentectomy and SABR) be accurately staged to maximize the potential for definitive treatment. In this article, we will review current approaches to the staging of patients being considered for segmentectomy or ablation. This will serve as a foundation to highlight important questions deserving further investigation.

Role of FDG PET/CT in the Eighth Edition of TNM Staging of Non-Small Cell Lung Cancer

Lung cancer is the leading cause of cancer-related mortality in the United States, and accurate staging plays a vital role in determining prognosis and treatment. The recently revised eighth edition of the TNM staging system for lung cancer defines new T and M descriptors and updates stage groupings on the basis of substantial differences in survival. There are new T descriptors that are based on the findings at histopathologic examination, and T descriptors are reassigned on the basis of tumor size and extent. No changes were made to the N descriptors in the eighth edition of the TNM staging of lung cancer, because the four N categories that are based on the location of the diseased nodes can be used to consistently predict prognosis. The eighth edition includes a new M1b descriptor for patients with a single extrathoracic metastatic lesion in a single organ (M1b), because they have better survival and different treatment options, compared with those with multiple extrathoracic lesions (M1c). Examination with fluorine 18 fluorodeoxyglucose (FDG) PET/CT is the standard of care and is an integral part of the clinical staging of patients with lung cancer. To provide the treating physicians with accurate staging information, radiologists and nuclear medicine physicians should be aware of the updated classification system and should be cognizant of the site-specific strengths and limitations of FDG PET/CT. In this article, the eighth edition of the TNM staging system is reviewed, as well as the role of FDG PET/CT in the staging of non-small cell lung carcinoma. ^©RSNA, 2018.

Volume-Based Consolidation-to-Tumor Ratio Is a Useful Predictor for Postoperative Upstaging in Stage I and II Lung Adenocarcinomas

BACKGROUND

 We investigated the postoperative upstaging of stage I and II lung adenocarcinoma patients to identify useful predictors for accurate staging.

METHODS

 We retrospectively reviewed data from 80 consecutive patients undergoing lobectomy and mediastinal lymph node dissection for clinical stage I and II lung adenocarcinomas. We evaluated clinical variables, including the preoperative serum carcinoembryonic antigen (CEA), tumor diameter, consolidation-to-tumor ratio (CTR), maximum standardized uptake value (SUVmax) on FDG- PET, expression of epithelial growth factor receptor mutations, and pathological invasion to the pleura (pl), lymph duct (ly), and vein (v).

RESULTS

 Eleven patients (13.8%) showed postoperative upstaging. Three cases had pN1 migrating from cN0, four cases had pN2 from cN0, and four cases showed malignant pleural effusion. The CEA level and CTR were significantly higher in the upstaging group. The tumors in the upstaging group showed more frequent pathological invasion to the visceral pleura and vein. In patients with 3 cm or smaller consolidation, two-dimensional (2D)-CTR and volume-based CTR were independent predictors of upstaging.

CONCLUSIONS

 Volume-based CTR could be a useful predictor for accurate clinical staging in stage I and II adenocarcinoma patients in addition to consolidation size, serum CEA level, and 2D-CTR. Both volume-based and 2D-CTRs might be especially useful in T1 diseases.

18F-fluorodeoxyglucose positron emission tomography/computed tomography in the evaluation of clinically node-negative non-small cell lung cancer

One in four non-small cell lung cancer (NSCLC) patients are diagnosed at an early-stage. Following the results of the National Lung Screening Trial that demonstrated a survival benefit for low-dose computed tomography screening in high-risk patients, the incidence of early-stage NSCLC is expected to increase. Use of 18F-fluorodeoxyglucose positron emission tomography/computed tomography during initial diagnosis of these early-stage lesions has been increasing. Traditionally, positron emission tomography/computed tomography scans have been utilized for mediastinal nodal staging and to rule out distant metastases in suspected early-stage NSCLC. In clinically node-negative NSCLC, the use of sublobar resection and selective lymph node dissection has been increasing as a therapeutic option. The higher rate of locoregional recurrences after limited resection and the significant incidence of occult lymph node metastases underscores the need to further stratify clinically node-negative NSCLC in order to select patients for limited resection versus lobectomy with complete mediastinal lymph node dissection. In this report, we review the published data, and discuss the significance and potential role of 18F-fluorodeoxyglucose positron emission tomography/computed tomography evaluation for clinically node-negative NSCLC. Consequently, the literature review demonstrates that maximum standardized uptake value is a predictive factor for occult nodal metastasis with an accuracy of 55-77%. In addition, maximum standardized uptake value is a predictor for worse overall, as well as disease-free, survival.

Comprehensive analysis of marker gene detection and computed tomography for the diagnosis of human lung cancer

Non-small cell lung cancer (NSCLC) is one of leading causes of cancer-associated mortality, with a high number of cases caused by metastasis. The early diagnosis of cancer contributes to the successful treatment of patients with lung cancer. The aim of the present study was to analyze the efficacy of marker gene detection and computed tomography (CT) in diagnosing human lung cancer. Lung cancer marker genes, including carcinoembryonic antigen (CEA), cancer antigen 125 (CA125), tissue polypeptide antigen (TPA), pro-gastrin-releasing peptide (ProGRB), cytokeratin fragment 21-1 (Cyfra21-1) and neuron-specific enolase (NSE), were analyzed in patients with lung cancer. The tumor size was evaluated using CT, and the association between lung serum levels of marker gene protein expression and tumor size was investigated. A total of 328 patients with lung cancer were identified, including 204 adenocarcinoma, 75 large cell carcinoma and 49 squamous cell carcinoma cases. All patients were indicated to have a high serum level of CEA, CA125, TPA, ProGRB, Cyfra21-1 and NSE, compared with the normal range. Immunohistochemistry demonstrated higher expression levels of CEA, CA125, TPA, ProGRB, Cyfra21-1 and NSE in lung tumor tissues, compared with the normal range. Results indicated that CT was able to diagnose tumor size for patients with lung cancer. The CEA and CA125 expression levels were associated with CT-diagnosed adenocarcinoma tumor size. Large cell carcinoma tumor size was associated with serum levels of CEA, TPA and ProGRB. Results indicated that Cyfra21-1 and NSE were associated with the squamous cell carcinoma cases, as demonstrated using CT. In conclusion, these results indicated that comprehensive analysis of marker gene detection and CT results may be used to diagnose human lung cancer.

Committee II: Guidelines for cytologic sampling techniques of lung and mediastinal lymph nodes

The Papanicolaou Society of Cytopathology has developed a set of guidelines for pulmonary cytology including indications for bronchial brushings, washings, and endobronchial ultrasound guided transbronchial fine-needle aspiration (EBUS-TBNA), technical recommendations for cytological sampling, recommended terminology and classification schemes, recommendations for ancillary testing and recommendations for post-cytological management and follow-up. All recommendations are based on the expertise of the authors, an extensive literature review and feedback from presentations at national and international conferences. This document selectively presents the results of these discussions. The present document summarizes recommendations regarding techniques used to obtain cytological and small histologic specimens from the lung and mediastinal lymph nodes including rapid on-site evaluation (ROSE), and the triage of specimens for immunocytochemical and molecular studies.

Non-Small-Cell Lung Cancer PET Imaging Beyond F18 Fluorodeoxyglucose

F18 Flurodeoxyglucose (FDG) is a nonspecific PET tracer representing tumor energy metabolism, with common false-positive and false-negative findings in clinical practice. Non-small cell lung cancer is highly heterogeneous histologically, biologically, and molecularly. Novel PET tracers designed to characterize a specific aspect of tumor biology or a pathway-specific molecular target have the potential to provide noninvasive key information in tumor heterogeneity for patient stratification and in the assessment of treatment response. Non-FDG PET tracers, including ⁶⁸Ga-somatostatin analogs, and some PET tracers targeting tumor proliferation, hypoxia, angiogenesis, and pathway-specific targets are briefly reviewed in this article.

Retrospective analysis for the false positive diagnosis of PET-CT scan in lung cancer patients

Early diagnosis is pivotal for prognosis of lung cancer patients. Positron emission tomography/computed tomography (PET-CT) is a useful method for human cancer diagnosis. In this study, we aimed to explore the false positive diagnosis of PET-CT in lung cancerIn total, 754 patients diagnosed with lung cancer via PET-CT were retrospectively collected in this study. Histopathological detection served as gold standard. The diagnostic accuracy of PET-CT was defined as the proportion of lung cancer cases confirmed by pathological diagnosis in the study subjects, and the percentages of misdiagnosed cases represented the false positive diagnosis of PET-CT. Chi-square test and logistic regression analysis were used to analyze the association of pathologically confirmed result with clinical characteristics.Among all the patients, 705 cases were pathologically confirmed with lung cancer. The diagnostic accuracy of PET-CT was 93.5%, and the false positive rate was 6.50%. Among the false positive patients, inflammatory pseudotumor (42.86%) and tuberculoma (36.74%) were the most pathological types. In the positive detection group, adenocarcinoma (57.16%) and squamous carcinoma (33.19%) were the main pathological types, and 68.09% of the lung cancer patients were at the advanced stages. The false positive rate were related with age, diabetes, interleukin-6 (IL-6) level, and T-spot test (all P < .05).PET-CT could be a good diagnostic method for lung cancer, but the false positive cases could appear. Detection of inflammatory indicators such as IL-6 and T-spot TB test may help improve the diagnostic accuracy of PET-CT.

Lymph node tuberculosis mimicking malignancy on 18F-FDG PET/CT in two patients: A case report

¹⁸F-fluorodeoxyglucose positron emission/computed tomography (¹⁸F-FDG PET/CT) imaging, an established procedure for evaluation of malignancy, reports an increased ¹⁸F-FDG uptake in acute or chronic inflammatory condition. Lymph node tuberculosis (LNTB) is the most common form of extrapulmonary tuberculosis. However, the absence of clinical symptoms and bacteriological basis makes it difficult to diagnose. In the current case report, two patients with LNTB mimicking malignant lymphoma are presented by ¹⁸F-FDG PET/CT. The objective of the present report is to emphasize that LNTB should be considered as a noteworthy differential diagnosis in patients with enlarged lymph nodes, particularly in tuberculosis-endemic countries, and that lymph node biopsy serves a vital role in diagnosing LNTB.

The clinical utility of FDG PET/CT among solid organ transplant recipients suspected of malignancy or infection

PURPOSE

Solid organ transplant (SOT) recipients are at high risk of developing infections and malignancies. 18F-FDG PET/CT may enable timely detection of these diseases and help to ensure early intervention. We aimed to describe the clinical utility of FDG PET/CT in consecutive, diagnostic unresolved SOT recipients transplanted from January 2004 to May 2015.

METHODS

Recipients with a post-transplant FDG PET/CT performed as part of diagnostic work-up were included. Detailed chart reviews were done to extract relevant clinical information and determine the final diagnosis related to the FDG PET/CT. Based on á priori defined criteria and the final diagnosis, results from each scan were classified as true or false, and diagnostic values determined.

RESULTS

Among the 1,814 recipients in the cohort, 145 had an FDG PET/CT performed; 122 under the indication of diagnostically unresolved symptoms with a suspicion of malignancy or infection. The remaining (N = 23) had an FDG PET/CT to follow-up on a known disease or to stage a known malignancy. The 122 recipients underwent a total of 133 FDG PET/CT scans performed for a suspected malignancy (66 %) or an infection (34 %). Sensitivity, specificity, and positive and negative predictive values of the FDG PET/CT in diagnosing these conditions were 97, 84, 87, and 96 %, respectively.

CONCLUSION

FDG PET/CT is an accurate diagnostic tool for the work-up of diagnostic unresolved SOT recipients suspected of malignancy or infection. The high sensitivity and NPV underlines the potential usefulness of PET/CT for excluding malignancy or focal infections in this often complex clinical situation.

Texture Analysis and Synthesis of Malignant and Benign Mediastinal Lymph Nodes in Patients with Lung Cancer on Computed Tomography

Texture analysis of computed tomography (CT) imaging has been found useful to distinguish subtle differences, which are in- visible to human eyes, between malignant and benign tissues in cancer patients. This study implemented two complementary methods of texture analysis, known as the gray-level co-occurrence matrix (GLCM) and the experimental semivariogram (SV) with an aim to improve the predictive value of evaluating mediastinal lymph nodes in lung cancer. The GLCM was explored with the use of a rich set of its derived features, whereas the SV feature was extracted on real and synthesized CT samples of benign and malignant lymph nodes. A distinct advantage of the computer methodology presented herein is the alleviation of the need for an automated precise segmentation of the lymph nodes. Using the logistic regression model, a sensitivity of 75%, specificity of 90%, and area under curve of 0.89 were obtained in the test population. A tenfold cross-validation of 70% accuracy of classifying between benign and malignant lymph nodes was obtained using the support vector machines as a pattern classifier. These results are higher than those recently reported in literature with similar studies.

PET-CT in presurgical lymph node staging in non-small cell lung cancer: the importance of false-negative and false-positive findings

OBJECTIVE

To assess the importance of false-negative and false-positive findings in computed tomography (CT) and ¹⁸F-FDG positron emission tomography (PET) in mediastinal lymph node staging in patients undergoing surgery for non-small cell lung cancer (NSCLC).

MATERIAL AND METHODS

This retrospective study included 113 consecutive patients and 120 resected NSCLCs; 22 patients received neoadjuvant treatment. We compared the findings on preoperative ¹⁸F-FDG PET-CT studies with the postoperative pathology findings. Lymph node size and primary tumor size were measured with CT, and lymph nodes and primary tumors were evaluated qualitatively and semiquantitatively (using standardized uptake values (SUVmax)) with PET.

RESULTS

Metastatic lymph nodes were found in 26 (21.7%) of the 120 tumors and in 41 (7.7%) of the 528 lymph node stations analyzed. ¹⁸F-FDG PET-CT yielded 53.8% sensitivity, 76.6% specificity, 38.9% positive predictive value, 85.7% negative predictive value, and 71.7% diagnostic accuracy. The false-negative rate was 14.2%. Multivariable analysis found that the factors associated with false-negative findings were a moderate degree of differentiation in the primary tumor (p = 0.005) and an SUVmax of the primary tumor >4 (p = 0.027). The false-positive rate was 61.1%, and the multivariable analysis found that lymph node size >1cm was associated with false-positive findings (p < 0.001).

CONCLUSIONS

In mediastinal lymph node staging in patients with NSCLC, ¹⁸F-FDG PET-CT improves the specificity and negative predictive value and helps clinicians to select the patients that will benefit from surgery. Given the high rate of false positives, histological confirmation of positive cases is recommendable.

Ratio of lymph node to primary tumor SUVmax multiplied by maximal tumor diameter on positron emission tomography/integrated computed tomography may be a predictor of mediastinal lymph node malignancy in lung cancer

Positron emission tomography/integrated computed tomography (PET/CT) provides the most accurate imaging modality for preoperative lung cancer staging. However, the diagnostic accuracy of maximum standardized uptake value (SUVmax) for mediastinal (N2) lymph nodes (LN) is unclear. We compared SUVmax, the ratio of LN to primary tumor SUVmax (SUVn/t), and SUVn/t multiplied by maximal tumor diameter (SUVindex) in terms of their abilities to predict mediastinal LN malignancy.We retrospectively analyzed 170 mediastinal LN stations from 73 consecutive patients who underwent systemic LN resection and PET/CT within 27 days. The SUVmax of the primary tumors was >2.0 and the SUVmax of the mediastinal LN stations ranged from 2.0 to 7.0 on PET/CT. Receiver-operating characteristic curves (ROCs) of SUVmax, SUVn/t, and SUVindex were calculated separately and the areas under the curves (AUCs) were used to assess the abilities of the parameters to predict LN malignancy. The optimal cutoff values were calculated from each ROC curve and the diagnostic abilities were also compared. The diagnostic accuracies of the 3 methods were also assessed separately in smoking and nonsmoking patients.Twenty-eight LN stations were malignancy-positive and the remaining 142 were malignancy-negative. The AUCs for SUVindex, SUVn/t, and SUVmax were 0.709, 0.590, and 0.673, respectively, and the optimal cutoff values for SUVindex, SUVn/t, and SUVmax were 1.11, 0.34, and 3.6, respectively. The differences between SUVindex and SUVn/t were significant, but there was no significant difference between SUVindex and SUVmax. There were no significant differences between smokers and nonsmokers in the AUCs for any of the methods for predicting LN malignancy (P values >0.05).SUVindex may be a predictor of mediastinal LN malignancy in lung cancer patients.

18F-FBPA as a tumor-specific probe of L-type amino acid transporter 1 (LAT1): a comparison study with 18F-FDG and 11C-Methionine PET

PURPOSE

The purpose of this study was to evaluate the usefulness of L-4-borono-2-¹⁸F-fluoro-phenylalanine (¹⁸F-FBPA) as a tumor-specific probe, in comparison to ¹⁸F-FDG and ¹¹C-methionine (Met), focusing on its transport selectivity by L-type amino acid transporter 1 (LAT1), which is highly upregulated in cancers.

METHODS

Cellular analyses of FBPA were performed to evaluate the transportablity and K_m value. PET studies were performed in rat xenograft models of C6 glioma (n = 12) and in rat models of turpentine oil-induced subcutaneous inflammation (n = 9). The kinetic parameters and uptake values on static PET images were compared using the one-tissue compartment model (K₁, k₂) and maximum standardized uptake value (SUVmax).

RESULTS

The cellular analyses showed that FBPA had a lower affinity to a normal cell-type transporter LAT2 and induced less efflux through LAT2 among FBPA, Met, and BPA, while the efflux through LAT1 induced by FBPA was similar among the three compounds. The K_m value of ¹⁸F-FBPA for LAT1 (196.8 ± 11.4 μM) was dramatically lower than that for LAT2 (2813.8 ± 574.5 μM), suggesting the higher selectivity of ¹⁸F-FBPA for LAT1. K₁ and k₂ values were significantly smaller in ¹⁸F-FBPA PET (K₁ = 0.04 ± 0.01 ml/ccm/min and k₂ = 0.07 ± 0.01 /min) as compared to ¹¹C-Met PET (0.22 ± 0.09 and 0.52 ± 0.10, respectively) in inflammatory lesions. Static PET analysis based on the SUVmax showed significantly higher accumulation of ¹⁸F-FDG in the tumor and inflammatory lesions (7.2 ± 2.1 and 4.6 ± 0.63, respectively) as compared to both ¹⁸F-FBPA (3.2 ± 0.40 and 1.9 ± 0.19) and ¹¹C-Met (3.4 ± 0.43 and 1.6 ± 0.11). No significant difference was observed between ¹⁸F-FBPA and ¹¹C-Met in the static PET images.

CONCLUSION

This study shows the utility of ¹⁸F-FBPA as a tumor-specific probe of LAT1 with low accumulation in the inflammatory lesions.

Prognostic factors in non-small cell lung cancer patients who received neoadjuvant therapy and curative resection

BACKGROUND

Lung cancer is the leading cause of cancer deaths in the world, and more and more treatment modalities have been introduced in order to improve patients' survival. For patients with advanced non-small cell lung cancer (NSCLC), survival prognosis is poor and multimodality neoadjuvant therapies are given to improve patients' survival. However, the possibility of occult metastases may lead to discrepancy between clinical and pathologic staging and underestimation of the disease severity. This discrepancy could be the reason for poor survival prediction reported by previous studies which conducted their analysis from the point of view of clinical stage. The aim of this study was to analyze the relationship between clinico-pathologic factors and survival from the pathologic point of view and to try to identify survival prognostic factors.

METHODS

From January 2005 to June 2011, 88 patients received neoadjuvant therapy because of initial locally advanced disease, followed by anatomic resection and mediastinal lymph node (LN) dissection. All their clinico-pathologic data were collected from a retrospective review of the medical records and subjected to further analysis.

RESULTS

We found that total metastatic LN ratio (P=0.01) and tumor size (P=0.02) were predictive factors for disease free survival (DFS). We used these two prognostic factors to stratify all patients into four groups. Group 4 (tumor size ≤5, total metastatic LN ratio ≤0.065) had the best DFS curve, while the DFS curve progressively deteriorated across group 3 (tumor size ≤5, total metastatic LN ratio >0.065), group 2 (tumor size >5, total metastatic LN ratio ≤0.065) and group 1 (tumor size >5, total metastatic LN ratio >0.065). However, no definitive prognostic factor could be identified in this study.

CONCLUSIONS

In conclusion, tumor size greater than 5 cm and total metastatic LN ratio greater than 0.065 could predict the DFS of patients with advanced NSCLC after multimodality therapies followed by surgical resection. Tumor size plays a more important role than total metastatic LN ratio in DFS. Moreover, patients identified with these factors need active post-operation surveillance and additional aggressive adjuvant therapies.

Ultrasound techniques in the evaluation of the mediastinum, part I: endoscopic ultrasound (EUS), endobronchial ultrasound (EBUS) and transcutaneous mediastinal ultrasound (TMUS), introduction into ultrasound techniques

Ultrasound imaging has gained importance in pulmonary medicine over the last decades including conventional transcutaneous ultrasound (TUS), endoscopic ultrasound (EUS), and endobronchial ultrasound (EBUS). Mediastinal lymph node staging affects the management of patients with both operable and inoperable lung cancer (e.g., surgery vs. combined chemoradiation therapy). Tissue sampling is often indicated for accurate nodal staging. Recent international lung cancer staging guidelines clearly state that endosonography (EUS and EBUS) should be the initial tissue sampling test over surgical staging. Mediastinal nodes can be sampled from the airways [EBUS combined with transbronchial needle aspiration (EBUS-TBNA)] or the esophagus [EUS fine needle aspiration (EUS-FNA)]. EBUS and EUS have a complementary diagnostic yield and in combination virtually all mediastinal lymph nodes can be biopsied. Additionally endosonography has an excellent yield in assessing granulomas in patients suspected of sarcoidosis. The aim of this review, in two integrative parts, is to discuss the current role and future perspectives of all ultrasound techniques available for the evaluation of mediastinal lymphadenopathy and mediastinal staging of lung cancer. A specific emphasis will be on learning mediastinal endosonography. Part I is dealing with an introduction into ultrasound techniques, mediastinal lymph node anatomy and diagnostic reach of ultrasound techniques and part II with the clinical work up of neoplastic and inflammatory mediastinal lymphadenopathy using ultrasound techniques and how to learn mediastinal endosonography.

Parathyroid adenoma upstaging the lung cancer

Mediastinal staging of NSCLC with noninvasive methods such as PET/CT can be misleading when a mediastinal disease accompany. Histopathologic confirmation should be made before any treatment plan. Herein, we presented a case of parathyroid adenoma upstaging the lung cancer.

Pulmonary tuberculosis with false-positive 18F-fluorodeoxyglucose positron emission tomography mimicking recurrent lung cancer: A case report

Recurrent lung cancer is a common clinical condition. ¹⁸F-fluorodeoxyglucose positron emission tomography (FDG-PET) is currently the predominant non-invasive imaging technique used for the detection of tumor recurrence. In the present study, the case of a 67-year-old male suspected to have postoperative recurrence of primary lung cancer was examined. Chest computed tomography (CT) scans identified a subpleural nodule grown within a short time period, along with the occurrence of multiple patchy shadows on the right lung. PET-CT scans revealed an increased FDG uptake in the surgical site, which exhibited features of a malignant disease. However, a video-assisted thoracoscopic biopsy provided the diagnosis of tuberculosis and guided further appropriate treatment. In conclusion, further evaluation is required in all patients with suspected metastatic and recurrent carcinoma.

Positron Emission Tomography (PET) in Oncology

Since its introduction in the early nineties as a promising functional imaging technique in the management of neoplastic disorders, FDG-PET, and subsequently FDG-PET/CT, has become a cornerstone in several oncologic procedures such as tumor staging and restaging, treatment efficacy assessment during or after treatment end and radiotherapy planning. Moreover, the continuous technological progress of image generation and the introduction of sophisticated software to use PET scan as a biomarker paved the way to calculate new prognostic markers such as the metabolic tumor volume (MTV) and the total amount of tumor glycolysis (TLG). FDG-PET/CT proved more sensitive than contrast-enhanced CT scan in staging of several type of lymphoma or in detecting widespread tumor dissemination in several solid cancers, such as breast, lung, colon, ovary and head and neck carcinoma. As a consequence the stage of patients was upgraded, with a change of treatment in 10%-15% of them. One of the most evident advantages of FDG-PET was its ability to detect, very early during treatment, significant changes in glucose metabolism or even complete shutoff of the neoplastic cell metabolism as a surrogate of tumor chemosensitivity assessment. This could enable clinicians to detect much earlier the effectiveness of a given antineoplastic treatment, as compared to the traditional radiological detection of tumor shrinkage, which usually takes time and occurs much later.