PET-CT has low specificity for mediastinal staging of non-small-cell lung cancer in an endemic area for tuberculosis: a diagnostic test study (LACOG 0114)

Approaching a patient with poststernal pain after eating: A case report

This article reports a case of mediastinal lymph node tuberculosis with no obvious symptoms and a concealed focus. This patient, a 33-year-old male, suffered from pain behind the sternum after eating. He underwent three gastroscopic examinations and two fine needle punctures guided by ultrasound gastroscopy but was not diagnosed. Chest-enhanced CT revealed a mediastinal mass compressing the adjacent esophagus, suggesting the possibility of enlarged lymph nodes. Furthermore, T cells from patients infected with tuberculosis tested positive. Ultrasound bronchoscopy revealed enlarged lymph nodes in area 7, and then EBUS-TBNA was performed in that region. Only a few scattered lymphocytes and necrotic tissue were found under the biopsy microscope. The EBUS-TBNA biopsy Xpert MTB/RIF showed low positive results, and the EBUS-TBNA puncture fluid Xpert MTB/RIF was positive. Therefore, he was diagnosed with mediastinal lymph node tuberculosis. After antituberculosis treatment with the 2HREZ/10HRE regimen, the patient's pain behind the sternum gradually alleviated, and the enlarged mediastinal lymph nodes gradually narrowed.

FDG-PET-CT as an early detection method for tuberculosis: a systematic review and meta-analysis

Tuberculosis (TB) causes major public health problems worldwide. Fighting TB requires sustained efforts in health prevention, diagnosis and treatment. Previous literature has shown that conventional diagnostic methods like X-ray and sputum microscopy often miss early or extrapulmonary TB due to their limited sensitivity. Blood tests, while useful, lack the anatomical detail needed for precise localization of TB lesions. A possible step forward in the fight against TB could be the use of Fluorodeoxyglucose Positron Emission Tomography (FDG-PET) and Computed Tomography (CT). This meta-analysis discusses the current literature, including the methods, results and implications of using FDG-PET-CT in the early diagnosis of TB. Analysis of the studies showed that the sensitivity of FDG-PET-CT as a potential method for early detection of TB was 82.6%.

Preoperative evaluation of mediastinal lymph nodes in non-small cell lung cancer using [68Ga]FAPI-46 PET/CT: a prospective pilot study

PURPOSE

Mediastinal nodal staging is crucial for surgical candidate selection in non-small cell lung cancer (NSCLC), but conventional imaging has limitations often necessitating invasive staging. We investigated the additive clinical value of fibroblast activation protein inhibitor (FAPI) PET/CT, an imaging technique targeting fibroblast activation protein, for mediastinal nodal staging of NSCLC.

METHODS

In this prospective pilot study, we enrolled patients scheduled for surgical resection of NSCLC based on specific criteria designed to align with indications for invasive staging procedures. Patients were included when meeting at least one of the following: (1) presence of FDG-positive N2 lymph nodes, (2) clinical N1 stage, (3) central tumor location or tumor diameter of ≥ 3 cm, and (4) adenocarcinoma exhibiting high FDG uptake. [68Ga]FAPI-46 PET/CT was performed before surgery after a staging workup including [18F]FDG PET/CT. The diagnostic accuracy of [68Ga]FAPI-46 PET/CT for "N2" nodes was assessed through per-patient visual assessment and per-station quantitative analysis using histopathologic results as reference standards.

RESULTS

Twenty-three patients with 75 nodal stations were analyzed. Histopathologic examination confirmed that nine patients (39.1%) were N2-positive. In per-patient assessment, [68Ga]FAPI-46 PET/CT successfully identified metastasis in eight patients (sensitivity 0.89 (0.52-1.00)), upstaging three patients compared to [18F]FDG PET/CT. [18F]FDG PET/CT detected FDG-avid nodes in six (42.8%) of 14 N2-negative patients. Among them, five were considered non-metastatic based on calcification and distribution pattern, and one was considered metastatic. In contrast, [68Ga]FAPI-46 PET/CT correctly identified all non-metastatic patients solely based on tracer avidity. In per-station analysis, [68Ga]FAPI-46 PET/CT discriminated metastasis more effectively compared to [18F]FDG PET/CT-based (AUC of ROC curve 0.96 (0.88-0.99) vs. 0.68 (0.56-0.78), P < 0.001).

CONCLUSION

[68Ga]FAPI-46 PET/CT holds promise as an imaging tool for preoperative mediastinal nodal staging in NSCLC, with improved sensitivity and the potential to reduce false-positive results, optimizing the need for invasive staging procedures.

A Review of the Current Approach and Treatment Landscape for Stage III Non-Small Cell Lung Cancer

The therapeutic landscape of the management of stage III non-small cell lung cancer (NSCLC) has drastically evolved with the incorporation of immunotherapy and targeted therapy. Stage III NSCLC accounts for one-third of the cases and the treatment strategy of these locally advanced presentations are diverse, ranging from surgical to non-surgical options; with the incorporation of chemo-immunotherapy, radiation, and targeted therapies wherever applicable. The staging of this disease has also changed, and it is essential to have a strong multidisciplinary approach to do justice to patient care. In this article, we aim to navigate the nuanced approaches in the diagnosis and treatment of stage III NSCLC and expand on the evolution of the management of this disease.

Combination of Circulating Cell-Free DNA and Positron Emission Tomography to Distinguish Non-Small Cell Lung Cancer from Tuberculosis

OBJECTIVE

Non-small cell lung cancer (NSCLC) holds high metabolic tumor burden and circulating cell-free DNA (cfDNA) levels, and the relationship between metabolic tumor burden and cfDNA in NSCLC and the underlying mechanism of their interaction therein remain poorly characterized. Our aim was to evaluate the clinical value of cfDNA and metabolic tumor burden by positron emission tomography-computed tomography (PET/CT) for NSCLC differential diagnosis from tuberculosis in patients with solitary pulmonary nodules.

METHODS

Metabolic tumor burden values in humans (subjects with NSCLC, subjects with tuberculosis, and healthy control subjects) and relevant mouse models were detected by preoperative 18F-fluorodeoxyglucose PET (18F-FDG PET/CT) and [3H]-2-deoxy-DG uptake, respectively. The cfDNA levels were detected by quantifying serum cfDNA fragments from the ALU (115 bp) gene using reverse transcription-polymerase chain reaction. RNA sequence was performed to determine the underlying target genes and knocked down or inhibited the target genes in vivo and in vitro to determine the mechanism therein.

RESULTS

Metabolic tumor burden correlated with serum cfDNA levels in NSCLC subjects but not in tuberculosis subjects or healthy controls. Mouse models showed a similar phenomenon. In addition, the RNA sequence showed that glucose transporter 1 (GLU1), factor-related apoptosis ligand (FasL), caspase 8, and caspase 3 were significantly increased in NSCLC mouse tumors compared with those in tuberculosis mouse masses. Inhibiting the metabolic tumor burden by blocking or knocking down GLU1 markedly reduced the expression of FasL, the phosphorylation of caspase 8/caspase 3, and serum cfDNA levels/apoptosis percentage in vivo and in vitro. Furthermore, the use of a combination of cfDNA and metabolic tumor burden allowed better ability to distinguish NSCLC subjects from those with tuberculosis or healthy controls than either method used alone.

CONCLUSION

Metabolic tumor burden promotes the formation of circulating cfDNA through GLU1-mediated apoptosis in NSCLC, and the combination of cfDNA and metabolic tumor burden could be valuable for distinguishing NSCLC from tuberculosis.

A Comprehensive Study on the Correlation of Treatment, Diagnosis and Epidemiology of Tuberculosis and Lung Cancer

The correlation between tuberculosis (TB) and lung cancer (LC) in diagnosis, epidemiology, and treatment is still unclear. Based on different cohort and retrospective studies, this correlation could be justified by immune weakness because of exposure to TB which may increase the risk of LC. In this study, we tried to exhibit a prominent connection between TB and LC. The diagnosis and treatment of patients with concomitant TB and LC differ from patients with only one of the diseases. In this review, it was well clarified that the most practical diagnostic method for LC is chest tomography, biopsy, and histopathology, and for pulmonary TB sputum microscopic examination, Autofluorescence bronchoscopy (AFB), culture, and PCR. Also, immunological methods can be a good alternative for differential diagnosis. Most epidemiological studies were about concomitant TB and LC in TB-endemic areas, especially in the Middle East. The most suggested methods for definite treatment of LC are chemotherapy, radiotherapy, and surgery while for TB, a long course of anti-TB therapy can be used. Moreover, immunotherapy is considered a good treatment for lung cancer if the interferon-gamma release assay (IGRA) is negative.

Primary mediastinal lymph node tuberculosis diagnosed using endobronchial ultrasound-guided transbronchial needle aspiration: Literature review and case report

Tuberculosis bacilli can enter the human body through the respiratory system, digestive system, or skin and mucous membranes, with the respiratory tract representing the primary point of entry. Once inside the body, tuberculosis bacilli can enter the bloodstream and attack other organs, including the lymphatic system. One manifestation associated with lymphatic tuberculosis infiltration is the presence of large hilar and mediastinal lymph nodes, which are common in children and classified as primary tuberculosis. A diagnosis of primary tuberculosis in adults is often overlooked by doctors due to its low frequency. When a single enlarged mediastinal lymph node is observed, most doctors suspect other causes, especially malignancy. Determining the correct diagnosis for enlarged hilar and mediastinal lymph nodes can be difficult because diagnostic interventions in this area are challenging to perform. We report a clinical case of primary lymph node tuberculosis in an adult, confirmed by endobronchial ultrasound-guided transbronchial needle aspiration. We aim to provide doctors with a more comprehensive approach for diagnosing this disease.

Is 18F-FDG PET/CT capable of differential diagnosis from tuberculous pleurisy from malignant mesothelioma?

AIM

18F-Fluorodeoxyglucose (FDG) PET/computerized tomography (CT) is a valuable method in the diagnosis of malignant pleural mesothelioma (MPM). But, some infections, particularly tuberculosis, are known to mimic cancer. We aimed to compare the FDG PET/CT findings of tuberculosis pleurisy (TP) and malignant mesothelioma and evaluate its role of differential diagnosis.

MATERIAL AND METHOD

We retrospectively reviewed the data from 85 patients (45 patients with MPM and 40 patients with TP) who underwent FDG PET/CT. All images were reevaluated and pleural thickening, maximum standardized uptake values (SUVmax), lymphatic uptake and accompanying parenchymal findings were noted.

RESULTS

There was no significant difference in age and sex between the two groups. Pleural thickening was more prominent in the MPM group. Mean pleural thickness was 21.4 ± 18.6 mm in the MPM group and 6.8 ± 3.5 mm in the TP group (P = 0.0). Besides pleural pathology, lymph nodes involvement in the thoracic (P = 0.0) and extrathoracic area (P = 0.34) and parenchymal findings were prominent in the TP group (P = 0.0). However, there was no significant difference in pleural SUVmax values between the two groups (P = 0.61).

CONCLUSION

Intense pleural FDG uptake can be observed in TP like malignant mesothelioma. For the evaluation of the pleural pathologies in the tuberculosis endemic countries, it should be considered that FDG PET/CT may have false-positive results. Evaluation of increased pleural FDG uptake together with the detected parenchymal findings and lymphatic involvement may help us to make more accurate interpretation of the diagnosis.

Improving accuracy of 18F-fluorodeoxyglucose PET computed tomography to diagnose nodal involvement in non-small cell lung cancer: utility of using various predictive models

PURPOSE

To determine predictive models (PM) that could improve the accuracy for identifying metastatic regional nodes in non-small cell lung cancer based on both PET and CT findings seen on 18F-FDG PET CT.

METHODS

Three hundred thirty-nine biopsy-proven NSCLC patients who underwent surgical resection and had a staging 18F-FDG PET CT were enrolled. PET parameters obtained were (1) presence of visual PET positive nodes, (2) SUVmax of nodes (NSUV), (3) ratio of node to aorta SUVmax (N/A ratio) and (4) ratio of node to primary tumour SUVmax (N/T ratio). CT parameters obtained were (1) short-axis diameter and (2) Hounsfield units (HU) of PET-positive nodes. PET and CT parameters were correlated with nodal histopathology to find out the sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and overall accuracy. Different PM combining these parameters were devised and the incremental improvement in accuracy was determined.

RESULTS

Visual PET positivity showed sensitivity, specificity, PPV, NPV and accuracy of 72.4, 76.1, 30.1, 95.1 and 75.6, respectively. PM2 which combined visual PET positivity, NSUV and HU appears more clinically relevant and showed sensitivity, specificity, PPV, NPV and accuracy of 53.5, 96.5, 68.9, 93.6 and 91.2, respectively. PM6 which combined visual PET positivity, NSUV, N/A ratio and HU showed the maximum PPV (80.0%), specificity (98.3%) and accuracy of (91.9%).

CONCLUSION

PM combining parameters like nodal SUVmax, N/A ratio, N/T ratio and HU values have shown to improve the PPV, specificity and overall accuracy of 18FDG PET CT in the preoperative diagnosis of nodal metastases.

Impact of invasive nodal staging on regional and distant recurrence rates after SBRT for inoperable stage I NSCLC

PURPOSE/OBJECTIVES

Before definitive stereotactic body radiation therapy (SBRT) for presumably node-negative, early-stage NSCLC, many patients are staged with PET/CT alone. In patients undergoing PET/CT prior to SBRT, the role of invasive nodal staging (INS) with endobronchial ultrasound (EBUS) or mediastinoscopy is uncertain. We sought to characterize the impact of nodal staging modality on outcomes.

MATERIALS/METHODS

Patients receiving definitive SBRT for T1-2N0 NSCLC deemed node-negative by either PET/CT plus INS (EBUS or mediastinoscopy) or PET/CT alone were identified. Patients with initially equivocal or positive nodes on PET/CT were excluded from this analysis. All patients received 3-5 fraction SBRT according to institutional guidelines. Control was assessed by at least one follow-up CT in all patients. Multivariable logistic regression (MVA) was performed to identify variables independently associated with use of INS.

RESULTS

We identified 651 eligible patients at our institution from 2005-2016. INS was performed in 15.2% of patients (n = 99) with EBUS (n = 78) or mediastinoscopy (n = 21). Median follow-up was 19.4 months (0.2-135.1). Median survival was 28.5 months (0.6-140). Factors predictive of increased likelihood of INS after negative PET/CT on MVA were age (OR for decreasing age 1.033; 95% CI 1.058-1.010), Caucasian race (OR vs. non-white 1.852; 1.044-3.289), male sex (1.629; 1.031-2.575), central location (1.978; 1.218-3.211) and squamous histology (2.564; 1.243-5.287). Nodal and/or distant control at 2 years was similar between PET/CT alone (78%, 95% CI 74-82%) and INS + PET/CT (75%, 95% CI 65-85%) (p = 0.877) as well as on MVA. Overall survival did not differ based on staging modality.

CONCLUSIONS

In patients with early-stage NSCLC deemed node-negative by PET/CT, addition of INS did not appreciably alter patterns of failure or survival after definitive SBRT. This study does not question the established value of INS for equivocal or suspicious nodes.

EUS-FNA, ancillary studies and their clinical utility in patients with mediastinal, pancreatic, and other abdominal lesions

BACKGROUND

Endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) is an important modality to obtain tissue diagnosis from mediastinal, pancreatic, and intra-abdominal lesions in close proximity to the pulmonary and gastrointestinal tract. It is considered to be a relatively safe, rapid, and minimally invasive technique with low complication rates.

AIMS

To determine the diagnostic accuracy, sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and outcome of EUS-FNA, with histological correlation where applicable.

METHODS

Data of all 1059 consecutive patients who underwent EUS-FNA from 1 January 2005 to 31 December 2017 at Shaukat Khanum Memorial Cancer Hospital and Research Centre, Lahore was reviewed in this retrospective study. The major sites that were targeted for EUS-FNA were pancreatic (423), mediastinal (376), and other abdominal lesions (260).

RESULTS

The average number of passes per patient was 2.22. Rapid on-site evaluation (ROSE) was adequate in 969 patients (91.4%). Concordance between ROSE and final cytology was 99.5%. Follow-up was available in 810 patients (76.4%). The overall diagnostic yield was 94.3%. Ancillary studies, including immunohistochemical stains and flow cytometry, helped to increase the diagnostic yield from 78.1% to 94.3%. The overall sensitivity, specificity, PPV, NPV, and diagnostic accuracy for EUS-FNA were 94.8%, 98.6%, 99.9%, 65.5%, and 95.1%, respectively. Seven of 1059 patients (0.6%) developed complications.

CONCLUSION

EUS-FNA is a very sensitive and specific diagnostic tool with a minimal complication rate. Ancillary studies helped to increase the sensitivity, as well as the diagnostic yield.

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.

IASLC Multidisciplinary Recommendations for Pathologic Assessment of Lung Cancer Resection Specimens After Neoadjuvant Therapy

Currently, there is no established guidance on how to process and evaluate resected lung cancer specimens after neoadjuvant therapy in the setting of clinical trials and clinical practice. There is also a lack of precise definitions on the degree of pathologic response, including major pathologic response or complete pathologic response. For other cancers such as osteosarcoma and colorectal, breast, and esophageal carcinomas, there have been multiple studies investigating pathologic assessment of the effects of neoadjuvant therapy, including some detailed recommendations on how to handle these specimens. A comprehensive mapping approach to gross and histologic processing of osteosarcomas after induction therapy has been used for over 40 years. The purpose of this article is to outline detailed recommendations on how to process lung cancer resection specimens and to define pathologic response, including major pathologic response or complete pathologic response after neoadjuvant therapy. A standardized approach is recommended to assess the percentages of (1) viable tumor, (2) necrosis, and (3) stroma (including inflammation and fibrosis) with a total adding up to 100%. This is recommended for all systemic therapies, including chemotherapy, chemoradiation, molecular-targeted therapy, immunotherapy, or any future novel therapies yet to be discovered, whether administered alone or in combination. Specific issues may differ for certain therapies such as immunotherapy, but the grossing process should be similar, and the histologic evaluation should contain these basic elements. Standard pathologic response assessment should allow for comparisons between different therapies and correlations with disease-free survival and overall survival in ongoing and future trials. The International Association for the Study of Lung Cancer has an effort to collect such data from existing and future clinical trials. These recommendations are intended as guidance for clinical trials, although it is hoped they can be viewed as suggestion for good clinical practice outside of clinical trials, to improve consistency of pathologic assessment of treatment response.

An update on the role of 18F-FDG-PET/CT in major infectious and inflammatory diseases

For decades, conventional nuclear medicine techniques have been utilized for the assessment of many infectious and inflammatory diseases. Most of these techniques have limitations such as the relatively low spatial resolution, being time consuming and low sensitivity or specificity. In recent years, FDG-PET/CT has shown promising role in the management of such diseases. An expanding set of studies illustrate the multifarious roles of FDG-PET/CT in the assessment of these conditions, both systemic diseases and more regional. Specifically, PET can provide vital information at a molecular level and consequently detect the disease activity at their earliest manifestation. With the continuing research on the diagnosis and treatment monitoring of patients with infectious and inflammatory diseases, the role of PET/CT can be further extended.