Lung Neoplasms with Low F18-Fluorodeoxyglucose Avidity

18 F-FDG PET/CT Imaging of Pulmonary Hamartomas : Metabolic and Functional Characterization

ABSTRACT

Pulmonary hamartoma is the most common benign tumor of the lung and often discovered incidentally on imaging. We report the case of a 49-year-old woman recently diagnosed with left breast cancer with suspicious left axillary lymph nodes. 18 F-FDG PET/CT showed well-circumscribed, lobulated, low-attenuation soft tissue mass in the right lower lobe lung with mild to no significant metabolic activity. CT-guided biopsy showed the lesion composed of fat, cartilage, and smooth muscle, admixed with fibroconnective tissue. The findings are consistent with pulmonary hamartoma. The presence of fat in a well-circumscribed solitary pulmonary nodule along with low metabolic activity helps in the characterization of the lesion, which can alter patient management.

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.

A Pilot Study of Radiomics Models Combining Multi-Probe and Multi-Modality Images of 68Ga-NOTA-PRGD2 and 18F-FDG PET/CT for Differentiating Benign and Malignant Pulmonary Space-Occupying Lesions

Background

This is a pilot study of radiomics based on ⁶⁸Ga-NOTA-PRGD2 [NOTA-PEG4-E[c(RGDfK)]2)] and ¹⁸F-FDG PET/CT to (i) evaluate the diagnostic efficacy of radiomics features of ⁶⁸Ga-NOTA-PRGD2 PET in the differential diagnosis of benign and malignant pulmonary space-occupying lesions and (ii) compare the diagnostic efficacy of multi-modality and multi-probe images.

Methods

We utilized a dataset of 48 patients who participated in ⁶⁸Ga-NOTA-PRGD2 PET/CT and ¹⁸F-FDG PET/CT clinical trials to extract image features and evaluate their diagnostic efficacy in the differentiation of benign and malignant lesions by the Mann-Whitney U test. After feature selection with sequential forward selection, random forest models were developed with tenfold cross-validation. The diagnostic performance of models based on different image features was visualized by receiver operating characteristic (ROC) curves and compared by permutation tests.

Results

Fourteen of the ⁶⁸Ga-NOTA-PRGD2 PET features between benign and malignant pulmonary space-occupying lesions had significant differences (P<0.05, Mann-Whitney U test). Eighteen of the ⁶⁸Ga-NOTA-PRGD2 PET features demonstrated higher AUC values than all CT features in the differential diagnosis of pulmonary lesions. The AUC value (0.908) ​​of the three-modal feature model was significantly higher (P<0.05, permutation test) than those of the single- and dual-modal models.

Conclusion

⁶⁸Ga-NOTA-PRGD2 PET features have better diagnostic capacity than CT features for pulmonary space-occupying lesions. The combination of multi-modality and multi-probe images can improve the diagnostic efficiency of models. Our preliminary clinical hypothesis of using radiomics based on ⁶⁸Ga-NOTA-PRGD2 PET images and multimodal images as a diagnostic tool warrants further validation in a larger multicenter sample size.

Contribution of 18F-FDG PET/CT in the Differential Diagnosis of Pulmonary Hamartomas and Pulmonary Carcinoids

Objectives:

This study aimed to evaluate ¹⁸fluorine-fluorodeoxyglucose (¹⁸F-FDG) positron emission tomography/computed tomography (PET/CT) findings in the differential diagnosis of pulmonary carcinoids and pulmonary hamartomas.

Methods:

¹⁸F-FDG PET/CT findings of 34 patients with pulmonary carcinoids (12 atypical, 22 typical) and 32 patients with pulmonary hamartomas were retrospectively evaluated. Both mean diameter and mean maximum standardized uptake value (SUV_max) of hamartomas and carcinoids were compared by Mann-Whitney U and Kruskall-Wallis H tests.

Results:

The mean longest diameter of atypical carcinoids (3.5±1.7 cm) was higher than that of hamartomas (2.1±1 cm) (p=0.038). No significant difference was found between the mean diameter of typical carcinoids and mean diameter of hamartomas (p=0.128). The mean SUV_max of atypical carcinoids (5.97±3.7) and typical carcinoids (4.22±1.7) were higher than those of hamartomas (1.65±0.9) (p=0.002 and p=0.003, respectively). There were collapse/consolidation in 55.8%, bronchiectasis or mucoid impaction in 47%, and air trapping in 14.7% in the peripheral parenchyma of the 34 carcinoids. Collapse/consolidation was detected in a patient with endobronchial hamartoma, and other finding was not found in the parenchyma around hamartomas.

Conclusion:

The ¹⁸F-FDG uptake of pulmonary carcinoids can vary from minimal to intense. ¹⁸F-FDG uptake can be seen in pulmonary hamartomas. However, the mean SUV_max of atypical carcinoids and typical carcinoids were higher compared to hamartomas. Pulmonary carcinoid must be suspected in cases with accompanying bronchial obstruction findings in the periphery of the mass.

Management of pulmonary ground-glass opacities: a position paper from a panel of experts of the Italian Society of Thoracic Surgery (SICT)

OBJECTIVES

A significant gap in our knowledge of how to manage pulmonary ground-glass opacities (GGOs) still exists. Accordingly, there is a lack of consensus among clinicians on this topic. The Italian Society of Thoracic Surgery (Società Italiana di Chirurgia Toracica, SICT) promoted a national expert meeting to provide insightful guidance for clinical practice. Our goal was to publish herein the final consensus document from this conference.

METHODS

The working panel of the PNR group (Pulmonary Nodules Recommendation Group, a branch of the SICT) together with 5 scientific supervisors (nominated by the SICT) identified a jury of expert thoracic surgeons who organized a multidisciplinary meeting to propose specific statements (n = 29); 73 participants discussed and voted on statements using a modified Delphi process (repeated iterations of anonymous voting over 2 rounds with electronic support) requiring 70% agreement to reach consensus on a statement.

RESULTS

Consensus was reached on several critical points in GGO management, in particular on the definition of GGO, radiological and radiometabolic evaluation, indications for a non-surgical biopsy, GGO management based on radiological characteristics, surgical strategies (extension of pulmonary resection and lymphadenectomy) and radiological surveillance. A list of 29 statements was finally approved.

CONCLUSIONS

The participants at this national expert meeting analysed this challenging topic and provided a list of suggestions for health institutions and physicians with practical indications for GGO management.

Roles of PET/Computed Tomography in the Evaluation of Neuroblastoma

Neuroblastoma is one of the most common pediatric malignant tumors. Functional imaging plays an important role in the diagnosis, staging, and therapy response monitoring of neuroblastoma. Although metaiodobenzylguanidine scan with single-photon emission computed tomography/computed tomography remains the mainstay in functional imaging of the neuroblastomas, PET/CT has begun to show increased utility in this clinical setting.

The Contribution of Fluorine 18F-FDG PET/CT to Lung Cancer Diagnosis, Staging and Treatment Planning

Objective:

Lung cancer is the most common cause of cancer-related death throughout the world, and the correct choice of treatment based on early diagnosis and staging increases the chance of survival. The present study aims to investigate the contribution of fluorine 18-fluorodeoxyglucose-positron emission tomography/computed tomography (¹⁸F-FDG PET/CT) to the management of lung cancer.

Methods:

In this study, 50 patients who underwent ¹⁸F-FDG PET/CT for lung cancer diagnosis and staging between February 2012 and February 2014 were included. The maximum standardized uptake value (SUV_max) of the primary lung lesion along with other findings of ¹⁸F-FDG PET/CT and the results of histopathologic and conventional examinations were evaluated retrospectively. The mean survival time of patients was determined, and the findings were compared by using statistical methods.

Results:

Histopathologic examinations revealed 51 lung cancers in 50 patients. The sensitivity, accuracy and positive predictive value of ¹⁸F-FDG PET/CT in detecting primary malignancy were 94%, 94%, 100%, respectively. Adenocarcinoma (n=23, 16.8±13.5) and squamous cell carcinoma (n=15, 17.9±5.6) did not differ significantly regarding their mean SUV_max values (p=0.2). A statistically significant positive correlation (r=0.4) was identified between tumor size and SUV_max value for 51 tumors (p=0.002). The ¹⁸F-FDG PET/CT result was true negative in nine, false positive in six, true positive in two, and false negative in four patients who underwent histopathologic evaluation of their lymph nodes. The ¹⁸F-FDG PET/CT changed treatment planning in 34% of the patients. No significant relationship was identified between SUV_max value of the tumor and patient survival in patients (p=0.118).

Conclusion:

The present study concluded that PET/CT was an efficient method in the diagnosis and staging of lung cancer since it provided useful information in addition to conventional methods. It was also observed that PET/CT scanning resulted in a change in therapeutic plans in the majority of patients. However, there was no statistically significant relationship between survival and the SUV_max of the primary mass.

The role of positron emission tomography in the diagnosis, staging and response assessment of non-small cell lung cancer

Lung cancer is a common disease and the leading cause of cancer-related mortality, with non-small cell lung cancer (NSCLC) accounting for the majority of cases. Following diagnosis of lung cancer, accurate staging is essential to guide clinical management and inform prognosis. Positron emission tomography (PET) in conjunction with computed tomography (CT)-as PET-CT has developed as an important tool in the multi-disciplinary management of lung cancer. This article will review the current evidence for the role of ¹⁸F-fluorodeoxyglucose (FDG) PET-CT in NSCLC diagnosis, staging, response assessment and follow up.