Use of [18F]Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography after Curative Treatment of Non-Small-Cell Lung Cancer Patients: A Nationwide Cohort Study.

[¹8F]Fluorodeoxyglucose positron emission tomography/computed tomography ([¹8F]FDG PET/CT) is a valuable imaging tool in the post-treatment management of non-small-cell lung cancer (NSCLC). This study aimed to investigate the trends in utilization and factors associated with the use of [¹8F]FDG PET/CT after curative-intent treatment. Data from 13,758 NSCLC patients diagnosed between 2007 and 2020 identified in the Danish Lung Cancer Registry, who underwent curative-intent treatment, were analyzed using multivariable regression. The results showed a significant increase in the use of [¹8F]FDG PET/CT scans, from 10.4 per 100 patients per year in 2007 to 39.6 in 2013, followed by a period of stability. Higher utilization rates were observed in patients who received radiotherapy (22% increase compared to surgical resection) and in patients with stage II-III disease (14% and 20% increase compared to stage I, respectively). Additionally, utilization was increased when other diagnostic procedures were performed, such as MRI, ultrasound, endoscopy, and biopsy. These findings highlight an increasing reliance on [¹8F]FDG PET/CT in post-treatment NSCLC, especially after radiotherapy and in patients with locally advanced disease, where treatment-induced radiographic changes and an increased risk of recurrence present a significant diagnostic challenge.

Myocardial Flow Reserve, an Independent Prognostic Marker of All-Cause Mortality Assessed by 82Rb PET Myocardial Perfusion Imaging: A Danish Multicenter Study.

BACKGROUND: Rubidium-82 positron emission tomography (82Rb PET) myocardial perfusion imaging is used in clinical practice to quantify regional perfusion defects. Additionally, 82Rb PET provides a measure of absolute myocardial flow reserve (MFR), describing the vasculature state of health. We assessed whether 82Rb PET-derived MFR is associated with all-cause mortality independently of the extent of perfusion defects. METHODS: We conducted a multicenter clinical registry-based study of patients undergoing 82Rb PET myocardial perfusion imaging on suspicion of chronic coronary syndromes. Patients were followed up in national registries for the primary outcome of all-cause mortality. Global MFR ≤2 was considered reduced. RESULTS: Among 7169 patients studied, 38.1% were women, the median age was 69 (IQR, 61-76) years, and 39.0% had MFR ≤2. A total of 667 (9.3%) patients died during a median follow-up of 3.1 (IQR, 2.6-4.0) years, more in patients with MFR ≤2 versus MFR >2 (15.7% versus 5.2%; P<0.001). MFR ≤2 was associated with all-cause mortality across subgroups defined by the extent of perfusion defects (all P<0.05). In a Cox survival regression model adjusting for sex, age, comorbidities, kidney function, left ventricular ejection fraction, and perfusion defects, MFR ≤2 was a robust predictor of mortality with a hazard ratio of 1.62 (95% CI, 1.31-2.02; P<0.001). Among patients with no reversible perfusion defects (n=3101), MFR ≤2 remained strongly associated with mortality (hazard ratio, 1.86 [95% CI, 1.26-2.73]; P<0.01). The prognostic value of impaired MFR was similar for cardiac and noncardiac death. CONCLUSIONS: MFR ≤2 predicts all-cause mortality independently of the extent of perfusion defects. Our results support the inclusion of MFR when assessing the prognosis of patients suspected of chronic coronary syndromes.

Surveillance With PET/CT and Liquid Biopsies of Stage I-III Lung Cancer Patients After Completion of Definitive Therapy: A Randomized Controlled Trial (SUPER).

Despite increased focus on prevention as well as improved treatment possibilities, lung cancer remains among the most frequent and deadliest cancer diagnoses worldwide. Even lung cancer patients treated with curative intent have a high risk of relapse, leading to a dismal prognosis. More knowledge on the efficacy of surveillance with both current and new technologies as well as on the impact on patient treatment, quality of life, and survival are urgently needed. We therefore designed a randomized phase 3 trial. In one arm, every other computed tomography (CT) scan is replaced by positron emission tomography/CT, the other arm is the standard follow-up scheme with CT. The standard arm is identical to the current national Danish follow-up program. The primary endpoint is to compare the number of relapses treatable with curative intent in the 2 arms. We aim to include 750 patients over a 3-year period. Additionally, we will test the feasibility of noninvasive lung cancer diagnostics and surveillance in the form of circulating tumor DNA analysis. For this purpose, blood samples are collected before treatment and at each following control. The blood samples are stored in a biobank for later analysis and will not be used for guiding patient treatment decisions.

Nuclear Molecular Imaging Strategies in Immune Checkpoint Inhibitor Therapy.

Immune checkpoint inhibitor therapy (ICT) is a new treatment strategy developed for the treatment of cancer. ICT inhibits pathways known to downregulate the innate immune response to cancer cells. These drugs have been shown to be effective in the treatment of a variety of cancers, including metastatic melanoma and lung cancer. Challenges in response evaluation of patients in ICT have risen as immune related side effects and immune cell infiltration may be confused with progressive disease. Furthermore, the timing of the evaluation scan may be challenged by relatively slow responses. To overcome this, new response criteria for evaluating these patients with morphologic imaging have been proposed. The aim of this paper is to review and discuss the current evidence for the use of molecular imaging, e.g., PET/CT (Positron Emission Tomography/Computer Tomography) with 18F-Fluorodeoxyglucoes (FDG) as an alternative imaging method for monitoring patients undergoing ICT. Following the currently available evidence, this review will primarily focus on patients with malignant melanoma.