Persistent FDG Uptake at Apical Aneurysm in a Patient With Cardiac Sarcoidosis

We present a case of cardiac sarcoidosis with persistent, focal fluorodeoxyglucose uptake at the left ventricular apical aneurysm concerning for ongoing active inflammatory injury, prompting aggressive immunosuppressive therapy. This case highlights the importance of understanding the various clinical entities that may resemble disease activity on fluorodeoxyglucose positron emission tomography/computed tomography imaging. (Level of Difficulty: Intermediate.

Characterizing Prednisone Regimens for Treatment of Cardiac Sarcoidosis

INTRODUCTION: Corticosteroids are the mainstay treatment for cardiac sarcoidosis (CS), which manifests clinically in about 5% of sarcoid patients. Current comparisons of steroid regimens in CS focus on starting dose and rarely describe taper rates or expected cumulative exposure. This study characterizes several prednisone regimens for CS to strengthen frameworks for defining treatment goals. METHODS: We queried a registry of 1,403 patients referred to the Hospital of the University of Pennsylvania for positron emission tomography (PET) investigation of CS. We performed chart reviews of 98 patients with myocardial inflammation on initial PET who were treatment naïve, initiated on prednisone for CS between 2008 and 2019, and whose dose was known throughout a 52-week period following treatment initiation. Patients were stratified by starting dose into low-dose (LD, n=22) (\u3c30 mg/day), moderate-dose (MD, n=52) (30-49 mg/day), and high-dose (HD, n=24) (≥50 mg/day) groups. We used one-way ANOVA to assess differences in cumulative exposure. Taper rate was derived using a quadratic mixed model. We included fixed effects for week number, starting dose, and their interaction and a random intercept term to account for correlations from repeated measures per patient. We performed post-hoc comparison of estimated marginal means to compare taper rates. RESULTS: Cumulative exposure over 52 weeks (mean±SD) increased proportionally with starting dose: 5,413±2,446 mg vs. 6,752±2,748 mg vs. 10,322±3,624 mg in LD, MD, and HD groups, respectively (F2, 95 = 18.3, p\u3c10-7). Taper rate (mean [95% CI]) was inversely proportional to starting dose: -0.223 [-0.252, -0.194] mg/week vs. -0.492 [-0.511, - 0.474] mg/week vs. -0.758 [-0.785, -0.730] mg/week in LD, MD, and HD groups, respectively (p\u3c0.001). CONCLUSIONS: Starting dose is related to cumulative exposure and taper rate. Future studies should investigate the association between cumulative exposure and adverse events and the relationship between taper rate and disease relapse

Racial and ethnic characteristics and cancer-specific survival in Primary Malignant Cardiac Tumors.

BACKGROUND: There is limited insight into the epidemiological characteristics and effect of race and ethnicity on Primary Malignant Cardiac Tumors (PMCTs). OBJECTIVES: Comparison of clinical characteristics and cancer-specific survival outcomes of major races in the United States from the Surveillance, Epidemiology and End-Result (SEER) registry. METHODS: ICD-O-3 codes were used to identify PMCTs for the years 1975 to 2015. Three major races were identified- White , Black , and Asian/Pacific Islander . Cancer-specific survival outcomes were compared using Kaplan-Meier analysis across and amongst races, based on tumor histology. A subgroup analysis of cancer-specific survival was performed between Hispanics and non-Hispanics. RESULTS: Seven hundred and twenty patients were identified-47% females and 79% White, mean age at diagnosis (47 ± 20 years). Black patients were significantly younger (39 ± 18 years) and presented more commonly with angiosarcomas (53%). Non-angiogenic sarcomas and lymphomas were the most common tumors in the White (38%) and Asian/Pacific Islander (34%) cohorts. For a median follow-up period of 50 (IQR3-86) months, cancer-specific survival (mean ± SD, in months) was worse in Blacks (9 ± 3) as compared to Whites (15 ± 1) and Asian/Pacific Islander (14 ± 1) ( CONCLUSION: Black and non-Hispanic patients have poorer cancer-specific survival in PMCTs

18 F-FDG-PET/CT in the assessment of atherosclerosis in lung cancer

The aim of this study was to assess the risk of atherosclerosis in patients with lung cancer compared to patients with extrapulmonary malignancies using 18F-fluorodeoxyglucose-positron emission tomography/computed tomography (FDG-PET/CT). We hypothesized that patients with lung cancer would demonstrate increased FDG uptake in the thoracic aorta compared to patients with extrapulmonary cancers. Thirty-four lung cancer patients (21 male, 13 female, 64.1 ± 12.9 yo) were retrospectively compared to seventy-eight patients with extrapulmonary malignancies (46 male, 32 female, 59.6 ± 12.8 yo). Average maximum standardized uptake value (avgSUVmax) and maximum target-to-blood pool ratio (TBRmax) were measured by mapping regions of interest of the ascending aorta, aortic arch, and descending aorta. Two-tailed Student’s t-test was used to assess the differences in avgSUVmax and TBRmax between the two groups and between smokers and non-smokers. Age and gender distribution between the groups were not statistically different. AvgSUVmax and TBRmax were statistically significant increase in lung cancer patients compared to extrapulmonary cancer patients in the ascending aorta, aortic arch, and descending aorta, suggesting a lung cancer-associated increased risk of atherosclerosis development. AvgSUVmax was not significantly different between smokers and non-smokers in all sections of the thoracic aorta. Moving forward, large, prospective studies that directly compare PET data between different malignancies of different stages will help determine the role of FDG-PET/CT in assessing paraneoplastic vascular disease

Global quantification of pulmonary artery atherosclerosis using 18F-sodium fluoride PET/CT in at-risk subjects

The goal of this study was to assess pulmonary artery calcification in healthy controls and subjects with suspicion of stable angina pectoris through the usage of quantitative 18F-sodium fluoride positron emission tomography/computed tomography (NaF-PET/CT). We hypothesized that these ‘at-risk subjects’ would demonstrate increase pulmonary artery NaF uptake compared to healthy controls. Retrospectively, 15 healthy controls were compared to 15 at-risk subjects, all of whom underwent full-body NaF-PET/CT scans. The healthy controls and at-risk patients were all randomly sampled from larger datasets. The two sampled groups were male-dominated and similar in age. The global mean standard uptake value (SUVmean), the max standard uptake value (SUVmax), and the mean target-to-background ratio (TBRmean) were acquired through mapping of regions of interest (ROI’s) around the pulmonary artery of the subjects. A two-tailed Mann-Whitney U test was used to determine the significance of difference between the two groups. For global SUVmean (0.79 compared to 0.58), global TBRmean (1.15 compared to 0.93), and global SUVmax (1.78 compared to 1.60), the NaF uptake was significantly higher in the at-risk patients compared to the controls (all P<0.05). NaF-PET/CT is a suitable imaging modality for quantification of molecular calcification in the pulmonary artery. Additionally, the connection between atherosclerosis and the risk factor of angina pectoris is further reinforced. We believe that future studies are needed to validate our proof-of-concept, and better confirm the clinical future of NaF-PET/CT as a tracer of atherosclerotic plaques

Incremental prognostic value of visually estimated coronary artery calcium in patients undergoing positron emission tomography imaging

Objective Visually estimated coronary artery calcium (VECAC) from chest CT or attenuation correction (AC)/CT obtained during positron emission tomography (PET)–myocardial perfusion imaging (MPI) is feasible. Our aim was to determine the prognostic value of VECAC beyond conventional risk factors and PET imaging parameters, including coronary flow reserve (CFR).Methods We analysed 608 patients without known coronary artery disease who underwent PET–MPI between 2012 and 2016 and had AC/CT and/or chest CT images. We used Cox regression to estimate the association of VECAC categories (≤10, 11–400, &gt;400 Agatston units (AU)) with the primary outcome of all-cause death, acute coronary syndrome or stroke (mean follow-up 4.3±1.8 years). C-statistics assessed the relationship between PET parameters and VECAC with the primary outcome.Results Mean age was 58±11 years, 65% were women and 67% were black. VECAC ≤10, 11–400 and &gt;400 AU was observed in 68%, 12% and 20% of subjects, respectively. Compared with VECAC ≤10, VECAC categories 11–400 (HR 2.25, 95% CI 1.24 to 4.08) and &gt;400 AU (HR 3.05, 95% CI 1.87 to 4.98) were associated with the primary outcome after adjusting for traditional risk factors, MPI findings and CFR. Adding VECAC to a model that included PET–MPI, CFR and clinical risk factors improved the prognostic value for the primary outcomes (c-statistic 0.71 to 0.75 with VECAC, p=0.01).Conclusions VECAC is a potent predictor of events beyond traditional risk factors and PET imaging markers, including CFR. These data further support the importance for routine VECAC implementation

18F-FDG-PET/CT in the quantification of photon radiation therapy-induced vasculitis

Radiation therapy (RT) is an important component of care for head and neck cancers (HNC). Photon RT vasculitis is a complication of incidental dose delivery to nearby vascular structures. However, optimal methods for early diagnosis are not clearly established. The aim of this study was to evaluate 18F-FDG-PET/CT in detecting radiation-induced vasculitis of the left common carotid (LCC) and the arch of the aorta (AoA) in patients treated for HNC. 18F-FDG-PET/CT scans obtained before RT (Pre-RT) and 3 months after RT (Post-RT) were retrospectively reviewed in 30 HNC patients (25 males, 5 females; average age 57.9±8.1 years) treated with photon RT. All subjects underwent 18F-FDG-PET/CT imaging 60 minutes after 5.0 MBq/kg 18F-FDG injection. Average standard uptake values (Avg SUVmean) of the LCC and AoA were obtained by global assessment. A two-tailed paired t-test was used to assess the difference in Avg SUVmean between pre- and post-RT imaging. Subjects demonstrated significant increased Avg SUVmean within the LCC post-RT (pre = 1.42, post = 1.65, P<0.001), with a mean increase of 0.23 SUV. Similarly, subjects exhibited higher 18F-FDG uptake in the AoA post-RT (pre = 1.44, post = 1.69, P<0.01), with a mean increase of 0.23 SUV. 18F-FDG-PET/CT may be used to detect and quantify photon RT vasculitis in HNC patients. Further investigation is warranted to evaluate the clinical implications of this pathology and the role for alternative treatment strategies in minimizing tissue toxicity

Venous thromboembolism detected by FDG-PET/CT in cancer patients: a common, yet life-threatening observation

Cancer patients are at markedly increased risk for venous thromboembolism (VTE). Early detection of VTE may decrease morbidity and mortality in this population. We conducted this study to evaluate the ability of FDG-PET/CT to detect thrombosis in cancer patients. This retrospective study included 131 cancer patients with a history of deep vein thrombosis (DVT) or pulmonary embolism (PE) referred for 2-deoxy-2-[18F]-fluorodeoxyglucose-positron emission tomography/computed tomography (FDG-PET/CT). All subjects underwent PET/CT imaging 60 minutes after FDG injection. Images were visually assessed for increased FDG uptake within the venous lumen. For positive cases, clinical follow-up and Doppler ultrasonography and/or contrast-enhanced CT scans were reviewed. FDG-PET/CT revealed abnormal uptake in the venous system of 26 (19.8%) patients. Eighteen (69.2%) had a history of DVT, and 13 (50%) had a history of PE. The most common site of thrombosis was the inferior vena cava (IVC) (n=14, 53.8%), followed by lower extremities veins (n=9, 34.6%), jugular veins (n=2, 7.7%), and superior vena cava (n=1, 3.8%). The presence of thrombi was confirmed by reviewing clinical follow-up in 6 (23.1%) patients. Among this group, thrombosis was detected in lower extremity veins (n=4, 15.8%), jugular veins (n=1, 3.8%), and IVC (n=1, 3.8%). Our study demonstrates that thrombi prior to their clinical manifestation can be detected by FDG-PET/CT in cancer patients. Moving forward, physicians must carefully consider the venous system when reporting FDG-PET/CT for cancer patients

Emerging role of 18F-FDG PET/CT in Castleman disease: a review

Castleman disease (CD) describes a group of rare hematologic conditions involving lymphadenopathy with characteristic histopathology and a spectrum of clinical abnormalities. CD is divided into localized or unicentric CD (UCD) and multicentric CD (MCD) by imaging. MCD is further divided based on etiological driver into human herpesvirus-8-associated MCD, POEMS-associated MCD, and idiopathic MCD. There is notable heterogeneity across MCD, but increased level of pro-inflammatory cytokines, particularly interleukin-6, is an established disease driver in a portion of patients. FDG-PET/CT can help determine UCD versus MCD, evaluate for neoplastic conditions that can mimic MCD clinico-pathologically, and monitor therapy responses. CD requires more robust characterization, earlier diagnosis, and an accurate tool for both monitoring and treatment response evaluation; FDG-PET/CT is particularly suited for this. Moving forward, future prospective studies should further characterize the use of FDG-PET/CT in CD and specifically explore the utility of global disease assessment and dual time point imaging. Trial registration ClinicalTrials.gov, NCT02817997, Registered 29 June 2016, https://clinicaltrials.gov/ct2/show/NCT0281799