Diffusely Increased Splenic Fluorodeoxyglucose Uptake in Lung Cancer Patients

Molecular imaging using 18F-FDG PET/CT and circulating inflammatory and immune indicators to predict pathological response to neoadjuvant camrelizumab plus chemotherapy in resectable stage IIIA-IIIB NSCLC

OBJECTIVE

This study aims to predict the pathological response of patients with non-small cell lung cancer (NSCLC) in prospective trials of neoadjuvant camrelizumab combined with chemotherapy by integrating the clinical characteristics, PET-associated parameters, and hematological indicators.

METHODS

A prospective analysis was conducted among 24 patients undergoing surgery after neoadjuvant camrelizumab plus chemotherapy. 18F-Fluorodeoxyglucose (FDG) scans were performed before and after neoadjuvant therapy (pre-NAT, post-NAT). Tumor and secondary lymphoid organ metabolic parameters, along with circulating inflammatory and immune indicators, were measured and correlated with pathological response. Receiver operating characteristic (ROC) curve was used to assess biomarkers' predictive accuracy.

RESULTS

Major pathological response (MPR) and pathological complete response (pCR) were achieved in 45.8% (11/24) and 33.3% (8/24) of patients. Before treatment, patients who achieved a pCR had significantly greater SUVmax values (p = 0.011) than non-pCR patients. After treatment, the MPR group exhibited significantly lower SUVmax values than the non-MPR group (p = 0.048). The rate of change in the SUVmax (ΔSUVmax%) differed significantly between the pCR and non-pCR groups (p = 0.019) and between the MPR and non-MPR groups (p = 0.013). After NAT, the lymph nodes' SUVmax in the ypN0 group was significantly lower than that in the ypN + group (p = 0.032). ROC analysis indicated that pre-NAT SUVmax and ΔSUVmax% best distinguished pCR and MPR patients, respectively, with AUCs of 0.82 (p = 0.012) and 0.80 (p = 0.014).

CONCLUSION

Pre-NAT SUVmax, and ΔSUVmax% are promising biomarkers for predicting pathological response to neoadjuvant camrelizumab and chemotherapy.

CLINICALTRIALS

GOV ID

NCT06241807.

Prognostic value of inflammatory response biomarkers using peripheral blood and [18F]-FDG PET/CT in advanced NSCLC patients treated with first-line chemo- or immunotherapy

OBJECTIVES

We aimed to compare the prognostic value of inflammatory biomarkers extracted from pretreatment peripheral blood and [18F]-FDG PET for estimating outcomes in non-small cell lung cancer (NSCLC) patients treated with first-line immunotherapy (IT) or chemotherapy (CT).

MATERIALS AND METHODS

In this retrospective multicenter study, we evaluated 111 patients with advanced NSCLC who underwent baseline [18F]-FDG PET/CT before IT or CT between 2016 and 2019. Several blood inflammatory indices were evaluated: derived neutrophil-to-lymphocyte ratio (dNLR), platelet-to-lymphocyte ratio (PLR), C-reactive protein (CRP) and systemic immune-inflammation index (SII). FDG-PET inflammatory parameters were extracted from lymphoid tissues (BLR and SLR: bone marrow or spleen-to-Liver SUVmax ratios). Association with survival and relationships between parameters were evaluated using Cox prediction models and Spearman's correlation respectively.

RESULTS

Overall, 90 patients were included (IT:CT) (51:39pts). Median PFS was 8.6:6.6 months and median OS was not reached:21.2 months. In the IT cohort, high dNLR (>3), high SII (≥1,270) and high SLR (0.77) were independent statistically significant prognostic factors for one-year progression-free survival (1y-PFS) and two-year overall survival (2y-OS) on multivariable analysis. In the CT cohort, high BLR (≥0.80) and high dNLR (>3) were associated with shorter 1y-PFS (HR 2.2, 95% CI 1.0-4.9) and 2y-OS (HR 3.4, 95CI 1.1-10.3) respectively, on multivariable analysis. Finally, BLR significantly but moderately correlated with most blood-based inflammatory indices (CRP, PLR and SII) while SLR was only associated with CRP (p < 0.01 for all).

CONCLUSION

In advanced NSCLC patients undergoing first-line IT or CT, pretreatment blood and inflammatory factors evaluating the spleen or bone marrow on [18F]-FDG PET/CT provided prognostic information for 1y-PFS and 2y-OS. These biomarkers should be further evaluated for potential clinical application.

Don't overlook spleen glucose metabolism on [18F]-FDG PET/CT for cancer drug discovery and development

Fluorine-18-fluorodeoxyglucose ([18F]-FDG) positron emission tomography/computed tomography (PET/CT) is a useful tool that assesses glucose metabolism in tumor cells to help guide management of cancer patients. However, the clinical relevance of glucose metabolism in healthy tissues, including hematopoietic tissues such as the spleen, has been potentially overlooked. Recent studies suggested that spleen glucose metabolism could improve the management of different cancers. Overall, the current literature includes 1,157 patients, with a wide range of tumor types. The prognostic and/or predictive value of spleen metabolism have been demonstrated in a broad spectrum of therapies including surgery and systemic cancer therapies. Most of these studies showed that high spleen glucose metabolism at baseline is associated with a poor outcome while treatment-induce change in spleen glucose metabolism is a multi-faceted surrogate of cancer-related inflammation, which correlates with immunosuppressive tumor microenvironment as well as with immune activation. In this systematic review, we seek to unravel the prognostic/predictive significance of spleen glucose metabolism on [18F]-FDG PET/CT and discuss how it could potentially guide cancer patient management in the future.

Prognostic significance of bone marrow and spleen 18F-FDG uptake in patients with colorectal cancer

Serum inflammatory markers are used in the prognostication of colorectal cancer (CRC); however, the corresponding role of positron emission tomography (PET)-derived inflammatory markers remains unclear. This study aimed to investigate the prognostic value of 18F-fluorodeoxyglucose (FDG) uptake in the bone marrow and spleen of patients with CRC and evaluate the relationship between FDG uptake estimates in these organs and serum inflammatory markers. In total, 411 patients who underwent preoperative FDG PET/computed tomography (CT) within 1 month of surgery were enrolled. The mean standardized uptake values of the bone marrow and spleen were normalized to the value of the liver, thereby generating bone marrow-to-liver uptake ratio (BLR) and spleen-to-liver uptake ratio (SLR) estimates. The value of BLR and SLR in predicting overall survival (OS) was assessed using the Cox proportional hazards model. The correlation between BLR or SLR and neutrophil-to-lymphocyte ratio (NLR) was evaluated. The predictive accuracy of BLR alone and in combination with SLR was compared using the integrated area under the receiver operating characteristic curves (iAUC). In the univariate analysis, BLR (> 1.06) and SLR (> 0.93) were significant predictors of OS. In the multivariate analysis, BLR was an independent predictor of OS (hazard ratio = 5.279; p < 0.001). Both BLR and SLR were correlated with NLR (p < 0.001). A combination of BLR and SLR was better than BLR alone at CRC prognostication (iAUC, 0.561 vs. 0.542). FDG uptake estimates in the bone marrow and spleen may be useful imaging-derived biomarkers of systemic inflammation, supporting CRC prognostication.

18F-fluorodeoxyglucose positron emission tomography/computed tomography for the diagnosis of native valve infective endocarditis: A prospective study

BACKGROUND

¹⁸F-fluorodeoxyglucose-positron emission tomography/computed tomography (¹⁸F-FDG PET/CT) has recently been added as a major criterion in the European Society of Cardiology (ESC) 2015 infective endocarditis guidelines. PET/CT is currently used in patients with suspected prosthetic valve and cardiac device-related endocarditis. However, the value of the ESC classification and the clinical impact of PET findings are unknown in patients with native valve endocarditis (NVE).

AIMS

Our aims were: to assess the value of the ESC criteria (including PET/CT) in NVE; to determine the usefulness of PET/CT concerning embolic detection; and to describe a new PET/CT feature (diffuse splenic uptake).

METHODS

Between 2012 and 2017, 75 patients with suspected NVE were included prospectively, after exclusion of patients with uninterpretable or unfeasible PET/CT. Using gold standard expert consensus, 63 cases of infective endocarditis were confirmed and 12 were rejected.

RESULTS

Significant valvular uptake was observed in 11 of 63 patients with definite NVE and in no patients who had the diagnosis of infective endocarditis rejected (sensitivity 17.5%, specificity 100%). Among the 63 patients with NVE, a peripheral embolism or mycotic aneurysm was observed in 20 (31.7%) cases. Application of the ESC criteria increased Duke criteria sensitivity from 63.5% to 69.8% (P<0.001), without a change in specificity. Diffuse splenic uptake was observed in 39 (52.0%) patients, including 37 (58.7%) with a final diagnosis of NVE (specificity 83.3%).

CONCLUSIONS

¹⁸F-FDG PET/CT has poor sensitivity but high specificity in the diagnosis of NVE. The usefulness of ¹⁸F-FDG PET/CT is high for embolic detection. Diffuse splenic uptake represents a possible new diagnostic criterion for NVE.

Comparison Between ESC and Duke Criteria for the Diagnosis of Prosthetic Valve Infective Endocarditis

OBJECTIVES

The primary objective was to assess the value of the European Society of Cardiology (ESC) criteria, including ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography (¹⁸F-FDG-PET/CT) in prosthetic valve infective endocarditis (PVE). Secondary objectives were: 1) to assess the reproducibility of ¹⁸F-FDG-PET/CT; 2) to compare its diagnostic value with that of echocardiography; and 3) to assess the diagnostic value of the presence of a diffuse splenic uptake BACKGROUND: ¹⁸F-FDG PET/CT has been added as a major criterion in the ESC 2015 infective endocarditis (IE) guidelines, but the benefit of the ESC criteria has not been prospectively compared with the conventional Duke criteria.

METHODS

Between 2014 and 2017, 175 patients with suspected PVE were prospectively included in 3 French centers. After exclusion of patients with uninterpretable ¹⁸F-FDG PET/CT, 115 patients were evaluated, including 91 definite and 24 rejected IE, as defined by an expert consensus.

RESULTS

Cardiac uptake by ¹⁸F-FDG PET/CT was observed in 67 of 91 patients with definite PVE and 6 with rejected IE (sensitivity 73.6% [95% confidence interval (CI): 63.3% to 82.3%], specificity 75% [95% CI: 53.3% to 90.2%]). The ESC 2015 classification increased the sensitivity of Duke criteria from 57.1% (95% CI: 46.3% to 67.5%) to 83.5% (95% CI: 74.3% to 90.5%) (p < 0.001), but decreased its specificity from 95.8% (95% CI: 78.9% to 99.9%) to 70.8% (95% CI: 48.9% to 87.4%). Intraobserver reproducibility of ¹⁸F-FDG PET/CT was good (kappa = 0.84) but interobserver reproducibility was less satisfactory (kappa = 0.63). A diffuse splenic uptake was observed in 24 (20.3%) patients, including 23 (25.3%) of definite PVE, and only 1 (4.2%) rejected PVE (p = 0.024).

CONCLUSIONS

¹⁸F-FDG PET/CT is a useful diagnostic tool in suspected PVE, and explains the greater sensitivity of ESC criteria than Duke criteria. However, ¹⁸F-FDG PET/CT also presents with important limitations concerning its feasibility, specificity, and reproducibility. Our study describes for the first time a new endocarditis criterion, that is, the presence of a diffuse splenic uptake on ¹⁸F-FDG PET/CT.

Diffuse splenic FDG uptake is predictive of clinical outcomes in patients with rectal cancer

This study aimed to investigate the correlations between diffuse splenic Fluorine-18-fluorodeoxyglucose (¹⁸F-FDG) uptake on positron emission tomography/computed tomography (PET/CT) and inflammatory markers and to evaluate the prognostic significance of splenic FDG uptake in rectal cancer patients who underwent curative surgery. We retrospectively analyzed the data from 161 patients who underwent splenic FDG PET/CT staging and subsequent curative surgical resection of rectal cancer between July 2006 and September 2014. The spleen-to-liver uptake ratio (S/L ratio) was calculated by dividing the spleen SUV_mean by liver SUV_mean. We found significant positive correlations between the S/L ratio and neutrophil-to-lymphocyte ratio (P = 0.013) and platelet-to-lymphocyte ratio (P = 0.007). In a Kaplan–Meier analysis, patients with S/L ratio ≤0.815 had a significantly higher recurrence-free survival rate than those with S/L ratio >0.815 (P = 0.028). Also, patients with S/L ratio ≤0.731 had a significantly higher overall survival rate than those with S/L ratio >0.731 (P = 0.036). In multivariate analysis, higher S/L ratio, as well as male, poor differentiation, higher TNM stage, perineural invasion, and larger tumor size, was independently predictive of cancer recurrence (>0.815 vs ≤0.815, hazard ratio [HR]: 2.04, P = 0.046). With regard to OS, S/L ratio was also an independent prognostic factor for death during follow-up (>0.731 vs ≤0.731, HR: 3.81, P = 0.017). Our results show significant correlations between S/L ratio on PET/CT and systemic inflammatory markers. Further, S/L ratio was an independent prognostic factor for predicting recurrence and death in patient with rectal cancer after curative surgery.