Prognosis predicting value of semiquantitative parameters of visceral adipose tissue and subcutaneous adipose tissue of 18F-FDG PET/CT in newly diagnosed secondary hemophagocytic lymphohistiocytosis

The prognostic value of 18F-FDG PET/CT intra-tumoural metabolic heterogeneity in pretreatment neuroblastoma patients

Background

Neuroblastoma (NB) is the most common tumour in children younger than 5 years old and notable for highly heterogeneous. Our aim was to quantify the intra-tumoural metabolic heterogeneity of primary tumour lesions by using ¹⁸F-FDG PET/CT and evaluate the prognostic value of intra-tumoural metabolic heterogeneity in NB patients.

Methods

We retrospectively enrolled 38 pretreatment NB patients in our study. ¹⁸F-FDG PET/CT images were reviewed and analyzed using 3D slicer software. The semi-quantitative metabolic parameters of primary tumour were measured, including the maximum standard uptake value (SUVmax), metabolic tumour volume (MTV), and total lesion glycolysis (TLG). The areas under the curve of cumulative SUV-volume histogram index (AUC-CSH index) was used to quantify intra-tumoural metabolic heterogeneity. The median follow-up was 21.3 months (range 3.6 - 33.4 months). The outcome endpoint was event-free survival (EFS), including progression-free survival and overall survival. Survival analysis was performed using Cox regression models and Kaplan Meier survival plots.

Results

In all 38 newly diagnosed NB patients, 2 patients died, and 17 patients experienced a relapse. The AUC-CSH_total (r=0.630, P<0.001) showed moderate correlation with the AUC-CSH_40%. In univariate analysis, chromosome 11q deletion (P=0.033), Children's Oncology Group (COG) risk grouping (P=0.009), bone marrow involvement (BMI, P=0.015), and AUC-CSH_total (P=0.007) were associated with EFS. The AUC-CSH_total (P=0.036) and BMI (P=0.045) remained significant in multivariate analysis. The Kaplan Meier survival analyses demonstrated that patients with higher intra-tumoural metabolic heterogeneity and BMI had worse outcomes (log-rank P=0.002).

Conclusion

The intra-tumoural metabolic heterogeneity of primary lesions in NB was an independent prognostic factor for EFS. The combined predictive effect of intra-tumoural metabolic heterogeneity and BMI provided prognostic survival information in NB patients.

Differential Diagnosis of Hemophagocytic Syndrome by 18F-FDG PET/CT: A Meta-Analysis

Hemophagocytic syndrome (HPS) is a rare disease in clinical practice, and there are often cases of delayed diagnosis. At present, researchers have applied 18F-FDG PET/CT in the differential diagnosis of HPS, but no consensus has been formed. Therefore, this study aims to systematically evaluate the application value of 18F-FDG PET/CT in the diagnosis of HPS patients. PubMed, Embase, Cochrane Library, Chinese National Knowledge Infrastructure (CNKI), Wangfang database (Wangfang), and Chinese Biomedical Network (CBM) were searched to collect the relevant studies of 18F-FDG PET/CT in the diagnosis of HPS. Data from the articles were screened and extracted for meta-analysis using Stata16.0 software. A total of 10 retrospective studies, including 300 patients, were included in this meta-analysis. The meta-analysis results showed that the pooled sensitivity was 0.82 (95% CI: 0.67-0.95), specificity was 0.72 (95% CI: 0.51-0.86), positive likelihood ratio was 2.89 (95% CI: 1.46-5.75), positive likelihood ratio was 0.25 (95% CI: 0.12-0.54), diagnostic odds ratio was 2.89 (95% CI: 1.46-5.75), and AUC was 0.84 (95% CI: 0.81-0.87). The SUVmax in the liver, spleen, lymph nodes, and bone marrow of HPS patients was greater than 2.5, and the SUVmax in the spleen, lymph nodes, and bone marrow of malignant HPS patients was higher than that of benign HPS patients. The difference was statistically significant (P < 0.05). According to the existing literature evidence, 18F-FDG PET/CT is an effective method for diagnosing HPS.

Development and Validation of a Nomogram Based on 18F-FDG PET/CT Radiomics to Predict the Overall Survival in Adult Hemophagocytic Lymphohistiocytosis

Purpose: Hemophagocytic lymphohistiocytosis (HLH) is a rare and severe disease with a poor prognosis. We aimed to determine if ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) PET/CT-derived radiomic features alone or combination with clinical parameters could predict survival in adult HLH.

Methods: This study included 70 adults with HLH (training cohort, n = 50; validation cohort, n = 20) who underwent pretherapeutic ¹⁸F-FDG PET/CT scans between August 2016 and June 2020. Radiomic features were extracted from the liver and spleen on CT and PET images. For evaluation of 6-month survival, the features exhibiting p < 0.1 in the univariate analysis between non-survivors and survivors were selected. The least absolute shrinkage and selection operator (LASSO) regression analysis was used to develop a radiomics score (Rad-score). A nomogram was built by the multivariate regression analysis to visualize the predictive model for 3-month, 6-month, and 1-year survival, while the performance and usefulness of the model were evaluated by calibration curves, the receiver operating characteristic (ROC) curves, and decision curves.

Results: The Rad-score was able to predict 6-month survival in adult HLH, with area under the ROC curves (AUCs) of 0.927 (95% CI: 0.878–0.974) and 0.869 (95% CI: 0.697–1.000) in the training and validation cohorts, respectively. The radiomics nomogram combining the Rad-score with the clinical parameters resulted in better performance for predicting 6-month survival than the clinical model or the Rad-score alone. Moreover, the nomogram displayed superior discrimination, calibration, and clinical usefulness in both the cohorts.

Conclusion: The newly developed Rad-score is a powerful predictor for overall survival (OS) in adults with HLH. The nomogram has great potential for predicting 3-month, 6-month, and 1-year survival, which may timely guide personalized treatments for adult HLH.

Multiple-Organ Involvement in Familial Hemophagocytic Lymphohistiocytosis Type 2 Shown on FDG PET/CT

ABSTRACT

FDG PET/CT in an 18-year-old man with known familial hemophagocytic lymphohistiocytosis (HLH) type 2 demonstrated abnormally in the brain, liver, and lymph nodes. Pathology showed no sign of lymphoproliferative disease. The patient underwent the chemotherapy of HLH. Six months after chemotherapy, a follow-up FDG PET/CT did not show any abnormal 18F-FDG activity, suggesting a complete response. The present case shows FDG PET/CT might not only be useful in staging the familial HLH but also able to evaluate the therapy response.