Dexamethasone Suppression FDG PET/CT for Differentiating between True- and False-Positive Pulmonary and Mediastinal Lymph Node Metastases in Non-Small Cell Lung Cancer: A Pilot Study of FDG PET/CT after Oral Administration of Dexamethasone

A case of grade1 follicular lymphoma diagnosed by laparoscopic lymph node resection: differentiating from late lymph node recurrence of endometrial cancer

Follicular lymphoma is a common hematologic malignancy; however, it is less common among all malignant diseases and is difficult to suspect in advance due to the lack of specific clinical findings. Here, we report a case in which a late recurrence of corpus cancer was first suspected and finally diagnosed as follicular lymphoma. A 67-year-old female presented to our department with enlarged pelvic lymph nodes. She was diagnosed with breast cancer (HER2-posiotive with lymph node metastasis) and corpus cancer (endometrioid carcinoma grade 2, stage IA) 16 years prior, received definitive therapy and was followed up. A positron emission tomography scan was performed, and an accumulation of 18F-fluorodeoxyglucose (FDG) was detected in multiple lymph nodes, including the lymph nodes with no change in size or enlargement. We performed laparoscopic resection of the enlarged and FDG-accumulated lymph nodes and a pathological examination. The patient was diagnosed with follicular lymphoma (FL) grade 1 and is currently under observation at the Department of Hematology. FL can be considered when there is a discrepancy between the change in lymph node size and the degree of FDG accumulation. A pathological examination is useful for accurate diagnosis. Therefore, it is important to consider tissue collection; however, care must be taken to minimize the invasiveness of the procedure for the patient.

Estimation of an Image Biomarker for Distant Recurrence Prediction in NSCLC Using Proliferation-Related Genes

This study aimed to identify a distant-recurrence image biomarker in NSCLC by investigating correlations between heterogeneity functional gene expression and fluorine-18-2-fluoro-2-deoxy-D-glucose positron emission tomography (¹⁸F-FDG PET) image features of NSCLC patients. RNA-sequencing data and ¹⁸F-FDG PET images of 53 patients with NSCLC (19 with distant recurrence and 34 without recurrence) from The Cancer Imaging Archive and The Cancer Genome Atlas Program databases were used in a combined analysis. Weighted correlation network analysis was performed to identify gene groups related to distant recurrence. Genes were selected for functions related to distant recurrence. In total, 47 image features were extracted from PET images as radiomics. The relationship between gene expression and image features was estimated using a hypergeometric distribution test with the Pearson correlation method. The distant recurrence prediction model was validated by a random forest (RF) algorithm using image texture features and related gene expression. In total, 37 gene modules were identified by gene-expression pattern with weighted gene co-expression network analysis. The gene modules with the highest significance were selected (p-value < 0.05). Nine genes with high protein-protein interaction and area under the curve (AUC) were identified as hub genes involved in the proliferation function, which plays an important role in distant recurrence of cancer. Four image features (GLRLM_SRHGE, GLRLM_HGRE, SUVmean, and GLZLM_GLNU) and six genes were identified to be correlated (p-value < 0.1). AUCs (accuracy: 0.59, AUC: 0.729) from the 47 image texture features and AUCs (accuracy: 0.767, AUC: 0.808) from hub genes were calculated using the RF algorithm. AUCs (accuracy: 0.783, AUC: 0.912) from the four image texture features and six correlated genes and AUCs (accuracy: 0.738, AUC: 0.779) from only the four image texture features were calculated using the RF algorithm. The four image texture features validated by heterogeneity group gene expression were found to be related to cancer heterogeneity. The identification of these image texture features demonstrated that advanced prediction of NSCLC distant recurrence is possible using the image biomarker.

Effect of steroid treatment on the diagnostic yield of baseline 18f-fluorodeoxyglucose positron emission tomography in aggressive B cell lymphoma

Aggressive B cell lymphoma often requires prompt steroid treatment, even before baseline ¹⁸f-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) and definitive treatment, to alleviate symptoms or prevent organ damage. Since lymphoma is a steroid-sensitive malignancy, there are concerns that steroids might affect the results of FDG PET/CT and decrease its diagnostic yield. The aim of the current study was to evaluate the effect of steroids administered before baseline PET/CT on the maximum standardized uptake value (SUVmax) and additional PET/CT parameters. Retrospective review of the database in a tertiary medical center yielded 178 patients newly diagnosed with aggressive B cell lymphoma between January 2017 and May 2020 who had an available baseline FDG PET/CT scan. The cohort was divided into patients who received steroids before PET/CT (n = 47) and those who did not (n = 131), and the groups were compared for SUVmax and additional PET/CT parameters. The steroid-treated group had a higher disease stage and lactate dehydrogenase level compared to the steroid-naïve group, with a trend toward a higher international prognostic index. There was no significant between-group difference in SUVmax (P = 0.61). This finding remained consistent across steroid treatment durations and dosage regimens. Further evaluation revealed a significantly larger mean tumor volume and a trend toward a higher tumor metabolic burden in the steroid-treated group, yet no between-group difference in SUV mean or other PET/CT parameters. In this retrospective analysis of patients with aggressive B cell lymphoma, steroid prophase prior to baseline PET/CT did not decrease the diagnostic yield of the scan. However, further studies are required to fully appreciate the impact of steroids on PET CT parameters.

Neurolymphomatosis of the median nerve, optic nerve, L4 spinal nerve root and cauda equina in patients with B-cell malignancies: a case series

BACKGROUND

Neurolymphomatosis is rare. Neoplastic lymphocytes are seen to invade nerves (cranial or peripheral), nerve roots or other related structures in patients with hematological malignancy. It is a separate entity from central nervous system lymphoma. Neurolymphomatosis has most commonly been described in association with B-cell non-Hodgkin lymphoma. Neurolymphomatosis in the context of Burkitt lymphoma and the post-renal transplant setting has not been described before.

CASE REPORTS

We report for the first time in the Arabian Gulf countries and nearby Arab states four cases of neurolymphomatosis (one Asian, and the other 3 are from Arabic nationals) occurring between 2012 and 2017 involving the median nerve, optic nerve, nerve root and cauda equina in patients with Burkitt lymphoma, Philadelphia chromosome-positive B-cell acute lymphoblastic leukemia and diffuse large B-cell lymphoma.

CONCLUSIONS

Neurolymphomatosis is rare and can be difficult to diagnose by biopsy but reliably confirmed by a combined imaging approach. Prior treatment with high-dose dexamethasone might suppress 18F-fluorodeoxyglucose (FDG) activity and decrease the sensitivity of positron emission tomography/computed tomography (PET/CT). The prognosis is generally poor but using high-dose methotrexate as well as high-dose chemotherapy and autologous stem cell transplantation may be an effective way to treat neurolymphomatosis.

Clinicopathologic Significance of False-Positive Lymph Node Status on FDG-PET in Lung Cancer

INTRODUCTION

2-[¹⁸F] Fluoro-d-deoxyglucose (FDG) positron emission tomography (PET) is a relevant diagnostic procedure for staging lung cancer. However, accurate evaluation of lymph node metastases by PET is controversial because of false-positive FDG uptake.

PATIENTS AND METHODS

A total of 245 patients with lung cancer were retrospectively analyzed. Standardized maximum uptake values (SUV_max) of the primary tumor and lymph nodes were compared to pathologic lymph node metastases to correlate PET findings with clinicopathologic variables and patient outcomes.

RESULTS

The SUV_max values of metastatic lymph nodes were significantly higher than those of lymph nodes without metastases (P = .0036). When SUV_max ≥ 4 was defined as PET positive for metastasis, the sensitivity, specificity, and accuracy were 48.1%, 79.8%, and 73.1%, respectively. Multivariate logistic regression analysis showed that age > 75 years, bilateral hilar FDG uptake, and no lymph node swelling were significant factors related to false-positive lymph node metastases. Smoking status, FDG uptake in the primary tumor, and concurrent lung diseases were not significant factors.

CONCLUSION

Metastatic lymph nodes show higher FDG uptake than false-positive lymph nodes, and older patient age, bilateral hilar FDG uptake, and no swollen nodes are associated with no metastases. Patients with lymph node metastases have worse survival than those with false-positive FDG-PET findings. However, abnormal FDG uptake in the lymph node is an important prognostic factor.

A Pilot Study of Texture Analysis of Primary Tumor [18F]FDG Uptake to Predict Recurrence in Surgically Treated Patients with Non-small Cell Lung Cancer

PURPOSE

To examine whether the heterogeneous texture parameters in primary tumor can predict prognosis of patients with non-small cell lung cancer (NSCLC) received surgery after 2-deoxy-2-[¹⁸F]fluoro-D-glucose ([¹⁸F]FDG) positron emission tomography (PET)/X-ray computed tomography (CT).

PROCEDURE

This retrospective study included 55 patients with NSCLC who underwent [¹⁸F]FDG-PET/CT before surgery from January 2011 and December 2015. SUV-related (SUVmax and SUVmean), volumetric (metabolic tumor volume [SUV ≥ 2.5], and total lesion glycolysis) and texture parameters (local parameters; entropy, homogeneity, and dissimilarity and regional parameters; intensity variability [IV], size-zone variability [SZV], and zone percentage [ZP]) were obtained. Tumor size, TNM stage, SUV-related, volumetric, and texture parameters were compared between the patients with progression and without progression using Mann-Whitney's U or χ² test and progression-free survival (PFS) and prognostic significance were assessed by Kaplan-Meier method and Cox regression analysis, respectively.

RESULTS

Nineteen patients eventually showed progression, and 36 patients were alive without progression during clinical follow-up (median follow-up PFS; 23 months [range, 1-71]). The patients with progression showed significantly larger tumor size (p < 0.001), higher IV (p = 0.010), and higher SZV (p = 0.007) than those without progression. PFS was significantly shorter in patients with large tumor size (p = 0.008), high T stage (p = 0.009), high stage (p = 0.013), high IV (p = 0.012), and high SZV (p = 0.015) at univariate analysis. At multivariate analysis, stage (hazard ratio [HR] 1.62, p = 0.035) and IV (hazard ratio 6.19, p = 0.048) were only remained independent predictors for PFS.

CONCLUSIONS

The regional heterogeneity texture parameters IV and SZV can predict tumor progression, and IV has the potential to predict prognosis of surgically treated NSCLC patients.

Plasma long non-coding RNA MALAT1 is associated with distant metastasis in patients with epithelial ovarian cancer

Human metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) is a newly identified metastasis-associated long non-coding RNA. In a previous study, it was identified that plasma levels of MALAT1 were significantly increased in gastric cancer patients with metastasis compared with gastric cancer patients without metastasis and healthy control individuals. However, it is unclear whether plasma levels of MALAT1 may act as a biomarker for evaluating the development of metastasis in epithelial ovarian cancer (EOC). In the present study, groups that consisted of 47 patients with EOC and metastasis (EOC/DM), 47 patients with EOC without metastasis (EOC/NDM), and 47 healthy control (HC) individuals were established. Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) was used to detect the level of plasma MALAT1 in these groups. The results showed that levels of plasma MALAT1 were significantly increased in the EOC/DM group compared with the EOC/NDM and HC groups (P<0.001). Receiver operating characteristic (ROC) analysis indicated that plasma MALAT1 yielded an area under the curve (AUC) of 0.820 [95% confidence interval (CI), 0.734–0.905; P<0.001], distinguishing between EOC/DM and EOC/NDM. ROC analysis also yielded an AUC of 0.884 (95% CI, 0.820–0.949; P<0.001), with 89.4% sensitivity and 72.3% specificity for distinguishing between EOC/DM and HC. Furthermore, multivariate analysis indicated that overexpression of MALAT1, differentiation (poor), tumor-node-metastasis stage (IV), lymph node metastasis (N3), peritoneal invasion (present) and higher serum carbohydrate antigen 125 levels were independent predictors of survival (hazard ratio, 3.322; P=0.028) in patients with EOC. Kaplan-Meier analysis revealed that patients with increased MALAT1 expression had a poorer disease-free survival time. In conclusion, the levels of plasma MALAT1 may act as a valuable biomarker for the diagnosis of metastasis.