Clinical features and 18F-FDG PET/CT for distinguishing of malignant lymphoma from inflammatory lymphadenopathy in HIV-infected patients

Association between cardiovascular inflammation and alterations in immune system induced by HIV infection detected on [18F]FDG PET/MRI

OBJECTIVE

To assess by [18F]FDG PET/MR the biomarkers of HIV-induced inflammation at baseline and 1 year post-antiretroviral therapy (ART).

METHODS

Prospective study, 14 patients, newly diagnosed HIV-positive, asymptomatic. [18F]FDG PET/MRI (PET/MR-3.0T, Signa.GE) whole body and heart was performed, baseline and 1 year post-ART. Qualitative vascular assessment (hepatic reference). Quantitative assessment (SUVmax) of the whole body. T1 and T2 value estimation in 16 myocardial segments.

RESULTS

Baseline CMR showed in 3 (21.4%) a decreased LVEF, normalising post-TAR. Fibrosis was ruled out (T1), with no signs of myocardial oedema (T2) at baseline or post-TAR. Four (28.6%) showed baseline vascular [18F]FDG uptake, two in ascending thoracic aorta and two in ascending and descending thoracic aorta, normalising post-TAR. All (100%) showed basal lymph-nodes activity; supra (n:14) and infradiaphragmatic (n:13), laterocervical (n:14) and inguinal (n:13), with variable number of territories (9 patients >6;64.3%). Post-ART, 7 patients (50%) showed resolution and the other 7 reduction in extension (0 patients >5): 7 supra (100%) and 2 infradiaphragmatic (28.6%), 5 in the axilla and 2 in the groin. All (100%) had persistent basal adenoid uptake post-ART, 9 (64.3%) splenic all resolved post-ART and 7 (50.5%) gastric, persistent 3 post-ART.

CONCLUSIONS

Cardiovascular biomarkers by [18F]FDG PET/MR have shown baseline 28.6% of patients with large vessel activity and 21.4% with low LVEF, normalising post-ART. Inflammatory/immune biomarkers showed baseline activity in 100% of lymph-nodes, 100% adenoids, 64.3% splenic and 50.5% gastric. Post-TAR the reduction was 50% lymph-nodes, 0% adenoid, 100% splenic and 57.1% gastric.

Recent advancements in 18F-FDG PET/CT for the diagnosis, staging, and treatment management of HIV-related lymphoma

Infection with the Human Immunodeficiency Virus (HIV) is one of the most pressing issues facing public health on a worldwide scale. Currently, HIV-related lymphoma is the most common cause of death among people living with HIV, and warrants more attention. The unique challenges associated with HIV-related lymphoma management derive from the underlying HIV infection and its immunosuppressive effects. 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) has gained significant prominence in the past few years as a valuable diagnostic and therapeutic instrument for the treatment of HIV-related lymphoma. This review will start with an overview of the subtypes, risk factors, and therapeutic choices for individuals with HIV-related lymphoma. We will then briefly discuss the current application of 18F-FDG PET/CT in the medical management of HIV-related lymphoma patients, followed by the initial staging of the disease, the evaluation of therapeutic response, the prediction of prognostic outcomes, the decision-making process for radiotherapy guided by PET findings, and the distinguishing of various diagnoses.

Differentiation of cancer of unknown primary and lymphoma in head and neck metastatic poorly differentiated cancer using 18 F-FDG PET/CT tumor metabolic heterogeneity index

OBJECTIVE

To explore the value of 18 F-FDG PET/CT tumor metabolic heterogeneity index (HI) and establish and validate a nomogram model for distinguishing head and neck cancer of unknown primary (HNCUP) from lymphoma with head and neck metastatic poorly differentiated cancer.

METHODS

This retrospective analysis was conducted on 1242 patients with cervical metastatic poorly differentiated cancer. 108 patients, who were clinically and pathologically confirmed as HNCUP or lymphoma, were finally enrolled. Two independent sample t-tests and χ 2 test were used to compare the clinical and imaging features. Binary logistic regression was used to screen for independent predictive factors.

RESULTS

Among the 108 patients), 65 patients were diagnosed with HNCUP and 43 were lymphoma. Gender ( P  = 0.001), SUV max ( P  < 0.001), SUV mean ( P  < 0.001), TLG ( P  = 0.012), and HI ( P  < 0.001) had statistical significance in distinguishing HNCUP and lymphoma. Female ( OR  = 4.546, P  = 0.003) and patients with HI ≥ 2.37 ( OR  = 3.461, P  = 0.047) were more likely to be diagnosed as lymphoma.

CONCLUSION

For patients with cervical metastatic poorly differentiated cancer, gender and HI were independent predictors of pathological type. For such patients, clinical attention should be paid to avoid misdiagnosing lymphoma as HNCUP, which may delay treatment.

Research to develop a diagnostic ultrasound nomogram to predict benign or malignant lymph nodes in HIV-infected patients

BACKGROUND

This study aimed to establish an effective ultrasound diagnostic nomogram for benign or malignant lymph nodes in HIV-infected patients.

METHODS

The nomogram is based on a retrospective study of 131 HIV-infected patients who underwent ultrasound assess at the Shanghai Public Health Clinical Center from December 2017 to July 2022. The nomogram's predictive accuracy and discriminative ability were determined by concordance index (C-index) and calibration curve analysis. A nomogram combining the lymph node US characteristics were generated based on the multivariate logistic regression results.

RESULTS

Predictors contained in the ultrasound diagnostic nomogram included age (OR 1.044 95%CI: 1.014-1.074 P = 0.004), number of enlarged lymph node regions (OR 5.445 95%CI: 1.139-26.029 P = 0.034), and color Doppler flow imaging (CDFI) grades (OR 9.614 95%CI: 1.889-48.930 P = 0.006). The model displayed good discrimination with a C (ROC) of 0.775 and good calibration.

CONCLUSIONS

The proposed nomogram may result in more-accurate diagnostic predictions for benign or malignant lymph nodes in patients with HIV infection.

Clinical value of 18F-FDG PET/CT in the management of HIV-associated lymphoma

HIV is still a major public health problem. At present, HIV-associated lymphoma remains the leading cause of deaths among people living with HIV, which should be paid more attention to. ¹⁸F-fluorodeoxglucose (FDG) PET/CT has been recommended in the initial staging, restaging, response assessment and prognostic prediction of lymphomas in general population. HIV-associated lymphoma is, however, a different entity from lymphoma in HIV-negative with a poorer prognosis. The ability to accurately risk-stratify HIV-infected patients with lymphoma will help guide treatment strategy and improve the prognosis. In the review, the current clinical applications of ¹⁸F-FDG PET/CT in HIV-associated lymphoma will be discussed, such as diagnosis, initial staging, response evaluation, prognostic prediction, PET-guided radiotherapy decision, and surveillance for recurrence. Moreover, future perspectives will also be presented.

Different Uptake of 68Ga-FAPI and 18F-FDG in Lymphadenopathy Caused by Angioimmunoblastic T-Cell Lymphoma in a Patient with Colon Cancer

An 82-year-old man with a history of colon cancer was found with multiple lymphadenopathies and a pulmonary mass. Fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography (¹⁸F-FDG PET/CT) detected generalized hypermetabolic lymph nodes and an FDG-avid pulmonary mass. PET/CT with ⁶⁸Ga-labeled fibroblast activation protein inhibitor (FAPI) revealed intense uptake in the lung mass, consistent with metastatic disease from colon cancer. However, the lymphadenopathies were not avid for ⁶⁸Ga-FAPI, suggesting a different etiology. The biopsy of a cervical node confirmed angioimmunoblastic T-cell lymphoma. The case showcased the potential of ⁶⁸Ga-FAPI in differentiation of solid tumor and hematological disease due to different histopathologic nature of stromal fibrosis.