Role of [68Ga]-pentixafor positron emission tomography/computed tomography imaging in assessing disease activity in patients with lupus nephritis: A pilot study

OBJECTIVE

The primary objective of our study was to evaluate renal uptake of 68Ga-pentixafor in patients with lupus nephritis. Eighteen patients who satisfied the inclusion criteria were included in our study.

METHODS

The study participants were patients with histopathologically confirmed lupus nephritis who were referred to our department for 68Ga-pentixafor PET/CT scan. We studied the renal images in these patients for uptake patterns based on purely visual as well as semi-quantitative parameters. The visual parameters included uptake relative to the spleen and liver. Semi-quantitative analysis involved the uptake as given by SUVmax. These parameters were correlated with the patients' biochemical as well as histological parameters. Kendall's tau-b test was used to look for an association between renal uptake by visual assessment and histopathological findings. Mean SUVmax values were compared by using the Mann-Whitney U test and a p value < .05 was considered to be statistically significant.

RESULTS

No significant association between the mean renal SUVmax of the bilateral kidneys in pentixafor PET and histopathological class was observed. We did not observe any heterogeneity in uptake patterns that could be attributed to the disease process in our patients.

CONCLUSION

68Ga-pentixafor PET is not a suitable imaging modality for assessment of disease activity in lupus nephritis patients. There is a void in non-invasive testing for patients with this chronic and often disabling condition which calls for further research in this area.

Engineering a Smart Agent for Enhanced Immunotherapy Effect by Simultaneously Blocking PD-L1 and CTLA-4

Combinations of immune checkpoint therapies show encouraging results in the treatment of many human cancers. However, the higher costs and greater side effects of such combinations compared with single-agent immunotherapies limit their further applications. In this work, a novel smart agent, KN046@19 F-ZIF-8, is developed to overcome these limitations. KN046 is a novel recombinant humanized PD-L1/CTLA-4 bispecific single-domain antibody-Fc fusion protein, which can bind to both PD-L1 and CTLA-4 effectively. ZIF-8 is a smart delivery system, which can safely and effectively deliver KN406 to a tumor. In vitro and in vivo results demonstrate that the smart agent KN046@19 F-ZIF-8 not only improves the immune response rate of the antibody drug in treatment of tumors but also reduces its toxic side effects, thereby achieving excellent antitumor efficacy. This study provides an engineering strategy for clinical applications of a more effective immunotherapy.

Tumor Targeting by αvβ3-Integrin-Specific Lipid Nanoparticles Occurs via Phagocyte Hitchhiking

Although the first nanomedicine was clinically approved more than two decades ago, nanoparticles' (NP) in vivo behavior is complex and the immune system's role in their application remains elusive. At present, only passive-targeting nanoformulations have been clinically approved, while more complicated active-targeting strategies typically fail to advance from the early clinical phase stage. This absence of clinical translation is, among others, due to the very limited understanding for in vivo targeting mechanisms. Dynamic in vivo phenomena such as NPs' real-time targeting kinetics and phagocytes' contribution to active NP targeting remain largely unexplored. To better understand in vivo targeting, monitoring NP accumulation and distribution at complementary levels of spatial and temporal resolution is imperative. Here, we integrate in vivo positron emission tomography/computed tomography imaging with intravital microscopy and flow cytometric analyses to study α_vβ₃-integrin-targeted cyclic arginine-glycine-aspartate decorated liposomes and oil-in-water nanoemulsions in tumor mouse models. We observed that ligand-mediated accumulation in cancerous lesions is multifaceted and identified "NP hitchhiking" with phagocytes to contribute considerably to this intricate process. We anticipate that this understanding can facilitate rational improvement of nanomedicine applications and that immune cell-NP interactions can be harnessed to develop clinically viable nanomedicine-based immunotherapies.

Imaging Characteristics of Breast Lymphoma; a Case Series

Introduction

Breast involvement by lymphoma is rare. It can occur as a primary breast tumour or as an extranodal manifestation of the systemic disease. The imaging features of breast lymphoma (BL) are not characteristic. Biopsy is necessary for diagnosis due to non-specific imaging features.

Materials and Methods

A retrospective electronic medical chart review was conducted of patients diagnosed with lymphoma of breast that underwent diagnostic radiological procedures (including mammography, ultrasound breast, computed tomography (CT) scan and positron emission tomography (PET/CT) scan from 1 July 2018 to 31 March 2019 at Shaukat Khanum Memorial Cancer Hospital and Research Centre, Pakistan.

Results

Four patients were identified. On mammogram, the most common finding consisted of the presence of high-density masses with circumscribed or indistinct margins. On ultrasound, hypoechoic masses and indistinct diffuse infiltrative patterns were observed. PET/CT and CT were helpful in detecting extramammary sites of disease and for classifying the disease into primary or secondary BL.

Conclusion

The early diagnosis of the BL is important. The radiologists should include lymphoma in the differential diagnosis when there is the absence of microcalcifications or spiculated margins on mammography and ultrasound.

Improving (18)F-Fluoro-D-Glucose-Positron Emission Tomography/Computed Tomography Imaging in Alzheimer's Disease Studies

The goal was to improve Alzheimer's 2-deoxy-2-¹⁸F-fluoro-D-glucose (¹⁸F FDG)-positron emission tomography (PET)/computed tomography (CT) imaging through application of a novel, hybrid Fourier-wavelet windowed Fourier transform (WFT) restoration technique, in order to provide earlier and more accurate clinical results. General Electric Medical Systems downward-looking sonar PET/CT 16 slice system was used to acquire studies. Patient data were acquired according the Alzheimer's disease Neuroimaging Initiative (ADNI) protocol. Here, we implemented Fourier-wavelet regularized restoration, with a Butterworth low-pass filter, order n = 6 and a cut-off frequency f = 0.35 cycles/pixel and wavelet (Daubechies, order 2) noise suppression. The original (PET-O) and restored (PET-R) ADNI subject PET images were compared using the Alzheimer's discrimination analysis by dedicated software. Forty-two PET/CT scans were used in the study. They were performed on eleven ADNI subjects at intervals of approximately 6 months. The final clinical diagnosis was used as a gold standard. For three subjects, the final clinical diagnosis was mild cognitive impairment and those 13 PET/CT studies were not included in the final comparison, as the result was considered as inconclusive. Using the reminding 29 PET/CT studies (23 AD and 6 normal), the sensitivity and specificity of the PET-O and PET-R were calculated. The sensitivity was 0.65 and 0.96 for PET-O and PET-R, respectively, and the specificity was 0.67 and 0.50 for PET-O and PET-R. The accuracy was 0.66 and 0.86 for PET-O and PET-R, respectively. The results of the study demonstrated that the accuracy of three-dimensional brain F-18 FDG PET images was significantly improved by Fourier-wavelet restoration filtering.