Interobserver Agreement Rates on C-X-C Motif Chemokine Receptor 4-Directed Molecular Imaging and Therapy

Interobserver Agreement Rates on CXCR4-Directed PET/CT in Patients with Marginal Zone Lymphoma

C-X-C motif chemokine receptor 4 (CXCR4)-directed molecular imaging provides excellent read-out capabilities in patients with marginal zone lymphoma (MZL). We aimed to determine the interobserver agreement rate of CXCR4-targeted PET/CT among readers with different levels of experience.

METHODS

50 subjects with MZL underwent CXCR4-targeted PET/CT, which were reviewed by four readers (including two experienced and two less experienced observers). The following 8 parameters were investigated: overall scan result, CXCR4 density in lymphoma tissue, extranodal organ involvement, No. of affected extranodal organs and extranodal organ metastases, lymph node (LN) involvement and No. of affected LN areas and LN metastases. We applied intraclass correlation coefficients (ICC; < 0.4, poor; 0.4-0.59, fair; 0.6-0.74, good and > 0.74 excellent agreement rates).

RESULTS

Among all readers, fair agreement was recorded for No. of affected extranodal organs (ICC, 0.40; 95% confidence interval [CI], 0.25-0.68), overall scan result (ICC, 0.42; 95%CI, 0.28-0.57), CXCR4 density in lymphoma tissue (ICC, 0.52; 95%CI, 0.38-0.66), and No. of extranodal organ metastases (ICC, 0.55; 95%CI, 0.41-0.61) and LN involvement (ICC, 0.59; 95%CI, 0.46-0.71). Good agreement rates were observed for No. of LN metastases (ICC, 0.71; 95%CI, 0.60-0.81) and No. of LN areas (ICC, 0.73; 95%CI, 0.63-0.82), while extranodal organ involvement (ICC, 0.35; 95%CI, 0.21-0.51) achieved poor concordance. On a reader-by-reader comparison, the experienced readers achieved significantly higher agreement rates in 4/8 (50%) investigated scan items (ICC, range, 0.21-0.90, P < / = 0.04). In the remaining 4/8 (50%), a similar trend with higher ICCs for the experienced readers was recorded (n.s.).

CONCLUSION

CXCR4-directed PET/CT mainly provided fair to good agreement rates for scan assessment, while a relevant level of experience seems to be required for an accurate imaging read-out.

Chemokines in the tumor microenvironment: implications for lung cancer and immunotherapy

The tumor microenvironment (TME) is a complex interconnected network of immune cells, fibroblasts, blood vessels, and extracellular matrix surrounding the tumor. Because of its immunosuppressive nature, the TME can pose a challenge for cancer immunotherapies targeting solid tumors. Chemokines have emerged as a crucial element in enhancing the efficacy of cancer immunotherapy, playing a direct role in immune cell signaling within the TME and facilitating immune cell migration towards cancer cells. However, chemokine ligands and their receptors exhibit context-dependent diversity, necessitating evaluation of their tumor-promoting or inhibitory effects based on tumor type and immune cell characteristics. This review explores the role of chemokines in tumor immunity and metastasis in the context of the TME. We also discuss current chemokine-related advances in cancer immunotherapy research, with a particular focus on lung cancer, a common cancer with a low survival rate and limited immunotherapy options.

Nanobiotechnology augmented cancer stem cell guided management of cancer: liquid-biopsy, imaging, and treatment

Cancer stem cells (CSCs) represent both a key driving force and therapeutic target of tumoral carcinogenesis, tumor evolution, progression, and recurrence. CSC-guided tumor diagnosis, treatment, and surveillance are strategically significant in improving cancer patients' overall survival. Due to the heterogeneity and plasticity of CSCs, high sensitivity, specificity, and outstanding targeting are demanded for CSC detection and targeting. Nanobiotechnologies, including biosensors, nano-probes, contrast enhancers, and drug delivery systems, share identical features required. Implementing these techniques may facilitate the overall performance of CSC detection and targeting. In this review, we focus on some of the most recent advances in how nanobiotechnologies leverage the characteristics of CSC to optimize cancer diagnosis and treatment in liquid biopsy, clinical imaging, and CSC-guided nano-treatment. Specifically, how nanobiotechnologies leverage the attributes of CSC to maximize the detection of circulating tumor DNA, circulating tumor cells, and exosomes, to improve positron emission computed tomography and magnetic resonance imaging, and to enhance the therapeutic effects of cytotoxic therapy, photodynamic therapy, immunotherapy therapy, and radioimmunotherapy are reviewed.

Exploring Theranostic Avenues in Adrenocortical Carcinoma Using Chemokine Receptor and Prostate-Specific Membrane Antigen-Directed PET/CT

ABSTRACT

We report on an adrenocortical carcinoma (ACC) patient, which has exhausted previous treatment options and was scheduled for prostate-specific membrane antigen (PSMA)- and C-X-C motif chemokine receptor 4 (CXCR4)-targeted PET/CT. We identified PSMA-avid pulmonary metastases exhibiting modest radiotracer accumulation, while chemokine receptor PET/CT provided intense uptake. This dual-tracer molecular imaging approach revealed that chemokine receptor PET appears to be more suitable in patients with advanced ACC, indicating that CXCR4-directed radioligand therapy may be considered in such patients suffering from end-stage disease. Given its dismal prognosis, chemokine receptor-directed theranostics may therefore extend the therapeutic armamentarium as last-line option in advanced ACC.

Chemokine receptor-targeted PET/CT provides superior diagnostic performance in newly diagnosed marginal zone lymphoma patients: a head-to-head comparison with [18F]FDG

BACKGROUND

In patients with marginal zone lymphoma (MZL), [18F]FDG PET/CT provided inconsistent diagnostic accuracy. C-X-C motif chemokine receptor 4 (CXCR4) is overexpressed in MZL and thus, may emerge as novel theranostic target. We aimed to evaluate the diagnostic performance of CXCR4-targeting [68Ga]Ga-PentixaFor when compared to [18F]FDG PET/CT in MZL.

METHODS

Thirty-two untreated MZL patients (nodal, n = 17; extranodal, n = 13; splenic, n = 2) received [68Ga]Ga-PentixaFor and [18F]FDG PET/CT within median 2 days. We performed a visual and quantitative analysis of the total lymphoma volume by measuring maximum/peak standardized uptake values (SUVmax/peak), and calculating target-to-background ratios (TBR, defined as lesion-based SUVpeak divided by SUVmean from blood pool). Visual comparisons for both radiotracers were carried out for all target lesions (TL), and quantitative analysis of concordant TL evident on both scans. Last, MZL subtype analyses were also conducted.

RESULTS

On a patient-based level, [68Ga]Ga-PentixaFor identified MZL manifestations in 32 (100%) subjects (vs. [18F]FDG, 25/32 [78.1%]). Of the 256 identified TL, 127/256 (49.6%) manifestations were evident only on CXCR4-directed imaging, while only 7/256 (2.7%) were identified on [18F]FDG but missed by [68Ga]Ga-PentixaFor. In the remaining 122/256 (47.7%) concordant TL, [68Ga]Ga-PentixaFor consistently provided increased metrics when compared to [18F]FDG: SUVmax, 10.3 (range, 2.53-37.2) vs. 5.72 (2.32-37.0); SUVpeak, 6.23 (1.58-25.7) vs. 3.87 (1.54-27.7); P < 0.01, respectively. Concordant TL TBR on [68Ga]Ga-PentixaFor (median, 3.85; range, 1.05-16.0) was also approximately 1.8-fold higher relative to [18F]FDG (median, 2.08; range, 0.81-28.8; P < 0.01). Those findings on image contrast, however, were driven by nodal MZL (P < 0.01), and just missed significance for extranodal MZL (P = 0.06).

CONCLUSIONS

In newly diagnosed MZL patients, [68Ga]Ga-PentixaFor identified more sites of disease when compared to [18F]FDG, irrespective of MZL subtype. Quantitative PET parameters including TBR were also higher on [68Ga]Ga-PentixaFor PET/CT, suggesting improved diagnostic read-out using chemokine receptor-targeted imaging.