Objective To investigate the value of ¹⁸F-FDG PET/CT metabolic parameters in the prognostic assessment of nasopharyngeal cancer patients. Methods The clinical data and PET/CT metabolic parameters of 185 nasopharyngeal cancer patients were retrospectively analyzed. The collected parameters were SUV_max, MTV, TLG, total metabolic tumor volume (TMTV) and whole-body total lesion glycolysis (WTLG). The ROC curve was used to determine the optimal cut-off values of PET/CT metabolic parameters. Univariate and multivariate Cox regression models were used to screen the independent prognostic factors. Kaplan–Meier curves were used to analyze the survival differences. Results The results of univariate Cox regression analysis showed that age, pathologic type, WTLG, TMTV, MTV, and TLG were closely associated with OS and PFS; and SUV_max was associated with PFS (P<0.05). Multivariate Cox regression analysis results showed that age, TMTV, and WTLG were the independent prognostic factors for OS and PFS (P<0.05). The combination of WTLG with T/N staging (AUC=0.781 and 0.781) and TMTV with T/N staging (AUC=0.800 and 0.790) yielded greater predictive accuracy than that of WTLG and TMTV alone (AUC=0.724 and 0.719) or T/N staging (AUC=0.593 and 0.575). Conclusion TMTV and WTLG are important prognostic predictors of nasopharyngeal carcinoma. TLG and MTV of primary lesions are prognostic factors for patients’ PFS and OS. SUV_max has limited prognostic value. Systemic metabolic indexes (TMTV and WTLG), when combined with T/N staging, can optimize prognostic stratification.

OBJECTIVE: To analyze the correlation between baseline ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography (¹⁸F-FDG PET/CT) and circulating tumor DNA (ctDNA) parameters in diffuse large B-cell lymphoma (DLBCL) and compare the value of the two methods in the prognosis assessment of DLBCL. METHODS: A total of 50 DLBCL patients confirmed by pathology, including 26 males and 24 females, with a median age of 55.5(43.5, 64.0) years from August 2018 to April 2021 were retrospectively analyzed. PET/CT parameters, including maximum standardized uptake value (SUVmax), metabolic tumor volume (MTV), total lesion glycolysis (TLG), ctDNA parameters, including mutation number, mutation gene number, mean variant allele frequency (meanVAF), and clinical data of patients were collected. The relationship between PET/CT, ctDNA parameters and patient clinical features was analyzed, as well as the correlation between PET/CT and ctDNA parameters. The diagnostic efficacy of PET/CT and ctDNA parameters was compared. Patients were followed up for 36-69 months. Progression-free survival (PFS) was calculated, and survival analysis was performed. RESULTS: PET/CT parameters all had good correlation with ctDNA parameters, among which MTV was moderately correlated with mutation number, mutation gene number, and meanVAF (r_s=0.72, 0.64, 0.71), TLG was strongly correlated with mutation number (r_s=0.83) and moderately correlated with mutation gene number and mean VAF (r_s=0.72, 0.79), while SUVmax was weakly correlated with mutation number, mutation gene number and meanVAF (r_s=0.47, 0.46, 0.47). PET/CT parameters and ctDNA parameters showed no statistically significant differences in predicting the prognosis of DLBCL and area under the curve (AUC) of receiver operating characteristic (ROC) (P >0.05). However, the specificity of MTV and TLG in predicting prognosis of 1-, 2- and 3-year PFS was better than that of meanVAF (all P < 0.05), while the sensitivity of meanVAF in predicting prognosis of 1-, 2- and 3-year PFS was better than that of MTV (all P < 0.05). The optimal cut-off values of SUVmax, MTV, TLG, mutation number, mutation gene number and meanVAF in predicting tumor progression were obtained using ROC curve analysis. Patients were divided into high and low expression groups according to the cut-off values and survival analysis was performed. The results of survival analysis showed that there were statistically significant differences in PFS between the high and low expression groups (all P < 0.05). CONCLUSION Baseline ¹⁸F-FDG PET/CT and ctDNA parameters can both predict the prognosis of DLBCL, and are equally valuable in the evaluation of DLBCL prognosis.
Humans ; Lymphoma, Large B-Cell, Diffuse/diagnosis* ; Positron Emission Tomography Computed Tomography ; Fluorodeoxyglucose F18 ; Middle Aged ; Prognosis ; Female ; Male ; Circulating Tumor DNA ; Retrospective Studies ; Adult ; Mutation

As the brain's resident immune cells, microglia perform crucial functions such as phagocytosis, neuronal network maintenance, and injury restoration by adopting various phenotypes. Dynamic imaging of these phenotypes is essential for accessing brain diseases and therapeutic responses. Although numerous probes are available for imaging pro-inflammatory microglia, no PET tracers have been developed specifically to visualize anti-inflammatory microglia. In this study, we present an ¹⁸F-labeled PET tracer (QTFT) that targets the P2Y₁₂, a receptor highly expressed on anti-inflammatory microglia. [¹⁸F]QTFT exhibited high binding affinity to the P2Y₁₂ (14.43 nmol/L) and superior blood-brain barrier permeability compared to other candidates. Micro-PET imaging in IL-4-induced neuroinflammation models showed higher [¹⁸F]QTFT uptake in lesions compared to the contralateral normal brain tissues. Importantly, this specific uptake could be blocked by QTFT or a P2Y₁₂ antagonist. Furthermore, [¹⁸F]QTFT visualized brain lesions in mouse models of epilepsy, glioma, and aging by targeting the aberrantly expressed P2Y₁₂ in anti-inflammatory microglia. In a pilot clinical study, [¹⁸F]QTFT successfully located epileptic foci, showing enhanced radioactive signals in a patient with epilepsy. Collectively, these studies suggest that [¹⁸F]QTFT could serve as a valuable diagnostic tool for imaging various brain disorders by targeting P2Y₁₂ overexpressed in anti-inflammatory microglia.

Peptide receptor radionuclide therapy (PRRT) with radiolabeled SSTR2 agonists is a treatment option that is highly effective in controlling metastatic and progressive neuroendocrine tumors (NETs). Previous studies have shown that an SSTR2 agonist combined with albumin binding moiety Evans blue (denoted as ¹⁷⁷Lu-EB-TATE) is characterized by a higher tumor uptake and residence time in preclinical models and in patients with metastatic NETs. This study aimed to enhance the in vivo stability, pharmacokinetics, and pharmacodynamics of ¹⁷⁷Lu-EB-TATE by replacing the maleimide-thiol group with a polyethylene glycol chain, resulting in a novel EB conjugated SSTR2-targeting radiopharmaceutical, ¹⁷⁷Lu-LNC1010, for PRRT. In preclinical studies, ¹⁷⁷Lu-LNC1010 exhibited good stability and SSTR2-binding affinity in AR42J tumor cells and enhanced uptake and prolonged retention in AR42J tumor xenografts. Thereafter, we presented the first-in-human dose escalation study of ¹⁷⁷Lu-LNC1010 in patients with advanced/metastatic NETs. ¹⁷⁷Lu-LNC1010 was well-tolerated by all patients, with minor adverse effects, and exhibited significant uptake and prolonged retention in tumor lesions, with higher tumor radiation doses than those of ¹⁷⁷Lu-EB-TATE. Preliminary PRRT efficacy results showed an 83% disease control rate and a 42% overall response rate after two ¹⁷⁷Lu-LNC1010 treatment cycles. These encouraging findings warrant further investigations through multicenter, prospective, and randomized controlled trials.

Triple-negative breast cancer is therapeutically challenging due to the low expression of tumor markers and 'cold' tumor immunosuppressive microenvironment. Here, we present a dual-targeting peptide-drug conjugate (PDC) for tumor inhibition. Our PDC efficiently and selectively delivers cytotoxic Monomethyl Auristatin E (MMAE) into tumor cells via C-X-C chemokine receptor type 4 (CXCR4) and folate receptor 1 (FOLR1) for synergistic inhibition of growth and metastasis. Our results show that the dual-targeting PDC has potent antitumor activity in cultured human cells and several murine transplanted tumor models without apparent toxicity. The combination of dual-targeting PDC and radiotherapy modulates the tumor immunosuppressive microenvironment by increasing CD8⁺ T cell infiltration and attenuating the proportion of myeloid-derived suppressor and regulatory T cells. Therefore, our dual-targeting PDC represents a promising new strategy for cancer therapy that rebalances the immune system and promotes tumor regression.