European Journal of Nuclear Medicine and Molecular Imaging最新文献

Purpose

To evaluate the diagnostic accuracy of PET/CT, cranial MRI, ultrasound and temporal artery biopsy (TAB) in patients with suspected giant cell arteritis (GCA) in a direct comparison.

Methods

Consecutive patients with a suspicion of GCA and at least 2 diagnostic tests ≤ 7 days after initiation of glucocorticoids between June 2021 and June 2024, were included retrospectively. The gold standard for the diagnosis of GCA was the judgment of experienced clinicians after a follow-up of ≥ 6 months. Examinations were compared within subgroups undergoing the same tests.

Results

Sixty-one GCA patients and 50 patients with an alternative diagnosis were included. Combined cranial and large vessel PET/CT had the highest sensitivity (89% [95%CI 77–96%]) and specificity (98% [95%CI 88–100%]). Cranial PET/CT and TAB yielded a better sensitivity compared to temporal artery ultrasound (83% [95%CI 64–94%], 77% [95%CI 59–90%] and 55% [95%CI 36–74%], respectively, p = 0.023) without difference in specificity (100% [95%CI 100 − 84%], 95% [95%CI 76–100%] and 81% [95%CI 58–95%], respectively, p = 0.136). Cranial MRI had a sensitivity of 56% (95%CI 21–86%) and specificity of 82% (95%CI 48–98%). Large vessel PET/CT resulted in a better sensitivity compared to axillary artery ultrasound (68% [95%CI 45–86%] vs. 18% [95%CI 5–40%], p = 0.001) without difference in specificity (100% [95% CI 82–100%] vs. 90% [95%CI 67–99%], p = 0.50).

Conclusion

PET/CT had a better sensitivity than ultrasound and cranial MRI. TAB and cranial PET/CT had a similar diagnostic yield.

Clinical trial number

Not applicable.

Purpose

Patients diagnosed with head and neck squamous cell carcinoma (HNSCC) face a significant risk of locoregional recurrence within the first two years after treatment. While early detection of recurrence could potentially improve patient outcomes, the impact of such detection on survival remains uncertain. The aim was to assess the potential benefit of a systematic post-treatment follow-up strategy using 18 F-FDG PET/CT imaging on overall survival.

Methods

In this multicenter case-control study, patients were treated in two health areas from two different regions in France. All adults diagnosed with histologically confirmed HNSCC and treated between January 2017 and December 2020 with curative intent, with a complete response on imaging were included in the study. Primary endpoint was 3-year overall survival. The log-rank test was used to compare 3-year OS rates between the CFU (conventional follow-up) and PET/CT groups. A Cox regression model was used to assess the effect of the addition of 18 F-FDG PET/CT on survival outcomes.

Results

A total of 697 patients were included (534 males [77%], median age[IQR] 62[57–69] years); 508 patients had CFU and 189 patients had CFU + systematic annual 18 F-FDG PET/CT. Cox regression analysis showed a protective effect (OR = 0.56, 95%CI:0.397–0.795, p = 0.001) of systematic 18 F-FDG PET/CT. The 3-year OS in the PET/CT group was better than in the CFU group (83.5 ± 2.8% vs. 73.4 ± 2.1%, p = 0.008). The analysis based on stage showed a significantly better 3-year OS for advanced stage III/IV in the PET/CT group (n = 124) than in the CFU group (n = 312)(79.9 ± 3.7% vs. 71.5 ± 2.7%, p = 0.045) as well as for early stage I/II (90.5 ± 3.7% vs. 76.3 ± 3.2%, p = 0.047).

Conclusion

In this multicenter study, the use of 18 F-FDG PET/CT as an alternative to annual chest CT in the follow-up of head and neck squamous cell carcinoma (HNSCC) is associated to a survival benefit at 3 years.

Clinical trial number

Not applicable (retrospective study).

Purpose

Accurate initial staging of differentiated thyroid carcinoma (DTC) is paramount to avoid disease persistence or relapses. Neck ultrasound (US) is the gold-standard examination for lymph node staging; however, it might miss the central compartment ones. [¹⁸F]FDG PET/CT has been used to characterise unclear or suspicious thyroid nodules and can also identify nodal disease. This study tested the diagnostic efficacy of a combined approach, including digital [¹⁸F]FDG PET/CT of the cervical region and neck US in DTC staging.

Methods

We retrospectively evaluated consecutive patients treated at our centre with high-risk thyroid who had had a neck US and a neck digital [¹⁸F]FDG PET/CT before surgery and at least one year of follow-up. Diagnostic parameters, including sensitivity (Se) and accuracy (Acc), were compared across US alone, [¹⁸F]FDG PET/CT alone, and the combined approach using a patient-based analysis (PBA); Se was also tested employing a lesion analysis (LBA). Clinical and SUV parameters were compared with the histology and the one-year outcome via a logistic regression model.

Results

Eighty-two patients (61 females) were included. At the PBA, the combined approach was superior to US alone regarding Se (44% vs 19%, p < 0.05) and Acc (80% vs 72%, p < 0.05) in the central compartment nodes. At the LBA, the combined approach was superior to either method overall (43%, 37%, and 36% for combined, [¹⁸F]FDG, and US, respectively, p < 0.01) and to US in the central nodes (25% vs 14%, p < 0.01). SUVratio was an independent predictor of histologically aggressive DTC variants (p = 0.009), central compartment metastases (p = 0.04), and incomplete response at follow-up (p = 0.004).

Conclusions

The combined cervical [¹⁸F]FDG PET/CT / US approach improves the initial staging and harbours valuable prognostic information for DTC patients.

Purpose

The Trop2-targeting antibody-drug conjugate (ADC) sacituzumab govitecan (Trodelvy) has demonstrated remarkable efficacy in patients with metastatic triple-negative breast cancer (TNBC). ImmunoPET imaging offers a noninvasive method to visualize the expression and distribution of target antigens in vivo. In this study, we developed F(ab’)₂ fragments of Trodelvy for immunoPET imaging to detect Trop2 expression in TNBC models, aiming to achieve a shorter imaging window.

Materials and methods

Trodelvy-F(ab’)₂ was prepared using the IdeS protease kit and purified with Magne Protein A beads and MagneHis™ Ni Particles. The products were characterized by non-reducing sodium dodecyl sulfate-polyacrylamide gel electrophoresis and high-performance liquid chromatography. Trodelvy-F(ab’)₂ was subsequently conjugated with p-SCN-Bn-NOTA (NOTA) for radiolabeling with ⁶⁴Cu. ImmunoPET imaging using [⁶⁴Cu]Cu-NOTA-Trodelvy-F(ab’)₂ was conducted at multiple time points to assess its in vivo targeting capability. Immunohistochemical and immunofluorescence analyses were performed on tumor tissues obtained from tumor-bearing mice.

Results

The radiochemical yield of [⁶⁴Cu]Cu-NOTA-Trodelvy-F(ab’)₂ exceeded 90%, with a radiochemical purity greater than 99%. High Trop2 expression was observed in MDA-MB-468 cells, whereas MDST8 cells exhibited low expression. The apparent dissociation constant (K_D) of [⁶⁴Cu]Cu-NOTA-Trodelvy-F(ab’)₂ for MDA-MB-468 cells was determined to be 14.60 nM. ImmunoPET imaging revealed clear uptake of [⁶⁴Cu]Cu-NOTA-Trodelvy-F(ab’)₂ in MDA-MB-468 tumors as early as 4 h post-injection (p.i.) (8.20 ± 0.98%ID/g), peaking at 12 h p.i. (11.13 ± 0.45%ID/g). Uptake was significantly higher compared to the MDST8 group (3.37 ± 0.45%ID/g at 4 h; 5.77 ± 0.74%ID/g at 12 h) and the blocking group (2.67 ± 0.21%ID/g at 4 h; 3.07 ± 0.37%ID/g at 12 h). [⁶⁴Cu]Cu-NOTA-Trodelvy-F(ab’)₂ achieved significantly higher tumor-to-heart ratios in MDA-MB-468 tumors (3.87 ± 0.58 vs. 0.74 ± 0.19, P = 0.0019) at 12 h p.i., compared to [⁶⁴Cu]Cu-NOTA-Trodelvy, indicating superior tumor contrast.

Conclusions

Our findings indicate that [⁶⁴Cu]Cu-NOTA-Trodelvy-F(ab’)₂ exhibits rapid, specific, and sustained tumor accumulation in TNBC models, enabling precise and noninvasive monitoring of Trop2 expression.

Purpose

We performed an external validation of a predictive model for persistent/metastatic disease in patients with differentiated thyroid cancer (DTC) at post-treatment ¹³¹I whole-body scintigraphy (WBS).

Methods

Our study population included 836 patients (median age 44 years, 78% women) with DTC referred from 1994 to 2021 at our center. Age, sex, histology, T stage, N stage, American Thyroid Association risk classes, thyroid-stimulating hormone, radioactive iodine (RAI) activity, and thyroglobulin (Tg) levels were considered potential predictors of post-treatment WBS results. For the external validation, N stage and Tg levels were put into the decision tree (DT) model using its same Tg cut-off values.

Results

Ninety-nine patients (12%) had positive post-treatment WBS. The area under receiver operating characteristic (ROC) curve for predicting WBS findings through the external validation was 0.60 (95% confidence interval, CI, 0.56–0.64), and positive and negative predictive values were 58% (95% CI, 41–74%) and 90% (95% CI, 88–92%). We also developed an internal model including the independent predictors of WBS findings (i.e., Tg levels, T stage, N stage, and RAI activity). For this model the area under ROC curve was 0.75 (95% CI, 0.69–0.81), and positive and negative predictive values were 90% (95% CI, 68–99% and 88–92%).

Conclusions

The external validation of the proposed DT model has a limited value for predicting post-treatment ¹³¹I-WBS findings in our patients. The internal model including also T stage and RAI activity demonstrates higher predictive value.

Purpose

Total metabolic tumor volume (TMTV) at baseline becomes a key biomarker in several lymphoma subtypes. Variability in segmentation methods such as 41%SUVmax and SUVmax > 4 has limited its clinical application. Additionally, immune-checkpoint-inhibitors introduced challenges in response assessment due to pseudoprogression, complicating the use of traditional metrics. This study investigates the prognostic impact of baseline- and residual-TMTV and introduces a novel personalized-liver-based-threshold (pTMTV_liver) to enhance precision in patient stratification.

Methods

We analyzed 91 patients with relapsed/refractory diffuse-large-B-cell lymphoma and follicular lymphoma from the GATA trial, comparing patient’s outcome according to three segmentation methods: TMTV_41%, TMTV₄, and pTMTV_liver. pTMTV_liver used a threshold of 200%SUVmean_liver aligning with 125%SUVmax_liver to enhance standardization and reduce variability.

Results

Baseline-TMTV significantly influenced prognosis with higher TMTV correlating with shorter PFS and OS (p < 0.0001 for all methods). Residual-TMTV, particularly with pTMTV_liver and TMTV₄, stratified no-CMR patients with the lowest predictive errors and better predictive accuracy compared to TMTV_41% Multivariate analyses confirmed residual-pTMTV_liver as superior for prognostic performance for PFS (HR:5.10; C-index:0.724) and OS (HR:4.00; C-index:0.853) compared to TMTV₄ and Deauville Score (DS). The DS alone did not fully capture the heterogeneity of outcomes of DS4-5 patients.

Conclusion

Baseline- and residual-TMTV strongly influence prognosis and response in lymphoma patients. The novel personalized pTMTV_liver method offers improved accuracy of patient stratification, particularly for those with DS4-5, providing more reliable risk assessment. Larger cohorts are needed to validate these findings and optimize residual-TMTV-based clinical applications.

Purpose

This systematic review and meta-analysis evaluates xerostomia occurrence in prostate cancer (PC) patients undergoing [²²⁵Ac]Ac-prostate-specific membrane antigen ([²²⁵Ac]Ac-PSMA) therapy.

Methods

Following the Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols (PRISMA-P) guidelines, comprehensive electronic searches were conducted across PubMed, Scopus, and Web of Science. The study included articles addressing xerostomia as a side effect of [²²⁵Ac]Ac-PSMA therapy in clinical settings, encompassing both tandem and monotherapy strategies. Methodological quality was assessed using the National Institutes of Health (NIH) Assessment Tool. Stata software was employed to perform pooled xerostomia rates, heterogeneity analysis, meta-regression, and publication bias analysis.

Results

Twenty studies met inclusion criteria, comprising 2949 [²²⁵Ac]Ac-PSMA cycles administered to 1207 PC patients. For [²²⁵Ac]Ac-PSMA monotherapy, the pooled rate of any-grade xerostomia was 84% (95%CI: 69–94%). Grade 1–2 xerostomia had a pooled rate 83% (95%CI: 71–93%), while therapy discontinuation due to xerostomia was 5% (95%CI: 0–13%). Grade 3 xerostomia was evident in 13% (95%CI: 7–20%). [²²⁵Ac]Ac/[¹⁷⁷Lu]Lu-PSMA tandem therapy resulted in lower pooled rate of 68% for grade 1–2 toxicity (95%CI: 17–100%). Indirect comparison revealed a two-fold decrease in xerostomia risk with tandem protocol compared to monotherapy. Significant heterogeneity was observed, primarily influenced by baseline median prostate-specific antigen values (p = 0.04). Publication bias was present in most xerostomia subgroups, with trim-and-fill analysis adjusting for effect size in specific categories.

Conclusion

Xerostomia is most pronounced in patients undergoing [²²⁵Ac]Ac-PSMA monotherapy. Tandem approach with [¹⁷⁷Lu]Lu-PSMA could reduce xerostomia rates and improve compliance. Further large-scale, prospective studies are necessary for generalization and result consolidation.