Evaluation of dual time-point fluorodeoxyglucose PET/computed tomography imaging in gastric cancer

Diagnostic performance of [68Ga]Ga-FAPI-04 PET vs. [18F]FDG PET in detecting lymph node metastasis in digestive system cancers: a head-to-head comparative meta-analysis

Purpose

This meta-analysis aimed to compare the diagnostic effectiveness of [68Ga]Ga-FAPI-04 PET and [18F]FDG PET for detecting lymph node metastasis in digestive system cancer patients.

Methods

A comprehensive search of PubMed, Web of Science, and Embase databases was conducted to identify relevant articles up to June 2024. Studies were included if they evaluated the diagnostic performance of [68Ga]Ga-FAPI-04 PET and [18F]FDG PET in detecting lymph node metastasis in digestive system cancer patients. Sensitivity and specificity were assessed using the DerSimonian and Laird method and were transformed using the Freeman-Tukey double arcsine transformation.

Results

Fifteen articles, encompassing a total of 617 patients, were included in this study. The overall sensitivity of [68Ga]Ga-FAPI-04 PET for diagnosing lymph node metastasis in digestive system cancers was 0.82 (95% CI: 0.67-0.93), and the specificity was 0.91 (95% CI: 0.84-0.97). In comparison, the sensitivity of [18F]FDG PET was 0.51 (95% CI: 0.38-0.63), with a specificity of 0.81 (95% CI: 0.64-0.94). These results suggest that [68Ga]Ga-FAPI-04 PET has a significantly higher sensitivity (P < 0.01) and similar specificity (P = 0.20) compared to [18F]FDG PET in detecting lymph node metastasis in digestive system cancers.

Conclusion

Our meta-analysis indicates that [68Ga]Ga-FAPI-04 PET has higher sensitivity and similar specificity compared to [18F]FDG PET in diagnosing lymph node metastasis in digestive system cancers. However, the high heterogeneity among the studies may impact the robustness of the current evidence. Therefore, future research should prioritize larger prospective studies with more diverse populations and specific cancer subtypes to draw more definitive conclusions.

Systematic review registration

https://www.crd.york.ac.uk/PROSPERO/view/CRD42024572412, Unique Identifier: CRD42024572412.

Comparative assessment of the diagnostic efficacy of [18F]AlF-NOTA-FAPI-04 and [18F]FDG PET/CT imaging for detecting postoperative recurrence in gastric cancer patients: a pilot study

Purpose

This study aimed to compare the efficacy of [18F]AlF-NOTA-FAPI-04 PET/CT with that of [18F]FDG PET/CT for detecting postoperative recurrence in patients with gastric cancer.

Methods

This single-center retrospective clinical study was performed at Hunan Cancer Hospital between December 2020 and June 2022. The participants underwent both [18F]AlF-NOTA-FAPI-04 and [18F]FDG within 14 days. Histopathologic examination, morphological imaging, and/or follow-up imaging were used as a reference for the final diagnosis. We recorded the sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy of [18F]AlF-NOTA-FAPI-04 and [18F]FDG PET/CT for detecting local recurrence, lymph node metastasis and distant metastasis. The SUVmax and background ratio (TBR) of local recurrence and metastases between [18F]FDG and [18F]AlF-NOTA-FAPI-04 PET/CT were compared using paired-sample t tests.

Results

Forty-seven patients (27 males, aged 25-68 years) with gastric cancer after curative resection (27 with adenocarcinoma, 17 with signet ring cell carcinoma and 4 with mucinous adenocarcinoma) were included in the study. [18F]AlF-NOTA-FAPI-04 accumulation was significantly greater than that of [18F]FDG in terms of local recurrence (SUVmax, 11.65 vs 3.48, p< 0.0001; TBR, 12.93 vs 2.94, p< 0.0001), lymph node metastasis (SUVmax, 13.45 vs 3.05, p=0.003875; TBR, 12.43 vs 2.21, p=0.001661), and distant metastasis (SUVmax, 11.89 vs 2.96, p < 0.0001; TBR, 13.32 vs 2.32, p< 0.0001). Despite no statistical comparison was made with [18F]FDG, [18F]AlF-NOTA-FAPI-04 imaging exhibited high levels of sensitivity, specificity, PPV, NPV, and accuracy for detecting postoperative local recurrence, lymph node metastasis, and distant metastasis in patients with gastric cancer.

Conclusion

[18F]AlF-NOTA-FAPI-04 has demonstrated potential for more accurate tumor re-evaluation in GC, thus enhancing treatment decision-making.

Comparison of 18 F-FDG and 68 Ga-FAPI-04 Uptake in Postoperative Re-evaluation of Gastric, Duodenal, and Colorectal Cancers

PURPOSE

To compare the potential efficacy of 68 Ga-FAPI-04 PET/CT with that of 18 F-FDG PET/CT for detecting tumor recurrence and nodal and distant metastases in gastric, duodenal, and colorectal cancers.

METHODS

This single-center retrospective clinical study was performed at the Affiliated Hospital of Southwest Medical University between January 2020 and June 2022. Participants with gastric, duodenal, and colorectal cancers after curative resection underwent both 68 Ga-FAPI-04 and 18 F-FDG PET/CT. Histopathologic examination, morphologic imaging, and/or follow-up imaging served as the reference standards. The SUV max of the tumor recurrence and nodal and distant metastases between 18 F-FDG and 68 Ga-FAPI-04 PET/CT were compared using the paired-sample t test.

RESULTS

Forty-one participants with gastric, duodenal, and colorectal cancers were enrolled in the study (median age, 51 years; range, 19-75 years). The sensitivity of 68 Ga-FAPI-04 PET/CT was higher than that of 18 F-FDG PET/CT for detecting tumor recurrence (6 of 6 [100%] vs 4 of 6 [67%]), nodal metastases (92 of 92 [100%] vs 31 of 92 [34%]), and distant metastases (28 of 30 [93%] vs 20 of 30 [67%]).

CONCLUSION

68 Ga-FAPI-04 PET/CT for tumor re-evaluation showed potential for more accurate performance of gastric, duodenal, and colorectal cancers, thereby improving treatment decision-making.

Normal values for 18F-FDG uptake in organs and tissues measured by dynamic whole body multiparametric FDG PET in 126 patients

BACKGROUND

Dynamic whole-body (D-WB) FDG PET/CT is a recently developed technique that allows direct reconstruction of multiparametric images of metabolic rate of FDG uptake (MR_FDG) and "free" FDG (DV_FDG). Multiparametric images have a markedly different appearance than the conventional SUV images obtained by static PET imaging, and normal values of MR_FDG and DV_FDG in frequently used reference tissues and organs are lacking. The aim of this study was therefore to: (1) provide an overview of normal MR_FDG and DV_FDG values and range of variation in organs and tissues; (2) analyse organ time-activity curves (TACs); (3) validate the accuracy of directly reconstructed MR_FDG tissue values versus manually calculated K_i (and MR_FDG) values; and (4) explore correlations between demographics, blood glucose levels and MR_FDG values. D-WB data from 126 prospectively recruited patients (100 without diabetes and 26 with diabetes) were retrospectively analysed. Participants were scanned using a 70-min multiparametric PET acquisition protocol on a Siemens Biograph Vision 600 PET/CT scanner. 13 regions (bone, brain grey and white matter, colon, heart, kidney, liver, lung, skeletal muscle of the back and thigh, pancreas, spleen, and stomach) as well as representative pathological findings were manually delineated, and values of static PET (SUV), D-WB PET (K_i, MR_FDG and DV_FDG) and individual TACs were extracted. Multiparametric values were compared with manual TAC-based calculations of K_i and MR_FDG, and correlations with blood glucose, age, weight, BMI, and injected tracer dose were explored.

RESULTS

Tissue and organ MR_FDG values showed little variation, comparable to corresponding SUV variation. All regional TACs were in line with previously published FDG kinetics, and the multiparametric metrics correlated well with manual TAC-based calculations (r² = 0.97, p < 0.0001). No correlations were observed between glucose levels and MR_FDG in tissues known not to be substrate driven, while tissues with substrate driven glucose uptake had significantly correlated glucose levels and MR_FDG values.

CONCLUSION

The multiparametric D-WB PET scan protocol provides normal MR_FDG values with little inter-subject variation and in agreement with manual TAC-based calculations and literature values. The technique therefore facilitates both accurate clinical reports and simpler acquisition of quantitative estimates of whole-body tissue glucose metabolism.

Delayed PET/CT of Pericardial Synovial Sarcoma

ABSTRACT

Pericardial synovial sarcoma is a rare malignancy. We report the case of a patient who was referred to our institution for a large pericardial effusion requiring pericardiocentesis. CT imaging revealed an inhomogeneous pericardial mass beside the right atrium, and then a PET/CT scan was performed. Standard images were inconclusive whether delayed images showed an FDG-avid pericardial lesion that was surgically removed with histological diagnosis of a poorly differentiated biphasic synovial sarcoma. When considering mediastinal or pericardial mass, a delayed PET/CT may improve lesion-to-background contrast by reducing blood pool activity.