FAP-Specific Signalling Is an Independent Diagnostic Approach in ACC and Not a Surrogate Marker of MRI Sequences
Background: Fibroblast Activation Protein (FAP) is a new target for positron emission tomography and computed tomography (PET/CT) imaging of epithelial tumours embedded in a fibrous stroma. Adenoid cystic carcinomas (ACCs) have shown elevated tracer uptake in <sup>68</sup>Gallium (<su...
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| Format: | Article |
| Language: | English |
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MDPI AG
2022-08-01
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| Series: | Cancers |
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| Online Access: | https://www.mdpi.com/2072-6694/14/17/4253 |
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| author | Dawn P. Liew Manuel Röhrich Lisa Loi Sebastian Adeberg Mustafa Syed Ewgenija Gutjahr Heinz Peter Schlemmer Frederik L. Giesel Martin Bendszus Uwe Haberkorn Daniel Paech |
| author_facet | Dawn P. Liew Manuel Röhrich Lisa Loi Sebastian Adeberg Mustafa Syed Ewgenija Gutjahr Heinz Peter Schlemmer Frederik L. Giesel Martin Bendszus Uwe Haberkorn Daniel Paech |
| author_sort | Dawn P. Liew |
| collection | DOAJ |
| description | Background: Fibroblast Activation Protein (FAP) is a new target for positron emission tomography and computed tomography (PET/CT) imaging of epithelial tumours embedded in a fibrous stroma. Adenoid cystic carcinomas (ACCs) have shown elevated tracer uptake in <sup>68</sup>Gallium (<sup>68</sup>Ga)-labelled FAPIs in previous studies. The current gold standard for ACC imaging is contrast-enhanced (ce) MRI, where intertumoural heterogeneity leads to variable appearance on T1-weighted (T1w) and T2-weighted (T2w) images. In this retrospective analysis, we correlated <sup>68</sup>Ga-FAPI PET signalling at three time points with ceT1w and T2w MRI signals to further characterise the significance of <sup>68</sup>Ga-FAPI uptake in ACCs. Methods: Clinical PET/CT scans of 12 ACC patients were performed at 10, 60 and 180 min post i.v. administration of <sup>68</sup>Ga-labelled-FAPI tracer molecules. <sup>68</sup>Ga-PET- and corresponding MRI-scans were co-registered, and 3D volumetric segmentations were performed on ceT1w and T2w lesions of co-registered MRI slides. Signal intensity values of <sup>68</sup>Ga-FAPI PET signalling and ceT1w/T2w MRI scans were analysed for their pixelwise correlation in each patient. Pooled estimates of the correlation coefficients were calculated using the Fisher z-transformation. Results: <sup>68</sup>Ga-FAPI PET signals showed a very weak positive correlation with ceT1w values (pooled correlation 0.114, 0.147 and 0.162 at 10, 60 and 180 min) and a weak negative correlation with T2w values (pooled correlation −0.148, −0.121 and −0.225 at 10, 60 and 180 min). Individual r-values at 60 min ranged from −0.130 to 0.434 in ceT1w and from −0.466 to 0.637 in T2w MRI scans. Conclusion: There are only slight correlations between the intensity of <sup>68</sup>Ga-FAPI PET signals and tumour appearance in ceT1w or T2w MRI scans, which underlines that <sup>68</sup>Ga-FAPI PET signalling is not a surrogate marker of MRI sequences but an independent signal. |
| first_indexed | 2024-03-10T01:58:42Z |
| format | Article |
| id | doaj.art-3f80b51737e74c948c85ed30f18466d3 |
| institution | Directory Open Access Journal |
| issn | 2072-6694 |
| language | English |
| last_indexed | 2024-03-10T01:58:42Z |
| publishDate | 2022-08-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Cancers |
| spelling | doaj.art-3f80b51737e74c948c85ed30f18466d32023-11-23T12:52:24ZengMDPI AGCancers2072-66942022-08-011417425310.3390/cancers14174253FAP-Specific Signalling Is an Independent Diagnostic Approach in ACC and Not a Surrogate Marker of MRI SequencesDawn P. Liew0Manuel Röhrich1Lisa Loi2Sebastian Adeberg3Mustafa Syed4Ewgenija Gutjahr5Heinz Peter Schlemmer6Frederik L. Giesel7Martin Bendszus8Uwe Haberkorn9Daniel Paech10Department of Nuclear Medicine, University Hospital Heidelberg, 69120 Heidelberg, GermanyDepartment of Nuclear Medicine, University Hospital Heidelberg, 69120 Heidelberg, GermanyDivision of Radiology, German Cancer Research Center (DKFZ), 69120 Heidelberg, GermanyDepartment of Radiation Oncology, University Hospital Heidelberg, 69120 Heidelberg, GermanyDepartment of Radiation Oncology, University Hospital Heidelberg, 69120 Heidelberg, GermanyDepartment of Pathology, University Hospital Heidelberg, 69120 Heidelberg, GermanyDivision of Radiology, German Cancer Research Center (DKFZ), 69120 Heidelberg, GermanyDepartment of Nuclear Medicine, University Hospital Heidelberg, 69120 Heidelberg, GermanyDepartment of Neuroradiology, University Hospital Heidelberg, 69120 Heidelberg, GermanyDepartment of Nuclear Medicine, University Hospital Heidelberg, 69120 Heidelberg, GermanyDivision of Radiology, German Cancer Research Center (DKFZ), 69120 Heidelberg, GermanyBackground: Fibroblast Activation Protein (FAP) is a new target for positron emission tomography and computed tomography (PET/CT) imaging of epithelial tumours embedded in a fibrous stroma. Adenoid cystic carcinomas (ACCs) have shown elevated tracer uptake in <sup>68</sup>Gallium (<sup>68</sup>Ga)-labelled FAPIs in previous studies. The current gold standard for ACC imaging is contrast-enhanced (ce) MRI, where intertumoural heterogeneity leads to variable appearance on T1-weighted (T1w) and T2-weighted (T2w) images. In this retrospective analysis, we correlated <sup>68</sup>Ga-FAPI PET signalling at three time points with ceT1w and T2w MRI signals to further characterise the significance of <sup>68</sup>Ga-FAPI uptake in ACCs. Methods: Clinical PET/CT scans of 12 ACC patients were performed at 10, 60 and 180 min post i.v. administration of <sup>68</sup>Ga-labelled-FAPI tracer molecules. <sup>68</sup>Ga-PET- and corresponding MRI-scans were co-registered, and 3D volumetric segmentations were performed on ceT1w and T2w lesions of co-registered MRI slides. Signal intensity values of <sup>68</sup>Ga-FAPI PET signalling and ceT1w/T2w MRI scans were analysed for their pixelwise correlation in each patient. Pooled estimates of the correlation coefficients were calculated using the Fisher z-transformation. Results: <sup>68</sup>Ga-FAPI PET signals showed a very weak positive correlation with ceT1w values (pooled correlation 0.114, 0.147 and 0.162 at 10, 60 and 180 min) and a weak negative correlation with T2w values (pooled correlation −0.148, −0.121 and −0.225 at 10, 60 and 180 min). Individual r-values at 60 min ranged from −0.130 to 0.434 in ceT1w and from −0.466 to 0.637 in T2w MRI scans. Conclusion: There are only slight correlations between the intensity of <sup>68</sup>Ga-FAPI PET signals and tumour appearance in ceT1w or T2w MRI scans, which underlines that <sup>68</sup>Ga-FAPI PET signalling is not a surrogate marker of MRI sequences but an independent signal.https://www.mdpi.com/2072-6694/14/17/4253fibroblast activation proteinFAPadenoid cystic carcinomaACCpositron emission tomographypixelwise correlation |
| spellingShingle | Dawn P. Liew Manuel Röhrich Lisa Loi Sebastian Adeberg Mustafa Syed Ewgenija Gutjahr Heinz Peter Schlemmer Frederik L. Giesel Martin Bendszus Uwe Haberkorn Daniel Paech FAP-Specific Signalling Is an Independent Diagnostic Approach in ACC and Not a Surrogate Marker of MRI Sequences Cancers fibroblast activation protein FAP adenoid cystic carcinoma ACC positron emission tomography pixelwise correlation |
| title | FAP-Specific Signalling Is an Independent Diagnostic Approach in ACC and Not a Surrogate Marker of MRI Sequences |
| title_full | FAP-Specific Signalling Is an Independent Diagnostic Approach in ACC and Not a Surrogate Marker of MRI Sequences |
| title_fullStr | FAP-Specific Signalling Is an Independent Diagnostic Approach in ACC and Not a Surrogate Marker of MRI Sequences |
| title_full_unstemmed | FAP-Specific Signalling Is an Independent Diagnostic Approach in ACC and Not a Surrogate Marker of MRI Sequences |
| title_short | FAP-Specific Signalling Is an Independent Diagnostic Approach in ACC and Not a Surrogate Marker of MRI Sequences |
| title_sort | fap specific signalling is an independent diagnostic approach in acc and not a surrogate marker of mri sequences |
| topic | fibroblast activation protein FAP adenoid cystic carcinoma ACC positron emission tomography pixelwise correlation |
| url | https://www.mdpi.com/2072-6694/14/17/4253 |
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