scholarly journals Head-to-head intra-individual comparison of biodistribution and tumor uptake of 68Ga-FAPI and 18F-FDG PET/CT in cancer patients

2021 ◽  
Author(s):  
Frederik L. Giesel ◽  
Clemens Kratochwil ◽  
Joel Schlittenhardt ◽  
Katharina Dendl ◽  
Matthias Eiber ◽  
...  
Keyword(s):  
Fdg Pet ◽  
Standard Of Care ◽  
Blood Pool ◽  
Tracer Uptake ◽  
Time Interval ◽  
Tumor Uptake ◽  
Primary Tumors ◽  
Individual Comparison ◽  
Pet Ct ◽  
Fdg Pet Ct

Abstract Purpose FAPI ligands (fibroblast activation protein inhibitor), a novel class of radiotracers for PET/CT imaging, demonstrated in previous studies rapid and high tumor uptake. The purpose of this study is the head-to-head intra-individual comparison of 68Ga-FAPI versus standard-of-care 18F-FDG in PET/CT in organ biodistribution and tumor uptake in patients with various cancers. Material and Methods This international retrospective multicenter analysis included PET/CT data from 71 patients from 6 centers who underwent both 68Ga-FAPI and 18F-FDG PET/CT within a median time interval of 10 days (range 1–89 days). Volumes of interest (VOIs) were manually drawn in normal organs and tumor lesions to quantify tracer uptake by SUVmax and SUVmean. Furthermore, tumor-to-background ratios (TBR) were generated (SUVmax tumor/ SUVmax organ). Results A total of 71 patients were studied of, which 28 were female and 43 male (median age 60). In 41 of 71 patients, the primary tumor was present. Forty-three of 71 patients exhibited 162 metastatic lesions. 68Ga-FAPI uptake in primary tumors and metastases was comparable to 18F-FDG in most cases. The SUVmax was significantly lower for 68Ga-FAPI than 18F-FDG in background tissues such as the brain, oral mucosa, myocardium, blood pool, liver, pancreas, and colon. Thus, 68Ga-FAPI TBRs were significantly higher than 18F-FDG TBRs in some sites, including liver and bone metastases. Conclusion Quantitative tumor uptake is comparable between 68Ga-FAPI and 18F-FDG, but lower background uptake in most normal organs results in equal or higher TBRs for 68Ga-FAPI. Thus, 68Ga-FAPI PET/CT may yield improved diagnostic information in various cancers and especially in tumor locations with high physiological 18F-FDG uptake.

scholarly journals 68Ga-FAPI-PET/CT in patients with various gynecological malignancies

2021 ◽  
Author(s):  
Katharina Dendl ◽  
Stefan A. Koerber ◽  
Rebecca Finck ◽  
Kgomotso M. G. Mokoala ◽  
Fabian Staudinger ◽  
...  
Keyword(s):  
Fdg Pet ◽  
Tracer Uptake ◽  
Time Interval ◽  
Imaging Method ◽  
Gynecological Tumors ◽  
Metastatic Lesions ◽  
Gynecological Malignancies ◽  
Pet Ct ◽  
Significant Difference ◽  
Fdg Pet Ct

Abstract Purpose 68Ga-FAPI (fibroblast activation protein inhibitor) is a novel and highly promising radiotracer for PET/CT imaging. The aim of this retrospective analysis is to explore the potential of FAPI-PET/CT in gynecological malignancies. We assessed biodistribution, tumor uptake, and the influence of pre- or postmenopausal status on tracer accumulation in hormone-sensitive organs. Furthermore, a comparison with the current standard oncological tracer 18F-FDG was performed in selected cases. Patients and methods A total of 31 patients (median age 59.5) from two centers with several gynecological tumors (breast cancer; ovarian cancer; cervical cancer; endometrial cancer; leiomyosarcoma of the uterus; tubal cancer) underwent 68Ga-FAPI-PET/CT. Out of 31 patients, 10 received an additional 18F-FDG scan within a median time interval of 12.5 days (range 1–76). Tracer uptake was quantified by standardized uptake values (SUV)max and (SUV)mean, and tumor-to-background ratio (TBR) was calculated (SUVmax tumor/ SUVmean organ). Moreover, a second cohort of 167 female patients with different malignancies was analyzed regarding their FAPI uptake in normal hormone-responsive organs: endometrium (n = 128), ovary (n = 64), and breast (n = 147). These patients were categorized by age as premenopausal (<35 years; n = 12), postmenopausal (>65 years; n = 68), and unknown menstrual status (35–65 years; n = 87), followed by an analysis of FAPI uptake of the pre- and postmenopausal group. Results In 8 out of 31 patients, the primary tumor was present, and all 31 patients showed lesions suspicious for metastasis (n = 81) demonstrating a high mean SUVmax in both the primary (SUVmax 11.6) and metastatic lesions (SUVmax 9.7). TBR was significantly higher in 68Ga-FAPI compared to 18F-FDG for distant metastases (13.0 vs. 5.7; p = 0.047) and by trend for regional lymph node metastases (31.9 vs 27.3; p = 0.6). Biodistribution of 68Ga-FAPI-PET/CT presented significantly lower uptake or no significant differences in 15 out of 16 organs, compared to 18F-FDG-PET/CT. The highest uptake of all primary lesions was obtained in endometrial carcinomas (mean SUVmax 18.4), followed by cervical carcinomas (mean SUVmax 15.22). In the second cohort, uptake in premenopausal patients differed significantly from postmenopausal patients in endometrium (11.7 vs 3.9; p < 0.0001) and breast (1.8 vs 1.0; p = 0.004), whereas no significant difference concerning ovaries (2.8 vs 1.6; p = 0.141) was observed. Conclusion Due to high tracer uptake resulting in sharp contrasts in primary and metastatic lesions and higher TBRs than 18F-FDG-PET/CT, 68Ga-FAPI-PET/CT presents a promising imaging method for staging and follow-up of gynecological tumors. The presence or absence of the menstrual cycle seems to correlate with FAPI accumulation in the normal endometrium and breast. This first investigation of FAP ligands in gynecological tumor entities supports clinical application and further research in this field.

scholarly journals Intra-Individual Comparison of 18F-PSMA-1007 and 18F-FDG PET/CT in the Evaluation of Patients With Prostate Cancer

2021 ◽  
Vol 10 ◽  
Author(s):  
Xing Zhou ◽  
YingChun Li ◽  
Xiao Jiang ◽  
XiaoXiong Wang ◽  
ShiRong Chen ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Fdg Pet ◽  
Careful Analysis ◽  
Tumor Uptake ◽  
Benign Lesions ◽  
Detection Rates ◽  
Individual Comparison ◽  
Pet Ct ◽  
18F Fdg ◽  
Fdg Pet Ct

Purpose18F labelled PSMA-1007 presents promising results in detecting prostate cancer (PC), while some pitfalls exists meanwhile. An intra-individual comparison of 18F-FDG and 18F-PSMA-1007 in patients with prostate cancer were aimed to be performed in the present study. Then, the pitfalls of 18F-PSMA-1007 PET/CT in imaging of patients with prostate cancer were analyzed.Methods and Material21 prostate cancer patients underwent 18F-PSMA-1007 PET/CT as well as 18F-FDG PET/CT before treatment. All positive lesions were noticed in both 18F-PSMA-1007 PET/CT and 18F-FDG PET/CT, then differentiated PC metastasis from benign lesions. the SUVmax, SUVmean and TBR of lesions, up to 10 metastases and 10 benign lesions per patients were recorded (5 for bone, 5 for soft tissue metastasis ). The distribution of positive lesions were analyzed for two imaging. Detection rates, SUVmax, SUVmean and TBR in 18F-PSMA-1007 PET/CT and 18F-FDG PET/CT were compared, respectively. The optimal cut-off values of SUVmax, SUVmean for metastases vs. benign lesions was found through areas under ROC in 18F-PSMA-1007.ResultsThe detection rates of primary lesions in 18F-PSMA-1007 PET/CT was higher than that of 18F-FDG PET/CT(100% (21/21) vs. 67%(14/21)). For extra- prostatic lesions, 18F-PSMA-1007 PET/CT revealed 124 positive lesions, 49(49/124, 40%) attributed to a benign origin; 18F-FDG PET/CT revealed 68 positive lesions, 14(14/68, 21%) attributed to a benign origin. The SUVmax, SUVmean, TBR of primary tumor in 18F-PSMA-1007 PET/CT was higher than that in 18F-FDG PET/CT (15.20 vs. 4.20 for SUVmax; 8.70 vs. 2.80 for SUVmean; 24.92 vs. 4.82 for TBR, respectively); The SUVmax, SUVmean, TBR of metastases in 18F-PSMA-1007 PET/CT was higher than that in 18F-FDG PET/CT (10.72 vs. 4.42 for SUVmax; 6.67 vs. 2.59 for SUVmean; The TBR of metastases was 13.3 vs. 7.91). For 18F-FDG PET/CT, the SUVmax, SUVmean in metastases was higher than that in benign lesions (4.42 vs. 3.04 for SUVmax, 2.59 vs. 1.75 for SUVmean, respectively). Similarly, for 18F-PSMA-1007 PET/CT, the SUVmax, SUVmean in metastases was significantly higher than that in benign lesions(10.72 vs. 3.14 for SUVmax, 6.67 vs. 1.91 for SUVmean, respectively), ROC suggested that SUVmax=7.71, SUVmean=5.35 might be the optimal cut-off values for metastases vs. benign lesions.ConclusionThe pilot study suggested that 18F-PSMA-1007 showed superiority over 18F-FDG because its high detecting rate of PC lesions and excellent tumor uptake. While non-tumor uptake in 18F-PSMA-1007 may lead to misdiagnosis, recognizing these pitfalls and careful analysis can improve the accuracy of diagnosis.

Correlation between Tumor Uptake on Indium-111 Ibritumomab Tiuxetan Imaging and Size on CT to Disease Response on FDG PET/CT Scans Obtained Pre- and Post-Yttrium-90 Ibritumomab Tiuxetan Therapy for Non-Hodgkin Lymphoma.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 4781-4781
Author(s):  
Jacob M. Alexnder ◽  
Judith M. Joyce ◽  
Barry M. McCook ◽  
Norbert Avril ◽  
Stephanie R. Land ◽  
...  
Keyword(s):  
B Cell ◽  
Fdg Pet ◽  
Large Cell ◽  
Ct Scans ◽  
Tumor Uptake ◽  
Ibritumomab Tiuxetan ◽  
Overall Response ◽  
Non Hodgkin Lymphoma ◽  
Pet Ct ◽  
Fdg Pet Ct

Abstract Background: Yttrium-90 ibritumomab tiuxetan (Zevalin, YZ), the first radioimmunotherapeutic agent approved for the treatment of relapsed or refractory B-cell non-Hodgkin Lymphoma (NHL), had an overall response rate of 80% vs 56% with rituximab alone based on CT assessment (IWRC criteria) without FDG PET correlation. Prior to the therapeutic administration of YZ, normal biodistribution must be confirmed by visual evaluation of whole-body In-111 Zevalin (IZ) images. Tumor uptake on IZ images has been noted to be variable and is not required to proceed with therapy. However, bulky lymphadenopathy has been reported to possibly predict poor response to radioimmunotherapy. We report our evaluation of the relation of tumor uptake on IZ images and size on CT scans to tumor response based on pre- and post-YZ therapy using FDG PET/CT scans. Methods: This retrospective review includes only patients with relapsed or refractory B-cell NHL treated with YZ who had fusion PET/CT scans pre- and post-YZ therapy and fulfilled all other standard eligibility critera for YZ. PET/CT scans were performed within 4 months prior and 8 months following IZ imaging and YZ therapy. The largest tumor mass on the pre-therapy CT was measured and categorized into subgroups of < or ≥5 cm. The IZ scans were reviewed for the presence or absence of tumor uptake over background activity. Response by CT was based on the IWRC criteria (CR/CRu, PR, Stable, and PD). Response on FDG PET was based upon comparison of the intensity of uptake in relation to adjacent background (CR, PR, Mixed and PD). Response rate comparisons by patient groups were performed with Fisher exact tests. Results: 24 patients (16M, 8F, 37–83 y.o.) fulfilled the criteria. The histologic diagnoses included: 14 follicular, 5 diffuse large B-cell, 4 mantle cell, and 1 MALT. All patients had increased FDG uptake in measurable CT lesions on the pre-therapy PET/CT scans. 14 IZ scans were positive, 10 were negative. Seven of 9 patients (78%) with lesions ≥5 cm had positive IZ versus 7 of 15 (47%) with lesions < 5 cm. The following tables display the cross-tabulation of tumor uptake on IZ, CT size, and the response to YZ. The overall response (ORR) based on FDG PET was 13/24 (54%) with a CR of 7/24 (29%) and a PR of 6/24 (25%). Excluding the patients with large cell histology, the ORR was 13/19 (68%). ORR for size ≥5 cm was 3/9 (33%) and for size <5 cm was 10/15 (66%), a suggestive but non-significant difference (p=0.2). The frequency of overall response was significantly reduced for large cell histology versus other histologies (p=0.011). The results show that those patients with tumor uptake on IZ imaging had significantly reduced overall response based on pre- and post-FDG PET/CT findings compared with patients without tumor uptake (p=0.047). Conclusions: The presence of tumor uptake on IZ imaging, tumor size (≥5 cm) and histology (large cell) may all adversely affect response to YZ. The identification of IZ tumor uptake may be related to large tumor size rather than tumor susceptibility to therapy. Responses (CR/CRu and PR) by PET # In+ In− CT≥5cm CT<5cm FL 9 4 5 1 8 DLBC 0 0 0 0 0 MCL 3 1 2 1 2 MALT 1 0 1 1 0 Nonresponses (Mixed and PD) by PET # In+ In− CT≥5cm CT<5cm FL 5 5 0 2 3 DLBC 5 3 2 3 2 MCL 1 1 0 1 0 MALT 0 0 0 0 0

scholarly journals Head-to-Head Comparison of68Ga-Citrate and18F-FDG PET/CT for Detection of Infectious Foci in Patients withStaphylococcus aureusBacteraemia

2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
Soile P. Salomäki ◽  
Jukka Kemppainen ◽  
Ulla Hohenthal ◽  
Pauliina Luoto ◽  
Olli Eskola ◽  
...  
Keyword(s):  
Soft Tissue ◽  
Fdg Pet ◽  
Vertebral Osteomyelitis ◽  
Whole Body ◽  
Time Interval ◽  
Standardised Uptake Value ◽  
Positron Emission ◽  
Pet Ct ◽  
Small Cohort ◽  
Fdg Pet Ct

Purpose. This study evaluated the potential of68Ga-citrate positron emission tomography/computed tomography (PET/CT) for the detection of infectious foci in patients withStaphylococcus aureusbacteraemia by comparing it with 2-[18F]fluoro-2-deoxy-D-glucose (18F-FDG) PET/CT.Methods.Four patients admitted to hospital due toS. aureusbacteraemia underwent both18F-FDG and68Ga-citrate whole-body PET/CT scans to detect infectious foci.Results.The time from hospital admission and the initiation of antibiotic treatment to the first PET/CT was 4–10 days. The time interval between18F-FDG and68Ga-citrate PET/CT was 1–4 days. Three patients had vertebral osteomyelitis (spondylodiscitis) and one had osteomyelitis in the toe; these were detected by both18F-FDG (maximum standardised uptake value [SUVmax]6.0±1.0) and68Ga-citrate (SUVmax  6.8±3.5,P=0.61). Three patients had soft tissue infectious foci, with more intense18F-FDG uptake (SUVmax  6.5±2.5) than68Ga-citrate uptake (SUVmax  3.9±1.2,P=0.0033).Conclusions.Our small cohort of patients withS. aureusbacteraemia revealed that68Ga-citrate PET/CT is comparable to18F-FDG PET/CT for detection of osteomyelitis, whereas18F-FDG resulted in a higher signal for the detection of soft tissue infectious foci.

scholarly journals Detection of additional primary malignancies: the role of CT and PET/CT combined with multiple percutaneous biopsy

2019 ◽  
Vol 52 (3) ◽  
pp. 166-171 ◽  
Author(s):  
Tiago Kojun Tibana ◽  
Rômulo Florêncio Tristão Santos ◽  
Adalberto Arão Filho ◽  
Bernardo Bacelar ◽  
Leticia de Assis Martins ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Fdg Pet ◽  
Percutaneous Biopsy ◽  
Primary Tumors ◽  
Additional Lesion ◽  
Positron Emission ◽  
Pet Ct ◽  
18F Fdg ◽  
Pathology Reports ◽  
Fdg Pet Ct

Abstract Objective: To evaluate the imaging findings of 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) and computed tomography (CT) in patients with additional primary tumors, correlating the results with those of the method used in order to elucidate the diagnosis and of the pathology reports. Materials and Methods: We retrospectively analyzed the medical records, pathology reports and images of 11 patients who underwent CT, 18F-FDG PET/CT, or both. We included patients with at least two tumors, with confirmed distinct histopathological profiles, at different sites. Patients in whom there was no diagnostic confirmation were excluded, as were those in whom the additional lesion was suspected of being a metastasis of the first. Results: New primary malignancies were identified in 11 patients, one new tumor being found in 10 and two new tumors being found in 1. The confirmed sites of the additional malignancies were the lung, kidney, prostate, jejunum, and breast. Single or multiple percutaneous biopsies were performed in 10 patients, and 1 patient underwent a surgical procedure for diagnostic and therapeutic purposes. The tumors were metachronous in 6 cases and synchronous in 5. Conclusion: CT and 18F-FDG PET-CT combined with multiple percutaneous biopsy could facilitate the diagnosis of additional lesions, thus optimizing the treatment and follow-up of the affected patients.

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