scholarly journals Impact of Primary Staging with Fibroblast Activation Protein Specific Enzyme Inhibitor (FAPI)-PET/CT on Radio-Oncologic Treatment Planning of Patients with Esophageal Cancer

2020 ◽  
Vol 22 (6) ◽  
pp. 1495-1500 ◽  
Author(s):  
J. Ristau ◽  
F. L. Giesel ◽  
M. F. Haefner ◽  
F. Staudinger ◽  
T. Lindner ◽  
...  
Keyword(s):  
Esophageal Cancer ◽  
Enzyme Inhibitor ◽  
Regional Lymph Node ◽  
Perfect Match ◽  
Tracer Uptake ◽  
Radiotherapy Planning ◽  
Primary Tumors ◽  
Standardized Uptake Values ◽  
Volume Delineation ◽  
Pet Ct

Abstract Purpose Quinoline-based ligands targeting cancer-associated fibroblasts have emerged as promising radiopharmaceuticals in different tumor entities. The aim of this retrospective study was to explore the potential of FAPI-PET/CT in the initial staging of esophageal cancer patients and its usefulness in radiotherapy planning as a first clinical analysis. Methods Seven patients with treatment-naive esophageal cancer underwent FAPI-PET/CT. Tracer uptake was quantified by standardized uptake values (SUV)max and (SUV)mean. Six patients received definitive and one neoadjuvant (chemo)radiation therapy. Endo-esophageal clipping, the gold standard to define tumor margins not delineable per CT, was performed in three patients. Results Primary tumors demonstrated high FAPI uptake with a median SUVmax of 17.2. Excellent tumor-to-background ratios resulted in accurate target volume delineation and were found in perfect match with clipping. Detection of regional lymph node metastases facilitated the use of simultaneous integrated boost radiotherapy plans for these patients. Conclusion FAPI-PET/CT may be beneficial for the management of esophageal cancer particularly in planning radiotherapy, but further research is necessary to increase patient number and statistical reliability.

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 Novel FAP ligands enable improved imaging contrast in sarcoma patients due to FAPI-PET/CT

2021 ◽  
Author(s):  
Stefan A. Koerber ◽  
R. Finck ◽  
K. Dendl ◽  
M. Uhl ◽  
T. Lindner ◽  
...  
Keyword(s):  
Hybrid Imaging ◽  
Background Activity ◽  
The Novel ◽  
Malignant Tissue ◽  
Primary Tumors ◽  
Aggressive Disease ◽  
Standardized Uptake Values ◽  
Pet Ct ◽  
Pet Scans

Abstract Purpose A high expression of fibroblast activation protein (FAP) was observed in multiple sarcomas, indicating an enormous potential for PET/CT using 68Ga-radiolabeled inhibitors of FAP (FAPI). Therefore, this retrospective study aimed to evaluate the role of the novel hybrid imaging probe for sarcomas as a first clinical evaluation. Methods A cohort of 15 patients underwent 68Ga-FAPI-PET/CT for staging or restaging. The acquisition of PET scans was performed 60 min after administration of 127 to 308 MBq of the tracer. The uptake of 68Ga-FAPI in malignant tissue as well as in healthy organs was quantified by standardized uptake values SUVmean and SUVmax. Results Excellent tumor-to-background ratios (> 7) could be achieved due to low background activity and high SUVmax in primary tumors (median 7.16), local relapses (median 11.47), and metastases (median 6.29). The highest uptake was found for liposarcomas and high-grade disease (range 18.86–33.61). A high SUVmax (> 10) was observed for clinically more aggressive disease. Conclusion These preliminary findings suggest a high potential for the clinical use of 68Ga-FAPI-PET/CT for patients diagnosed with sarcoma.

scholarly journals 18F-FDOPA PET/CT Combined with MRI for Gross Tumor Volume Delineation in Patients with Skull Base Paraganglioma

Cancers ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 54 ◽  
Author(s):  
Mehdi Helali ◽  
Matthieu Moreau ◽  
Clara Le Fèvre ◽  
Céline Heimburger ◽  
Caroline Bund ◽  
...  
Keyword(s):  
Skull Base ◽  
Gross Tumor Volume ◽  
Tumor Volume ◽  
Organs At Risk ◽  
Radiotherapy Planning ◽  
Dice Similarity Coefficient ◽  
Diagnostic Modality ◽  
Data Set ◽  
Volume Delineation ◽  
Pet Ct

In this simulation study, we assessed differences in gross tumor volume (GTV) in a series of skull base paragangliomas (SBPGLs) using magnetic resonance imaging (MRI), 18F-dihydroxyphenylalanine (18F-FDOPA) combined positron emission tomography/computed tomography (PET/CT), and 18F-FDOPA PET/MRI images obtained by rigid alignment of PET and MRI. GTV was delineated in 16 patients with SBPGLs on MRI (GTVMRI), 18F-FDOPA PET/CT (GTVPET), and combined PET/MRI (GTVPET/MRI). GTVPET/MRI was the union of GTVMRI and GTVPET after visual adjustment. Three observers delineated GTVMRI and GTVPET/MRI independently. Excellent interobserver reproducibility was found for both GTVMRI and GTVPET/MRI. GTVPET and GTVMRI were not significantly different. However, there was some spatial difference between the locations of GTVMRI, GTVPET, and GTVPET/MRI. The Dice similarity coefficient median value was 0.4 between PET/CT and MRI, and 0.8 between MRI and PET/MRI. The combined use of PET/MRI produced a larger GTV than MRI alone. Nevertheless, both the target-delivered dose and organs-at-risk conservancy were respected when treatment was planned on the PET/MRI-matched data set. Future integration of 18F-FDOPA PET/CT into clinical practice will be necessary to evaluate the influence of this diagnostic modality on SBPGL therapeutic management. If the clinical utility of 18F-FDOPA PET/CT and/or PET/MRI is confirmed, GTVPET/MRI should be considered for tailored radiotherapy planning in patients with SBPGL.

Impact of 18F-fluorodeoxyglucose position emission tomography/computed tomography on radiotherapy treatment planning and outcomes in esophageal cancer.

2016 ◽  
Vol 34 (4_suppl) ◽  
pp. 67-67
Author(s):  
Sweet Ping Ng ◽  
Jennifer Tan ◽  
Glen Osbourne ◽  
Luke Williams ◽  
Mathias Bressel ◽  
...  
Keyword(s):  
Overall Survival ◽  
Esophageal Cancer ◽  
Survival Rates ◽  
Ct Scanning ◽  
Radiotherapy Planning ◽  
Position Emission Tomography ◽  
Pet Ct ◽  
Ct Data ◽  
The Impact ◽  
Radiotherapy Treatment

67 Background: Currently there is no universally accepted method to accurately delineate the gross tumor volume (GTV) of primary esophageal cancer in patients undergoing radiotherapy. This prospective study aims to determine the impact of PET/CT on radiotherapy planning and outcomes in patients with localized esophageal cancer. Methods: 54 patients were recruited between June 2003 - May 2008. All underwent PET/CT scanning in the radiotherapy treatment position and received treatment planned using the PET/CT dataset. Of these, 13 (24.1%) had metastatic disease detected on PET and 3 patients had no radical radiotherapy, while another 3 patients had missing planning PET/CT data (excluded from planning component analysis). GTV was defined separately on PET/CT (GTV-PET) and CT (GTV-CT) data sets. A corresponding planning target volume (PTV) was generated for each patient. Volumetric and spatial analysis quantified the proportion of FDG-avid disease not included in CT-based volumes. Clinical data was collected for 38 patients treated radically to determine locoregional control and overall survival rates. Results: Mean age was 67 years (range:32 - 88). Median follow up was 4 years (range:2.7 – 6.8). FDG-avid disease would have been excluded from GTV-CT in 29 patients (79%) with a mean volume of 17% (range:1-100%). In 5 patients, FDG-avid disease would have been completely excluded from the PTV-CT (median volume missed = 6%, range:2-92%). For 8 patients, less than 95% of PTV-PET would have received at least 95% of prescription dose based on the CT-based plan. GTV-CT underestimated the cranial and caudal extent of FDG-avid tumor in 14 (36%) and 10 (26%) patients respectively. There were no significant differences in radiation doses to the lungs and liver. 5-year overall survival and locoregional failure free survival were 24%, and 42% respectively. Conclusions: PET/CT prevented futile radiotherapy for 1 in 4 patients and avoided geographic misses without significant impact on normal tissues in apparently localized esophageal cancer. However, survival remains suboptimal and indicates the need for further improvement in planning and therapeutic paradigms.

scholarly journals Comparison of integrated PET/MRI with PET/CT in evaluation of endometrial cancer: a retrospective analysis of 81 cases

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e7081 ◽  
Author(s):  
Li-hua Bian ◽  
Min Wang ◽  
Jing Gong ◽  
Hong-hong Liu ◽  
Nan Wang ◽  
...  
Keyword(s):  
Endometrial Cancer ◽  
Lymph Node ◽  
Lymph Node Metastasis ◽  
Regional Lymph Node ◽  
Myometrial Invasion ◽  
Regional Lymph Node Metastasis ◽  
Primary Tumors ◽  
Node Metastasis ◽  
Pet Ct ◽  
Invasion Detection

Background The objective of this study was to compare the diagnostic value of integrated PET/MRI with PET/CT for assessment of regional lymph node metastasis and deep myometrial invasion detection of endometrial cancer. Methods Eighty-one patients with biopsy-proven endometrial cancer underwent preoperative PET/CT (n = 37) and integrated PET/MRI (n = 44) for initial staging. The diagnostic performance of PET/CT and integrated PET/MRI for assessing the extent of the primary tumor and metastasis to the regional lymph nodes was evaluated by two experienced readers. Histopathological and follow-up imaging results were used as the gold standard. McNemar’s test was employed for statistical analysis. Results Integrated PET/MRI and PET/CT both detected 100% of the primary tumors. Integrated PET/MRI proved significantly more sensitivity and specificity than PET/CT in regional lymph node metastasis detection (P = 0.015 and P < 0.001, respectively). The overall accuracy of myometrial invasion detection for PET/CT and Integrated PET/MRI was 45.9% and 81.8%, respectively. Integrated PET/MRI proved significantly more accurate than PET/CT (P < 0.001). Conclusion Integrated PET/MRI, which complements the individual advantages of MRI and PET, is a valuable technique for the assessment of the lymph node metastasis and myometrial invasion in patients with endometrial cancer.

scholarly journals [F18] FDG-PET/CT for manual or semiautomated GTV delineation of the primary tumor for radiation therapy planning in patients with esophageal cancer: is it useful?

2020 ◽  
Author(s):  
Franziska Walter ◽  
Constanze Jell ◽  
Barbara Zollner ◽  
Claudia Andrae ◽  
Sabine Gerum ◽  
...  
Keyword(s):  
Esophageal Cancer ◽  
Primary Tumor ◽  
Fdg Pet ◽  
Interobserver Variability ◽  
Target Volume ◽  
Standardized Uptake Values ◽  
Positron Emission ◽  
Pet Ct ◽  
Significant Difference ◽  
Fdg Pet Ct

Abstract Background Target volume definition of the primary tumor in esophageal cancer is usually based on computed tomography (CT) supported by endoscopy and/or endoscopic ultrasound and can be difficult given the low soft-tissue contrast of CT resulting in large interobserver variability. We evaluated the value of a dedicated planning [F18] FDG-Positron emission tomography/computer tomography (PET/CT) for harmonization of gross tumor volume (GTV) delineation and the feasibility of semiautomated structures for planning purposes in a large cohort. Methods Patients receiving a dedicated planning [F18] FDG-PET/CT (06/2011–03/2016) were included. GTV was delineated on CT and on PET/CT (GTVCT and GTVPET/CT, respectively) by three independent radiation oncologists. Interobserver variability was evaluated by comparison of mean GTV and mean tumor lengths, and via Sørensen–Dice coefficients (DSC) for spatial overlap. Semiautomated volumes were constructed based on PET/CT using fixed standardized uptake values (SUV) thresholds (SUV30, 35, and 40) or background- and metabolically corrected PERCIST-TLG and Schaefer algorithms, and compared to manually delineated volumes. Results 45 cases were evaluated. Mean GTVCT and GTVPET/CT were 59.2/58.0 ml, 65.4/64.1 ml, and 60.4/59.2 ml for observers A–C. No significant difference between CT- and PET/CT-based delineation was found comparing the mean volumes or lengths. Mean Dice coefficients on CT and PET/CT were 0.79/0.77, 0.81/0.78, and 0.8/0.78 for observer pairs AB, AC, and BC, respectively, with no significant differences. Mean GTV volumes delineated semiautomatically with SUV30/SUV35/SUV40/Schaefer’s and PERCIST-TLG threshold were 69.1/23.9/18.8/18.6 and 70.9 ml. The best concordance of a semiautomatically delineated structure with the manually delineated GTVCT/GTVPET/CT was observed for PERCIST-TLG. Conclusion We were not able to show that the integration of PET/CT for GTV delineation of the primary tumor resulted in reduced interobserver variability. The PERCIST-TLG algorithm seemed most promising compared to other thresholds for further evaluation of semiautomated delineation of esophageal cancer.

scholarly journals Visualization of 4D-PET/CT, Target Volumes and Dose Distribution: Applications in Radiotherapy Planning

2014 ◽  
Author(s):  
Matthias Schlachter ◽  
Tobias Fechter ◽  
Ursula Nestle ◽  
Katja Bühler
Keyword(s):  
Dose Distribution ◽  
Visual Information ◽  
Radiation Treatment ◽  
Target Volume ◽  
Radiotherapy Planning ◽  
Medical Doctors ◽  
Visualization System ◽  
Volume Delineation ◽  
Pet Ct ◽  
Target Volumes

In radiation treatment (RT) planning medical doctors need to consider a variety of information sources for anatomical and functional target volume delineation. The validation and inspection of the defined target volumes and the resulting RT plan is a complex task, especially in the presence of moving target areas as it is the case for tumors of the chest and the upper abdomen. A 4D-PET/CT visualization system may become a helpful tool for validating RT plans. We define major requirements such a visualization system should fulfill to provide medical doctors with the necessary visual information to validate tumor delineations, and review the dose distribution of a RT plan. We present an implementation of such a system, and present qualitative results of its applications for a lung cancer patient.

scholarly journals Prognostic Value of Quantitative 18F-FDG PET/CT Parameters Measured in Primary Tumors and Suspicious Lymph Nodes in Patients With Esophageal Carcinoma

2020 ◽  
Author(s):  
Francisco Tustumi ◽  
Flávio Roberto Takeda ◽  
Paulo Schiavom Duarte ◽  
David Gutiérrez Albenda ◽  
Rubens Antonio Aissar Sallum ◽  
...  
Keyword(s):  
Esophageal Cancer ◽  
Lymph Nodes ◽  
Neoadjuvant Therapy ◽  
Burden Of Disease ◽  
Primary Tumor ◽  
Fdg Pet ◽  
Prognostic Value ◽  
Primary Tumors ◽  
Pet Ct ◽  
Fdg Pet Ct

Abstract Objective:Quantitative 18F-FDG PET/CT parameters have been described as prognostic indicators in esophageal cancer. The objective of this study isto evaluate the prognostic value of the maximum standardized uptake value (SUVmax), metabolic tumor value (MTV) and total lesion glycolysis (TLG) measured in the primary tumor and suspicious lymph nodes.Methods: A cohort study was performed to assess the association of SUVmax, MTV and TLG measured prior to and post neoadjuvant therapywithoverall survival (OS) of patients with esophageal cancer who received trimodal therapy. The quantitative techniques were applied in the primary tumor and suspicious lymph nodes. The OS rates were analyzed. Results: Before neoadjuvant therapy, 106 patients underwent PET/CT, and 39 patients underwent post-neoadjuvant therapy PET/CT exams. Before neoadjuvanttherapy, PET/CT showed that all the variables of the evaluated lymph nodes were statistically significant in predicting OS. Postneoadjuvanttherapy, none of the PET/CT variables of lymph nodes were related to prognosis. On the other hand, all primary tumor volumetric variables were related to overall survival. The MTV (HR: 4.66; 95% CI: 1.54-14.08) and TLG (HR: 4.86; 95% CI: 1.66-14.26) of the primary tumor post neoadjuvanttherapy and the variations in MTV (HR: 2.95; 95% CI: 1.01-3.52) and TLG (HR: 3.49; 95% CI: 1.01-3.52) of the primary tumor pre-to-post-neoadjuvanttherapy were prognostic variables. Conclusion: In patients with esophageal cancer, the burden of disease in suspicious lymph nodes and the primary tumor prior to therapy and the residual burden of disease in the primary tumor post therapy assessed by PET/CT were associated with prognosis.

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