Hellenic journal of nuclear medicine最新文献

{"title":"Quality assurance in clinical dosimetry.","authors":"Manuel Bardiès","doi":"","DOIUrl":"","url":null,"abstract":"<p><strong>Introduction: </strong>Clinical dosimetry in nuclear medicine is developing fast, with an increasing number of procedures performed for a variety of therapeutic applications. In that context, the advent of CE-marked commercial clinical dosimetry software is a positive signal, as they should, in principle, optimize the workflow and increase robustness. However, they pose the problem of the evaluation of their performances, in terms of accuracy but also ease of use (user-friendliness).</p><p><strong>Aim: </strong>The aim of this presentation is to discuss the various steps required for the evaluation of clinical dosimetry procedures in general, and dosimetry software in particular.</p><p><strong>Materials and methods: </strong>The clinical dosimetry workflow (CDW) is the suite of steps that lead from calibration procedures to the final reporting of the clinical dosimetry procedure. The study of the CDW implemented in various software shows a age variability in the implementation of the steps that constitute the CDW, and the order of their implementation. This can be accepted, however it raises the issue of comparing software that, basically, do not do the same thing, or do things in a different order.</p><p><strong>Results and discussion: </strong>The various steps that compose the CDW have to be studied (benchmarked) using specific tools: If assessing calibrations/reconstructions can be made using phantoms filled with radioactive sources, rigid objects are not adapted to the evaluation of registration procedures. Computing anthropomorphic models can be used to verify absorbed dose calculation algorithms (for example using Monte Carlo radiation transport modelling as the gold standard). As can be seen, a range of tools of different type (test objects, models, patient data) must be used - and sometimes developed - to evaluate each step of the CDW. Finally, the end-to-end process must be benchmarked on \"real\" clinical data, but the price to pay is that the ground truth is not known, thereby limiting these approaches to precision rather than accuracy.</p><p><strong>Conclusion: </strong>Nuclear medicine dosimetry quality assurance (QA) is in its infancy. However, procedures already applied in external beam radiotherapy may be easily transposed to nuclear medicine, and it will not take decades until nuclear medicine benefits from sound, reproducible procedures that will increase the robustness of clinical dosimetry procedures.</p>","PeriodicalId":12871,"journal":{"name":"Hellenic journal of nuclear medicine","volume":"26 Suppl ","pages":"14"},"PeriodicalIF":1.5,"publicationDate":"2023-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10141292","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comparison of Al ¹⁸F-NOTA-FAPI-04 and ¹⁸F-FDG in recurrent esophageal cancer after surgery.","authors":"Wei Zhang,&nbsp;Wei Diao,&nbsp;Zhuzhong Cheng","doi":"10.1967/s002449912559","DOIUrl":"https://doi.org/10.1967/s002449912559","url":null,"abstract":"<p><p>Recently, radionuclide labelling fibroblast activating protein inhibitors (FAPI) is regarded as the most promising imaging tracer forvarious tumours. Here we present the imaging finding of aluminium-[¹⁸F] fluoride (Al¹⁸F)-labelled 1,4,7-triazacyclononane-N,N',N\"-triacetic acid (Al¹⁸F-NOTA-FAPI-04) and fluorine-18-fluorodeoxyglucose (¹⁸F-FDG) in postoperative recurrence esophageal cancer. The results presented that imaging with Al¹⁸F-NOTA-FAPI-04 showed significant improvement in detection of local recurrence and distant metastasis with higher maximum standardized uptake value (SUVmax) in the lesions compared with ¹⁸F-FDG.</p>","PeriodicalId":12871,"journal":{"name":"Hellenic journal of nuclear medicine","volume":"26 1","pages":"75-77"},"PeriodicalIF":1.5,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9361281","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"¹⁸F-FDG PET/CT in Waldenström associated amyloidosis.","authors":"Lynn De Mey,&nbsp;Sim Vermeulen,&nbsp;Sophie Bourgeois,&nbsp;Lode Goethals,&nbsp;Frank De Geeter","doi":"10.1967/s002449912557","DOIUrl":"https://doi.org/10.1967/s002449912557","url":null,"abstract":"<p><p>Amyloidoisis in patients with Waldenström macroglobulinemia (WM) mostly involves the heart, peripheral nerves and kidneys. Retroperitoneal amyloidosis is a rare finding. We describe a 62-year-old man with an incidental finding of a monoclonal gammopathy and elevated inflammatory parameters. Bilateral moderately active retroperitoneal infiltration with punctiform calcifications was found on fluorine-18-fluorodeoxyglucose (¹⁸F-FDG) positron emission tomography/computed tomography (PET/CT) imaging. Taken together, these findings are suggestive of Waldenström associated amyloidosis. Computed tomography-guided retroperitoneal biopsy confirmed the diagnosis.</p>","PeriodicalId":12871,"journal":{"name":"Hellenic journal of nuclear medicine","volume":"26 1","pages":"70-72"},"PeriodicalIF":1.5,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9367651","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Artificial intelligence in Nuclear Medicine Physics and Imaging.","authors":"Konstantinos Papachristou,&nbsp;Emmanouil Panagiotidis,&nbsp;Anna Makridou,&nbsp;Theodoros Kalathas,&nbsp;Vasilis Masganis,&nbsp;Anna Paschali,&nbsp;Maria Aliberti,&nbsp;Vassiliki Chatzipavlidou","doi":"10.1967/s002449912561","DOIUrl":"https://doi.org/10.1967/s002449912561","url":null,"abstract":"<p><p>No one can deny the significant impact of artificial intelligence (AI) on everyday life, especially in the health sector where it has emerged as a crucial and beneficial tool in Nuclear Medicine (NM) and molecular imaging. The objective of this review is to provide a summary of the various applications of AI in single-photon emission computed tomography (SPECT) and positron emission tomography (PET), with or without anatomical information (CT or magnetic resonance imaging (MRI)). This review analyzes subsets of AI, such as machine learning (ML) and Deep Learning (DL), and elaborates on their applications in NM imaging (NMI) physics, including the generation of attenuation maps, estimation of scattered events, depth of interaction (DOI), time of flight (TOF), NM image reconstruction (optimization of the reconstruction algorithm), and low dose imaging.</p>","PeriodicalId":12871,"journal":{"name":"Hellenic journal of nuclear medicine","volume":"26 1","pages":"57-65"},"PeriodicalIF":1.5,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9373451","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evaluation of diffuse lymphadenopathy via various quantitative PET/CT parameters.","authors":"Güler Silov,&nbsp;Emel Çankaya,&nbsp;Seyhan Karaçavuş","doi":"10.1967/s002449912555","DOIUrl":"https://doi.org/10.1967/s002449912555","url":null,"abstract":"<p><strong>Objective: </strong>Discovery of diffuse lymphadenopathy (DLAP) in fluorine-18-fluorodeoxyglucose (¹⁸F-FDG) positron emission tomography/computed tomography (PET/CT) imaging alerts for the existence of many pathologic conditions with severity ranging from benign to malignancy. This study examines the role of various metabolic parameters reflecting ¹⁸F-FDG characteristics of organs/tissues to reach an accurate differential diagnosis for further clinical assessment.</p><p><strong>Materials and methods: </strong>Positron emission tomography/CT images of 78 patients with DLAP were reviewed retrospectively. The diameter of the largest lymph node (DLlyn), maximum standardized uptake value (SUVmax) of the liver (L), the largest lymph node (Llyn), spleen (S), and bone marrow (BM) were measured. Ratios to liver SUVmax were calculated for all, resulting LLRmax, SLRmax, and BMLRmax respectively.</p><p><strong>Results: </strong>The diameter of the largest lymph node, Llyn.SUVmax, LLRmax, and SLRmax produced cut-off values as 25.5, 8.86, 2.80, and 0.82 with corresponding sensitivity:specificity values as 65%:83%, 74%:77%, 74%:71%, and 79%:63% respectively for risk stratification of malignant causes. To differentiate lymphoma from sarcoidosis, DLlyn, SLRmax, and BMLRmax were found valuable with cut-off values obtained as 28.5, 0.84, and 1.19 with corresponding sensitivity:specificity values as 79%:91%, 79%:82%, and 54%:91%, respectively.Interdependency between parameters was also evaluated.</p><p><strong>Conclusion: </strong>High values of Llyn.Maximum SUV and LLRmax are the main characteristics of lymphoma, metastasis, and sarcoidosis. The diameter of the largest lymph node, SLRmax, and BMLRmax are determined as distinct parameters for distinguishing lymphoma from sarcoidosis. Besides, observed correlation structures amongst some PET/CT parameters were identified as nodal, extranodal, and diffuse patterns for three disease groups except sarcoidosis. These findings extend the knowledge about diagnostic factors based on ¹⁸F-FDG PET/CT patterns for DLAP.</p>","PeriodicalId":12871,"journal":{"name":"Hellenic journal of nuclear medicine","volume":"26 1","pages":"47-56"},"PeriodicalIF":1.5,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9361280","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Intravenous insulin preparation administration for myocardial viability ¹⁸F-FDG imaging has the potential to reduce radiation exposure dose.","authors":"Yangchun Chen,&nbsp;Qingqing Wang,&nbsp;Peihao Huang,&nbsp;Yuehui Wang,&nbsp;Yuxuan Chen,&nbsp;Huilin Zhuo,&nbsp;Ruozhu Dai,&nbsp;Huoqiang Wang","doi":"10.1967/s002449912552","DOIUrl":"https://doi.org/10.1967/s002449912552","url":null,"abstract":"<p><strong>Objective: </strong>Fluorine-18-fluorodeoxyglucose (¹⁸F-FDG) injection activity is positively associated with radiation dose and positron emission tomography (PET) image count. Measurement error is greater with smaller counts; therefore, precise analysis is needed to avoid high doses of radiation exposure caused by high ¹⁸F-FDG injection. We aimed to identify and validate the optimal ¹⁸F-FDG injection activity and acquisition time for cardiac viability imaging with intravenous insulin preparation administration based on fixed ¹⁸F-FDG activity.</p><p><strong>Materials and methods: </strong>Cardiac PET images from 30 patients with coronary artery disease (CAD) were retrospectively reconstructed into different durations. An optimal product of the maximum standardized uptake value (SUV) of the myocardium, and segmental uptake (SU), and acquisition time (MSAT) was determined through a receiver operating characteristic curve.</p><p><strong>Results: </strong>The optimal acquisition time (OAT) was equal to MSAT divided by mean SUV of the myocardium (MyoSUV) and was validated in another 26 patients with CAD. The optimal MSAT was 848.2s. In the validation group, the OAT was 129±76s (95% confidence interval, 99-160s), approximately one-third of the usual acquisition time. The MyoSUV and SU were equivalent between PET image duration of OAT and 600s (7.71±3.01 vs. 7.56±2.94; 67.1±15.4% vs. 67.7±15.6%).</p><p><strong>Conclusion: </strong>Intravenous insulin preparation administration has the potential to decrease the radiation exposure or acquisition time in cardiac viability ¹⁸F-FDG imaging to one-third, without losing the accurate measurement of MyoSUV or SU when reaching an OAT.</p>","PeriodicalId":12871,"journal":{"name":"Hellenic journal of nuclear medicine","volume":"26 1","pages":"20-25"},"PeriodicalIF":1.5,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9361277","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect tracking of ¹³¹I treatment in Graves' hyperthyroidism patients within 1 year and analysis of the factors that may influence the cure.","authors":"Yue Zhao,&nbsp;Xin Tian,&nbsp;Zhaowei Meng","doi":"10.1967/s002449912554","DOIUrl":"https://doi.org/10.1967/s002449912554","url":null,"abstract":"<p><strong>Objective: </strong>To observe the disease development and outcome of Graves' disease (GD) patients within 1 year after iodine-131 (¹³¹I) treatment, and analyze the factors affecting the treatment effect.</p><p><strong>Subjects and methods: </strong>Clinical data of 221 patients who received the first treatment with ¹³¹I in our department from June 2016 to October 2018 were retrospectively analyzed and they were followed up at 3 months, 6 months and 1 year after the treatment. According to the three follow-up records, the cure rate was calculated and the follow-up chart was drawn. The factors that may affect the clinical cure were analyzed according to the follow-up results after 1 year: Independent risk factors affecting the prognosis were screened out by Logistic regression analysis, and the effects of the above factors on the prognosis were further analyzed by Chi-square test, and the cure multiple relationship caused by the influencing factors was analyzed by Logistic regression analysis.</p><p><strong>Results: </strong>The cure rate was 58.82% and the effective rate was 71.95%. At the 3-month follow-up, 11 patients (4.98%) presented complete response, 99 patients (44.80%) presented hypothyroidism, 93 patients (42.08%) presented partial response, and 18 patients (8.14%) presented no effect or recurrence. At 6 months, 18 cases (8.14%) had complete response, 90 cases (40.72%) had hypothyroidism, 59 cases (26.70%) had partial response, and 54 cases (24.43%) had no effect or recurrence. At 12 months, 36 cases (16.29%) had complete response, 94 cases (42.53%) had hypothyroidism, 29 cases (13.12%) had partial response, and 62 cases (28.05%) had no effect or recurrence. Thyroid weight and thyroid peroxidase antibody (TPOAb) were the influencing factors. Among all patients, patients with thyroid weight ≤28.70g were 4.25 times more likely to achieve clinical cure than patients with >28.70g [OR (95%CI):4.252 (2.383-7.588), P<0.01)], female patients with the thyroid weight ≤28.70g was 5.78 times than those with >28.70g [OR (95%CI): 5.776 (2.951-11.308), P<0.01]. In male, patients with TPOAb≤449.00IU/mL were 0.27 times more likely to achieve clinical cure than those with >449.00IU/mL [OR (95%CI): 0.274 (0.081-0.919), P<0.05].</p><p><strong>Conclusion: </strong>Iodine-131 was an effective treatment to GD. Thyroid weight before treatment was the influencing factor for all patients and female patients, while TPOAb was the influencing factor for male patients.</p>","PeriodicalId":12871,"journal":{"name":"Hellenic journal of nuclear medicine","volume":"26 1","pages":"35-40"},"PeriodicalIF":1.5,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9367650","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Validation of RAH VQ SPECT/CT lobar quantification program using a modified version of GE Q lung.","authors":"Chong Ghee Chew,&nbsp;Benjamin Crouch,&nbsp;Stirling Ha,&nbsp;Alice Burke,&nbsp;Jennie Louise","doi":"10.1967/s002449912551","DOIUrl":"https://doi.org/10.1967/s002449912551","url":null,"abstract":"<p><strong>Objective: </strong>The value of ventilation-perfusion (VQ) single photon emission tomography/computed tomography (SPECT/CT) lobar quantification for pre-operative assessment of lobectomy and lung volume reduction is known. Our in-house developed software, RAH ventilation perfusion SPECT/CT quantification (RAHVQSQ) has been shown to be able to identify the target lobe for collapse in bronchoscopic lung volume reduction (BLVR) for advanced emphysema. We have proven inter and intra observer reproducibility but are yet to validate the accuracy of our program. This study aims to validate the accuracy of our quantitative program through comparison with a modified version of GE Q lung which is a commercial program certified for clinical use.</p><p><strong>Subjects and methods: </strong>Ventilation-perfusion SPECT/CT data of 19 subjects from our previous study using RAHVQSQ for BLVR assessment were re-analysed using Q lung by 2 technologists independently and in a blinded fashion to determine lobar differential ventilation, perfusion and volume percentages. The data were from GE Hawkeye 4 and external CT, thus a modified version of Q lung was used. To determine interobserver variation in the 3 parameters between the 3 assessors, intraclass correlation coefficient (ICC) and Bland-Altman limits of agreement (LoA) were generated.</p><p><strong>Results: </strong>Paired comparisons between the 3 assessors had high ICC (range for ventilation: 0.69-0.97; perfusion: 0.69-0.97; volume: 0.63-0.97) and means of LoA differences close to zero (range for ventilation: -0.04 - 0.10; perfusion: 0.00-0.02; volume: -0.12 - 0.09) were noted indicative of good concordance for all parameters.</p><p><strong>Conclusion: </strong>Using VQ SPECT/CT data of participants with advanced airway disease, our study has found a close concordance of estimated differential lobar ventilation, perfusion and volume percentages using RAHVQSQ when compared with a duplicated blinded assessment using Q lung. The good concordance supports the validity of our quantitative methodology.</p>","PeriodicalId":12871,"journal":{"name":"Hellenic journal of nuclear medicine","volume":"26 1","pages":"9-19"},"PeriodicalIF":1.5,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9361279","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Differentiated thyroid cancer: Case report of false positive ¹³¹I uptake on whole body scintigraphy in a patient with bilateral femur osteonecrosis.","authors":"Evanthia Giannoula,&nbsp;Georgia Koutsouki,&nbsp;Paraskevi Exadaktylou,&nbsp;Nikitas Papadopoulos,&nbsp;Emmanouil Papanastasiou,&nbsp;Argirios Doumas,&nbsp;Ioannis Iakovou","doi":"10.1967/s002449912556","DOIUrl":"https://doi.org/10.1967/s002449912556","url":null,"abstract":"<p><strong>Objective: </strong>Differentiated thyroid cancer (DTC) is one of the fastest growing cancers worldwide. Despite the generally good prognosis of thyroid carcinoma, about 5% of patients will develop metastatic disease, exhibiting a more aggressive behavior. Radioiodine whole-body scintigraphy (WBS) has been used in the detection of DTC. Radioiodine is a sensitive marker for detection of thyroid cancer; however, radioiodine uptake is not specific for thyroid tissue. It can also be seen in healthy tissue as well as in inflammation, or in a variety of benign and malignant non-thyroidal entities.</p><p><strong>Subject and methods: </strong>The subject of the present case report is a 52 years old man with brain metastatic DTC who received radioiodine therapy and corticosteroids as palliative therapy. Whole-body scintigraphy revealed bilateral iodine uptake of the femur. Corticosteroid therapy is among the most widely recognized risk factor for osteonecrosis, which at the present case had to be recognized as a false positive (iodine-131) ¹³¹I uptake in order to avoid diagnostic error.</p><p><strong>Results: </strong>Post therapeutic whole body scintigraphy revealed no uptake in the thyroid bed as well as pathologic uptake of radioiodine in both femurs. The magnetic resonance imaging (MRI) of the femurs combined with the history of long term exposition on high doses of corticosteroids evidenced diagnosis of steroid-induced osteonecrosis of the femurs.</p><p><strong>Conclusion: </strong>Radioiodine WBS plays an important role in clinical decision making for the evaluation and the management of patients with DTC. Despite its high range of sensitivity and specificity, a variety of reports of false positive whole body scans has demonstrated a diversity of causes. Comprehension of the physiology of iodine uptake and of the pathophysiology of clinical entities which end up giving false positives scans, provides clinicians a useful tool in order to avoid diagnostic and therapeutic errors as far as DTC is concerned.</p>","PeriodicalId":12871,"journal":{"name":"Hellenic journal of nuclear medicine","volume":"26 1","pages":"66-69"},"PeriodicalIF":1.5,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9367652","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comparison of ⁶⁸Ga-FAPI-04 and ¹⁸F-FDG PET/CT for diagnosis of metastatic lesions in patients with recurrent papillary thyroid carcinoma.","authors":"Zeynel Abidin Sayiner,&nbsp;Umut Elboğa,&nbsp;Ertan Sahin,&nbsp;Sadettin Ozturk,&nbsp;Yusuf Burak Cayirli,&nbsp;Yusuf Zeki Celen,&nbsp;Ersin Akarsu,&nbsp;Ilkay Dogan,&nbsp;Benan Kilbas,&nbsp;Kurtulus Eryilmaz,&nbsp;Davut Cakici","doi":"10.1967/s002449912560","DOIUrl":"https://doi.org/10.1967/s002449912560","url":null,"abstract":"<p><strong>Objective: </strong>We aimed to evaluate the gallium-68-labeled fibroblast-activation protein inhibitor (⁶⁸Ga-FAPI) positron emission tomography/computed tomography (PET/CT) in localizing papillary thyroid carcinoma (PTC) foci in patients with biochemical relapse. Papillary thyroid carcinoma has achieved biochemical recovery after appropriate treatment and had biochemical relapse in the last follow-up were included in this retrospective study. Gallium-68-FAPI and fluorine-18-fluorodeoxyglucose (⁶⁸F-FDG) PET/CT were performed to detect recurrence foci.</p><p><strong>Subjects and methods: </strong>Biochemically relapsed patients who underwent total thyroidectomy and were diagnosed with pathologically differentiated thyroid cancer were included in our study. Gallium-68-FAPI and ¹⁸F-FDG PET/CT imaging methods were used to determine the focus of metastasis or recurrence in all patients.</p><p><strong>Results: </strong>Among 29 patients enrolled to the study, pathological subgroups were papillary (n=26) and poorly differentiated (n=3) PTC. Anti-thyroglobulin (TG) antibody positivity were noted in 5 of the patients, while all 29 of them were TG positive and had been consist of three groups as follows: 2-10ng/mL (n=4), 11-300ng/mL (n=14), 301ng/mL and above (n=11). Recurrence was detected in 72.4% (n=21) and 86% (n=25) of the patients via ¹⁸F-FDG and ⁶⁸Ga-FAPI, respectively. Accuracy of detection noted as 100% (5/5), 75% (3/4), and 92.9% (13/14) in groups with the anti-TG antibody positivity, TG levels of 2-10ng/mL and 11-300ng/mL, respectively, when the two imaging modalities were utilized together. Furthermore, accuracy of ⁶⁸Ga-FAPI was 100% (11/11) in the group with TG levels of 301ng/mL and above, whereas accuracy of ¹⁸F-FDG was 81.8% (9/11). Lastly, median maximum standardized uptake value (SUVmax) of recurrent lesions detected by the ⁶⁸Ga-FAPI (median SUVmax: 6.0) were statistically higher than the ones detected by the ¹⁸F-FDG (median SUVmax: 3.7) (P=0.002).</p><p><strong>Conclusion: </strong>In recurrent PTC especially in case of higher TG levels, ⁶⁸Ga-FAPI can be used in patients with inconclusive ¹⁸F-FDG findings.</p>","PeriodicalId":12871,"journal":{"name":"Hellenic journal of nuclear medicine","volume":"26 1","pages":"41-46"},"PeriodicalIF":1.5,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9378845","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}