Yazar "Gundogan, Cihan" seçeneğine göre listele

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    18F-FDG PET/CT and 68Ga-FAPI-04 PET/CT Findings of Abdominal Leiomyosarcoma
    (Lippincott Williams & Wilkins, 2021) Guzel, Yunus; Can, Canan; Sogutcu, Nilgun; Gundes, Ebubekir; Gundogan, Cihan
    A 56-year-old woman presented with abdominal pain and vomiting. Her abdominal CT revealed an retroperitoneal mass in the left upper quadrant of the abdomen. F-18-FDG PET/CT performed for metabolic characterization showed low to moderate heterogenous FDG uptake. Ga-68-fibroblast activation protein-specific inhibitor (FAPI)-04 PET/CT performed according to a research carried out in our department showed high heterogenous radiopharmaceutical uptake. The patient was diagnosed with leiomyosarcoma after R0 tumor resection. This case showed that Ga-68-FAPI-04 PET/CT could be a promising radiopharmaceutical in the evaluation of leiomyosarcomas.
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    68Ga-FAPI-04 PET/CT Versus 18F-FDG PET/CT in Malignant Peritoneal Mesothelioma
    (Lippincott Williams & Wilkins, 2022) Gundogan, Cihan; Guzel, Yunus; Komek, Halil; Etem, Hulya; Kaplan, Ihsan
    [Abstract Not Available]
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    Comparison of 18F-FDG PET/CT and 68Ga-FAPI-04 PET/CT in patients with non-small cell lung cancer
    (Lippincott Williams & Wilkins, 2022) Can, Canan; Kepenek, Ferat; Komek, Halil; Gundogan, Cihan; Kaplan, Ihsan; Tasdemir, Bekir; Guzel, Yunus
    Aim In this study, we aimed to compare the diagnostic accuracy of F-18-fluorodeoxyglucose (F-18-FDG) and Gallium-68 labeled fibroblast activator protein inhibitor (Ga-68-FAPI)-04 PET/CT in the tumor-node-metastasis (TNM) staging of patients with nonsmall cell lung cancer (NSCLC) and investigate whether adenocarcinoma (ADC) and squamous cell cancer (SCC) exhibit different uptake patterns on Ga-68-FAPI-04 PET/CT. Materials and method Twenty-nine patients with a histopathologically-confirmed diagnosis of NSCLC, who had no history of previous radiation therapy or chemotherapy and underwent F-18-FDG PET/CT and Ga-68-FAPI-04 PET/CT imaging between January 2021 and December 2021 were included in this retrospective study. Staging was performed using the 8th edition of the TNM staging system on both F-18-FDG PET/CT and Ga-68-FAPI-04 PET/CT images. Standardized uptake value (SUV)(max) and tumor-to-background ratios (TBR) were calculated on primary lesions and metastases. Results There was no statistically significant difference in primary lesions in terms of SUVmax and TBR values. However, Ga-68-FAPI-04 PET/CT was significantly superior to F-18-FDG PET/CT in terms of the number of lymph nodes and bone metastases revealed. The SUVmax and TBR values of lymph nodes, hepatic lesions and bone lesions were significantly higher on Ga-68-FAPI-04 PET/CT than on F-18-FDG PET/CT. Ga-68-FAPI-04 PET/CT changed the disease stage of three patients (10.9%). The diagnostic accuracy of Ga-68-FAPI-04 PET/CT was 100%, whereas the diagnostic accuracy of F-18-FDG PET/CT was 89.6% (P = 0.250). Conclusion Although Ga-68-FAPI-04 PET/CT detected more lesions and higher diagnostic accuracy than F-18-FDG PET/CT in NSCLC, neither method was statistically superior to each other in terms of diagnostic accuracy in TNM staging.
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    Correlations between whole body volumetric parameters of 68Ga-PSMA PET/CT and biochemical-histopathological parameters in castration-naive and resistant prostate cancer patients
    (Springer, 2021) Yildirim, Ozgen Ahmet; Gundogan, Cihan; Can, Canan; Poyraz, Kerem; Erdur, Erkan; Komek, Halil
    Objective To evaluate the relationship between whole body volumetric (Wbv) results of Ga-68-PSMA PET/CT with biochemical and histopathological parameters. Methods One hundred twenty-one prostate cancer patients who underwent Ga-68-PSMA PET/CT between January 2018 and December 2019 were included. Imaging was conducted for staging upon new diagnosis with moderate- and high-risk disease and for confirming the progression of castration resistance. The relationships between the Wbv Ga-68-PSMA PET/CT parameters and prostate-specific antigen (PSA) levels, PSA doubling time and Gleason score (GS) were evaluated. Results The median GS and mean PSA levels were similar between the castration-naive and resistant patients. The PSA levels were positively correlated with MTVwb (p: 0.009, r: 0.286) and TLPwb (p: 0.002, r: 0.344). Gleason scores were positively correlated with MTVwb (p: 0.050, r: 0.216), TLPwb (p: 0.007, r: 0.296) and highest standard uptake value (HSUV) max (p: 0.047, r: 0.220). In the castration-naive group, Gleason scores (from p < 0.001 to p = 0.04 and r = 0.331 to 0.549) and PSA levels (from p = 0.002 to p = 0.045 and from r = 0.323 to 0.473) correlated with all Ga-68-PSMA-PET/CT parameters. PSA doubling time was negatively correlated with whole-body metabolic tumour volume (MTVwb) (p: 0.050, r: 0.232) and whole-body total lesion PSMA (TLPwb) (p: 0.026, r: 0.262). The MTVwb, TLPwb and HSUVpeak values of the patients with biochemical recurrence (BR) of 0-6 months (n = 18) were higher than those with BR > 2 years (n = 35) (p = 0.046, 0.047 and 0.042, respectively). Conclusions Wbv Ga-68-PSMA PET/CT results were correlated with PSA levels and Gleason scores. The correlation was relatively stronger in the castration-naive group. The prognostic accuracy of PSA in the resistant group may be weaker than in the naive group. The difference in volumetric parameters of patients with short BR compared to long BR supports the idea that Ga-68-PSMA PET/CT can distinguish patients with rapid relapse from others.
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    The effect of coronavirus disease 2019 pneumonia on myocardial ischemia detected by single-photon emission computed tomography myocardial perfusion imaging
    (Lippincott Williams & Wilkins, 2022) Bilge, Onder; Komek, Halil; Kepenek, Ferat; Tastan, Ercan; Gundogan, Cihan; Tatli, Ismail; ozturk, Cansu
    Objective We aimed to examine the effects of COVID-19 pneumonia on cardiac ischemia detected by myocardial perfusion imaging with single-photon emission computed tomography myocardial perfusion imaging (SPECT-MPI) in patients presenting with chest pain and shortness of breath after recovery from COVID-19. Materials and method Patients with a history of COVID-19 confirmed by reverse transcriptase-PCR test who underwent SPECT-MPI for the evaluation of ischemia with the complaints of chest pain and shortness of breath were screened for this study. Patients who underwent thorax CT during the acute period of the COVID-19 were included. Patients with and without pneumonia were determined based on computed tomographic criteria. The patients with a summed stress score of at least 4 on SPECT-MPI were considered to have abnormal MPI in terms of ischemia. Results A total of 266 patients were included in the study. Sixty-five (24%) patients had ischemia findings on SPECT-MPI. Thorax CT showed pneumonia in 152 (57%) patients, and the patients were divided into two groups as pneumonia and nonpneumonia. Abnormal SPECT-MPI scores, which represented myocardial ischemia, were higher in the pneumonia group. Multivariate logistic regression analyses showed that the presence of hyperlipidemia and pneumonia on CT increased the risk of ischemia on SPECT-MPI (OR, 2.08; 95% CI, 1.08-3.99; P-value = 0.029; and OR, 2.90; 95% Cl, 1.52-5.54; P-value = 0.001, respectively). Conclusion COVID-19 pneumonia was identified as an independent predictor of ischemia on SPECT-MPI. Symptoms including chest pain and shortness of breath in patients who have had COVID-19 pneumonia may be attributed to coronary ischemia.
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    False-Positive 68Ga-Fibroblast Activation Protein-Specific Inhibitor Uptake of Benign Lymphoid Tissue in a Patient With Breast Cancer
    (Lippincott Williams & Wilkins, 2021) Gundogan, Cihan; Guzel, Yunus; Can, Canan; Alabalik, Ulas; Komek, Halil
    Ga-68-fibroblast activation protein-specific inhibitor (FAPI)-04 PET/CT was performed in a patient with left lower outer quadrant breast cancer who had F-18-FDG PET/CT imaging. Ga-68-FAPI-04 PET/CT showed higher accumulation of radiotracer in primary tumor and axillary lymph nodes than F-18-FDG PET/CT. In addition, focal increased FAPI uptake was observed in another nodular lesion in the lower inner quadrant in the same breast, which was considered malignant. However, Tru-Cut biopsy of this lesion was reported as benign lymphoid tissue. This case showed that all FAPI accumulation in breast tissue should not be interpreted in favor of malignancy; histopathological confirmation is required.
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    Incidental Detection of a Type B3 Thymoma on 68Ga-FAPI-04 PET/CT Imaging
    (Lippincott Williams & Wilkins, 2023) Kepenek, Ferat; Gundogan, Cihan; Kaplan, Ihsan; Sogutcu, Nilguen; Can, Canan
    F-18-FDG PET/CT performed for staging of colon cancer in a 60-year-old woman revealed a thymic neoplasm with increased radiopharmaceutical uptake in the anterior mediastinum. Ga-68-FAPI PET/CT showed low FAPI uptake in the anterior mediastinal mass. The patient was diagnosed with type B3 thymoma by histopathologic evaluation. In this case, thymoma demonstrated lower uptake with FAPI than FDG. Larger studies are required for the differentiation of malignant and benign mediastinal masses with FAPI.
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    Nivolumab-Related Dry Mouth and Dry Eye: Cross-Sectional Study
    (Taylor & Francis Inc, 2021) Yildirim, Ozgen Ahmet; Poyraz, Kerem; Erdur, Erkan; Can, Canan; Gundogan, Cihan; Guzel, Yunus; Etem, Hulya
    To evaluate ICIs related dry eye and dry mouth in nivolumab therapy, 24 patients receiving nivolumab (group 1), 30 patients in remission without treatment for 6 months (group 2), 30 healthy participants (group 3) were cross-sectionally examined. Schirmer's 1, 2, TSH blood tests, serological analysis, salivary flow scintigraphy and minor-salivary gland biopsy were performed. Schirmer's tests were performed with anesthetic (1) and without anesthetic (2). Schirmer's scores were lower in group 1 with more frequent reduced tear production (p < 0.001). TSH levels negatively correlated with Schirmer's scores. Functional insufficiency was detected by salivary flow scintigraphy in 7 out of 10 patients with Schirmer's test positivity. In Schirmer's positive patients, lymphocytic sialadenitis was confirmed in 4 patients (focus score > 1) and CD4 T lymphocyte precipitation was observed in 6 patients. Nivolumab therapy may be associated with ICIs related immune sicca.
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    Role of 68Ga-PSMA PET/CT parameters in treatment evaluation and survival prediction in prostate cancer patients compared with biochemical response assessment
    (Hellenic Soc Nuclear Medicine, 2021) Can, Canan; Gundogan, Cihan; Yildirim, Ozgen Ahmet; Poyraz, Kerem; Guzel, Yunus; Komek, Halil
    Objective: In this study, we aimed to evaluate the concordance of biochemical treatment response with gallium-68-prostate specific membrane antigen (Ga-68-PSMA) positron emission tomography/computed tomography (PET/CT) treatment response in prostate cancer (PCa) and investigate their prognostic effects on survival. Materials and Methods: One hundred and fifty-one patients with PCa, who underwent Ga-68-PSMA PET/CT imaging in our clinic between May 2016 and December 2019, were on treatment, and had pre-treatment and post-treatment imaging studies were included in our study. The treatment patients received and prostate-specific antigen (PSA) levels at the time of PET/CT imaging were recorded. Pre- and post-treatment whole-body metabolic tumor volume (MTVw), whole-body total lesion PSMA (TLPw), percent change in PSA (Delta PSA), Delta MTV, and Delta TLP values were calculated in all patients. Survival time of all patients was measured from the time of initial PET imaging. Results: Median age of patients included in our study was 71 years (range: 51-88). When Delta PSA response and Delta TLP response were evaluated together (r:0.71, P<0.001 and k:0.541, P<0.001), statistically significance strong correlation and moderate concordance was observed. Delta PSA response and Delta MTV treatment response had statistically significant moderate correlation and moderate concordance (r: 0.66, P<0.01 and k: 0.454, P<0.001, significantly). Between Delta PSA response and Delta TLP and Delta MTV response had stronger correlation and higher concordance when PSA levels were above 10. Multivariate analyses using multiple Cox regression analysis revealed MTVw1 and Delta MTV parameters to be independent prognostic factors for mortality (P:0.003 and P:0.001, respectively). Conclusion: We observed that biochemical response and whole-body volumetric Ga-68-PSMA PET/CT parameter response showed correlation and concordance in all groups with PCa, which was more significant when PSA level was >= 10ng/mL. MTVw1 and Delta MTV parameters obtained via Ga-68-PSMA PET/CT were independent prognostic factors for mortality in Pca. Gallium-68-PSMA PET/CT is a valuable imaging technique for diagnostic purposes as well as follow-up and prognostic evaluation.
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    Role of volumetric parameters obtained from 68 Ga-PSMA PET/CT and 18F-FDG PET/CT in predicting overall survival in patients with mCRPC receiving taxane therapy
    (Springer, 2023) Guzel, Yunus; Komek, Halil; Can, Canan; Kaplan, Ihsan; Akdeniz, Nadiye; Kepenek, Ferat; Gundogan, Cihan
    ObjectiveThe aim of this study was to determine the prognostic role of volumetric parameters and Pro-PET scores obtained from (68) Ga-prostate-specific membrane antigen (PSMA) PET/CT and F-18-FDG PET/CT in patients with metastatic castration-resistant prostate cancer (mCRPC) receiving taxane therapy.Materials and methodsThe study included 71 patients who underwent simultaneous PSMA and F-18-FDG PET/CT imaging between January 2019 and January 2022, had a Pro-PET score of 3-5 and had received taxane therapy after imaging. F-18-FDG tumor volume (TV-F) and PSMA tumor volume (TV-P) values of the lesions and total lesion glycolysis (TL-G) and total lesion PSMA (TL-P) values of the lesions were calculated on both imaging studies and the effects of these parameters on overall survival (OS) were investigated.ResultsThe median age of the patients included herein was 71 years (56-89) and the median prostate-specific antigen (PSA) level was 16.4 (0.01-1852 ng/dL). According to the Kaplan-Meier survival analysis, TTV-P >= 78.5, TTL-P >= 278.8, TTV-F >= 94.98, TTL-G >= 458.3, TTV-P + F >= 195.45, TTL-G + P >= 855.78, lymph node (L)TV-FDG >= 3.4, LFDG-SUVmax >= 3.2, LFDG-SUVmean >= 2.25, LFDG-SUVpeak >= 2.55, and bone (B)TV-F >= 51.15 values were found to be prognostic factors in predicting short OS. Multivariate Cox regression analysis showed that a Vscore >= 3 (95% confidence interval [CI]: 7.069-98.251, p < 0.001) and TTL-G + P >= 855.78 (95% CI: 4.878-1037.860, p = 0.006) were found to be independent prognostic factors in predicting short OS.ConclusionVolumetric parameters and Pro-PET scores obtained from (68) Ga-PSMA PET/CT and F-18-FDG PET/CT imaging have been shown to have an impact on OS in patients with mCRPC receiving taxane therapy.