Evaluation of hypermetabolic mediastinal-hilar lymph nodes determined by PET/CT with EBUS-TBNA and calculation of SUVmax cutoff values in differentiation of malignancy.

Computed tomography (CT) and positron emission tomography (PET) are the most commonly used methods for diagnosis and staging in both malignant and benign diseases of the lung parenchyma and mediastinum. Endobronchial ultrasonography (EBUS) guided transbronchial needle aspiration biopsy (TBNA) has become widespread in recent years because it allows minimally invasive tissue sampling. PET-CT has high sensitivity in the diagnosis of malignancy but has low specificity. The false positive rate is high with the SUVmax 2.5 cutoff value, which is widely used in studies about malignancy. In our study, we evaluated lymph nodes with high F18-fluorodeoxyglucose (FDG) uptake on PET/CT and sampled by EBUS-TBNA. We aimed to calculate the new SUVmax cutoff values in the differentiation of malignancy. Our study included 103 patients who were examined for any reason and who underwent biopsy with EBUS-TBNA due to mediastinal or hilar lymph node enlargement on PET-CT. The relationship between PET-CT findings and EBUS findings, EBUS-TBNA results was evaluated. Biopsies were taken from 140 lymph nodes in 103 patients included in our study, and 39 (27.8%) were diagnosed as malignant. In our study, when the SUVmax cutoff value in PET-CT is taken as 2.54, the sensitivity is 98%, but the specificity remains at the level of 12%. When the SUVmax cutoff value in PET-CT was taken as 4.58, the sensitivity was 92% and the specificity was 49%. When this value was accepted as 5.25, and 6.09 the sensitivity was respectively 90% and 85%, the specificity was respectively 52% and 60%. In evaluations, we conducted in order to determine different SUVmax cutoff values that can be used for higher sensitivity and specificity in malignancy studies, the cutoff values were 4.58, 5.25, and 6.09. It is thought that these cutoff values will be useful both for diagnosing malignancy and for distinguishing benign pathologies.

Confirmation of PSMA expression measured on [68Ga]Ga-PSMA PET/CT by immunohistochemistry in prostate adenocarcinoma.

BACKGROUND: Our aim is to determine the accuracy of [68Ga]Ga-PSMA PET/CT in showing PSMA expression in primary prostate cancer and to investigate the relationship between SUVmax and immunohistochemical PSMA expression, Gleason score, and PSA value. MATERIAL AND METHODS: We retrospectively analyzed 66 male patients who were diagnosed with primary prostate adenocarcinoma, underwent pre-treatment [68Ga]Ga-PSMA PET/CT examination for staging, and performed radical prostatectomy between March 2018-August 2020. Immunohistochemical staining was applied to the radical prostatectomy specimens of all patients to detect PSMA expression. The results were evaluated as an immunoreactive score (IRS) and a modified IRS was obtained. Gleason score groups and prostate-specific antigen (PSA) serum values of the patients were obtained from the patient files. RESULTS: The high SUVmax of primary prostate tumors was significantly correlated with a high modified IRS score (score 2; 3), high PSA value, high Gleason score, and metastasis. In correlation analysis, a positive correlation was found between SUVmax and PSA value and modified IRS score (r = 0.69, p = 0.001; r = 0.39, p = 0.001). In addition, there was a statistically significant weak correlation between PSA serum concentration and modified IRS scores (r = 0.267; p = 0.03). In regression analysis, the percentage of positive cells had a statistically significant and increasing effect on SUVmax (p = 0.031; std beta = 0.268; 95% CI = 0.231-4.596). CONCLUSIONS: In prostate adenocarcinoma, SUVmax of the primary tumor in [68Ga]Ga-PSMA PET/CT correlates with immunohistochemical PSMA expression. In addition, high SUVmax is associated with markers of poor prognoses, such as high PSMA expression, PSA value, and Gleason score.

Role of F-18 FDG PET/CT in Predicting Response to Neoadjuvant Chemotherapy in Invasive Ductal Breast Cancer.

Objective: The role of baseline and post-treatment standardized uptake value (SUVmax) values in predicting pathological response in patients with breast cancer after neoadjuvant chemotherapy (NAC). Materials and Methods: Thirty patients with invasive ductal breast cancer were included in this retrospective study. F-18 fluorodeoxyglucose (FDG) positron emission tomography/computerized tomography (PET/CT) examinations were performed before and after NAC. Pretreatment SUVmax (SUVmax I), post-treatment SUVmax (SUVmax II) and ΔSUVmax values of primary breast cancer were obtained. Breast tumor pathology preparations were examined for the evaluation of tumor response according to the Miller and Payne classification. Patients were grouped as responding to treatment (pCR) and unresponsive to treatment (nonpCR). In all analyses, p<0.05 was considered statistically significant. Results: The mean age of the 30 patients included in the study was 51.2±11.98 years. In the study-defined grouping, 13 patients (43.3%) were nonresponders and 17 patients (56.7%) were responders. ΔSUVmax was significantly greater in the responders group compared to the nonresponders group, while SUVmax II was lower (p = 0.001 and p = 0.004, respectively). There was no significant difference between the responders and nonresponders in terms of age, tumor diameter, and SUVmax I values. Multivariate logistic regression analysis showed ΔSUVmax to be the only independent predictive factor for pCR. Conclusion: F-18 FDG PET/CT was an effective method in evaluating the treatment response after NAC in breast cancer, and ΔSUVmax and post-treatment SUVmax can be used to predict the response of the primary tumor to treatment.

Relationships of 18F-FDG uptake by primary tumors with prognostic factors and molecular subtype in ductal breast cancer.

OBJECTIVES: In this study, we aimed to investigate the correlation between SUVmax of primary tumor and prognostic factors/molecular subtype in ductal breast cancer patients. MATERIALS AND METHODS: We retrospectively reviewed 150 female patients with pathologically proven invasive ductal breast cancer from January 2015 to October 2019 who underwent 18F-FDG PET/CT for initial staging. Histopathological prognostic features of the primary tumor (histological grade, hormone receptor status, Ki-67 index, vb.) were obtained from the tru-cut biopsy report. In 18F-FDG PET/CT studies, the maximum standardized uptake value (SUVmax) of the primary breast tumor was calculated and compared with the presence of axillary lymphadenopathy and/or distant metastases, histopathological prognostic factors and molecular subtype. RESULTS: The high SUVmax of primary breast tumors is significantly correlated with the clinicopathological factors: high tumor size, high histologic grade, high Ki-67 index, axillary lymph node positivity and distant metastasis. SUVmax value was significantly higher in patients with basal subtype than patients with Luminal A subtype (8,14 ±â€¯3,71 and 4,64 ±â€¯2,45, p = 0,002). Correlation analysis revealed a low correlation between Ki-67 index and SUVmax (r = 0,276, p = 0,001) and moderate correlation between tumor size and SUVmax (r = 0,470, p = 0,001). In multivariate linear regression analysis, Ki-67 index and tumor size had a statistically significant effect on SUVmax values. As these parameters increase, it is seen that it increases SUVmax values (p = 0,004, Std Beta: 0,228, 95% CI:0,010-0,055 and p = 0,001, Std Beta:0,374, 95% CI:0,55-0,136, respectively). CONCLUSION: High SUVmax value is associated with factors suggesting poor prognosis. Pretreatment 18F-FDG PET/CT can be used as a tool to predict prognosis in breast cancer.

Hemorheology and oxidative stress in patients with differentiated thyroid cancer following I-131 ablation/metastasis treatment.

BACKGROUND: Although radioiodine theraphy (RAIT) is thought to affect blood cells and oxidative stress, hemorheological alterations following dose-dependent RAIT remains unknown. OBJECTIVE: The aim of this study was to determine the effects of RAIT on hemorheological and oxidative stress parameters in patients with differentiated thyroid cancers (DTC). METHODS: Totally 31 DTC patients (mean age 46.32±11.15 years) and 26 healthy controls (mean age 50.50±6.22 years) were included. Venous blood samples were collected from each patient before and after treatment (7th day, 1th month and 6th month). Erythrocyte aggregation-deformability and oxidative stress parameters were determined. p < 0.05 was considered as statistically significant. RESULTS: Erythrocyte deformability of the patients determined at 16.87 and 30 Pascal were significantly lower than healthy individuals. Erythrocyte aggregation index (AI) of the patients was higher, whereas erythrocyte aggregation half-time (t½) was lower compared to control. Erythrocyte deformability values and AI were not significantly different from the pre- and post-radioiodine treatment groups. There was no statistically significant difference between the oxidative stress parameters before and after the treatment. CONCLUSIONS: Patients were in a worse hemorheological condition compared to healthy individuals. After RAIT, RBC deformability and aggregation were not affected and no significant change in oxidative stress parameters was detected.

18F-FDG PET/CT Findings in Metastatic Pilomatrix Carcinoma.

We describe a rare case of metastatic pilomatrix carcinoma with distant metastases 10 months after diagnosis. A 37-year-old woman was diagnosed with pilomatrix carcinoma by excisional biopsy from the occipital region and referred to us for F-FDG PET/CT examinations at the time of diagnosis and 10 months after diagnosis. The first PET/CT did not show any pathological activity, whereas the second PET/CT showed multiple intensive F-FDG uptakes in the right lung parenchyma, right hemithorax pleura, liver, and bones.

Intraobserver and interobserver agreement for the interpretation of 68Ga-prostate-specific membrane antigen-I&T positron emission tomography/computed tomography imaging.

OBJECTIVES: The use of Ga-prostate-specific membrane antigen positron emission tomography/computed tomography is spreading due to its clinical benefits. In this study, we aim to determine the intra- and interobserver agreement levels of Ga- prostate-specific membrane antigen-I&T positron emission tomography/computed tomography according to molecular imaging tumor-lymph node-metastases reporting system. MATERIALS AND METHODS: Eighty prostate cancer patients and underwent Ga- prostate-specific membrane antigen positron emission tomography/computed tomography were blindly evaluated twice by four nuclear medicine specialists at intervals of 4 weeks. The evaluations were performed according to molecular imaging tumour-lymph node-metastases (miTNM) classification. We used Cohen's Kappa and Fleiss' Kappa analysis to analyse intra- and interobserver agreements. RESULTS: When Ga-prostate-specific membrane antigen positron emission tomography/computed tomography findings were evaluated according to miTNM classification, the obtained kappa values were as follows. The intraobserver Cohen's kappa coefficient was found to be 0.79 (substantial agreement), 0.93 (almost perfect agreement), and 0.94 (almost perfect agreement) for miT, miN, and miM, respectively. During interobserver evaluation between the four observers, the kappa coefficient was 0.52 (moderate agreement) for miT, 0.74 (substantial agreement) for miN, and 0.84 (almost perfect agreement) for miM. CONCLUSION: There is no research on the intraobserver agreement analysis of Ga-prostate-specific membrane antigen positron emission tomography/computed tomography in the literature. Our findings are the first ones. The intraobserver agreement was almost perfect. Moreover, although Ga-prostate-specific membrane antigen I&T positron emission tomography/computed tomography had moderate interobserver evaluation compliance of the primary tumour, it had excellent interobserver agreement levels in local lymph node metastasis and distant metastasis evaluation.4012501255.

Incidental "Urinoma" in 18F-FDG PET/CT Scan

18F-FDG PET/CT scanning was performed for the primary staging of a 47-year-old man with urothelial carcinoma. The patient underwent biopsy by ureteroscopy 15 days ago and the PET images revealed 18F-FDG accumulation in the right retroperitenal region, compatible with an "urinoma".

Quantitative volumetric metabolic measurement of solitary pulmonary nodules by F-18 fluorodeoxyglucose positron emission tomography-computed tomography.

BACKGROUND: This study aims to evaluate the effect of quantitative volumetric metabolic measurements in F-18 fluorodeoxyglucose positron emission tomographycomputed tomography to distinguish benign and malignant solitary pulmonary nodules. METHODS: We retrospectively reviewed 78 patients (56 males; 22 females; mean age 61±11.9 years; range, 32 to 82 years) with solitary pulmonary nodules who underwent F-18 fluorodeoxyglucose positron emission tomography-computed tomography. Patients were classified as benign, malignant and metastatic lesions according to pathology results. Metabolic volume, maximum standardized uptake value, mean standardized uptake value, maximum metabolic index and mean metabolic index were measured. Mean, median and standard error values were calculated for each group. Nonparametric tests were used for the comparison of each group. Partial correlation analysis was used for the relationship between parameters. For all parameters, cut-off values were obtained with receiver operating characteristic analysis. RESULTS: Of 78 lesions, 10 were benign (12.8%), 38 were primary lung carcinoma (48.7%) and 30 were metastatic lung nodules (38.5%). There was a significant difference between benign lesions and primary lung cancer and between primary lung cancer and metastatic groups in all parameters (p<0.05). We determined highly significant positive correlation between maximum standardized uptake value and maximum metabolic index (r=0.73; p<0.05), and moderate positive correlation between mean standardized uptake value and mean metabolic index (r=0.56; p<0.05). In receiver operating characteristic analysis, maximum standardized uptake value and mean standardized uptake value were found to be the most sensitive and specific methods for benign/malignant discrimination. In the cut-off value=2.59, the sensitivity and specificity for maximum standardized uptake value were 98.0% and 91.7%, respectively. In the cut-off value=1.65, the sensitivity and specificity for mean standardized uptake value were 94.0% and 91.7%, respectively. CONCLUSION: Maximum metabolic index value is highly correlated with maximum standardized uptake value in benign/malignant solitary pulmonary nodules discrimination by F-18 fluorodeoxyglucose positron emission tomographycomputed tomography. Maximum metabolic index can also be used for discrimination of primary/metastatic malignant lesions.

Hemorheological dysfunction in cardiac syndrome X.

BACKGROUND: Cardiac syndrome X (CSX) is often described as angina or angina-like chest pain with a normal coronary arteriogram, yet the underlying pathophysiological mechanisms have not been fully elucidated. The aim of the current study was to determine alterations in blood rheology (erythrocyte aggregation and deformability, plasma viscosity - PV) in patients with CSX. METHODS: The study comprised 26 CSX patients (55.77 ± 12.33 years) and 37 age- and sex-matched (56.32 ± 11.98 years) healthy controls. Erythrocyte aggregation and deformability were measured by an ektacytometer and PV with a rotational viscometer. RESULTS: Erythrocyte deformability measured at 1.69 and 3.00 Pa was lower in the CSX patients compared to the controls (p = .0001 and .017, respectively). Erythrocyte aggregation index (AI) (72.758 ± 7.65 vs. 66.483 ± 6.63, p = .002) and PV measured at a shear rate of 375 s-1 (1.932 ± 0.225 vs. 1.725 ± 0.331, p = .019) were significantly higher in patients with CSX. When AI, RDW and erythrocyte deformability measured at 1.69 Pa were evaluated together, it was observed that the increase in AI and RDW augments the risk of having CSX (OR: 1.2 and 2.65, respectively), while the rise in deformability decreases this risk (OR = 0.02). CONCLUSIONS: Hemorheological impairments are associated with CSX.

Liver metabolic activity changes over time with neoadjuvant therapy in locally advanced rectal cancer.

OBJECTIVE: The aim of this study was to evaluate, using PET/computed tomography (CT), changes in liver metabolic activity in patients with locally advanced rectal cancer (LARC) after neoadjuvant chemoradiotherapy (CRT). PATIENTS AND METHODS: A total of 29 biopsy-proven LARC patients between 2009 and 2012 were studied. Liver standardized uptake values (SUVs) and SUVs adjusted for lean body mass (SULs) were obtained from PET/CT images obtained at 1 h (early) and 2 h (late) after (18)F-fluorodeoxyglucose ((18)F-FDG) administration both before and after neoadjuvant CRT. Age, sex, BMI, lean body mass, blood glucose level, and (18)F-FDG dose, which can influence liver SUVs and SULs, were also analyzed. RESULTS: Fourteen (48%) men and 15 (52%) women with a mean age of 62±11 years (range 34-80 years) were included in the study. The mean SUVs and SULs were significantly decreased in the late scans. Sex was significantly correlated with the mean liver SUV in early and late scans. The mean SUV differed significantly between male and female patients in early and late images (P<0.05). In a multivariate stepwise regression analysis, only liver SUVs (maximum and mean) were significantly associated with BMI before and after therapy. SUVs were significantly higher in the high (≥25) BMI group after but not before therapy. Mean SUL was not influenced by BMI. CONCLUSION: Liver (18)F-FDG uptake is consistent before and after neoadjuvant CRT therapy in patients with LARC. When assessing response to therapy and using liver metabolic activity to indicate background activity, BMI should be considered as it can influence liver metabolic activity.

Temporary changes in neutrophil-to-lymphocyte, platelet-to-lymphocyte ratios, and mean platelet volume reflecting the inflammatory process after radioiodine therapy.

OBJECTIVE: Data on the effects of radioiodine (RAI) therapy on systemic inflammation are very limited. The aim of this study is to explore alterations of subclinical systemic inflammatory markers, such as neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and mean platelet volume (MPV), after RAI therapy in patients with differentiated thyroid carcinoma (DTC). MATERIALS AND METHODS: We evaluated 57 DTC patients treated with RAI (RAI group), 37 DTC patients not treated with RAI (non-RAI control group), and 37 age-matched healthy individuals (healthy control group). NLR, PLR, and MPV levels were compared among the study groups; these were also examined after RAI in the RAI group. RESULTS: Initially, NLR was significantly higher in the RAI group than in the healthy controls. NLR and PLR increased significantly and MPV decreased significantly 2 months after RAI therapy (P=0.021, 0.001, and 0.008, respectively). Although NLR and PLR levels decreased, they were still high compared with the preoperative values. MPV returned to normal levels at 6 months. These parameters did not change significantly in the non-RAI control group. CONCLUSION: This is the first study to evaluate changes in NLR, PLR, and MPV after RAI therapy. Our findings suggest that NLR, PLR, and MPV changes indicate systemic inflammation that occurs after RAI therapy because of thyroid remnant tissue ablation.

The correlation between the metabolic tumor volume and hematological parameters in patients with esophageal cancer.

INTRODUCTION: The aim of this study is to evaluate the correlation of the serum neutrophil/lymphocyte ratio (NLR), platelet/lymphocyte ratio (PLR), and mean platelet volume (MPV), with the standardized uptake value (SUVmax), and metabolic tumor volume (MTV) in F-18 fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) in patient with esophageal squamous cell cancer at baseline. METHODS: PET/CTs were performed in 52 patients with esophageal squamous cell cancer, making up the patient group. An additional 52 patients who underwent endoscopy due to dyspepsia with normal esophagus (as a control group) were included in the study to compare the hematological parameters between the patient groups. RESULTS: The median age was 60.0 ± 12.8 years (range 39-84 years) for the patients with esophageal cancer, and 56.9 ± 12.3 years for the control group. Statistical differences were found in terms of the neutrophils, lymphocytes, NLR, PLT, PLR, and MPV between the patients with esophageal cancer and the control group. In the correlation analysis, only the NLR was correlated with the MTV for all of the patients (p = 0.013, r = 0.344). The SUVmax was not correlated with these hematological parameters. CONCLUSION: At baseline neutrophil-to-lymphocyte ratio is associated with the metabolic tumor volume, which was assessed using the PET/CT in patients with esophageal squamous cell cancer. The SUVmax values were not related to these parameters.

The effect of radioiodine on the intima media thickness of the carotid artery.

AIM: The radiation can induce vessel injury. The result of this injury can be severe and life-threatening. There are a few studies demonstrating an increase in intima-media thickness (IMT) of the common carotid artery (CCA) after radiotherapy, especially in head and neck cancers. We evaluated the effect of I-131 to the IMT of the CCA in the patients who were treated for hyperthyroidism. METHODS: 38 patients (25M, 13W) referred to our department for radioiodine treatment with the diagnosis of nodular goitre (25 patients) and diffuse hyperplasia (Graves disease (GD), 13 patients) were included to the prospective study. An USG was performed for all the patients before therapy, 3, 6 and 12 months after radioiodine therapy in order to measure IMT of CCA and the femoral artery (FA). The IMT was measured at the level of proximal part of bulbus anteriorly on the left and right side. The IMT of FA was measured just before the bifurcation. RESULTS: There was a statistically significant increase in IMT of both CCA and FA bilaterally in nodular hyperthyroid patients. However, in the patients with Graves disease, there was only statistically significant increase in the left IMT of CCA at 0-3rd, 0-6th month measurements and in the right IMT of FA at 0-3rd month measurements. CONCLUSION: Though the limitation of the study is the interobserver and intraobserver variability, it was seen that I-131 therapy might affect the IMT of CCA in the patients with NG. I-131 effect on the IMT of CCA in patients with nodular goitre was higher than the IMT of CCA in patients with GD. I-131 effect on the IMT of CCA might be due to administered dose and adjacency. The interesting point of our study was the increased thickness of IMT in FA. We think that the increase in IMT is due to the systemic effect of radioactivity circulating in the blood vessel. I-131 effect on the IMT of FA in patients with nodular goitre was higher than the IMT of FA in the patients with GD due to I-131 uptake of thyroid gland. Because I-131 uptake was lower in patients with nodular goitre, I-131 in systemic circulation was higher. CONFLICT OF INTEREST: None declared.

The Effects of the Factors Related to the Patient and the Disease on the Performance of Ablation Therapy in Patients with Differentiated Thyroid Cancer who have Received I-131 Ablation Therapy.

OBJECTIVE: To investigate whether the factors related to the patient and the disease have any effect on the success of ablation therapy in patients with differentiated thyroid cancer who have received I-131 ablation therapy. MATERIAL AND METHODS: All the patients with differentiated thyroid cancer were referred for I-131 ablation therapy after thyroidectomy between July 2007 and September 2009. The patients had at least six months of follow-up. Age, gender, type of tumor, presence of capsule invasion, size of tumor, number of the tumors, localization of the tumor, invasion of thyroid capsule, lymph/vessel invasion, presence of metastatic lymph nodes, type of surgery, preablation values of thyroglobulin (Tg), AntiTg, TSH, surveys for the evaluation of metastatic disease, (thyroid and bone scintigraphy, neck and abdominal ultrasonography, chest and brain computerized tomography), administered dose, postablation I-131 whole body scan (WBS) and diagnostic I-131 WBS, neck USG, values of Tg and AntiTg at the 6th month were recorded. The presence of residual thyroid activity on the 6th month diagnostic I-131 WBS image was accepted as the criterion for ablation success. RESULTS: 191 patients with differentiated thyroid cancer were assessed in this study. The overall success rate of the first ablation therapy was 74.3%. The success rate of the ablation therapy was 66% and 75% in metastatic group and non-metastatic group, respectively. Except the significant correlation between the number of pathologic lymph nodes and the success of ablation (p=0.025), there was no other significant correlation between the patient/disease related factors and the success of ablation therapy. CONCLUSION: Significant correlation between the number of the pathologic lymph nodes and the ablation therapy performance can also be due to statistical error because of the limited sample size. There was no significant correlation between other patient/disease related prognostic factors and the success of ablation therapy. CONFLICT OF INTEREST: None declared.