Can 18Fluoro-deoxy-glukose-Positron Emission Tomography/Computed Tomography be a Useful for Decision of Elective Surgery in Thoracic Aortic Aneurysm.

Thoracic aortic aneurysm (TAA) should be treated before the complications with prophylactic surgery. However, important number of ruptures have been occurred below the cut-off size for surgery. In addition, in some cases, who in the cut-off value limit, decision of surgery may sometimes be difficult. 18Fluoro-deoxy-glukose positron emission tomography/computed tomography (18FDG-PET/CT) may useful such situations. We present a case that, TAA in 18FDG-PET/CT in a patient with larynx carcinoma. He had a TAA with near the cut-off value and increased metabolic activity in baseline imaging. After 3 months, SUVmax value increased and elective surgery was performed. We think that aneurysms may be another pathology that 18FDG-PET/CT potentially be useful apart from imaging malignant diseases.

Can PET/CT be used more effectively in pleural effusion evaluation?

PURPOSE: Sometimes, characterization of pleural effusion (PE) can be challenging especially in patients whom invasive procedures/recurrent invasive procedures cannot be performed. The main purpose of the study is to answer this question, Can 18F-FDG-PET/CT contribute to reduction in the number of invasive procedures or patients undergoing to invasive procedures? Results may increase the effectiveness of patient management by facilitating clinical decision-making, especially in patients who cannot undergo invasive/recurrent invasive procedures. METHODS: Sixty-seven patients' 18F-FDG-PET/CT, pleural fluid cytologies (PFCs) and, if any, pleural biopsies were re-assessed. If patient's PFC/biopsy was malignant, effusion was considered as malignant. If two consecutive PFCs were negative in patients without biopsy, effusion was considered as benign. Characterization was based on consensus with baseline/follow-up 18F-FDG-PET/CT and clinical parameters in patients with one negative PFC (n = 6). RESULTS: None of the 18F-FDG-PET/CT parameters could characterize PE alone. However, if PE maximum standardized uptake value (SUVmax) > 1.3 or PE SUVmax/mean standardized uptake value of mediastinal blood pool (MBP SUVmean) > 1.2 was combined with at least one of the following, specificity and positive predictive value (PPV) were 100%, accuracy was around 90%. Diffuse-nodular/nodular pleural thickness, post-obstructive atelectasis, nodule/mass with SUVmax > 2.5 in lung, multiple pulmonary nodules. All 29 patients who had SUVmax > 1.3 together with at least one of the mentioned four parameters diagnosed malignant pleural effusion (MPE). However, sensitivity and negative predictive value (NPV) were still insufficient. CONCLUSION: Patients who have contraindications for invasive diagnostic methods, and meet the aforementioned criteria may be considered as MPE primarily. On the other hand, if PE SUVmax < 1.3 or PE SUVmax/MBP SUVmean < 1.2 with the negativity of the all four parameters mentioned above, it is difficult to say that this can be considered as benign pleural effusion (BPE) according to our results.

Is it possible to achieve more accurate mediastinal nodal radiotherapy planning for NSCLC with PET/CT?

Objective: To assess whether more accurate mediastinal lymph nodes radiotherapy can be performed with fluorode oxyglu cosepositron emission tomogaphy/computed tomography. METHODS: The retrospective study was conducted at Inonu University Medical Faculty, Malatya, Turkey, and Afyon Kocatepe University Medical Faculty, Afyon, Turkey, and comprised record of patients histopathologically diagnosed with non-small cell lung carcinoma and who underwent fluorodeoxyglucose positron emission tomography / computed tomography between January 2013 and December 2016. Surgery and pathology reports of the patients were reviewed. Histopathologically proven malignant and benign lymph nodes were re-identified with fluorodeoxyglucose positron emission tomography / computed tomography imaging. Anatomical and metabolic parameters of lymph nodes were re-assessed by specialists and compared with histopathology reports. Maximum standardised uptake values were used to assess sensitivity, specificity, positive predictive value, and negative predictive values. SPSS 22 was used for data analysis. RESULTS: The study included 144 mediastinal lymph nodes related to 42 patients who had a mean age of 62.4±9.8 years (range: 41-79 years). In terms of subtypes of the primary squamous cell carcinoma was found in 24(57.2%) patients, adenocarcinoma in 12(27.5%), and other subtypes in 6(15.3%) patients. Of the 144 lymph nodes, 48(33.3%) were metastatic. Sensitivity, specificity, positive predictive value, and negative predictive value were 92.8%, 64.3%, 56.9%, and 94.7%, respectively when maximum standardised uptake value >2.5 was used as the malignancy criterion. When lymph node maximum standardised uptake value / liver standardised uptake value-mean>1.69 was used as the criterion, the sensitivity, specificity, positive predictive value, and negative predictive value were 95.83%, 91.67%, 85.2%, and 97.8%, respectively. When the same values with lymph node >8mm was used as the criterion, the four resultant values were 89.6%, 93.8%, 87.8%, and 94.7%, respectively. When lymph node was replaced with mean attenuation >35 as the criterion, the consequent values were 79.2%, 93.8%, 86.4%, and 90.0%, respectively. CONCLUSIONS: Lymph node maximum standardised uptake value / liver standardised uptake valuemean> 1.69 was associated with higher negative predictive value and more useful positive predictive value compared to maximum standardised uptake value >2.5. When this parameter was used along with short axis or mean attenuation value, there were no significant increase in positive predictive value, but there was a decrease in negative predictive value.

A retrospective evaluation of the pulmonary function tests and quality of life assessment surveys of emphysema patients subject to coil treatment.

INTRODUCTION: Bronchoscopic volume reduction treatments are among the important alternatives for selected emphysema patients with a dyspneic course despite optimal medical treatment. Our aim was to carry out a retrospective scan of the data for COPD patients subject to coil treatment at our center for assessing whether coil procedure has an impact on the respiratory symptom and pulmonary function tests in COPD patients. MATERIALS AND METHODS: The data of 41 patients with severe emphysema and treated with coils between 2017-2020 were evaluated retrospectively. Cardiopulmonary rehabilitation programs were completed for all patients prior to the procedure and they were assessed with pulmonary function test (PFT), diffusing capacity for carbonmonoxide test (DLCO), body plethysmography, 6-minute walk test, ventilation/perfusion scintigraphy, St. George's Respiratory Questionnaire (SGRQ). Data acquired prior to the procedure and 3rd month control data after the procedure were recorded and SGRQ was applied via face-to-face interviews during the controls by doctors working on Pulmonary Diseases as was the case before the procedure. RESULT: SGRQ questionnaires of 32 patients were evaluated. Statistically significant changes were observed after the procedure in symptom, activity, impact score and total score which were calculated prior to the procedure. Pre and post procedure FEV1, FVC, FEV1/FVC, PEF, FEF25/75 parameters were used for the comparison made via SFT. Statistically significant changes were observed in FEV1, FVC, FEF25/75 when the pre and post-procedure SFT parameters of the 32 patients included in the study were compared. CONCLUSIONS: A statistically significant improvement was observed in the PFT parameters and quality of life questionnaires following the coil procedure which is a bronchoscopic volume reduction procedure.

The Role of Pre-ablative Stimulated Thyroglobulin and Thyroglobulin/Thyroid-Stimulating Hormone Ratio for Predicting Metastasis in Thyroid Cancer

Objectives: In this study, we aimed to investigate the predictive value of pre-ablative stimulated thyroglobulin (Tg) and Tg/thyroid-stimulating hormone (TSH) to identify lymph node metastasis (LNM) or distant metastases (DM) prior to radioactive iodine (RAI) treatment. Methods: Patients without metastasis were included in group 1 (n=100), those with LNM were included in group 2 (n=83), and those with DM constituted group 3 (n=23). Tg and TSH values were measured approximately 4 hours prior to RAI ablation therapy. Results: There was a significant difference between group 3 and other groups (group 1 and group 2) in terms of Tg (p<0.001) and Tg/ TSH (p<0.001). For Tg level and Tg/TSH ratio, the areas under ROC were 0.990 [95% confidence interval (CI): 0.979-1] and 0.991 (95% CI: 0.981-1), respectively. The cut-off points for Tg and Tg/TSH were 102 ng/mL and 1.06, respectively. Conclusion: Our results suggest that Tg and Tg/TSH values can be used to predict DM. On the other hand, our study indicates that patients should be carefully evaluated for LNM even when Tg levels are l ow.

An exceptional group of non-small cell lung cancer difficult to diagnose: Evaluation of lipid-poor adrenal lesions.

In some non-small cell lung cancer (NSCLC) patients, lipid-poor adrenal adenomas cannot be adequately differentiated from metastases using imaging methods. Invasive diagnostic procedures also have a low negative predictive value (NPV) in such cases. The current study aims to establish a specific and clinically practical metabolic parameter for lipid-poor adrenal lesions (ALs) in NSCLC patients. This diagnostic approach may prevent unnecessary abdominal enhanced computed tomography (CT), magnetic resonance imaging, or invasive diagnostic procedures. Sixty-four NSCLC patients with 69 lipid-poor ALs and 28 control patients with 30 benign lipid-poor ALs, who underwent FDG-PET/CT, were retrospectively reviewed. Two morphological and four metabolic parameters were analyzed in FDG-PET/CT images of NSCLC and control patients. Baseline and post-chemotherapy images of 64 NSCLC patients were re-evaluated according to the PERCIST 1.0. In cases where ALs could not be differentiated, follow-up FDG-PET/CT images were re-examined. The receiver operating characteristic (ROC) curve method was used for the evaluation of diagnostic parameters. Out of 69 ALs, 39 were determined as metastatic lesions (adrenal metastasis), while 30 lesions were considered non-metastatic (adrenal adenomas). The mean attenuation value, SUVmax AL/SUVmax primary tumor, SUVmax, SUVmax AL/liver, and SUVmax AL/SUVmean liver were significantly different between metastatic and benign ALs from NSCLC patients. The SUVmax AL/SUVmean liver ≥1.81 had the best positive (PPV, 94.3%) and negative (NPV, 82.4%) predictive values, and the highest specificity (93.3%), sensitivity (84.6%) and accuracy (86.9%). Lipid-poor ALs with SUVmax AL/SUVmean liver ≥1.81 can be accepted as malignant in NSCLC. However, if SUVmax AL/SUVmean liver is <1.81, a pathologic examination is required. Utilizing this cut-off value to decide on adrenal core biopsy may prevent its unnecessary use. Moreover, this diagnostic approach can save time and reduce the healthcare costs.

Can we differentiate malignant peripheral nerve sheath tumor from benign neurofibroma without invasive sampling.

One of the most important benign tumors in neurofibromatosis type 1 (NF1) is plexiform neurofibroma, and there is a risk of developing malignant peripheral nerve sheath tumor (MPNST) throughout life approximately 10%. However lesion characterization by anatomical imaging methods are not possible. Because of that most of cases goes to biopsy. Using of fluorodeoxyglucose-positron emission tomography/computed tomography (FDG-PET/CT) for lesion characterization can be helpful in NF1 patients. We aimed to present an example of the efficacy of FDG-PET/CT in distinguishing benign neurofibroma from MPNST. A 6-year-old male patient who had NF1 admitted to emergency service due to high fever. Acute upper respiratory tract infection was diagnosed; antipyretic and abundant fluid intake was suggested. When high fever continued, the patient referred to our hospital on detection of axillary lymphadenopathy. Leukocytosis was detected in patient's blood count. Sedimentation was 54 mm/h, C-reactive protein 166 g/L, and lactate dehydrogenase 276U/L. Blood and throat cultures did not show pathogenic bacteria. In serological tests, VZV-IgG, EBV-VCA-IgG, and CMV-IgG were avidite positive; Hepatitis B Ag, Anti-HIV, Anti-HAV IgG and IgM, Anti-HCV, EBV-VCA IgM, and VZV-IgM were negative. Based on these results, cervical and thoracic contrast-enhanced computed tomography was performed on preliminary diagnosis of MPNST. Solid lesions with rounded margins, large one being 49 mm in size, that extend from superior mediastinum to posterior mediastinum, left axillary region, and left part of neck were detected, and they were surrounding the vascular structures. Since neurofibroma, MPNST, and lymphoma could not be distinguished, patient referred to FDG-PET/CT scanning. In FDG-PET/CT, highest lesion maximum standardized uptake value (SUVmax) was 1.5; SUVmax lesion/SUVmax liver 1.0, and SUVmax/ SUV mean liver 1.5. Biopsy from mediastinal and axillary region did not have LN structure and was positive for S-100 immunostaining, and patient was diagnosed as benign neurofibroma. We believe that there is no need for biopsy in lesions considered benign based on FDG-PET/CT parameters.

Considering the Relationship between Quantitative Parameters and Prognostic Factors in Breast Cancer: Can Mean Standardized Uptake Value be an Alternative to Maximum Standardized Uptake Value?

It was aimed to investigate the correlation between maximum standardized uptake value (SUVmax), mean standardized uptake value (SUVmean), and retention index (RI), which represents the quantitative evaluation of the uptake of 18F-fluoro-2-deoxy-D-glucose (18F-FDG) used in positron emission tomography (PET) and clinicopathologic as well as biologic prognostic factors. Forty-one women with breast cancer who were histopathologically diagnosed were included in this study. Neoadjuvant chemotherapy was applied to all patients before PET/computed tomography (CT). After FDG injection, PET/CT screening was applied within the 1st h (PET-1) and in the 2nd h (PET-2). SUVmax, SUVmean, SUVmax RI, and SUVmean RI of every image were calculated qualitatively and semiquantitatively. The correlation between quantitative and semiquantitative PET parameters and biologic as well as clinicopathologic prognosis factors was evaluated. Statistically, significant positive correlation was found between lymph nodes (LNs), which were evaluated by clinical picture, clinical stage as well as histopathologically and quantitative PET parameters (SUVmax1, SUVmax2,, RImax, SUVmean1, SUVmean2, RImean) (P < 0.05). While statistically significant correlation with RImax was detected only by LN (histopathological), correlations with RImean were detected by clinical picture, clinical stage, metabolic stage, and LN (histopathological). Statistically, significant correlation was found between RImax and estrogen receptor in patients who were histopathologically diagnosed with invasive ductal carcinoma (n = 34) (P < 0.05). We detected correlations between biologic and clinicopathologic prognostic factors and SUVmax as well as SUVmean values in breast carcinoma. SUVmean values may provide important knowledge when the correlation between prognostic factors and PET parameters is investigated even if they are not used routinely.

Transthoracic Biopsy Causes Massive Subcutaneous Emphysema in a Low Risk Patient.

Subcutaneous Emphysema (SE) can be defined as air leakage under skin from the respiratory or gastrointestinal system. It is frequently accompanied by pneumomediastinum. Thoracentesis, image-guided lung biopsies, pulmonary diseases and therapies resulting in necrosis can cause this pathology. The risk of pneumothorax and SE increased with the distance of the lesion to the pleura, and small size of the lesion. Although, our patient had low risk for SE, there were minimal pneumothoraces and massive SE. We consider that tumour necrosis and subcutaneous tissue may be related via transthoracic biopsy and this leads to massive SE.