Yusuf Demir

The diagnostic role of dual-phase 18F-FDG PET/CT in the characterization of solitary pulmonary nodules

ObjectiveOur objective was to evaluate the diagnostic role of dual-phase 18F-fluorodeoxyglucose (18F-FDG) PET/computed tomography (CT) in the characterization of solitary pulmonary nodules (SPNs). Patients and methodsA total of 48 SPNs in 48 patients were included in this retrospective study. The final diagnosis was confirmed histopathologically or by follow-up CT. Two PET/CT scans were performed: the first (early scan) was performed 1 h after injection and the second (delayed scan) was performed 2 h later. Standardized uptake values (SUVs) [early and delayed SUVmax and SUVmean adjusted to body weight, body surface area (BSA), lean body mass (LBM) and blood glucose level (Glc)], retention index and nodule-to-mediastinum (nodule activity/subcarinal region of interest activity) ratios were calculated, along with the receiver operating characteristic curve. Intraobserver and interobserver variabilities among nuclear medicine physicians were analysed for the two phases. ResultsEighteen patients had malignant tumour, whereas 30 had benign lesions. The median (min−max) SUVmax was 1.5 (0.5–4.1) in the benign group and 3.6 (1.3–38) in the malignant group. With the threshold value of early SUVmax as 2.5 and 2.75 using the receiver operating characteristic curve, a sensitivity of 94–75%, specificity of 75–80% and an accuracy of 83–78% were calculated. With the same threshold values for delayed images, 94–100% sensitivity, 77–80% specificity and 83–88% accuracy were obtained. BSA-SUVmax, LBM-SUVmax and Glc-SUVmax did not show any advantage over other quantitative parameters in the SPN characterization. There was no variability in the results obtained between the two nuclear medicine physicians. ConclusionDual-phase PET/CT may increase the diagnostic potential of PET/CT in the characterization of SPNs. In this particular study group, a threshold value could not be determined for the retention index, but higher retention indices may show higher malignant potential in SPNs.

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.

Dyke-davidoff-masson Syndrome With Cerebral Hypometabolism and Unique Crossed Cerebellar Diaschisis in 18f-fdg Pet/ct

A 23-year-old man with Dyke-Davidoff-Masson syndrome (DDMS) was admitted to the hospital with increasing frequency of epileptic seizures. Physical examination revealed mental retardation, left facial asymmetry, and left-sided spastic hemiparesis. Dysdiadochokinesia on the left upper limb was detected, and there was no dysmetria. MRI confirmed the well-known radiological features of DDMS. PET/CT demonstrated cerebral and contralateral cerebellar hypometabolism. We present DDMS with crossed cerebellar diaschisis, which was demonstrated by PET/CT.

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.

An evaluation of thyrotoxic autoimmune thyroiditis patients with triplex Doppler ultrasonography.

OBJECTIVE This study aimed to investigate the usefulness of blood flow parameters obtained from STA and CCA with Triplex Doppler ultrasonography (TDU) on patients with thyrotoxicosis. MATERIALS AND METHODS This cross-sectional study included consecutive 24 patients with thyrotoxicosis and 18 healthy controls. The thyroid gland blood flow parameters were evaluated with TDU. RESULTS The thyroid volumes and FT3, TRAb, 4-h and 24-h radioactive iodine uptake (RAIU) levels of Group 1 were significantly high compared to those of Group 2. The thyroid volumes and FT3, FT4 and TSH levels of both Group 1 and Group 2 showed a statistically significant difference compared to Group 3. STA-PSV values for Group 1, Group 2 and Group 3 were 138 cm/s, 54 cm/s and 37 cm/s, respectively. STA-EDV values for these groups were 60 cm/s, 25 cm/s and 15 cm/s, respectively. PSVR values for these groups were 1.01, 0.45, 0.34 cm/s, respectively. EDVR values for these groups were 1.29, 0.70 and 0.49 cm/s, respectively. In Group 1, STA-PSV, STA-EDV, PSVR and EDVR values were significantly high compared to those of Group 2. RAIU levels showed a significant positive correlation with the STA-PSV, STA-EDV and PSVR. CONCLUSION The thyroid gland blood flow parameters may be used in clinical diagnosis of patients with thyrotoxicosis.

Renkli akım doppler ultrasonografi ile tirotoksik otoimmün tiroiditli hastaların değerlendirilmesi

Objective: In this study, we aimed to examine the availability and the effects of differential diagnosis of thyroid gland morphological changes and blood flow patterns in patients with thyrotoxic phase Graves’ disease (BGD) and Hashimoto’s thyroiditis (HT) by color flow doppler ul trasonography (CDUS). Methods: This cross-sectional study was included 24 consecutive patients with thyrotoxicosis and 18 healthy controls. There were Basedow-Graves’ disease in 17 and Hashimoto thyroiditis in 7 of previously untreated 24 patients. Morphological information of thyroid gland was obtained by B-mode ultrasonography in all cases. Blood flow pattern of the thyroid gland was determined by CDUS. Results: The thyroid volumes and FT3, TRAb, 4-h and 24-h RAIU levels of the patients with Graves’s disease were significantly higher than the patients with HT. Whereas thyroid gland echogenicity was decreased in 14 of BGH cases, it was diminished in 2 patients with HT. Significant difference was found between BGD and HT groups in terms of thyroid gland echogenicity. In all patients with BGD and HT, echopattern was heterogenous. In all patients, blood flow patterns of thyroid gland were obtained by CDUS. Color flow doppler ultrasonography and pattern 3 blood flows were only observed in BGD. Significant difference was found between HT and BGD groups in blood flow pattern. Conclusion: Heterojen echopattern, decreased echogenicity, volume changes and type 3 blood flow pattern of thyroid gland obtained using B-mode Ultrasound and CDUS may be useful in the determination and differentiation of thyrotoxic BGD and HT diseases. J Clin Exp Invest 2013; 4 (1): 73-79 OZET

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

ObjectiveThe 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 methodsA 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 18F-fluorodeoxyglucose (18F-FDG) administration both before and after neoadjuvant CRT. Age, sex, BMI, lean body mass, blood glucose level, and 18F-FDG dose, which can influence liver SUVs and SULs, were also analyzed. ResultsFourteen (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. ConclusionLiver 18F-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.

ObjectiveData 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 methodsWe 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. ResultsInitially, 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. ConclusionThis 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 value of liver-based standardized uptake value and other quantitative 18F-FDG PET-CT parameters in neoadjuvant therapy response in patients with locally advanced rectal cancer: correlation with histopathology.

AimWe aimed to investigate the value of PET-CT in therapy response and the correlation of quantitative PET parameters with histopathologic results in patients with locally advanced rectal cancer (LARC) before and after neoadjuvant chemoradiotherapy. We also analyzed the correlation of PET-CT parameters between Ki-67 and glucose transporter 1 (GLUT1). Patients and methodsA total of 29 patients diagnosed with LARC who had undergone a biopsy between 2009 and 2012 were included in our study. Quantitative PET parameters [standardized uptake value (SUV)max−mean, lean body mass SUVmax−mean, tumor/liver SUV, retention index , and [INCREMENT]SUVmax] were measured before and after therapy using PET-CT. Tumor regression grade (TRG) was evaluated according to Wheeler’s classification. Patients in grade 1 were considered responders, whereas patients at grades 2 and 3 were considered nonresponders. Immunohistochemical staining with Ki-67 and GLUT1 was performed on biopsy and surgical specimens. The correlation between staining ratios and SUV was also investigated. ResultsSUV parameters were significantly decreased after therapy (P<0.001). Twelve (41%) patients were at TRG1, 10 (35%) were at TRG2, and seven (24%) were at TRG3. A cutoff SUVmax of 5.05 to discriminate between responders and nonresponders after treatment revealed a sensitivity of 57%, specificity of 73%, negative predictive value of 65%, positive predictive value of 67%, and accuracy of 66%. Using a cutoff of 3.55 for the SUVmean (standardized measurement of SUV with 1.2-cm-diameter region of interest) revealed a sensitivity, specificity, negative predictive value, positive predictive value, and accuracy of 67, 76, 67, 76, and 72%, respectively. For a cutoff of 1.95 for the tumor SUVmean/liver SUVmean, these diagnostic values after therapy were 73, 78, 82, 67, and 76%, respectively. We found a moderate correlation between liver-based SUVmax (r=−0.35, P=0.019) and SUVmean (r=−0.31, P=0.036) with GLUT1 after therapy. Quantitative PET parameters and retention index were moderately correlated with Ki-67. ConclusionPET-CT is a useful method for assessing the response to neoadjuvant chemoradiotherapy in patients with LARC. The most significant parameter for assessing treatment response using SUV parameters is the tumor/liver ratio.

Accurately localizing the thyroid tissue in mature cystic teratoma of ovary by single-photon emission computerized tomography/computerized tomography

A 30-year-old woman with hyperthyroidism was admitted to hospital. Although increased thyroid function was found, the gland was normal in ultrasonography (USG). Additionally, thyroid iodine uptake and Tc-99m pertechnetate scintigraphy was normal. Abdomen USG detected a cystic pelvic mass in left ovary. A whole-body scan was performed 48 hours after oral ingestion of 29.6 MBq (0.8 mCi) I-131 (iodine-131) revealed a round structure located to the left lower abdomen. Iodine uptake was detected in this cyst which was compatible with functional thyroid tissue demonstrated by SPECT/CT. The patient was underwent surgical operation and histopathology confirmed mature cystic teratoma. Accurate localization and depiction of thyroid tissue in ovary mass was provided with SPECT/CT.