Fasciola Hepatica Mimicking Malignancy on 18F-Fluorodeoxyglucose-Positron Emission Tomography/Computed Tomography.

A 48-year-old female with complaints of gastrointestinal symptoms such as abdominal pain, fatigue, vomiting, nausea, and weight loss was diagnosed with neuroendocrine tumor after removal of a 2 mm lesion from the stomach with endoscopic biopsy. Her magnetic resonance imaging that was performed due to on-going symptoms showed multiple linear hypointense lesions in the liver. Positron emission tomography/computed tomography (PET/CT) scan was performed for differential diagnosis, which showed high fluorodeoxyglucose (FDG) uptake in these lesions. Clinical and laboratory findings revealed the final diagnosis as Fasciola hepatica. The imaging features of this case is presented to aid in differentiating this infectious disease from malignancy and avoid misdiagnosis on FDG-PET/CT.

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.

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 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.

AIM: We 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 METHODS: A 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 SUV(max-mean), tumor/liver SUV, retention index , and [INCREMENT]SUV(max)] 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. RESULTS: SUV 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 SUV(max) 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 SUV(mean) (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 SUV(mean)/liver SUV(mean), these diagnostic values after therapy were 73, 78, 82, 67, and 76%, respectively. We found a moderate correlation between liver-based SUV(max) (r = -0.35, P = 0.019) and SUV(mean )(r = -0.31, P = 0.036) with GLUT1 after therapy. Quantitative PET parameters and retention index were moderately correlated with Ki-67. CONCLUSION: PET-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.

Dual-phase F-18 FDG PET-CT in staging and lymphoscintigraphy for detection of sentinel lymph nodes in oral cavity cancers.

AIM: Our objective was to evaluate the diagnostic role of dual-phase fluor-18 fluorodeoxyglucose (F-18 FDG) positron emission tomography-computed tomography (PET-CT) and planar lymphoscintigraphy in patients with oral cavity cancer (OCC). We also investigated the combined impact of F-18 FDG PET-CT and sentinel lymph node biopsy (SLNB) in decision making for patients with OCC. METHODS: Sixteen patients (4 female, 12 male; age range, 29-81 years) were included in this prospective study. F-18 FDG PET-CT [1 (early) and 2 h (delayed) after injection] and planar lymphoscintigraphy (2h before the surgery) were performed for all the patients before surgery. The sensitivity, specificity, and negative and positive predictive values in F-18 FDG PET-CT for the early and the delayed scans and tumor/liver uptake (T/L) in the lymph nodes were calculated. Receiver operating characteristic curves were obtained for standardized uptake value (SUV)max and T/L. RESULTS: Histopathological evaluations revealed that 5 patients had metastatic lymph nodes (pN+) whereas 11 patients had benign lymph nodes (pN-). Out of 43 lymph nodes visualized as cN(+) in F-18 FDG PET-CT, 14 were pathologically positive for malignancy, whereas 29 were pathologically benign. There was no statistical difference between the N(+) and N(-) patients in terms of age, depth of primary tumor, and the number of mitoses. However, there was a significant difference between the N(+) and N(-) patients (P=.011) in terms of early and delayed F-18 FDG uptake of primary tumors. There was a statistically significant difference in the value of SUVmax between the early and the delayed scans for the malignant lymph nodes (P=.00). CONCLUSION: This study indicates that F-18 FDG PET-CT is a reliable method for the correct evaluation of primary tumor and N staging in OCCs. Delayed phase of F-18 FDG imaging may increase primary lesion detectability due to higher FDG uptake in primary tumors compared to the early phase of imaging. F-18 FDG PET-CT might demonstrate skip metastasis in lymph nodes which can be missed with SLNB. Although SUV values increased in the delayed phase of F-18 PET-CT imaging in detecting lymph node metastases, the specificity and positive predictive value did not increase.

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

OBJECTIVE: Our objective was to evaluate the diagnostic role of dual-phase (18)F-fluorodeoxyglucose ((18)F-FDG) PET/computed tomography (CT) in the characterization of solitary pulmonary nodules (SPNs). PATIENTS AND METHODS: A 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. RESULTS: Eighteen 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. CONCLUSION: Dual-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.

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.

Rest myocardial perfusion scintigraphy showing the invasion of the hydatid cyst in the myocardium.

A cardiac hydatid cyst is a rare complication of the Echinococcus infection, and it is seen in just 0.5% to 2% of all cases. Because it can cause sudden death, removing the cyst is recommended. It is important to determinate the relationship between the cyst and the intra/extracardiac structures before the operation because it is of vital importance during the operation. In our case, we showed that rest myocardial perfusion scintigraphy provided an additional contribution to anatomic imaging in that it showed the invasion of the cyst in the myocardium, which was effectively directing the course of the operation.

Is Imaging Time Between two Tc 99m DMSA Scans Sufficient for Reporting as Renal Parenchymal Scarring? Healed Parenchymal Renal Defect After 6 Years.

UNLABELLED: We aimed to report a healed renal parenchymal defect after 6 years in a 9-year-old girl who was being followed for recurrent urinary tract infection (UTI). The first UTI was at the age of two. She was being followed with ultrasonography, urine analysis and urine culture since the first UTI. Technetium-99m dimercaptosuccinic acid (DMSA) scintigraphy was repeated four times up to the present day. She had a renal parenchymal defect reported as parenchymal scarring, which healed 6 years after the first DMSA scintigraphy. CONFLICT OF INTEREST: None declared.

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.

Preparation of (131)I-Pyrimethamine and evaluation for scintigraphy of experimentally Toxoplasma gondii-infected rats.

We aimed to assess the ability of (131)I-Pyrimethamine scintigraphy to detect the lesions of Toxoplasma gondii infection. An experimental model of toxoplasmosis was developed. The presence of toxoplasmosis was confirmed 60 days after implantation. Pyrimethamine was radioiodinated with I-131. The radioligand was validated by the requisite quality control tests to check its radiolabeling efficiency, in vitro stability and radiochemical purity etc. (131)I-Pyrimethamine (specific activity: 7.08 MBq/µmol) was injected intravenously into the tail vein of the control and infected rats. Static whole body images of the rats were acquired under the gamma camera at 5 min, 45 min, 2 h, 6 h, and 24 h following the intravenous administration of the radioactivity (3.7 MBq/rat). Then the scintigraphic data were analyzed both visually and semiquantitatively. Regions of interest (ROIs) were drawn over the organs (thyroid, stomach, liver, bladder, and soft tissues) to calculate the ratios of the radiotracer in infected vs. control rats. The mean ratio of radiotracer in infected/control rats in the liver and diaphragm was over 1 at 45 min which persisted till 24 h. In conclusion, (131)I-Pyrimethamine may be useful agent for diagnosis toxoplasmosis especially involving liver and diaphragm, needs further preclinical validation before being extended for use in clinical applications.

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.