Prognostic role of metabolic 18F-FDG PET/CT parameters and hematological prognostic indicators in patients with colorectal cancer.

Background: The aim of this study is to evaluate the role of preoperative 18F-fluorodeoxyglucose (FDG) positron emission tomography-computed tomography (PET/CT) parameters, including maximum standardized uptake value (SUVmax), metabolic tumor volume (MTV), and total lesion glycolysis (TLG), hematologic prognostic indicators in patients with colorectal cancer (CRC) in terms of predicting prognosis. Methods: One hundred and one patients who had undergone 18F-FDG PET/CT for initial staging were evaluated retrospectively. Patient data including pathologic stage at presentation, histology, tumor location, and overall survival (OS) were analyzed. Neutrophil to lymphocyte ratio (NLR), platelet to lymphocyte ratio (PLR), serum carcinoembryonic antigen (CEA) (ng/mL), CA-125 (cancer antigen 125) (U/mL), and CA19-9 (U/mL) levels, which were obtained within 2 weeks of the PET/CT examination, were used for hematological data. Results: The TNM Classification of Malignant Tumors stage and PET/CT parameters, including SUVmax, MTV, and TLG, were found to be correlated with survival rate in univariate analysis (P < 0.05). All hematological markers excluding PLR were also significantly associated with survival time. Receiver operating characteristics (ROC) analysis revealed that the optimal SUVmax cutoff value for predicting survival time in patients with CRC was >17.9 (Area under curve (AUC) = 0.625; P < 0.05). The calculated sensitivity and specificity values for this cutoff were 60% and 65.7%, respectively. To predict the survival time in these patients, the optimal MTV cutoff value was >34.29 (AUC = 0.775; P < 0.001; sensitivity = 85%; specificity = 62.3%). The optimal TLG cutoff value for predicting survival time was >270.4 (AUC = 0.790; P < 0.001; sensitivity = 77.5%; specificity = 68.9%). Conclusions: FDG PET/CT metabolical parameters are useful for predicting the prognosis in patients with CRC. High preoperative NLR and high tumor markers were also shown to be negative independent prognostic factors in these patients.

Prognostic impact of the 18F-fluorodeoxyglucose positron-emission tomography/computed tomography metabolic parameters and correlation with hematological inflammatory markers in lung cancer.

INTRODUCTION: Hematological inflammatory markers and metabolic parameters in positron-emission tomography/computed tomography (PET/CT) are important indicators predicting the prognosis of the disease in lung cancer as in many cancers. This study aimed to evaluate the correlation between pretreatment hematological inflammatory markers and PET/CT metabolic parameters in nonsmall cell lung cancer (NSCLC) patients and to predict the prognostic value of these parameters. MATERIALS AND METHODS: A total of 132 patients with diagnosed NSCLC who underwent PET/CT at staging were retrospectively evaluated. Hematological parameters were obtained from the hemogram taken no more than 2 weeks prior to PET/CT. Neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and mean platelet volume (MPV) were recorded. Maximum standard uptake value, SUVmean, metabolic tumor volume (MTV), and total lesion glycolysis (TLG) were calculated. Clinical stage, tumor pathology, and overall survival were analyzed with these parameters. RESULTS: NLR and PLR were significantly positively correlated with MTV and TLG (all P < 0.001), MPV was negatively correlated with TLG (P = 0.021). While TLG, MTV, NLR, and PLR were increased in advanced stage disease, MPV was decreased. Univariate Cox-regression analysis demonstrated that greater age (P = 0.015), advanced stage (P < 0.001), low MPV (P = 0.017), high NLR (P < 0.001), PLR (P < 0.001), MTV (P = 0.004), TLG (P = 0.001) values, multivariate Cox-regression analysis revealed that NLR (P < 0.001) and advanced stage (P < 0.001) were significant predictors of poor prognosis in patients with NSCLC. CONCLUSIONS: There were significant associations between hematological inflammatory markers and PET/CT metabolic parameters in the patients with NSCLC at the time of diagnosis. These indicators can contribute to predicting prognosis in patients with NSCLC.

The Role of 18F-FDG PET/CT in Detecting Ovarian Cancer Recurrence in Patients with Elevated CA-125 Levels

Objectives: To investigate the role of 18F-FDG positron emission tomography/computed tomography (PET/CT) in detection of recurrence in ovarian cancer patients with increased CA-125 levels. Methods: Fifty-two patients (30-80 years old, mean: 58.5±10.6 years) who had been histopathologically diagnosed with ovarian cancer, underwent 18F-FDG PET/CT imaging for re-staging due to elevation of CA-125 levels were included in this retrospective study. 18F-FDG PET/CT findings were compared with histopathological, radiological and clinical follow-up results. Results: CA-125 levels ranged between 35.2-2740 U/mL (N: 0-35 U/mL). Recurrent disease was detected in 45 of 52 patients on PET/CT imaging. There were three false negative and one false positive result. In addition to abdominal and pelvic lesions, 14 distant metastatic lesions (brain, lung, liver and bone metastasis) were identified correctly on PET/CT imaging. Sensitivity, specificity, positive and negative predictive value and accuracy of 18F-FDG PET/CT were calculated as 94%, 75%, 98%, 50% and 96%, respectively. Conclusion: 18F-FDG PET/CT is a useful imaging method that can be used in detection of ovarian cancer recurrence in patients with elevated CA-125 levels. Since this modality offers whole body imaging, distant metastases could be detected in addition to abdominal and pelvic lesions thus contributing to patient management.

Diagnostic Value of 18F-FDG PET/CT in Patients with Carcinoma of Unknown Primary

Objective: The aim of this study is to investigate the clinical role of 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) in patients with carcinoma of unknown primary (CUP). Methods: One hundred twenty one patients with a diagnosis of CUP who underwent whole body 18F-FDG PET/CT imaging were included in this retrospective study. The final diagnoses were confirmed either histopathologically or by clinical follow-up. Results: The 18F-FDG-PET/CT successfully detected the primary tumor in 59 out of 121 (49%) patients. The most common primary tumor as detected by 18F-FDG PET/CT was lung cancer (n=31). In a patient, two primary tumors (colon and prostate) were detected on PET/CT imaging. Bone marrow biopsy revealed prostate cancer in this patient and the colon cancer was accepted as a synchronous second primary tumor. 18F-FDG PET/CT findings were false-positive in 11 patients. 18F-FDG PET/CT could not detect any primary lesion in 51 patients, whose conventional work-up detected a primary tumor in 11 and thus considered as false-negative. The sensitivity, specificity rate and accuracy of 18F-FDG PET/CT in detection of primary tumor were identified as 84%, 78% and 82%, respectively. Conclusion: Whole body 18F-FDG PET/CT is an effective method for detecting the primary tumor in patients with CUP. In addition to detecting the primary tumor, it can also help determine disease extent and contribute to patient management.

The role of F-18 FDG PET/CT in differentiating benign from malignant pulmonary masses and accompanying lymph nodes.

INTRODUCTION: The aim of this study was to evaluate the usefulness of SUVmax and lesion size to differentiate benign and malignant lesions of the lung and accompanying mediastinal lymph node on F-18 FDG PET/CT imaging. MATERIALS AND METHODS: A retrospective analysis was carried out on 100 patients with suspected lung cancer who were recommended for PET/CT scans for diagnosis and staging. The results of the SUVmax, lesion size and patient's age were compared with histopathology which was considered to be the 'gold standard' and sensitivity and specificity were calculated respectively. Lymph nodes greater than 1 cm in patients with benign pathology were evaluated and the SUVmax values were recorded. RESULT: Of the 100 patients, 38 were found to have benign, whereas 62 had malignant on histopathology. The SUVmax was significantly more elevated in malign masses (13.1 ± 6.4) than in benign masses (8 ± 5.7) (p< 0.05). The dimensions of malignant masses (4.5 ± 2.5 cm) were larger than benign ones (3 ± 1.6 cm) (p< 0.05). SUVmax of 7.6 was determined as the cut-off value, while the sensitivity and specificity were 82% and 55% respectively. The sensitivity was 87% and specificity was 45% for the lesion sizes in differentiation of the malignant and benign lesions. CONCLUSIONS: There are significant overlaps between benign and malignant lesions and specialists must be aware of the various pathological conditions that can give false positives and negatives.

The correlation of prognostic biomarkers (Ki-67, Bcl-2, HIF-1α, cyclin D1) with metabolic tumor volume measured by F-FDG PET/CT inlaryngeal cancer.

OBJECTIVES: To investigate the correlation between tumor stage, Ki-67, Bcl-2, hypoxia inducible factor-1α (HIF-1α), cyclin D1 and metabolic tumor volume (MTV), total lesion glycolysis (TLG), maximum standardized uptake value (SUVmax) measured by 18F fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) in patients diagnosed with laryngeal cancer. PATIENTS AND METHODS: In this study, included 25 consecutive laryngeal cancer patients (2 women, 23 men) diagnosed and treated in the Otorhinolaryngology Department of our tertiary care center. All cases underwent 18F FDG PET/CT and SUVmax, mean standardized uptake value, MTV, and TLG values were calculated. Tumor staging was made and immunohistochemical staining was carried out for Ki-67, Bcl-2, HIF-1α and cyclin D1. RESULTS: Eight (32%) patients had glottic laryngeal cancer, 6 (24%) had supraglottic laryngeal cancer and 11 (44%) had transglottic laryngeal cancer. Cyclin D1 was significantly correlated with MTV (r = 0.45, P = 0.03), TLG (r = 0.492, P = 0.01) and T-stage (r = 0.483, P = 0.02). Bcl-2 was significantly correlated with SUVmax (r = -0.41, P = 0.05) and tumor stage (r = -0.442, P = 0.03). MTV and TLG are significantly correlated with nodal stage (r = 0.422, P = 0.04, r = 0.419, P = 0.04), while TLG (r = 0.403, P = 0.05) and SUVmax (r = 0.440, P = 0.03) were correlated with tumor stage. CONCLUSION: Our results indicated that biomarkers such as cyclin D1 and Bcl-2 were correlated with measures such as MTV, TLG, and SUV in 18F-FDG PET/CT. Integrative and combined evaluation of biomarkers and imaging data derived from 18F-FDG PET/CT are important for staging and appropriate management of patients with laryngeal cancer.

Laryngeal Tuberculosis Mimicking Laryngeal Carcinoma on 18F-FDG PET/CT Imaging.

Laryngeal tuberculosis is a rare presentation of tuberculosis. It can mimic laryngeal carcinoma with its clinical and imaging findings. A 51-year old woman underwent 18F-fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT) imaging for clinically suspected carcinoma of the larynx. PET/CT revealed lung lesions consistent with tuberculosis in additional to hypermetabolic focus on larynx. The patient was histopathologically diagnosed with lung and laryngeal tuberculosis.

Correlation Between Baseline 18F-FDG PET/CT Findings and CD38- and CD138-Expressing Myeloma Cells in Bone Marrow and Clinical Parameters in Patients with Multiple Myeloma

Objective: The aim of this study was to evaluate the relation between the rate of fluorine-18 (18F) fludeoxyglucose (FDG) uptake and CD38 and CD138 expression in myeloma cells in bone marrow and other clinical parameters in patients with multiple myeloma (MM). Materials and Methods: Patients with the diagnosis of MM who underwent 18F-FDG positron emission tomography/computed tomography (PET/CT) for initial staging were evaluated retrospectively. We analyzed a total of 42 patients (43-83 years old, mean: 64.4±9.9). Hematological and biochemical tests including hemoglobin, hematocrit, C-reactive protein, ß2-microglobulin, creatinine, albumin, calcium, lactate dehydrogenase, and erythrocyte sedimentation rate were recorded. In bone marrow samples, plasma cell ratio and CD38 and CD138 immunohistochemical staining were evaluated. On PET/CT images, mean standardized uptake values (SUVmean) of the right anterior and posterior iliac crest and right proximal femora were calculated. The correlations between the average SUVmean of bone marrow and CD38- and CD138-expressing myeloma cells and other parameters were analyzed by Spearman's correlation test. Values of p<0.05 were considered statistically significant. Results: Types of MM were IgGK (45%), IgGL (21%), IgAK (7%), IgAL (10%), and others (17%). Thirty-two (76%) patients were at stage III according to the Salmon-Durie staging system. There was a statistically significant positive correlation between bone marrow FDG uptake and percentage of plasma cells in bone marrow and CD38 and CD138 expression in plasma cells (r=0.403, r=0.339, and r=0.409) and ß2-microglobulin and C-reactive protein levels (r=0.676, r=0.541). There was a negative correlation between bone marrow FDG uptake and hemoglobin and hematocrit values (r=-0.377 and r=-0.368). Other hematological parameters were not correlated with FDG uptake in bone marrow. Conclusion: Increased FDG uptake is correlated with the percentage of CD38 and CD138 expression in plasma cells in bone marrow. In addition to initial staging, 18F-FDG PET/CT is useful in treatment planning and prognostic evaluation in MM patients.

18F-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography Imaging in a Patient with HIV (-) Kaposi Sarcoma.

Kaposi sarcoma (KS) is a vascular neoplasm that often manifests with multiple vascular nodules on the skin and other organs. Various imaging modalities can be used to display disease extent. Herein we present a 65-year-old female patient with human immunodeficiency virus negative KS along with her whole-body positron emission tomography/computed tomography imaging findings.

Hypertrophic pulmonary osteoarthropathy on bone scintigraphy and 18F-fluorodeoxyglucose positron emission tomography/computed tomography in a patient with lung adenocarcinoma.

Hypertrophic pulmonary osteoarthropathy (HPOA) is not an uncommon paraneoplastic syndrome that is frequently associated with lung cancer. A 54-year-old male patient with lung adenocarcinoma underwent bone scintigraphy and fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) scanning for initial staging. Bone scintigraphy revealed increased periosteal activity in lower extremities. FDG PET/CT revealed hypermetabolic right lung mass, mediastinal lymph nodes, and mildly increased periosteal FDG uptake in both femurs and tibias. The findings in lower extremities on bone scan and FDG PET/CT were interpreted as HPOA.

Sacroiliac indicis increase the specificity of bone scintigraphy in the diagnosis of sacroiliitis.

OBJECTIVE: Bone scintigraphy is a highly sensitive method in the evaluation of sacroiliitis. Aim of this study is firstly to evaluate interobserver variation of partial and whole sacroiliac indicis, secondly investigation of clinical importance of these indicis in the diagnosis of sacroiliitis. METHODS: Fourty-six subjects (24 female: 35.4±11.9; 22 male: 43.1±12.4) without sacroiliitis 45 subjects with low back pain (33 female: 43.3±11.5, 11 male: 35.5±17.2) were included in the study. For right (R) and left (L) whole indices (WSI) irregular region of interest (ROI), for partial indices superior (S) and inferior (I) rectangular ROI were used. For background activity, rectangular ROI was drawn from the sacral region. Indices were calculated from ratio of average counts of sacroiliac and background regions. Two independent observers calculated sacroiliac indices. Interobserver agreement was evaluated by Pearson analysis. RESULTS: There was no significant interobserver difference (p>0.05). Significant correlation existed between all calculated indices. Among 45 patients with suspicion of sacroiliitis 15 had final diagnosis of sacroiliitis and all of the Tc-99m methilenediphosphonate planar and SPECT bone scintigraphy results of these patients were concordant with sacroiliitis. There were 8 false positive results in other 30 patients. Seven of these eight patients had normal index values. If the scintigraphy would be evaluated in conjuction with indicis the specificity would increase from 73% to 97% but sensitivity decreases from 100% to 80%. There was significant correlation between the observers calculated indicis (p<0.001). CONCLUSION: Superior and inferior sacroiliac index values can be used with confidence. If we use sacroiliac index values to confirm positive results; index values can increase the specificity of bone scintigraphy.

The effect of amifostine on pathophysiological changes in vasogenic brain edema induced by an experimental cold injury model.

AIM: To investigate the effects of amifostine, a cytoprotective agent, on pathophysiological changes in vasogenic brain edema induced by an experimental cold injury model and to compare these changes with dexamethasone. MATERIAL AND METHODS: A total of 138 rats divided into 6 groups. Brain water content (BWC), malondialdehyde (MDA) concentration and myeloperoxidase (MPO) activity in brain tissue were calculated to evaluate the pathophysiological changes following experimental cold injury. In addition, effects of cold injury on cell structure were assessed with direct light and transmission electron microscopy (TEM). RESULTS: Extent of edema, MDA and MPO levels were significantly higher in cold injury groups than in controls. Although a decrease was noted in these parameters in both the amifostine and dexamethasone groups, the differences were significant only for MDA concentration in dexamethasone group, and for MPO activity in both groups. In addition, there was a significant difference between the group in which amifostine was administered prior to cold injury and dexamethasone group for MPO activity. Histopathologically, positive effects were observed in treatment groups. CONCLUSION: Despite several positive effects of amifostine, its superiority to dexamethasone could not be clearly demonstrated. Further experimental and clinical studies are warranted to better delineate the neuroprotective effects of amifostine.

Effectiveness of Radioiodine Treatment for Toxic Nodular Goiter.

OBJECTIVE: The aim of this retrospective study is to evaluate the treatment outcomes in patients with toxic nodular goiter (TNG) that received radioiodine treatment (RAIT) and to determine the influence of age, gender, nodule size, I-131 dose, underlying etiology and antithyroid drugs on the outcomes of RAIT. METHODS: Two hundred thirty three patients (mean 64±10 years old) with TNG that received RAIT were included in the study. Treatment success was analyzed according to demographic (age and gender) and clinical data (thyroid function tests before and after RAIT, thyroid sonography and scintigraphy, I-131 dose, antithyroid drugs). A fixed dose of 555 MBq was administered to patients with nodules smaller than 2 cm in diameter and of 740 MBq to patients with nodules larger than 2 cm. Hyperthyroidism treatment success was defined as achieving hypothyroidism or euthyroidism six months after RAIT. RESULTS: In our study, the cure rate was 93.9% six months after RAIT. Hypothyroidism was observed in 74 (31.7%) patients, and euthyroidism was achieved in 145 (62.2%) patients while 14 (6%) patients remained in hyperthyroid state. Age and gender did not affect treatment outcomes. No correlation was found between underlying etiology or antithyroid drugs and therapeutic effectiveness. The effectiveness of RAIT was better in patients with nodules smaller than 2 cm. CONCLUSION: We observed that high cure rates were obtained in patients with TNG with 555 MBq and 740 MBq doses of I-131. While nodule diameter and RAI dose are important factors for treatment efficacy; age, gender, underlying etiology and antithyroid drugs do not affect the outcome of RAIT.

Graves Disease Induced by Radioiodine Therapy for Toxic Nodular Goiter: A Case Report.

Graves' disease (GD) may be observed as an infrequent adverse effect after radioiodine therapy (RAIT) for toxic thyroid adenoma (TA) and toxic multi nodular goiter (MNG). We present a case of a 55-year-old male with a toxic nodule who was treated with RAI. After therapy, the patient's serum free triiodothyronine (fT3) and free thyroxine (fT4) levels gradually increased. Antithyroid peroxidase (TPOAb), antithyroglobulin (TgAb) and TSH-receptor antibodies (TRAb) were also positive. Thyroid scintigraphy revealed diffuse intense uptake after four months of RAIT. Radiation-induced GD should be considered in patients with aggravated hyperthyroidism 3-4 months after therapy.

Scintigraphic evaluation of thyroid pyramidal lobe.

OBJECTIVE: The aim of this study is to investigate the presence of pyramidal lobe in thyroid scintigraphy and to compare the presence of pyramidal lobe in different thyroid pathologies between genders. METHODS: Images of 866 patients (663 female, 203 male) with ages ranging from 8 to 85 were evaluated retrospectively. Presence of pyramidal lobe and its location were established in images. Patients were divided into groups in terms of gender, presence of nodular/diffuse goiter, thyroid function test results and rate of the presence of pyramidal lobe and whether a significant difference existed between the groups were calculated. RESULTS: Of the 866 patients, 156 (18%) had pyramidal lobe observed in scintigraphy. Hundred and 26 (81%) of patients observed to have pyramidal lobe were female and 30 (19%) were male. Pyramidal lob stemmed from the left lobe in 76 (48%) patients, right lobe in 61 (40%) patients, and isthmus in 19 (12%) patients. Pyramidal lobe visualization rate was 18% for euthyroidism and hyperthyroidism, it was found as 15% for hypothyroidism. The rate of pyramidal lobe visualization was 13% in nodular goiter patients, 43% in diffuse goiter patients, and 20% in patients whose scintigraphy showed normal thyroid glands. In the statistical evaluation, rate of pyramidal lobe visualization in diffuse goiter patients was found to be significantly higher compared to other patients (p<0.001). CONCLUSION: Preoperative imaging of pyramidal lobe especially in patients requiring total thyroidectomy would decrease relapses that may occur later and thus facilitate the treatment and monitoring of patients. CONFLICT OF INTEREST: None declared.

Tc-99m Labeled HMPAO white Blood Cell Scintigraphy in Pediatric Patients.

OBJECTIVE: (99m)Tc labeled hexamethylpropylene amine oxime (HMPAO) white blood cell (WBC) scintigraphy is a frequently used option for acute infection, particularly in pediatric patients. This scintigraphy is applied to detect sites of infection/inflammation in patients with fever of unknown origin, to find and follow up osteomyelitis, and to detect suspicion of acute appendicitis. The aim of this retrospective study was to evaluate the value of (99m)Tc-HMPAO labeled WBC scintigraphy in pediatric patients. MATERIAL AND METHODS: The study was conducted between January 2006 and December 2008 and included 13 patients (5 boys, 8 girls; mean age 6.9±6.2 years). Those patients who had suspicion of bone infection (n=7), fever of unknown origin (n=3), and suspicion of acute appendicitis (n=3) were evaluated retrospectively. (99m)Tc-HMPAO labeled WBC scintigraphy imaging was performed to all patients. Diagnosis was done according to operation and pathological results or clinical follow-up. RESULTS: (99m)Tc-HMPAO labeled WBC scintigraphy has been found to be true positive in 6 cases, true negative in 6 cases, and false negative in one patient who had fewer unknown origin. The false negative case has been found to have encephalitis with MRI. CONCLUSION: Leukocyte scintigraphy has been described as a useful diagnostic tool in the diagnosis of suspicion of bone infection, fever of unknown origin and suspicion of acute appendicitis. (99m)Tc-HMPAO labeled WBC scintigraphy is a rapid and very accurate method for detecting those pathologies. Our results showed that WBC scintigraphy might be reliably used for diagnosis of suspected bone infection and acute appendicitis, fever of unknown origin, and acute appendicitis, in pediatric patient population. CONFLICT OF INTEREST: None declared.

Bone scintigraphy in osseous sarcoidosis.

Sarcoidosis is a systemic, granulomatous disorder that affects multiple organ systems, but most often the lungs and the skin. The incidence of radiographically evident osseous involvement is between 1% and 13%, with an average of 5% on conventional imaging. Sarcoidosis generally involves the peripheral skeleton with the phalanges, metacarpals, and metatarsals being most frequently affected. The majority of osseous lesions occur in the phalanges of the hands. Involvement of the axial skeleton is rather uncommon. Sarcoid bone lesions are usually asymptomatic. Nuclear medicine studies, in particular bone scintigraphy, gallium-67 (Ga-67) and F-18 fluoro-2-deoxyglucose positron emission tomography (F-18 FDG PET) have been used in staging of sarcoidosis, including assessment of extrapulmonary involvement. Here, we present a case of osseous sarcoidosis in a man whom the disease presented with multiple lesions in the axial skeleton and the long bones.