Imaging of Hypoxia in Liver Tumors With 18F-FMISO PET Before Selective Internal Radiotherapy With 90Y Microspheres.

ABSTRACT: Hypoxia is a known cause of resistance to radiotherapy and chemotherapy. Although there are multiple studies in external radiation therapies based on hypoxia PET, the effect of hypoxia in radioembolization is largely unknown. Here we present 2 cases of hepatocellular carcinoma patients from a prospective study with different lesion characteristics on pretreatment 18F-FMISO PET and varying responses on 18F-FDG PET.

Comparison of 68Ga-PSMA PET/CT and 18F-PSMA PET/CT of a Patient with Prostate Cancer Recurrence on Urinary Bladder Wall.

Prostate cancer is one of the most prevalent cancers in the world. After radical prostatectomy, prostate-specific antigen (PSA) levels are usually used as a marker of recurrence for prostate cancer. In the case of increased PSA levels, 68Ga-prostate-specific membrane antigen (PSMA) or 18F-PSMA, a new alternative, can be performed for the detection of recurrent disease. We report a case of a 49-year-old male patient with increasing PSA levels who was previously operated 8 years ago. Although no obvious pathological uptake was detected in 68Ga-PSMA positron emission tomography/computed tomography (PET/CT), 18F-PSMA PET/CT revealed a lesion with pathological uptake on the urinary bladder wall.

The Role of 18F-FDOPA PET/CT in Recurrent Medullary Thyroid Cancer Patients with Elevated Serum Calcitonin Levels.

Objectives: To evaluate the diagnostic performance of 18F-dihydroxyphenylalanine (FDOPA) positron emission tomography/computed tomography (PET/CT) in the detection of medullary thyroid carcinoma (MTC) recurrence in patients with elevated calcitonin levels. Methods: The patients who had undergone 18F-FDOPA PET/CT imaging for elevated calcitonin levels after primary surgery of MTC were included in the study. addition, if available 18F-fluorodeoxyglucose (FDG) PET/CT and Gallium-68 (68Ga)- DOTATATE PET/CT images of the patients were evaluated retrospectively. The sensitivity and diagnostic performance of 18F-DOPA PET/CT were investigated. Results: A total of 14 patients (9 F and 5 M; median age: 45) were included in the analysis. Three patients had MEN IIA syndrome and 1 patient had MEN IIB syndrome, 10 patients had a diagnosis of sporadic MTC. Median calcitonin levels of the patients were calculated as 757.5 (min-max: 28.5-7911) pg/mL. Nine patients and 5 patients had undergone ultrasound and contrast-enhanced computed tomography (ceCT) of the neck, respectively, before 18F-FDOPA PET/CT imaging. 18F-FDOPA PET/CT revealed pathological uptake in the thyroid bed, lymph nodes, and distant organs in three, five and two patients, respectively. Median maximum standardized uptake value for the recurrent or metastatic lesions were calculated as 6.4 (min-max: 1.9-18.4). The sensitivity of 18F-FDOPA PET/CT in the detection of recurrent disease was calculated as 64%. Eight patients had 68Ga-DOTATATE PET/CT and 7 of them had 18F-FDG PET/CT within 3 months period before 18F-FDOPA PET/CT. 18F-FDOPA PET/CT revealed recurrent disease in 4 of 5 and 2 of the 5 patients who had negative 18F-FDG PET/CT and negative 68Ga- DOTATATE PET/CT, respectively. Conclusion: 18F-FDOPA PET/CT can detect recurrence in about two- thirds of patients with elevated calcitonin levels after primary surgery for MTC. Due to variable differentiation degree, different receptor status, and clinical behavior of MTC, all three radiopharmaceuticals can be beneficial and are complementary to each other in patient management.

Clinical value of fluorine-18-fluorodeoxyglucose PET/MRI for liver metastasis in colorectal cancer: a prospective study.

PURPOSE: To evaluate the diagnostic performance of liver 18F-FDG PET/MRI in addition to whole-body PET/CT and to compare it with MRI in the detection and clinical management of liver metastasis in patients with colorectal cancer (CRC). MATERIAL AND METHODS: Seventy-eight patients with CRC who underwent whole-body 18F-FDG PET/CT followed by liver PET/MRI were prospectively included. Histopathological confirmation and/or at least 3 months of clinical follow-up after PET/MRI were accepted as gold standard. Lesion and patient-based analyses were performed to evaluate the diagnostics performances of PET/CT, PET/MRI and MRI. In addition, changes of clinical management were evaluated. RESULTS: On lesion-based analysis, for PET/CT, PET/MRI and MRI; sensitivity (Se): 55.6%, 97.2% and 100%; specificity (Sp): 98.5%, 100% and 80.5%; and accuracy (Acc): 70.7%, 98.2% and 93.1% were calculated, respectively. Se and Acc of PET/MRI and MRI were significantly superior than PET/CT (P < 0.001). Se and Acc of PET/MRI and MRI were comparable; however, Sp of PET/MRI was significantly better than MRI (P < 0.001). On patient-based analysis, Se: 75.6%, 100% and 100%; Sp: 97.3%, 100% and 86.5%; and Acc: 85.9%, 100% and 93.5% were calculated, respectively. Se and Acc of PET/MRI were significantly superior than PET/CT (P < 0.001). Also, Se of MRI was significantly superior than PET/CT (P < 0.001). Se of PET/MRI and MRI were comparable, but Sp and Acc of PET/MRI were significantly better than MRI. The additional information obtained from liver PET/MRI changed treatment strategy in 14/78 (18%) patients compared to PET/CT or alone liver MRI. CONCLUSION: Diagnostic performances of PET/MRI and MRI for detection of CRC liver metastasis is superior to PET/CT. PET/MRI especially helps in the accurate detection of liver metastases that are suspicious on MRI and has the potential to change the clinical management of especially oligometastatic patients by identifying uncertain liver lesions.

Which is responsible for aphasia by subcortical lesions? Subcortical lesions or the cortical hypoperfusion?

Cerebral lesions causing aphasia involve morphological and functional changes. In this study, it was aimed to explain the connection between aphasia and subcortical lesions with SPECT. The study included 30 patients diagnosed in the first three days of stroke with a single hemorrhagic or ischemic lesion in the dominant hemisphere subcortical area. Gulhane Aphasia Test and SPECT were performed. Aphasia was detected in 19 cases (63.3%). The relationship between aphasia and perfusion dysfunction in cortical and subcortical regions of the brain was evaluated, aphasia was found to be present in 15 (71.4%) of the 21 patients with cortical hypoperfusion in the dominant hemisphere and 4 (44.4%) of the 9 patients without cortical hypoperfusion; the difference was not statistically significant (p = 0.16). In the ischemia group, aphasia was present in 11 (78.5%) of the 14 cases with cortical hypoperfusion in the dominant hemisphere. Aphasia wasn't detected in any of the 5 cases that did not have cortical hypoperfusion, the difference was statistically significant (p = 0.005). When cerebral regions were evaluated separately, significant difference was reported in the aphasia seen with frontal, anterior parietal, and occipital hypoperfusion compared to cases with normal perfusion in these areas, with p = 0.003, p = 0.021, and p = 0.004, respectively. This study showed that aphasia to be more common in cases with cortical hypoperfusion in the dominant hemisphere than in cases without hypoperfusion. Our results provide evidence that direct effect of the lesion in the basal ganglia on the development of aphasia is doubtful.

The Role of 18F-FLT PET/CT in Assessing Early Response to Transarterial Radioembolization and Chemoembolization in Patients with Primary and Metastatic Liver Tumors.

Objectives: Metastases and primary malignancies are common in the liver. Local ablative applications such as transarterial chemoembolization (TACE), and transarterial radioembolization (TARE) provide minimally invasive and safe treatment in unresectable liver tumors. Early detection of response to treatment prevents unnecessary toxicity and cost in non-responder patients and provides an earlier use of other options that may be effective. This study aimed to identify the role of 18F-fluorothymidine (FLT) positron emission tomography/computed tomography (PET/CT) in the assessment of early response to TACE and TARE treatments in patients with unresectable primary and metastatic liver tumors. Methods: This single-center study included 63 patients who underwent 18F-FLT PET/CT for response evaluation after TACE and TARE. After excluding 20 patients whose data were missing 43 TARE-receiving patients were analyzed. The compatibility of change in semi-quantitative values obtained from the 18F-FLT PET/CT images with the treatment responses detected in 18F-fluorodeoxyglucose PET/CT, CT, and MR images and survival was evaluated. Results: There was no correlation between early metabolic, morphological response, and 18F-FLT uptake pattern, and change in standardized uptake values (SUV) which were ΔSUVmax, ΔSUVmean, ΔSUVpeak., ΔSUVmean, Δ SUVpeak values. There was no significant correlation between 18F-FLT uptake pattern, ΔSUVmax, ΔSUVmean, ΔSUVpeak, and overall survival, progression-free survival (PFS) for the target lobe PFS for the whole-body. The survival distributions for the patients with >30% change in Δ SUVmax and ΔSUVpeak values were statistically significantly longer than the patients with <30% change (p<0.009 and p<0.024, respectively). Conclusion: There was significant longer PFS for target liver lobe in patients with more than 30% decrease in 18F-FLT SUVmax and SUVpeak of the liver lesion in primary and metastatic unresectable liver tumors undergoing TARE.

Elevated Angiogenic Factor Levels After Transarterial Radioembolization for Colorectal Cancer Liver Metastases May Predict a Poor Prognosis.

Objectives: To analyze the change in circulating angiogenic factor levels after transarterial radioembolization (TARE) for colorectal cancer liver metastases (CRCLMs) and its prognostic significance. Methods: Blood samples immediately before TARE and on 1 day, 1 week and 6 weeks after were collected for angiogenic factor analysis in 23 patients. Results: Patients with elevated serum basic fibroblast growth factor and platelet-derived growth factor levels in the 1st week and vascular endothelial growth factor (VEGF) levels in the 6th week after TARE had significantly shorter median overall survival (OS) times. Conclusion: Some early increases in serum angiogenic factor levels and in serum VEGF in the 6th week after TARE for CRCLMs are related to short OS and progression-free survival.

Differentiated thyroid carcinomas in childhood: clinicopathologic results of 26 patients.

Epithelial solid tumors which are rare in childhood are responsible for about 9% of all childhood cancers. However, differentiated thyroid carcinomas (DTCs) are the most common of the endocrine neoplasia (0.5%-3%) in all childhood malignancies. Pediatric thyroid cancers have some clinicopathological differences from adult thyroid cancers. This analysis investigates the clinical behavior and pathological characteristics of childhood thyroid cancers, with treatment options and outcomes. A total of 26 patients who had been diagnosed as having differentiated thyroid cancer when they were younger than 18 years old, and who took radioiodine ablation treatment, were included in this analysis. The incidence of multifocality, capsule invasion and lymph node metastasis were calculated as 11.5%, 42.3% and 53.8%, respectively. At the 6th month, an absence of I-131 uptake in the neck, with a serum thyroglobulin (Tg) level < 1 ng/mL in the T4 off state, was accepted as the criterion for ablation of thyroid remnant. The mean follow-up period was 20.4 months (range 6 months-5 years). As a result, 19 patients were ablated with a single dose of I-131 (2-4 GBq). A total of 6 patients took a second dose of radioiodine treatment for lymph node or distant metastases. One of these patients was 6 years old and had recently received ablation. He had diffuse lung metastasis, which was detected on the 6th day post ablation with whole body scintigraphy, and he is now under follow-up. Successful surgery and an effective radioiodine ablation have a crucial role in good outcomes of childhood DTCs.

Gallbladder Uptake Mimicking Liver Metastasis on 177Lu-DOTATATE Posttherapy Scan Gallbladder Uptake on 177Lu-DOTATATE Scan.

ABSTRACT: We represent the case of a 61-year-old man with atypical carcinoid tumor of the lung. On posttherapy 177Lu-DOTATATE whole-body scan, focal intense uptake in the inferomedial side of the liver was detected. Pretherapy 68Ga-DOTATATE PET/CT showed no sign of liver metastasis, and posttherapy diagnostic dynamic liver MRI is used to exclude metastatic liver disease. Focal intense uptake was attributed to physiological gallbladder uptake.

The position of transarterial chemoembolization with drug-eluting beads and yttrium-90 transarterial radioembolization in patients with hepatocellular carcinoma: Consensus statements from a Delphi-method expert panel in Turkey.

PURPOSE: Clinical studies conducted in different geographic regions using different methods to compare transarterial chemoembolization (TACE) and transarterial radioembolization (TARE) have demonstrated discordant results. Meta-analyses in this field indicate comparable overall survival (OS) with TACE and TARE, while reporting a longer time to progression and a higher downstaging effect with TARE treatment. In terms of isolated procedure costs, treatment with TARE is 2 to 3 times more, and in some countries even more, expensive than TACE. However, relevant literature indicates that TARE is more advantageous compared to TACE regarding the need for repeat procedures, costs of complication management, total hospital stay and quality of life. Heterogeneity of hepatocellular carcinoma (HCC) patients as well as the shortcomings of clinical classifications, randomized clinical trials and cost-effectiveness studies make it difficult to choose between treatment alternatives in this field. As in other countries, these challenges lead to differences in treatment choice across different centers in Turkey. METHODS: The present expert panel used two round modified Delphi method to investigate the resources and clinical parameters referenced while selecting patients for drug-eluting beads (DEB)-TACE and TARE treatment modalities in Turkish clinical practice. The cost-effectiveness parameters and comparisons of these treatments have also been evaluated at a prediction level. RESULTS: The panelists stated that they most commonly use the BCLC staging system for the management of HCC patients in Turkey. However, they did not find any of the staging systems or treatment guidelines sufficient enough for their clinical practice in terms of covering the down-staging intent of treatments. Since living donor transplant preference is higher in Turkey than the rest of the Western countries, down-staging treatments are thought to be more prioritized in Turkey than that in other Western countries. The panelists reached a consensus that TARE may provide improved OS and reduce the number of repeat procedures compared to DEB-TACE in intermediate-stage patients with a single tumor spanning a diameter above 5 cm who experience recurrence after previous treatment with TACE and most TACE-naïve patient groups in intermediate stage. CONCLUSION: Based on the consensus on OS and the number of procedures, the panelists assumed that TARE would be more cost-effective than DEB-TACE in most groups of TACE-naïve patients in intermediate stage and in those with a single tumor spanning a diameter above 5 cm. It was also stated that the predicted cost-effectiveness advantage of TARE could be more pronounced in patients with a tumor diameter greater than 7 cm.

Analysis of prognostic factors in patients receiving transarterial radioembolization for unresectable hepatocellular carcinoma.

AIM: This study aimed to analyze the prognostic factors of patients receiving transarterial radioembolization for unresectable hepatocellular carcinoma. MATERIAL AND METHOD: Eighty-six (73 M and 13F; mean age: 64.3 ± 9.8 years) patients who received transarterial radioembolization for unresectable hepatocellular carcinoma were included. Relationship between serum alpha-fetoprotein and international normalization ratio level, albumin-bilirubin grade, neutrophil-lymphocyte ratio, presence of portal venous thrombosis and extrahepatic metastases, the dimension of index lesion and OS were analyzed. RESULTS: Neutrophil lymphocyte ratio was ≤ 5 in 76 (88%) and >5 in 10 (12%) of patients. Sixty-two (72%) patients died during a mean of 25.6± 9.7 months follow-up. Mean OS for all patients was calculated as 12.9 ± 14.6 months. In univariate analysis, albumin-bilirubin grade (22.3 ± 3.8 vs. 11.6 ± 4.2; P = 0.03), neutrophil-lymphocyte ratio (21.8 ± 3.6 vs. 7.3 ± 2.6; P =0.04), presence of extrahepatic metastases (30.1 ± 5.4 vs. 7.4 ± 2.0; P = 0.001) and portal venous thrombosis (26.5± 4.8 vs. 10.5 ± 2.1; P = 0.01) had significant effect on OS. In multivariate analysis, serum international normalization ratio (P = 0.005) and alpha-fetoprotein level (P = 0.004), albumin-bilirubin grade (P = 0.05), neutrophil-lymphocyte ratio (P = 0.007), Child-Pugh score (0.006) and presence of ascites (P = 0.005) were significantly correlated with OS. CONCLUSION: Patients with low basal albumin-bilirubin grade and neutrophil-lymphocyte ratio survive longer after transarterial radioembolization for unresectable hepatocellular carcinoma. Presence of extrahepatic metastases and portal venous thrombosis seems to have a prognostic value.

68Ga-DOTATATE Uptake in Pancreatic Metastasis of Renal Cell Carcinoma Mimicking Pancreatic Neuroendocrine Tumor.

A 61-year-old man, with a history of prior clear cell renal cell carcinoma in remission, was referred to Ga-DOTATATE PET/CT for the further evaluation of pancreatic tail mass. Ga-DOTATATE PET/CT showed pathologically intense uptake on the pancreatic mass; subsequent biopsy of the pancreatic mass confirmed the diagnosis of clear cell renal cell carcinoma metastasis. Ga-DOTATATE uptake is not specific for neuroendocrine tumors. In the presence of prior malignancy, it should be kept in mind that malignancies apart from neuroendocrine tumors express somatostatin receptors, and they can show Ga-DOTATATE uptake.

Comparison of bone scintigraphy and Ga-68 prostate-specific membrane antigen positron emission tomography/computed tomography in the detection of bone metastases of prostate carcinoma.

AIM: This study aims to assess the diagnostic performance of Ga-68 prostate-specific membrane antigen PET/computed tomography in the comparison of planar bone scintigraphy in the detection of bone metastases. Another purpose is to define the additional benefit of bone scintigraphy subsequent to prostate-specific membrane antigen PET/computed tomography and the role of prostate-specific membrane antigen PET/computed tomography in the treatment planning. MATERIAL AND METHOD: Forty-six patients with a median interval of 19 (range: 3-90) days between prostate-specific membrane antigen PET/computed tomography and bone scintigraphy included in the analysis. Diagnostic performance of both modalities was calculated and compared. RESULTS: Prostate-specific membrane antigen PET/computed tomography and bone scintigraphy were performed for initial staging in 25 (54%), for evaluation of biochemical recurrence in 11 (24%) and metastatic castration-resistant prostate carcinoma in 10 (22%) patients. In the patient-based analysis sensitivity, specificity, accuracy, positive predictive value, and negative predictive value for bone scintigraphy for detection of bone metastases were calculated as 50%, 19-29%, 32-39%, 32-39%, and 33-39%, respectively, based on whether equivocal findings were classified as positive or negative. For prostate-specific membrane antigen PET/computed tomography, these values were found significantly higher as 100%, 95-100%, 98-100%, 96-100%, and 100%, respectively. The diagnostic performance of bone scintigraphy and PET/computed tomography in clinical subgroups was analyzed, prostate-specific membrane antigen PET/computed tomography was superior to bone scintigraphy in three groups. CONCLUSION: In this retrospective study, prostate-specific membrane antigen PET/computed tomography was found to be superior to planar bone scintigraphy in the detection of bone metastases. Additional bone scintigraphy seems to be unnecessary in patients who underwent prostate-specific membrane antigen PET/computed tomography within three months period without additional treatment.

18F-Flourodeoxy glucose PET-computed tomography in testicular carcinoma: diagnostic and prognostic value.

AIM: This study aims to assess the diagnostic role of F-FDG PET/computed tomography in primary staging and restaging of testicular cancer in comparison with contrast-enhanced diagnostic thoracic-abdominopelvic computed tomography. MATERIAL AND METHOD: Thirty-two consecutive male patients with testicular carcinoma (median age: 29, min-max: 17-65) who were referred to the nuclear medicine department for F-FDG PET/computed tomography were retrospectively included in the study. Patients were evaluated based on the F-FDG PET/computed tomography indications and germ cell tumor subtypes. RESULTS: On patient-based analysis, overall sensitivity, specificity, PPV, NPV and accuracy of 18F-FDG PET/computed tomography were 71%, 100%, 100%, 30% and 75%. On lesion-based analysis, for evaluation of lymph node metastasis they were 76%, 100%, 100%, 57% and 81%, and for detection of distant metastasis 85%, 100%, 100%, 90% and 93%, respectively. Median SUVmax for seminomas were calculated as 14.2 and for nonseminomas 7.8 (P = 0.62) Mean time to progression and overall survival were calculated as 76.6 ± 10.7 and 111 ± 7.5 months, respectively. Mean overall survival and time to progression for PET-positive and negative groups was not found significant (P = 0.69 and P = 0.81). The only significant factor in predict overall survival was the presence of distant organ metastases in PET/computed tomography (124.6 ± 5.2 vs. 78.7 ± 14.0 months, P = 0.02). CONCLUSION: In this single-center experience with a limited number of patients, F-FDG PET/computed tomography appears to have a value of staging and restaging for both seminomatous and non-seminomatous GCTs.

Risk Factors for Predicting Osteoporosis in Patients Who Receive Thyrotropin Suppressive Levothyroxine Treatment for Differentiated Thyroid Carcinoma

Objectives: Endogenous hyperthyroidism accelerates bone turnover and shortens the normal bone remodeling cycle, which results in reduced bone density. It is estimated that suppressive levothyroxine (LT4) therapy also decreases bone density. The aim of this study was to define risk factors for osteoporosis development in patients under thyrotropin-stimulating hormone (TSH) suppressive treatment for differentiated thyroid cancer (DTC). Methods: Patients with a diagnosis of low or intermediate risk group DTC according to the American Thyroid Association 2015 guidelines and who have been receiving LT4 suppression therapy and were physically fit to undergo femur and lumbar vertebra bone density study were included in the study. Patients lacking information on demographic data, medical history, preoperative thyroid hormone status, or routine follow-up data were excluded from the study. A study form consisting of patient information on possible risk factors for osteoporosis such as gender, age, menopausal status, smoking, family history of osteoporosis, preoperative thyroid hormone status, postoperative hypoparathyroidism history, mean serum TSH levels, and duration of TSH suppression was created and filled out for each participant. Bone mineral densitometries of the femur and lumbar vertebrae were measured along with serum vitamin D and parathyroid hormone levels. Results: During TSH suppression (mean 7.2±4.5 years, range: 1-26), osteoporosis was detected in 89 (9.6%) patients. The mean time to develop osteoporosis was significantly different in patients with or without a family history of osteoporosis (15.3±0.4 versus 20.3±0.6 years; p=0.002). Similarly, the mean time to develop osteoporosis for was found to be significantly shorter in postmenopausal patients than that for premenopausal women (18.6±0.7 versus 20.4±0.4 years; p<0.001). Male gender (p<0.001), a family history of osteoporosis (p=0.001) and menopausal state (p<0.001) were identified as independent predictive factors for developing osteoporosis. Conclusion: Postmenopausal women, men, and patients with a family history who receive TSH-suppression treatment have a tendency to develop osteoporosis.

A rapid lateral flow stool antigen immunoassay and (14)C-urea breath test for the diagnosis and eradication of Helicobacter pylori infection in children.

Our aim was to evaluate diagnostic accuracy of rapid immunochromatographic stool antigen test (Rapid HpSA; LINEAR Chemical, Barcelona, Spain) and a practical low-dose (14)C urea breath test (UBT) (Heliprobetrade mark) test before and after eradication therapy. One hundred nine children with abdominal symptoms (age range, 5-17 years; mean, 12.1) underwent endoscopy, (14)C-UBT, and Rapid HpSA. Patients were defined as Hp infected when histology was positive for Hp. Forty children (36.6%) were Hp infected. The sensitivity of Rapid HpSA and (14)C-UBT was 65% and 92.5% (P = 0.0003), respectively; the specificity of Rapid HpSA and (14)C-UBT was 92.3% and 85.5% (P = 0.180), respectively. After eradication therapy endoscopy, (14)C-UBT and Rapid HpSA were repeated. The eradication rate was 70.5%. After eradication, the sensitivity of Rapid HpSA and (14)C-UBT was 60% and 100%, respectively; the specificity of Rapid HpSA and (14)C-UBT was 100%. (14)C-UBT was more reliable than the Rapid HpSA test for the diagnosis and for confirming eradication of Hp infection.

The additive clinical value of combined thyroglobulin and antithyroglobulin antibody measurements to define persistent and recurrent disease in patients with differentiated thyroid cancer.

AIM: To evaluate retrospectively the additive clinical value of combined thyroglobulin (Tg) and antithyroglobulin antibody (TgAb) measurements to define recurrent and persistent disease in patients with differentiated thyroid cancer. MATERIALS/METHODS: 181 patients with differentiated thyroid cancer were included in the study. The nonstable disease group (recurrent and persistent disease) had 61 patients with 24-36 months follow-up period. The stable disease group (without recurrence or persistence) had 120 patients with 21-28 months follow-up period. We compared Tg and combined Tg-TgAb levels on the sixth month after the ablation between two groups. RESULTS: Optimal threshold values for Tg, TgAb measurements were calculated statistically as 4.45 ng/ml and 27.8 IU/ml. Optimal sensitivity and specificity for 4.45 ng/ml Tg levels were 52.5 and 91.7%. We also evaluated different Tg threshold values. We found sensitivity was 54.2% and specificity 86.7% for 2 ng/ml and sensitivity was 40.7% and specificity 96.7% for 10 ng/ml Tg levels. By the odds ratio (OR) rule, the obtained sensitivity and specificity were 68.3 and 90% (if Tg>10 ng/ml or TgAb>27.8 IU/ml), 78.3 and 90% (if Tg>4.45 ng/ml or TgAb>27.8 IU/ml), and 80% and 85% (if Tg>2 ng/ml or TgAb>27.8 IU/ml). Sensitivity increased with statistical significance from 52.5 to 78.3% (P<0.001) and decreased with statistical insignificance from 91.7 to 90% (P>0.05) for the optimal thresholds. CONCLUSION: Combined Tg-TgAb values were found more useful than only Tg for recurrent and persistent diseases. Combined Tg and TgAb measurements seemed to be a useful marker.

Treatment for microcarcinoma of the thyroid--clinical experience.

AIMS AND BACKGROUND: Papillary microcarcinoma of the thyroid is a specific subgroup of papillary thyroid carcinoma (PTC) and account for up to 30% of all PTC. According to the World Health Organization, papillary microcarcinoma of the thyroid (PMC) is defined as a papillary thyroid carcinoma measuring