Clinical significance of thyroid incidentalomas identified by 18F-FDG PET/CT: correlation of ultrasonograpy findings with cytology results.

AIM: The aim of this study was to investigate the clinical importance of incidental focal or diffuse fluorine-18 fluorodeoxyglucose (F-FDG) uptake in the thyroid gland on positron emission tomography (PET)/computed tomography (CT) and to evaluate the additive value of thyroid ultrasonography (US) in defining the malignancy potential of thyroid incidentalomas. PATIENTS AND METHODS: A total of 1450 patients, who had undergone a PET/CT scan for staging or restaging of various malignancies, were screened retrospectively and 52 (3.6%) patients with focal or diffuse F-FDG uptake in the thyroid gland on PET/CT were enrolled in the study. None of the patients had any history of thyroid diseases. Thyroid US with elastography for a thyroid nodule was performed for all the patients cross-sectionally. Thyroid fine-needle aspiration biopsy (FNAB) was also applied at the same time as the thyroid US to 34 patients with a nodule(s) 10 mm or more in diameter or less than 10 mm, but with malignancy potential ultrasonographically. The cytology results were compared with the thyroid US and F-FDG PET/CT findings. RESULTS: Although 39 patients had focal (group 1) F-FDG uptake in the thyroid gland, the remaining 13 patients had diffuse (group 2) uptake. In group 1, FNAB was performed in 32 patients. In 10 of 32 (31%) patients, FNAB results were concordant with malignant cytology (seven primary thyroid malignancy and three metastasis to thyroid). In group 2, in one of two patients who had undergone FNAB, malignant cytology (metastasis to thyroid) was detected. Although the difference between the maximum standardized uptake value (SUVmax) of malignant and benign nodules was statistically significant (10.2±8.9 vs. 5.6±3.0, P=0.013), the difference between the nodule sizes was not statistically significant (20.0±7.3 vs. 16.7±7.4, P=0.923). The presence of suspicious US findings and a high elastography score (≥4) were also statistically significant (P<0.001 and P=0.035, respectively). In the receiver-operator characteristic analysis, a 5.3 cut-off SUVmax was calculated with 82% sensitivity and 65% specificity for predicting malignant cytology. CONCLUSION: Focal F-FDG uptake was associated with a higher prevalence of malignant thyroid nodule compared with diffuse F-FDG uptake. In particular, if a focal thyroid incidentaloma with high SUVmax (>5.5), suspicious US findings, and a high elastography score (≥4) is detected, a pathological diagnosis, either by histology or by cytology examination, should be made, especially when the patient has a long life expectancy.

The role of 18F-NaF PET/CT in metastatic bone disease.

AIM: To investigate the role of 18F-NaF PET/CT and compare it with 99m Tc-MDP whole body bone scintigraphy and 18F-FDG PET/CT in detecting the extent of metastatic bone disease and to present our first experience with 18F-NaF PET/CT in our country. MATERIALS AND METHODS: A total of 37 histopathologically proven cancer patients (22 male, 15 female) with bone metastasis detected on Tc-99m MDP whole body bone scan were prospectively enrolled Cebeci, following ethics committee approval. 18F-NaF PET/CT was performed to the participants in Ankara University Medical Faculty Nuclear Medicine Department for evaluation of symptomatic skeletal sites which were negative on Tc-99m MDP whole body bone scan. A lesion based comparison was made between 18F-NaF PET/CT and Tc-99m MDP whole body bone scan for each patient and between 18F-NaF PET/CT and 18F-FDG PET/CT in 12/37 patients. RESULTS: The number of lesions demonstrated by 99m Tc-MDP bone scan and 18F-NaF PET/CT was equal in 4/37 (%11) of the cases. 18F-NaF PET/CT showed a greater number of pathological foci in 89% of participants. 18F-NaF PET/CT was able to show both lytic and blastic lesions and small lesions were better visualized due to the advantage of sectional imaging with much better resolution and higher target/background ratio. 18F-NaF PET/CT demonstrated a greater number of metastases in 10/12 (83%) of the patients when compared to 18F-FDG PET/CT. In the other two patients, bone metastasis could be demonstrated only by 18F-NaF PET/CT. The uptake of 18F-FDG was variable in blastic lesions and cranial bone involvement was missed by 18F-FDG PET/CT in some cases due to physiological brain metabolism. CONCLUSION: Although further prospective clinical studies in specific cancer populations are indicated to set the place of 18F-NaF PET/CT in diagnostic scheme, the results of this pilot study from our country support the superiority of 18F-NaF PET/CT in investigation of bone metastasis over 99mTc-MDP bone scan and 18F-FDG PET/CT in various malignancies. 18F-NaF PET/CT is coming forward as a single step bone seeking study, considering all the advantages, but especially potential of detecting occult metastases and reliably directing patient management.

Assessment of recurrence rates in papillary thyroid microcarcinoma patients with and without histopathological risk factors after radioiodine ablation treatment.

AIM: We aimed to assess the recurrence rates of papillary thyroid microcarcinoma in patients with and without histopathological risk factors after radioiodine (RAI) ablation treatment. MATERIALS AND METHODS: A total of 357 papillary thyroid microcarcinoma patients who were referred to Ankara University Medical School, Department of Nuclear Medicine for RAI ablation treatment after total or near-total thyroidectomy were included in the study. All patients received RAI ablation treatment 4-6 weeks after surgery. After RAI ablation, patients were monitored every 3 months within the first 6 months and then every year. RESULTS: During follow-up, sixth-month iodine-131 (I-131) whole-body scans showed successful ablation in 333 (93.3%) patients. However, one (0.2%) patient had a focal lung uptake on the sixth-month I-131 whole-body scan, although the postablative scan gave no evidence of lung metastasis. Lung metastasis of this patient was treated with a second dose of RAI. The mean follow-up period was 124 (min-max: 6-216) months. No recurrence was detected in 344 (96.3%) patients during the follow-up period. However, in 13 (3.6%) patients, new recurrence or metastasis had developed. Lymph node metastasis was detected using fluorine-18 flourodeoxyglucose PET/computed tomography in four and using neck ultrasound in eight of them. The metastasis rates of patients with papillary microcarcinoma at a single focus with no thyroid capsule or lymphovascular invasion (n=268) and those of patients with thyroid capsule and/or lymphovascular invasion (n=89) were compared. Metastasis was seen in six and seven patients in those groups, respectively. The difference in metastasis rate between the two groups was statistically significant (2.2 vs. 9.2%, P=0.008). CONCLUSION: RAI ablation is beneficial in the management of papillary thyroid microcarcinoma patients with histopathological risk factors. It also improves the sensitivity of thyroglobulin and antithyroglobulin, facilitating easier and safer follow-up.

Correlation of 18F-FDG PET/CT findings with histopathological results in differentiated thyroid cancer patients who have increased thyroglobulin or antithyroglobulin antibody levels and negative 131I whole-body scan results.

AIM: This study aimed to investigate the correlation of 18F-FDG PET/CT findings with histopathological results in defining the recurrence of the disease in patients with differentiated thyroid cancer (DTC) who have increased thyroglobuline (Tg) or anti-Tg antibody (TgAb) levels and negative 131I whole-body scan (WBS) result. PATIENTS AND METHODS: A total of 59 patients with DTC (44 women, 15 men; mean [SD] age, 48.2 [22.6] years) were included in the study. All of the patients had previous papillary thyroid cancer, and all of them had undergone radioiodine ablation after a total or near-total thyroidectomy. After radioiodine ablation, patients were followed up for approximately 2.5 years. In the follow-up, the patients with negative 131I-WBS results and increased Tg or TgAb levels under thyroid-stimulating hormone-stimulated conditions underwent an 18F-FDG PET/CT scan to determine any recurrence of disease. There were negative or uncertain findings in the neck ultrasonography and/or thorax CT in most of the patients. The 18F-FDG PET/CT findings were compared with the histopathological results in all patients. RESULTS: Although 49 patients had increased Tg levels, the remaining 10 patients had increased TgAb levels. In patients with high Tg levels, 18F-FDG PET/CT scan results were negative in 10 and positive in 39 patients. In this patient group, 18F-FDG PET/CT findings were true positive, true negative, false positive, and false negative in 32, 3, 7, and 7 patients, respectively. The sensitivity, specificity, positive predictive value, negative predictive value and accuracy of 18F-FDG PET/CT in this group were calculated as 82%, 30%, 80%, 30%, and 71%, separately. In the receiver operating characteristic analysis, a 4.5 cutoff SUV(max) was calculated with 75% sensitivity and 70% specificity for predicting disease recurrence. Cutoff Tg level was calculated as 20.7 ng/mL with 75% sensitivity and 55% specificity. In 10 patients with high TgAb levels, 18F-FDG PET/CT was true positive, true negative and false positive in 6, 2, and 2 patients, respectively. The sensitivity, specificity, positive predictive value, negative predictive value and accuracy of 18F-FDG PET/CT in this patient group were calculated as 100%, 50%, 75%, 100%, and 80%, respectively. CONCLUSIONS: 18F-FDG PET/CT may be a useful imaging modality in defining recurrence of the disease in patients with DTC who have increased Tg or TgAb levels, negative 131I-WBS results, and negative or suspicious neck ultrasonography and/or thorax CT results. Although 18F-FDG PET/CT seems to be a more sensitive method in patients with increased TgAb levels, the number of patients is not enough to make a substantiated comment.

Evaluation of the response to selective internal radiation therapy in patients with hepatocellular cancer according to pretreatment (99m)Tc-MAA uptake.

AIM: The aim of the study was to evaluate if there is a prognostic importance of pretreatment Tc-MAA uptake of liver lesion of patients who received Y selective internal radiation therapy (SIRT) treatment for hepatocellular cancer (HCC) or not. METHODS: Nineteen patients (5 female and 14 male patients; mean age, 64.5 ± 14.7 years; range, 57-73 years) who received SIRT treatment in our department for HCC between June 2008 and May 2011 were included in the study. All the patients have undergone Tc-MAA scintigraphy within 2 weeks' period before treatment for evaluation of presence of extrahepatic uptake. Patients were evaluated according to their lesions' Tc-MAA uptake patterns. Response to the treatment, presence of progression after treatment, and progression-free survival of all the patients were calculated. RESULTS: Treatment has been administered on the right and left lobes of the liver in 18 and 1 patient, respectively. The mean treatment dose was estimated as 1.4 + 1.0 GBq. In the pretreatment Tc-MAA scintigraphy, liver lesions of 5 patients were hypoactive, and 14 patients were hyperactive. In the hypoactive group, whereas 2 patients (40%) were responders to treatment, 3 were nonresponders (60%). In the hyperactive group, 8 (58%) and 6 (42%) patients were responders and nonresponders, respectively (P = 0.51). Disease progression was seen in 4 (80%) and 8 patients (58%) in the hypoactive group and hyperactive groups, respectively (P = 0.36). Progression-free survival of the hypoactive group was calculated as 8 ± 4.3 months and of the hyperactive group 11 ± 4.7 months (P = 0.22). CONCLUSIONS: Despite the small number of patients, this study revealed that there is no significance between tumor response and progression rates of patients who received SIRT for HCC with or without pretreatment Tc-MAA uptake in liver lesions. Selective internal radiation therapy could be safely performed in patients who have hypoactive lesions in Tc-MAA scintigraphy.

Serum carcinoembryonic antigen measurement, abdominal contrast-enhanced computed tomography, and fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography in the detection of colorectal cancer recurrence: a correlative study.

INTRODUCTION: The aim of this study was to evaluate the correlative role of fluorine-18 fluorodeoxyglucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) in carcinoembryonic antigen (CEA) measurement and contrast-enhanced abdominal computed tomography (ceCT) in the detection of colorectal cancer (CRC) recurrence. MATERIALS AND METHODS: A total of 96 patients (40 female, 56 male; mean age, 60.6 ± 12 years) with a previous diagnosis of CRC underwent 18F-FDG PET/CT on suspicion of recurrence and were evaluated retrospectively. Inclusion criteria were accepted as the presence of increased serum CEA levels or positive findings on abdominal ceCT or both. 18F-FDG PET/CT findings were compared with histopathological findings and/or clinical follow-up data as the gold standard. Patients were divided into three groups: group 1, with increased CEA levels and normal abdominal ceCT; group 2, with normal CEA levels and positive ceCT; and group 3, with increased CEA levels and positive ceCT. RESULTS: Whereas sensitivities of CEA, ceCT, and 18F-FDG PET/CT in the three patient groups were calculated as 91, 67, and 96%, specificities were 13, 51, and 62%, respectively. There were 35, 14, and 46 patients in groups 1, 2, and 3, respectively. In separate analyses conducted on the groups, sensitivity of 18F-FDG PET/CT was computed as 100 and 100% and specificity as 88 and 80% for groups 1 and 2. In group 3, which comprised four patients with secondary malignancies, sensitivity and specificity of 18F-FDG PET/CT were 94 and 16%, respectively. CONCLUSION: 18F-FDG PET/CT has an additional role in the detection of CRC recurrence with a higher sensitivity compared with CEA and ceCT alone, and 18F-FDG PET/CT is especially more successful in patients with isolated elevated CEA levels or positive ceCT findings without accompanying CEA elevation.

The additive clinical value of 18F-FDG PET/CT in defining the recurrence of disease in patients with differentiated thyroid cancer who have isolated increased antithyroglobulin antibody levels.

AIM: The aim of this study was to investigate the additive clinical value of 18F-FDG PET/CT in defining the recurrence of disease in patients with differentiated thyroid cancer (DTC) who have isolated increased antithyroglobulin antibody (TgAb) levels with undetectable thyroglobulin (Tg) levels and negative 131I whole-body scintigraphy (wbs). MATERIALS AND METHODS: Clinical follow-up data of 231 patients with DTC who underwent 18F-FDG PET/CT between June 2006 and March 2011 were evaluated retrospectively. There were a total of 48 patients who underwent 18F-FDG PET/CT for isolated increased serum TgAb levels. When 17 patients who have lymphocytic thyroiditis were excluded, the remaining 31 patients [27 women and 4 men; mean (SD) age, 50.29 (15.2) y] were included in this study. The inclusion criteria were undetectable serum Tg and increased TgAb levels under the condition of thyroid-stimulating hormone greater than 30 IU/mL with negative 131I wbs and absence of pathologic findings in neck ultrasound and thoracic CT if performed. Findings from the 18F-FDG PET/CT were compared with the clinical follow-up data and the results of histopathologic examinations. RESULTS: Results of 18F-FDG PET/CT were negative in 15 and positive in 16 patients. Sixteen FDG-positive sites (15 lymph nodes and 1 bone) were seen in 16 patients who had positive findings in 18F-FDG PET/CT. In the comparison with 18F-FDG PET/CT findings and clinical follow-up data and histopathologic examination results, 4, 12, 2, and 13 patients were false-positive, true-positive, false-negative and true-negative retrospectively. In the receiver operating characteristic analysis, a 5.4 cutoff SUVmax value was calculated with 82% sensitivity and 81% specificity in distinguishing malignant and benign lesions. As a result, the sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of 18F-FDG PET/CT in the detection of recurrent disease were calculated as 75%, 76%, 75%, 86%, and 80%, respectively. CONCLUSIONS: Isolated increased TgAb levels might be a predictor of the recurrent DTC and 18F-FDG PET/CT might be an additive imaging method in detecting the recurrent disease in patients with DTC who have increased TgAb levels with undetectable Tg levels and negative 131I wbs.

Potential genotoxic effect of 186Re-HEDP on human lymphocyte cells: in-vitro evaluation with micronucleus-FISH analysis.

AIM: Systemic and local therapies can be used to treat painful bone metastases. It has been shown that certain pharmaceuticals such as 186Re (rhenium-186) are effective in the treatment of pains caused by bone metastasis and a correlation between bone metastases and T cells has also been shown. The aim of this study was to investigate the genotoxic effect of 186Re-1,1-hydroxyethylidenediphosphonate (186Re-HEDP) on the cultured peripheral blood lymphocytes using an micronucleus (MN)-fluorescence in-situ hybridization assay. METHODS: Two lymphocyte cultures, with and without 186Re-HEDP, were set up from 20 healthy individuals. MN frequencies were determined by a classical cytokinesis-blocked micronucleus assay and samples with the highest MN frequencies were used for fluorescent in-situ hybridization analyses with the 'all human centromeres' probe. RESULTS: Our results show a significant increase in the MN frequency in 186Re-treated lymphocytes compared with the untreated group (P<0.001). The frequencies of centromere-positive [CEN(+)] and centromere-negative [CEN(-)] MN in the 186Re-treated and untreated groups were found to be similar; however, the ratio of CEN(-)/CEN(+) MN frequency was lower in 186Re-treated samples. CONCLUSION: These preliminary results support the idea that 186Re-HEDP is a highly genotoxic radiopharmaceutical and shows a proaneugenic effect. Causing genotoxicity in lymphocytes, especially in T cells, that regulate bone metastases and tumor growth in bone, might be a mechanism of this pharmaceutical to reduce the pain of patients.

Intraoperative gamma probe guidance with 99mTc-pertechnetate in the completion thyroidectomy.

AIM: Intraoperative gamma probe (GP) guidance with (99m)Tc-pertechnetate in the completion total thyroidectomy after a first thyroidectomy was investigated in this prospective study. METHODS: The study group comprises of fourteen consecutive patients (14 females, age mean 50.2 +/- 12.0 years, age range 29-73 years). All patients underwent a second thyroidectomy due to inadequate (5/14 patients) and complementary (9/14 patients) interventions. Serum-free three iodothyronine, free thyroxin and thyroid stimulating hormone measurements, a neck ultrasonography (USG) and thyroid scintigraphy (TS) were performed in the preoperative and postoperative period. After a 185 MBq (5 mCi) injection of (99m)Tc-pertechnetate, background (BG), left thyroid lobe (LTL), right thyroid lobe (RTL) and pyramidal tyroid lobe (PTL) regions were counted in time before and after resection of thyroid remnants by intraoperative GP. All resection materials were evaluated by histopathologic examination. RESULTS: Preoperative TSH was less than 30 mIU/mL (mean 21 +/- 7) in all patients. Functioning thyroid remnants were shown in 13/14 patients on the preoperative TS and USG, which were diagnosed by USG in one but by TS in other one. We calculated that percentage median (minimum-maximum) values were 220.90% (56.00-411.11%) in LTL, 80.43% (11.54-471.05%) in RTL and 66.60% (-3.33 to 158.33%) in PTL for counts before resection, on the other hand, 15.96% (-20.55 to 47.62%) in LTL, 17.59% (-15.07 to 38.46%) in RTL and 17.59% (-1.96 to 57.14%) in PTL regions for counts after resection. There were statistically significant differences between these values belonging to before and after resection for LTL (p = 0.001), RTL (p = 0.001) and PTL (p = 0.008). Bilateral small foci in a patient and unilateral focus in other patient were observed in postoperative TS. Unilateral focus was detected on the RTL by GP, but not bilateral foci. Postoperative TSH levels increased to 30 mIU/mL (mean 69 +/- 26) at least. There was a statistically significant difference between preoperative and postoperative TSH values (p < 0.001). Histopathologic confirmation revealed that all removed materials were the thyroid tissues. CONCLUSIONS: Gamma probe guidance with (99m)Tc-pertechnetate seemed to be a good option and easy available method in patients undergoing the completion total thyroidectomy.

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.

Is thyroglobulin the stronger indicator for progressive disease than the other conventional factors in same age patient groups with differentiated thyroid cancer?

AIM: To determine the thyroglobulin cut-off value as an indicator for progressive disease and to research relationships between sex, histological type, extra-capsular invasion and progressive disease in differentiated thyroid cancer. METHODS: Four hundred and eight patients were evaluated retrospectively. One hundred and fifty-eight patients (group 1) treated for progressive disease and 166 patients (group 2) that were ablated for thyroid remnant were included in our study. Sex, age, histological type, presence of extra-capsular invasion at the diagnosis and L-thyroxine off thyroglobulin values (6-12 months after the ablation) were obtained. Data were analysed by statistical methods. RESULTS: There was no statistically significant difference for ages (group 1, 45.3+/-16.1 years; group 2, 47+/-12 years, P>0.05). The chi-squared test revealed statistically significant differences for histological type (P>0.05) and extra-capsular invasion (P<0.001) but not for sex (P>0.05). Feasible cut-off level, sensitivity and specificity were found as a 10 ng.ml thyroglobulin value, 79% and 97%, respectively. However, sensitivity and specificity were 80%, 92% for 5 ng.ml and 82% for 2 ng.ml thyroglobulin levels. Multivariate analysis showed that a 10 ng.ml thyroglobulin cut-off value and extra-capsular invasion were independent prognostic factors. CONCLUSION: Increased thyroglobulin level, extra-capsular invasion and follicular type were poor prognostic factors but sex was not, whereas only extra-capsular invasion and increased thyroglobulin level were independent prognostic indicators for our groups. A 10 ng.ml thyroglobulin level was a feasible cut-off and seemed to be a stronger factor than other indicators to predict progressive disease.

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

Lymphoscintigraphy in detection of the regional lymph node involvement in gastric cancer.

INTRODUCTION: Involvement of regional lymph node is a critical sign in prognosis of gastric cancer. Radiological techniques are commonly used to evaluate the extension of gastric cancer. But their sensitivity and specificity are low especially in the early stage. Our aim was to assess the value of gastric lymphoscintigraphy in identifying regional lymph node involvement in patients with gastric cancer, as compared to the abdominal ultrasonography, computed tomography and postoperative histopathological evaluation. PATIENTS AND METHODS: 50 patients (12 females) with a median age of 61 years (range, 35-73 years) were included in the study. Pre-operative staging in all cases included upper gastrointestinal endoscopy and biopsy, followed by ultrasound, computed tomography and lymphoscintigraphy. 148 MBq Technetium-99m lymphoscint was injected around the tumour during endoscopy and immediately after injection, anterior, lateral and posterior images were taken in 5-min intervals using a gamma camera. Findings were compared to the findings of other tests. The sensitivity, specificity, positive predictive value, and negative predictive value of each test were calculated and compared. RESULTS: Histologically, 68% of cases (34/50) had metastasis in regional lymph nodes and all cases were accurately diagnosed by lymphoscintigraphy. Lymphoscintigraphy was significantly more sensitive for detecting lymph node involvement (P < 0.01). Both abdominal ultrasonography and CT had very low sensitivity in identifying lymph nodes. CONCLUSIONS: Lymphoscintigraphy is a promising test in the identification of regional lymph nodes pre-operatively in patients with gastric cancer. It might help the surgeon to plan the extent of dissection before surgery which may decrease postoperative complications related to unnecessary extensive lymph node dissection.

Clinical importance of anti-thyroglobulin auto-antibodies in patients with differentiated thyroid carcinoma: comparison with 99mTc-MIBI scans.

AIMS: (1) To investigate whether elevated serum anti-thyroglobulin antibody (ATG) reflects the recurrence of cancer in patients with differentiated thyroid carcinoma (DTC) in whom thyroglobulin was undetectable after radioiodine ablation. (2) To assess the sensitivity of disease detection for (99m)Tc-MIBI whole-body scans (WBSs) in these patients and investigate the correlation between MIBI WBS results and high serum ATG levels. MATERIALS AND METHODS: In this retrospective study, we evaluated 14 patients (13 women and 1 man; mean age 44 +/- 19 years) with DTC who underwent total or near-total thyroidectomy followed by an ablative dose of I at various time intervals. According to histopathological findings, 10 patients (71.4%) who were diagnosed as having papillary carcinoma and four patients (28.6%) as having follicular cell carcinoma, had high serum ATG concentrations (> 40 IU x ml(-1); range, 62-2000 IU x ml(-1)), but low serum thyroglobulin concentrations (< 1.6 ng x ml). Post-therapeutic and diagnostic (131)I WBSs and (99m)Tc-MIBI WBSs were performed. Scans were visually evaluated for detecting recurrence. If necessary, bone scans, chest X-rays, computerized tomography, ultrasonography and histopathological evaluation were performed. RESULTS: Recurrent and/or persistent disease was found in 12 of the patients. This was confirmed pathologically in four patients and by using other imaging methods in eight (bone scans, computerized tomography, ultrasonography). The sensitivity and specificity of disease detection for MIBI WBSs was 66.7% and 100%, respectively. For (131)I WBSs, the sensitivity of disease detection was 55.6%. Among these 12 patients, 10 responded to treatment (three underwent surgery, seven received radioiodine therapy, and two had surgery + radioiodine therapy). ATG levels decreased in eight of the 10 patients, but remained persistently elevated in two despite treatment. CONCLUSIONS: (1) Persistently elevated ATG levels appear to serve as a useful marker for recurrent or persistent DTC in patients with undetectable serum tyroglobulin levels. Thus, the routine measurement of ATG antibody in such patients is of great value. (2) In these patients, (99m)Tc-MIBI has a relatively high sensitivity in the diagnosis of a recurrence of thyroid cancer or metastases. So, in patients with elevated ATG but undetectable serum thyroglobulin levels, (99m)Tc-MIBI can be used to determine whether there is a recurrence of DTC or metastases.

Clinical importance of technetium-99m-methoxyisobutylisonitrile (MIBI) scintigraphy in differentiated thyroid carcinoma patients with elevated thyroglobulin levels and negative I-131 scanning results.

AIMS AND BACKGROUND: The aim of this study was to evaluate the potential contribution of Tc-99m-MIBI scintigraphy to the follow-up of patients with differentiated thyroid carcinoma, who had elevated Tg levels and negative I-131 whole-body scan results. MATERIALS AND METHODS: In this retrospective study, we evaluated 28 patients with differentiated thyroid carcinoma, who had total or near total thyroidectomy followed by an ablative dose of I-131 at various time intervals (15 women, 13 men; mean age 43 +/- 17 years). All patients were treated with T4 suppression. After a mean follow-up period of 6.1 years (range 3-15) all patients were determined to have a high serum Tg concentrations (>2 ng/ml) and previous negative I-131 WBS results. All patients were examined for metastatic sites using Tc-99m-MIBI scan. Scans were visually evaluated for detecting lymph node metastases and/or local recurrence, lung metastases and skeletal metastases. RESULTS: Tc-99m-MIBI scan demonstrated lesions in 23 patients (83.3%). In five patients with negative Tc-99m-MIBI scan findings (FN results): Chest CT showed small-sized mediastinal LN metastases in 2 patients and lung metastases in another 2 patients (<1 cm). Neck CT showed small-sized cervical LN involvement in 1 patient. The sensitivity of detection for neck was 94.4%, for lung 63.6%, and for bone lesions 100%. For all scan sites taken together, the sensitivity of disease detection was 83.3%, the specificity was 50%, positive predictive value (PPV) was 96.2%, and finally negative predictive value (NPV) was 16.7%. CONCLUSION: We concluded that Tc-99m-MIBI scan should be considered as a supplementary scintigraphic method for the follow-up of patients with high serum Tg levels and negative I-131 WBS results, and it can help clinicians in making the decision to treat these patients.

Hürthle cell carcinoma: a clinicopathological study of thirteen cases.

BACKGROUND: Hürthle cell carcinoma (HCC) of the thyroid is a variant of follicular cancer which has been considered by many as a more aggressive disease than the usual well-differentiated carcinoma of the thyroid. AIM: To investigate the clinico-pathologic characteristics, treatment and outcome of Hürthle cell carcinoma. MATERIAL AND METHODS: During a 7-year period, 13 patients (seven male, six female; mean age at diagnosis 48.4+/-13.2 years) with HCC were treated and monitored at the Ankara University. The measured diameter of the tumours varied from 1 to 6 cm in diameter with pathological examination. Three of the HCC had extra thyroid invasion, five had intrathyroid invasion, and five were encapsulated. One of the patients had a history of low-dose external radiation to the head and neck in childhood. Treatment consisted of a total thyroidectomy in 12 patients, and a near total thyroidectomy in one patient. At surgery, lymph node metastases were present in three patients and lymph node dissection were performed in these patients. Distant metastases were detected in only one patient (lung metastasis). RESULTS: All patients had radioiodine ablation therapy for residual thyroid tissue. Twelve of the 13 patients were ablated with a single dose of 131 I (3.7-5.5 GBq). A second dose of radioiodine therapy was required in only one patient who had lung metastases and this patient is still being followed up. After a median follow-up period of 85 months, there was no recorded mortality due to the disease and 12/13 of the patients were categorized as disease free (criteria for ablation were a negative I whole-body scan and very low serum thyroglobulin levels). CONCLUSION: We did not find higher incidences of local recurrences, distant metastases or mortality rates compared to well differentiated thyroid carcinomas. HCC of the thyroid and well differentiated thyroid carcinomas have similar biological behaviour. Their treatment should be similar, including total or near-total thyroidectomy plus modified cervical node dissection when there is lymph node involvement. Radioactive iodine therapy and suppressive laevothyroxin therapy should follow.

Radioiodine whole-body scans, thyroglobulin levels, 99mTc-MIBI scans and computed tomography: results in patients with lung metastases from differentiated thyroid cancer.

OBJECTIVES: The correlation between a 131I whole-body scan (WBS), a 99mTc sestamibi (99mTc-MIBI) WBS, a computed tomography (CT) scan and the value of routine follow-up for 131I WBS and thyroglobulin (Tg) levels in patients with lung metastases from differentiated thyroid cancer was assessed. METHOD: Pulmonary metastases were detected in 32 patients out of 583 with differentiated thyroid cancer (DTC) who were admitted to our clinic between 1985 and 2004 (age range, 22-79 years; mean, 58 +/- 19 years; 15 women and 17 men). Pulmonary metastases were diagnosed by considering the 131I WBS, increased Tg levels and/or other positive radiological findings. Papillary carcinoma was diagnosed in 15/32 patients and follicular carcinoma in 13/32. A mixed type found in 4/32 patients was classified histopathologically. A total of 3.7-53.65 GBq (100-1450 mCi) 131I was given to each patient. The duration of follow-up ranged from 36 to 240 months. A 131I WBS, the determination of Tg levels and/or a CT scan were carried out in the assessment of a diagnosis and follow-up of patients with lung metastases. A 99mTc-MIBI WBS was performed on 19 patients who were chosen at random from the 583. RESULTS: Nineteen of 32 patients had lung metastases before they received the first 131I treatment. Six of the 32 had distant-organ metastases other than in the lungs. Four of these six patients had only lung and bone metastases. Pulmonary metastases were observed on the 131I WBS patients 31/32 (96.8%) whereas no pulmonary metastases, were detected on the CT scans in 3/32 patients. The last diagnostic whole-body scan (DWBS) was normal in 13/32 patients. At the first examination, the Tg levels in 27/32 (84.4%) patients were below 30 ng . ml(-1). At the final examination, 20/32 (62.5%) patients had Tg levels higher than 30 ng . ml(-1), while Tg levels were lower than 30 ng . ml(-1) in 12/32 patients. Tg levels decreased in 21/32 and increased in 3/32 patients. The 131I WBS continued to be abnormal in 2/3 patients with increased Tg levels but became normal in one patient whose CT scan still showed macro-nodular lesions. Tg levels did not change significantly in 8/32 patients. The 131I WBS became normal in 5/8 patients, while the CT scans for 4/5 showed micro-nodules. Metastases were detected in 12/19 patients who underwent 99mTc-MIBI whole-body scanning: 18/19 showed metastases on the 131I WBSs and 17/19 on the CT scans. Of the seven patients without a sign of metastasis on the 99mTc-MIBI WBS, one was negative in terms of metastasis on the 131I WBS and one on the CT scan. Fibrosis was observed on the CT scans of 2/32 patients. One patient developed dedifferentiation, as determined by the negative 131I WBS and positive CT scan. CONCLUSION: 131I whole-body scanning and the determination of Tg levels are the most important procedures for the evaluation of lung metastases in differentiated thyroid cancer. Computed tomography is a useful addition to 131I whole-body scanning. MIBI imaging alone may not be enough to detect lung metastases from differentiated thyroid cancer.

Intraoperative lymphatic mapping and sentinel lymph node biopsy using radioactive tracer in gastric cancer.

BACKGROUND: Gastric cancer continues to be a significant health problem around the world. Surgical resection with a lymph node dissection remains the only potentially curative treatment with gastric cancer. Determination of the extent of lymph node dissection required on the basis of actual node involvement in patients with gastric cancer is important as less extensive dissection may reduce postoperative morbidity and mortality rates. The current study examines the feasibility and reliability of sentinel lymph node biopsy in gastric cancer. METHODS: A total of 32 patients who underwent gastrectomy with extended lymphadenectomy were enrolled in this study. A total volume of 148 MBq (2 mL) technetium-99m-radiolabeled, filtered sulphur colloid solution was injected into the primary lesion under gastroscopy 2 hours before the operation. Lymph nodes were examined as soon as possible by a hand-held gamma probe during the operation, without significant manipulation of the stomach or greater omentum. A sentinel lymph node (SLN) was defined by a level of radioactivity 10 times higher than the background. RESULTS: Thirty-one of 32 patients had successful SLN biopsy, with a success rate of 97%. The sensitivity, specificity, positive predictive value, and negative predictive value of SLN biopsy were 100%, 95%, 90%, and 100%, respectively. CONCLUSIONS: SLN biopsy using gamma probe in gastric cancer is a feasible procedure with high sensitivity and accuracy. This technique may be of a great benefit to surgeons in planning the extend of lymph node dissection in gastric cancer.

Mediastinal intraoperative radioisotope sentinel lymph node mapping in non-small-cell lung cancer.

BACKGROUND: Lymph node metastases are significant prognostic factors in localized non-small-cell lung cancer (NSCLC). Nodal micrometastases may not be detected using current histological methods. AIM: To determine the accuracy and role of sentinel lymph nodes (SLNs) in patients with NSCLC. METHODS: Intraoperative technetium-99m (Tc) sulphur colloid SLN mapping was performed in patients with NSCLC. Serial section histology and immunohistochemistry were used to validate the SLNs and to identify the presence of micrometastatic disease. The study was carried out on 28 consecutive patients (male/female, 25/3; mean age, 57.05+/-7.1 years) with resectable NSCLC. During thoracotomy, 0.25 mCi of Tc sulphur colloid was injected into four quadrants peritumorally. Radioactivity was counted intraoperatively, a mean of 45 min (range, 30-60 min) after injection. SLN was defined as the node with the highest count rate using a hand-held gamma probe counter. Resection with mediastinal node dissection was performed and the findings were correlated with histological examination. RESULTS: SLNs were identified in 26 of 28 patients (92.8%) with a total number of 32 SLNs. Seven of 32 (21.8%) of these SLNs were positive for metastatic involvement after histological and immunohistochemical examination. In two patients (7.1%), SLNs could not be found. CONCLUSIONS: These results demonstrate the feasibility of this procedure in identifying the first site of potential nodal metastasis of NSCLC. This method may improve the precision of pathological staging.

Effect of radioiodine therapy on thyroid nodule size and function in patients with toxic adenomas.

BACKGROUND: Autonomously functioning toxic adenomas are a common cause of hyperthyroidism. Although 131I seems to be a good therapeutic option with little postablative hypothyroidism for these patients, only a small number of recent studies have objectively evaluated changes in nodule size by ultrasonography following radioiodine therapy. METHODS: We prospectively followed 39 patients with a mean age of 51.2 (35-75) years for 12 months and the patients who remained toxic thereafter, until euthyroidism was provided. Thyroid function tests, sonographic volumes were determined initially and 3, 6 and 12 months after treatment. Radioiodine doses of 3.7 MBq.g(-1) thyroid tissue corrected to a 100% 24 h 131I uptake were given. Thirty patients received a single dose, two required two doses and three required three to five doses of 131I due to persistent thyrotoxicosis. Sonographic volumes of the diffuse parts of the glands decreased significantly by 18% from a mean+/-SD value of 50+/-27.6 ml to 41+/-27.4 ml by the end of the 12 months. A significant decrease (8.3%, P=0.002) was achieved in the first three months. Toxic adenomas decreased in size more efficiently (54%) from a mean of 26+/-24 ml to 12+/-10 ml during 12 months, but also most significantly (28.8%, P=0.003) in the first 3 months of the follow-up. Thirty of the patients (76.9%) became euthyroid at the end of 12 months of follow-up. Four patients (10.3%) became overtly hypothyroid during the follow-up. CONCLUSION: Single or multiple doses of radioiodine can successfully treat toxic adenomas with a low rate of hypothyroidism and considerable nodule-volume reduction.