Long-term Intense 18F-FDG Uptake by the Homeostatic Matrix-associated Inflammatory Response May Mimic Malignancy Recurrence.

A 70-year-old man underwent right upper lobectomy for lung adenocarcinoma. During the operation, hemostatic matrix (as known Floseal®) was used to prevent pulmonary laceration-associated bleeding. When 18F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography was performed for staging after surgery, intense 18F-FDG uptake was observed in the cicatricial fibrotic tissue in the operation area, and no significant change was observed in that area during the 4-year follow-up. Because it remained stable for several years without treatment, this finding was thought to be due to a foreign body reaction caused by the homeostatic material.

Magnetic Resonance Imaging Signal Changes Mimicking Bone Metastasis in Patients Receiving Bisphosphonate Therapy

Bisphosphonates are inorganic pyrophosphate agents that reduce bone turnover. These agents reduce bone pain and delay skeletal complications, such as fractures in patients with metastatic lytic lesions, malignant-related hypercalcemia, multiple myeloma, Paget's disease of bone, and osteoporosis. Osteonecrosis, developing in the jaw bones specifically, has been described as a complication associated with the use of bisphosphonates. In this report, we presented osteonecrosis-like magnetic resonance imaging findings that can be confused with bone metastasis in two patients who underwent long-term bisphosphonate treatment and the value of bone scan and 18flor-fluorodeoxyglucose positron emission tomography/computerized tomography in the differential diagnosis.

PET Parameters are Useful in Predicting Endometrial Cancer Risk Classes and Prognosis.

AIM: We investigate the role of preoperative PET parameters to determine risk classes and prognosis of endometrial cancer (EC). METHODS: We enrolled 81 patients with EC who underwent preoperative F-18 FDG PET/CT. PET parameters (SUVmax, SUVmean, MTV, TLG), grade, histology and size of the primary tumor, stage of the disease, the degree of myometrial invasion (MI), and the presence of lymphovascular invasion (LVI), cervical invasion (CI), distant metastasis (DM) and lymph node metastasis (LNM) were recorded. The relationship between PET parameters, clinicopathological risk factors and overall survival (OS) was evaluated. RESULTS: The present study included 81 patients with EC (mean age 60). Of the total sample, 21 patients were considered low risk (endometrioid histology, stage 1A, grade 1 or 2, tumor diameter < 4 cm, and LVI negative) and 60 were deemed high risk. All of the PET parameters were higher in the presence of a high-risk state, greater tumor size, deep MI, LVI and stage 1B-4B. MTV and TLG values were higher in the patients with non-endometrioid histology, CI, grade 3 and LNM. The optimum cut-off levels for differentiating between the high and low risk patients were: 11.1 for SUVmax (AUC = 0.757), 6 for SUVmean (AUC = 0.750), 6.6 for MTV(AUC = 0.838) and 56.2 for TLG(AUC = 0.835). MTV and TLG values were found as independent prognostic factors for OS, whereas SUVmax and SUVmean values were not predictive. CONCLUSIONS: The PET parameters are useful in noninvasively differentiating between risk groups of EC. Furthermore, volumetric PET parameters can be predictive for OS of EC.

Clinical behavior and outcome of papillary T1 thyroid cancers: South Korea vs. Turkey vs. Colombia in a cohort study analyzing oncological outcomes.

BACKGROUND/PURPOSE: There has not been an international multicentric study to examine the relationship between thyroid cancer clinical outcomes and geographic location for South Korea, Colombia, and Turkey, whereas thyroid cancer is amongst the highest three cancer types seen in South Korea and Turkey. The aim of the study was to assess regional differences of T1 papillary thyroid cancer outcomes in Korea, Turkey and Colombia. METHODS: This is an observational non-randomized study. A total of 2720 patients who have been operated for T1 papillary thyroid cancer between 2011 and 2014 and are on routine follow-up have been recruited. The mean follow-up was 46.4 ± 10.7 months. Data were collected in a commonly used database and analyses were conducted. RESULTS: Patients participated in South Korea (88.2%), Turkey (9.1%) and Colombia (2.6%). Eighty percent were female. Female dominance tended to be higher in Colombia (p = 0.01). Mean age at diagnosis was 45.2 years. There was no mortality. Recurrence tended to be higher in Colombia (p < 0.001). Moreover, statistical analysis revealed differences among patients regarding symptoms (p < 0.001), family history (p < 0.001), euthyroidism (p < 0.001), anti-Tg and/or anti-TPO positivity (p < 0.001), FNAB results (p < 0.001), type of resection (p < 0.001), prophylactic central node dissection (p < 0.001), tumor size (p < 0.001), multifocality (p < 0.001), bilaterality (p < 0.001), tumor subtype (p < 0.001) and radioactive iodine treatment (p < 0.01). CONCLUSION: Thyroid cancer is becoming more commonly diagnosed worldwide. This international multicentric study has identified differences in disease presentation, treatment approaches and outcome, which need to be investigated, especially by increasing the number of participating countries. Future comparisons will facilitate developments in treatment for the benefit of patient outcomes.

False-positive I-131 Uptakes at Pulmonary Wedge-resection Site and Soft Tissue Lateral to the Femoral Heads in a Patient with Papillary Thyroid Carcinoma

A hyper-metabolic pulmonary nodule was detected on 18F-FDG PET/CT in a 65-year-old woman who had been followed up for 12 years without any complaints following treatment for papillary thyroid cancer (PTC). Wedge resection was performed to the pulmonary nodule and the pathologic examination revealed PTC metastasis. On the post-therapeutic I-131 scan after radioiodine treatment, focal I-131 uptake was detected at the site of pulmonary wedge resection. At first, this finding was thought to be related to the residual lesion but diagnostic CT demonstrated only focal traction bronchiectasis at that region. In addition, a false-positive I-131 uptake was also detected at the soft tissue just lateral to the femoral heads probably due to inflammation.

Early predictive value of baseline renal transplant scintigraphy in pediatric patients.

OBJECTIVES: The value of baseline renal transplant scintigraphy (RTS) with technetium-99m diethylenetriaminepentaacetic acid (Tc-DTPA) performed within 2 days after transplantation in predicting early renal transplant outcome in pediatric recipients was assessed in this study. PATIENTS AND METHODS: Baseline RTS of 48 pediatric patients were studied retrospectively. Hilson's perfusion index, graft index (GI), time between peak perfusion and iliac artery (ΔP), and the ratios of peak perfusion to plateau (P : Pl), to peak iliac artery (P : A), and to peak uptake (P : U) were obtained. In 14 patients younger than 9 years old, because of faint visualization of iliac artery, the perfusion indices and GI could not be calculated. The 'Bedside Schwartz' formula was used for calculation of follow-up estimated glomerular filtrate rate (eGFR) values. The need for dialysis in the first week or decreasing serum creatinine of less than 10%/day during 3 consecutive days after the transplantation was accepted as delayed graft function (DGF). The patients, whose creatinine reduction ratio was less than 70% on day 7 after transplantation without DGF, were accepted as slow graft function (SGF). RESULTS: The means of GI, P : U, and Hilson's perfusion index were significantly high in SGF/DGF (n=10). GI and P : U had very high accuracy in the diagnosis of DGF/SGF (area under the curve>0.90). A strong correlation was found between P : U and same day and between GI and day 15 eGFR values. GI, P : U, and P : A were significant for the prediction of follow-up eGFR of less than 60 ml/min/1.73 m. GI was more accurate than the others. CONCLUSION: Our experience in this study underlines the importance of RTS, especially with the use of GI and P : U, which are very valuable in diagnosing DGF/SGF and predicting early transplant outcome in pediatric recipients.

Contribution of SPECT/CT to Evaluate Urinary Leakage Suspicion in Renal Transplant Patients.

It is known that renal scintigraphy is the best imaging modality in the diagnosis of urinary leakage. Usually, only planar images are diagnostic but sometimes they are unclear when urinoma is small and adjacent to kidney or bladder. In other respects, planar images can be false-positive in the case of increased blood flow of abdominal wall. We suggested using SPECT/CT in differential diagnosis. An atlas of SPECT/CT is presented, which includes 3 cases that urinoma was diagnosed by SPECT/CT, which were unclear on planar images, and one case that urinary leakage suspicion on planar image was ruled out by SPECT/CT.

The Contribution of Fluorine 18F-FDG PET/CT to Lung Cancer Diagnosis, Staging and Treatment Planning.

OBJECTIVE: Lung cancer is the most common cause of cancer-related death throughout the world, and the correct choice of treatment based on early diagnosis and staging increases the chance of survival. The present study aims to investigate the contribution of fluorine 18-fluorodeoxyglucose-positron emission tomography/computed tomography (18F-FDG PET/CT) to the management of lung cancer. METHODS: In this study, 50 patients who underwent 18F-FDG PET/CT for lung cancer diagnosis and staging between February 2012 and February 2014 were included. The maximum standardized uptake value (SUVmax) of the primary lung lesion along with other findings of 18F-FDG PET/CT and the results of histopathologic and conventional examinations were evaluated retrospectively. The mean survival time of patients was determined, and the findings were compared by using statistical methods. RESULTS: Histopathologic examinations revealed 51 lung cancers in 50 patients. The sensitivity, accuracy and positive predictive value of 18F-FDG PET/CT in detecting primary malignancy were 94%, 94%, 100%, respectively. Adenocarcinoma (n=23, 16.8±13.5) and squamous cell carcinoma (n=15, 17.9±5.6) did not differ significantly regarding their mean SUVmax values (p=0.2). A statistically significant positive correlation (r=0.4) was identified between tumor size and SUVmax value for 51 tumors (p=0.002). The 18F-FDG PET/CT result was true negative in nine, false positive in six, true positive in two, and false negative in four patients who underwent histopathologic evaluation of their lymph nodes. The 18F-FDG PET/CT changed treatment planning in 34% of the patients. No significant relationship was identified between SUVmax value of the tumor and patient survival in patients (p=0.118). CONCLUSION: The present study concluded that PET/CT was an efficient method in the diagnosis and staging of lung cancer since it provided useful information in addition to conventional methods. It was also observed that PET/CT scanning resulted in a change in therapeutic plans in the majority of patients. However, there was no statistically significant relationship between survival and the SUVmax of the primary mass.

Two Different Causes of Decreased Activity on Ipsilateral Iliac Artery in Renal Transplant Scintigraphy.

In 2 patients, perfusion images of renal transplant scintigraphy showed similarly decreased activity on ipsilateral iliac artery. One's graft was photopenic because of arterial thrombosis. However, the other's graft had sufficient perfusion and no abnormality in iliac arteries, but he had femoral arteriovenous graft for hemodialysis on the contralateral side. So, in this patient, decreased activity on ipsilateral iliac artery was probably related to increased arterial flow of the contralateral side. It should be considered that decreased activity on ipsilateral iliac artery in perfusion images is not only due to ipsilateral problem; the cause could be on the contralateral side.

Scintigraphic and Sonographic Findings of Subcapsular Cortical Necrosis in a Transplanted Kidney.

Renal transplant scintigraphy, performed in a 23-year-old man who had renal graft from a living donor, showed nearly normal perfusion and moderately low function of the graft. But the margins of the graft were blurred, and it was interestingly appearing enlarged late in the study. Ultrasound demonstrated a hypoechoic rim surrounding the whole kidney. Biopsy revealed necrosis besides normal cortical tissue. Necrosis was thought to be limited to the subcapsular cortical area. It should be considered that these scintigraphic findings could be due to greatly reduced and delayed perfusion of edematous subcapsular necrotic area of the graft even in normal perfusion images.

Recurrence Incidence in Differentiated Thyroid Cancers and the Importance of Diagnostic Iodine-131 Scintigraphy in Clinical Follow-up.

OBJECTIVE: Differentiated thyroid cancers (DTC) are tumors with good prognosis. However, local recurrence or distant metastasis can be observed. In our study, we aimed to investigate the incidence of recurrence and the importance of diagnostic iodine-131 whole body scan (WBS) in clinical follow-up in patients with DTC. METHODS: The clinical data of 217 patients with DTC who were followed-up more than 3 years were reviewed retrospectively. The incidence of recurrence was investigated in a group of patients who had radioactive iodine (RAI) treatment and showed no sign of residual thyroid tissue or metastasis with diagnostic WBS that was performed at 6-12 months after therapy and had a thyroglobulin (Tg) level lower than 2 ng/dl. RESULTS: At the time of diagnosis, ten cases had thyroid capsule invasion, 25 cases had extra-thyroid soft tissue invasion, 11 patients showed lymph node metastasis and four patients had distant organ metastasis. One hundred forty-five patients had RAI treatment at ablation dose (75-100 mCi), whereas 35 patients had RAI treatment at metastasis dose (150-200 mCi). Thirty-seven patients with papillary microcarcinoma did not receive RAI treatment. In 12 (%7.5) of the 160 patients who were considered as "successful ablation", a recurrence was identified. Recurrence was detected by diagnostic WBS in all cases and stimulated Tg level was <2 ng/dL with the exception of the two cases who had distant metastasis. CONCLUSION: Identification of pathological findings with WBS in patients who developed local recurrence in the absence of elevated Tg highlights the importance of diagnostic WBS in clinical follow-up.

Risk factors for persistent disease in papillary thyroid carcinoma with lymph node metastasis.

PURPOSE: It is known that the presence of neck lymph node (LN) metastasis is correlated with persistent disease in papillary thyroid carcinoma (PTC) patients. After appropriate therapy, most patients become disease free, whereas some may still have persistent disease. The present study aimed to determine the potential variables affecting the clinical course of the disease and persistent disease patterns in PTC patients with LN metastasis. MATERIALS AND METHODS: The study group included consecutive PTC patients with LN metastasis. Clinicopathological characteristics and persistent disease pattern during the follow-up period were examined to identify risk factors for persistent disease using univariate and multivariate analyses. RESULTS: At the end of a median follow-up of 84 months, 90 (69%) patients became disease free and 40 (31%) patients had persistent disease. Univariate analysis showed that male sex, older age at initial diagnose (≥45 years), larger tumor size (>4 cm), presence of lateral cervical LN metastasis, extrathyroidal invasion, and higher number of metastatic LN (≥10) were significant predictors for persistent disease. Multivariate analysis showed that extrathyroidal involvement, presence of lateral cervical LN metastasis, and older age at initial diagnosis (≥45 years) were independent predictors for persistent disease. CONCLUSION: Despite the presence of LN involvement, most patients may become disease free with therapy. Patients with extrathyroidal invasion, lateral cervical LN involvement, and those at least 45 years old at initial diagnosis are more likely to have persistent disease. However, disease control can be achieved with close clinical follow-up and therapy.

A New Quantitative Index for Baseline Renal Transplant Scintigraphy With 99mTc-DTPA in Evaluation of Delayed Graft Function and Prediction of 1-Year Graft Function.

PURPOSE: The aims of this study were to assess quantitative indices of baseline renal transplant scintigraphy (RTS) with Tc-DTPA for evaluation of delayed graft function (DGF) and prediction of 1-year graft function and to describe a new inclusive index for RTS. PATIENTS AND METHODS: A total of 179 patients to whom RTS with Tc-DTPA was performed within 2 days after kidney transplantation were analyzed retrospectively. Hilson perfusion index, perfusion time (ΔP), peak-to-plateau ratio, peak perfusion-to-iliac artery ratio, T½ of graft washout, peak perfusion-to-uptake ratio, and ratio of uptake at 20 to 3 minutes (R20/3) were obtained. In addition, we first described the following formula defined as graft index (GI): GI = (ΔP × arterial peak × plateau)/(perfusion peak × uptake at 3 minutes). At 1 year, a serum creatinine level of more than 1.5 mg/dL was considered to be abnormal. Mann-Whitney U, Spearman coefficient of correlation test, and receiver operating characteristic curve were used for statistical analyses. P < 0.05 was considered statistically significant. RESULTS: Mean values of all the indices were significant. The most accurate, sensitive, and specific index for both identification of DGF and prediction of 1-year serum creatinine level of more than 1.5 mg/dL was GI. Area under the curve of GI was 0.94 for identification of DGF and 0.79 for 1-year prediction. CONCLUSIONS: The question is, "Which index is the best indicator?" This study demonstrated that the parameters of ΔP, plateau, arterial peak, perfusion peak, and uptake at 3 minutes of RTS could be assessed together by the formula of GI, which provides more accurate information to identify DGF and predict 1-year graft function.

A Clear Cell Variant of Papillary Thyroid Microcarcinoma With Lung, Bone, and Soft Tissue Metastases.

A 56-year-old woman presented with a mass lesion on the right occipital bone underwent total resection of the tumor. An adenocarcinoma with immunostaining positive for thyroid transcription factor-1 and thyroglobulin was found. An ultrasound/thyroid scan detected a hot nodule of 9 mm in the right lobe. Fine needle biopsy revealed the similar histological findings with the previous bone resection material. Then, a total thyroidectomy was performed. Histopathologic examination revealed clear cell variant of papillary thyroid microcarcinoma. She received 7.4 GBq of I. On posttherapy scan, metastatic focuses were seen in the left lung and soft tissue between the left paravertebral muscles.

Evaluation of Renal Transplant Scintigraphy and Resistance Index Performed Within 2 Days After Transplantation in Predicting Long-Term Graft Function.

PURPOSE: Value of renal transplant scintigraphy and resistance index (RI) in the assessment of renal graft function is well known. The aim of this study was to evaluate the predictive value of renal transplant scintigraphy and RI for long-term graft function. MATERIALS AND METHODS: A total of 119 patients were analyzed retrospectively. Renal transplant scintigraphy with technetium Tc 99 m DTPA and color Doppler ultrasonography for RI were performed to each patient within 2 days after transplantation. Resistance index and the results of the tests in perfusion/renographic curve analysis of scintigraphy were compared with the serum creatinine (sCr) levels at 3 months, 1 year, and 5 years after transplantation. A sCr level of more than 1.5 mg/dL was considered abnormal. RESULTS: Differences of the mean values of T½ of graft washout (GW½), time difference between peak renal perfusion and arterial count ([INCREMENT]P), and accumulation index (R20/3) were significantly high in patients with high follow-up sCr (>1.5 mg/dL) (P < 0.01). The correlation of these tests with the follow-up sCr levels was significant (P < 0.01). The number of recipients with high perfusion curve grade was also significant in the follow-up groups with high sCr levels. However, difference of the mean value of RI was insignificant between the follow-up groups, and there was no correlation between the RI and sCr levels. CONCLUSION: Renal transplant scintigraphy performed within 2 days after transplantation is useful in the prediction of long-term graft function at 3 months, 1 year, and 5 years; and it is superior to resistance index.

To what extent estimated or measured GFR could predict subclinical graft fibrosis: a comparative prospective study with protocol biopsies.

Monitoring of allograft function entails methods more accurate than serum creatinine and creatinine-based GFR equations (eGFR). This prospective trial aimed at investigating the diagnostic accuracy of creatinine- and cystatin C-based eGFR with measured GFR (mGFR) and compared them with graft fibrosis detected by protocol biopsies (PBx). Forty-four kidney transplant recipients were enrolled. PBx were obtained postengraftment and at 6th and 12th months. GFR was measured by Tc-99m DTPA at 3th, 6th, and 12th months after transplantation. Significant correlation existed between eGFR and mGFR at 3, 6, and 12 months (P < 0.0001). Cystatin C-based Hoek and Larsson equations had the lowest bias and highest accuracy. The sum of interstitial fibrosis and tubular atrophy score increased from implantation to 6th and 12th months (0.52 ± 0.79, 0.84 ± 0.88, 1.50 ± 1.35). This was accompanied by reduction of mGFR from 54.1 ± 15.2 to 49.9 ± 15.2 and 46.8 ± 16.5 ml/min/1.73 m(2) , while serum creatinine, cystatin C, and eGFR remained stable. Neither creatinine- nor cystatin C-based GFR equations are reliable for detecting insidious graft fibrosis. In the first year after transplantation, mGFR, with its best proximity to histopathology, can be used to monitor allograft function and insidious graft fibrosis.

Comparison of renal transplant scintigraphy with renal resistance index for prediction of early graft dysfunction and evaluation of acute tubular necrosis and acute rejection.

PURPOSE: We discuss whether resistance index (RI) and renal scintigraphy obtained within 48 hours after operation could predict the early graft dysfunction. We also aimed to assess the uses of scintigraphy and RI in diagnosis of acute rejection (AR) and acute tubular necrosis (ATN). METHODS: A total of 153 studies were performed in 109 patients. T½ of perfusion peak, perfusion curve grades, and accumulation index (R20/3) were used as scintigraphic parameters. Baseline studies obtained within 48 hours after transplantation were evaluated for prediction of early graft dysfunction. All data were then assessed for specific diagnosis. RESULTS: Scintigraphic parameters were significantly higher in patients with delayed graft function (DGF) and slow graft function (SGF) than in patients with immediate graft function. These parameters in DGF were also considerably different from those in SGF. The mean RI was significantly high in DGF, but there was no difference between SGF and immediate graft function. In diagnostic groups, the mean values of all tests were significantly different between normal functioning grafts and pathological grafts (ATN + AR). There was no significant difference between AR and ATN. However, renal scintigraphy has higher sensitivity and specificity for AR as compared with RI of Doppler ultrasonography (US). CONCLUSIONS: In predicting graft dysfunction and separating normal functioning graft from pathological graft (ATN + AR), renal scintigraphy provides more accurate information than Doppler US. Even though it is superior to Doppler US, renal scintigraphy also cannot reliably separate ATN from AR. The major advantage of renal scintigraphy is the early detection of reduced renal function.

Comparison of exercise-rest-reinjection Tl-201 imaging and rest sublingual isosorbide dinitrate Tc-99m MIBI imaging for the assessment of myocardial viability.

PURPOSE: Nitrate administration has been proposed to enhance the detection of myocardial viability when performing myocardial perfusion imaging. In this study, we aimed to compare Tl-201 exercise-rest-reinjection protocol with rest isosorbide dinitrate (ISDN)-Tc99m MIBI study in the same population examined for the myocardial viability. METHODS: Twenty-six patients with coronary artery disease who had fixed segmental defects on exercise-rest-Tl-201 imaging were studied. All of them underwent Tl-201 reinjection study. Within 1 week of Tl-201 imaging, rest-Tc99m MIBI imaging was performed after sublingual 5 mg ISDN administration (2-day protocol). For each study, tomograms were divided into 20 segments based on three short-axis slices, one vertical long-axis representing the totality of the left ventricle and regional tracer uptake was quantitatively analyzed. Regional tracer uptake was evaluated in 20 myocardial segments for all patients. Viability was defined as presence of tracer uptake >/=50% of peak activity on each study. A total 520 myocardial segments were assessed by semi quantitative analysis. RESULT: On the baseline rest Tl-201 studies, 211 segments of the 520 segments that were analyzed had <50% of peak activity. Of these segments, 42 (20%) showed reversibility after reinjection Tl-201 imaging and 55 segments (27%) described as viable on the rest ISDN-Tc99m MIBI imaging. There was 89% concordance between the ISDN-Tc99m MIBI study and Tl-201 reinjection study regarding viable myocardial segments. Of the 23 segments with discordant results, 18 were irreversible on Tl-201 reinjection study, but showed >/=50% uptake on ISDN-Tc99m MIBI. CONCLUSION: Observation of good agreement between Tl-201 reinjection and ISDN-Tc99m MIBI study studies led us to suggest the use of ISDN enhanced imaging in the evaluation of myocardial viability.

Hypothyroid Hashimoto's thyroiditis with scintigraphic and color flow doppler sonography features mimicking a hot nodule.

We report a 59-year-old woman who had Hashimoto's thyroiditis (HT) with hypothyroidism. A solid hypervascularized nodule in the right lobe was detected by color flow doppler sonography (CFDS). Thyroid (99m)Tc pertechnetate scintigraphy revealed a hot area in the right lobe. After three months, thyroid function tests also revealed hypothyroidism and (131)I scintigraphy was similar to the previous scintigraphy. No nodular or hypervascularized lesion in the right lobe could be identified at the sixth month of L-T4 substitution therapy. In conclusion, HT may present as a single hot nodule and hypothyroidism. Imaging findings of HT should be carefully evaluated for the precise diagnosis.

Clinical implications of diffuse hepatic uptake observed in postablative and post-therapeutic I-131 scans.

Diffuse hepatic uptake of I-131 either on diagnostic or post-therapeutic scans is a usual finding in patients with differentiated thyroid carcinoma. The aim of this study was to evaluate the frequency and clinical significance of diffuse hepatic uptake of radioiodine on post-therapeutic (PT) and postablative (PA) whole-body scans.A total of 720 PA and 172 PT I-131 scans in a total of 732 patients with differentiated thyroid carcinoma were retrospectively reviewed. Residual thyroid tissue and diffuse liver uptake of I-131 were classified from 0 to 4. The correlation between the liver and thyroid remnant uptake score, dose of radioiodine, serum thyroglobuline (Tg), liver function test levels (ALT, AST), liver ultrasonography, presence of metastatic foci, and recurrent disease were examined.Diffuse hepatic uptake was observed in 701 of 722 (94.2%) PA and 162 of 172 (97%) PT whole body I-131 scans. Hepatic radioiodine uptake was positively correlated with the dose of administered I-131 and increased levels of serum AST and ALT. Liver uptake scores of patients with hepatosteatosis were significantly higher than all study groups. However, no evidence of a relationship between diffuse visualization of liver and serum thyroglobulin levels, uptake score of thyroid remnants, presence of local or distant metastatic foci on I-131 scan, and recurrence rate could be demonstrated.The lack of correlation between hepatic radioactive iodine (RAI) uptake and Tg levels, functioning metastatic tissue or thyroid remnants suggests that this finding may be related to factors other than thyroid tissue. The positive correlation between administered RAI dose, hepatic enzymes and hepatosteatosis support the conclusion that diffuse hepatic RAI uptake may be related to different mechanisms as well.