PURPOSE: Radioimmunoassay (RIA) was usually performed by the batch assay. To improve the efficiency of RIA without increase of the cost and time, random assay could be a choice. We investigated the possibility of the random assay using automatic dispenser by assessing the agreement between batch assay and random assay. MATERIALS AND METHODS: The experiments were performed with four items; Triiodothyronine (T3), free thyroxine (fT4), Prostate specific antigen (PSA), Carcinoembryonic antigen (CEA). In each item, the sera of twenty patients, the standard, and the control samples were used. The measurements were done 4 times with 3 hour time intervals by random assay and batch assay. The coefficient of variation (CV) of the standard samples and patients' data in T3, fT4, PSA, and CEA were assessed. ICC (Intraclass correlation coefficient) and coefficient of correlation were measured to assessing the agreement between two methods. RESULTS: The CVs (%) of T3, fT4, PSA, and CEA measured by batch assay were 3.2+/-1.7%, 3.9+/-2.1%, 7.1+/-6.2%, 11.2+/-7.2%. The CVs by random assay were 2.1+/-1.7%, 4.8+/-3.1%, 3.6+/-4.8%, and 7.4+/-6.2%. The ICC between the batch assay and random assay were 0.9968 (T3), 0.9973 (fT4), 0.9996 (PSA), and 0.9901 (CEA). The coefficient of correlation between the batch assay and random assay were 0.9924(T3), 0.9974 (fT4), 0.9994 (PSA), and 0.9989 (CEA) (p<0.05). CONCLUSION: The results of random assay showed strong agreement with the batch assay in a day. These results suggest that random assay using automatic dispenser could be used in radioimmunoassay.
Carcinoembryonic Antigen ; Humans ; Prostate-Specific Antigen ; Radioimmunoassay ; Thyroxine ; Triiodothyronine

PURPOSE: 18F-flurodeoxyglucose (FDG) uptake on positron emission tomography (PET) scan has been found to reflect tumor aggressiveness and prognosis in various types of cancer. However, pattern of FDG uptake in biliary malignancies and its clinical significance have not been studied well. The purpose of this study was to assess the additional value of 18F-FDG PET in differential diagnosis and prognosis of cholangiocarcinoma (CC) according to the tumor location and tumor morphology. MATERIALS AND METHODS: From April 2005 to May 2008, eighty two patients (M:F=55:27, age 66.2+/-9.6 yrs) with CC underwent 18F-FDG PET. For semiquantitative analysis, the maximum standardized uptake value (SUVmax) was obtained from the primary tumor. The difference of SUVmax according to the tumor location and tumor growth pattern, such as scirrhous type, nodular type, polypoid type were compared. RESULTS: Overall sensitivity of PET scan was 81.7% in CC. SUVmax on PET scan in intrahepatic CC was significantly higher compared to extrahepatic CC. In extrahepatic CC, polypoid type showed significantly higher SUVmax compared to scirrhous type. CONCLUSION: 18F-FDG PET may have a significant impact on clinical decision-making and on the management of Intrahepatic cholangiocarcinoma. And it is related to the shape of the tumor and the sensitivity of detection is higher in the mass-forming type than in the scirrhous type.
Cholangiocarcinoma ; Diagnosis, Differential ; Fluorodeoxyglucose F18 ; Humans ; Liver Neoplasms ; Positron-Emission Tomography ; Prognosis

PURPOSE: F-18 FDG can be accumulated in the liver, bowel, kidney, urinary tract, and muscles physiologically. The aim of this study was to evaluate the clinical value of dual time point 18F-FDG PET/CT imaging for the differentiation of the colonic focal uptake lesions. MATERIALS AND METHODS: One hundred thirty two patients (M:F=77:55, Age 62.8 +/-11.6 years) underwent 18F-FDG PET/CT at two time points, prospectively: early image at 50-60 min and delayed image at 4-4.5 hours after the intravenous injection of 18F-FDG. Focally increased uptake lesions on early images but disappeared or shifted on delayed images defined a physiological uptake. For the differential evaluation of persistent focal uptake lesions on delayed images, colonoscopy and histopathologic examination were performed. SUVmax changes between early and delayed images were also compared. RESULTS: Among the 132 patients, 153 lesions of focal colonic uptake were detected on early images of 18F-FDG PET/CT. Of these, 72 (47.1%) lesions were able to judge with physiological uptake because the focal increased uptake disappeared from delayed image. Among 81 lesions which was showed persistent increased uptake in delayed image, 61 (75.3%) lesions were confirmed as the malignant tumor and 14 (17.3%) lesions were confirmed as the benign lesions including adenoma and inflammatory disease. Remaining 6 (7.4%) lesions were confirmed as the physiological uptake because there was no particular lesion in the colonoscopy. In the malignant lesions, the calculated dual time point change for SUVmax (delta%SUVmax) was 20.8%+/-18.7%, indicating a significant increase in SUVmax between the two point (p<0.01). In contrast, the change in SUVmax for the non-malignant lesions including benign lesions and physiological uptake was -13.7%+/-24.2%. For the differentiation of the malignant and non-malignant focal colonic uptake lesions, delta%SUVmax was the most effective parameter, and the cut-off value using -5% provided the best sensitivity, specificity, and accuracy. CONCLUSION: The dual time point 18F-FDG PET/CT imaging with SUVmax change evaluation could be an important noninvasive method for the differentiation of malignant and benign focal colonic uptake lesions including physiologic uptake.
Adenoma ; Colon ; Colonoscopy ; Fluorodeoxyglucose F18 ; Humans ; Injections, Intravenous ; Kidney ; Liver ; Muscles ; Sensitivity and Specificity ; Urinary Tract

PURPOSE: The aim of this study was to evaluate the usefulness of FDG-PET/CT as follow up imaging tool in patients with endometrial cancer after therapy. Material and Methods: One hundred one patients with endometrial cancer who underwent FDG PET/CT after the treatment of this disease were included in this study population (25-79 yr old, Mean age 50.6 yr old) and all these patients also performed various laboratory and imaging studies such as serum tumor marker, CT or MRI. The lesions having increased focal FDG uptake were classified into benign, equivocal, and malignant one according to their pattern and activity. Tumor recurrence was confirmed by histopathological results and other clinical and imaging data. RESULTS: Among the 19 patients with 30 malignant or equivocal hot uptakes, 11 of 14 patients supposed to be malignant finding in PET/CT were proved to be tumor recurrence, while one of 5 patients with equivocal lesions were recurred malignancy. Two false negative cases were turned out to be peritoneal carcinomatosis. Estimated sensitivity, specificity and accuracy of PET/CT for diagnosis of recurrence in endometrial carcinoma after treatment were 86 %, 92 % and 91%, respectively. Positive and negative predictive values in the same issue were 63% and 98%, respectively. CONCLUSION: FDG-PET/CT is useful for regular work up of endometrial carcinoma after the treatment because of its high negative predictive value as well as high sensitivity and specificity.
Carcinoma ; Endometrial Neoplasms ; Female ; Follow-Up Studies ; Humans ; Recurrence ; Sensitivity and Specificity

PURPOSE: The purpose of this study was to evaluate if short-term serum thyroglobulin (Tg) elevation after radioiodine administration can predict successful radioiodine remnant ablation (RRA) and whether comparable RRA effectiveness is exhibited between a group administered with recombinant human thyrotropin (rhTSH) and a group experiencing thyroid hormone withdrawal (THW), in preparation for RRA. MATERIALS AND METHODS: A retrospective chart review was performed on 39 patients in the rhTSH group and 46 patients in the THW group. They were treated for differentiated thyroid carcinoma by total or near total thyroidectomy, and referred for RRA between 2003 and 2006 (the rhTSH group) and between January and June of 2006 (the THW group). They were assessed for serum Tg levels just before I-131 administration (TgD0), reassessed 9 days later (TgD9), and again 6-12 months later. RESULTS: RRA was successful in 64 (37 from the THW group and 27 from the rhTSH group) of the total 85 patients. The success rates of RRA had no statistically significant differences between the two groups. In both groups, TgD9/TgD0 values were significantly higher in the RRA success group (the rhTSH group; P=0.03, the THW group; P=0.04). By combining cutoff values of TgD0 and TgD9/TgD0, the successful RRA value was determined to be 96.7% (29/30) with TgD0< or =5.28 ng/mL and TgD9/TgD0>4.37 in both groups (the rhTSH group; 100% (16/16), the THW group; 92.9% (13/14)). Using logistic multivariate analysis, only TgD0 was independently associated with successful RRA. CONCLUSION: We may predict successful ablation by evaluating short-term serum Tg elevation after I-131 administration for RRA, in both rhTSH and THW patients.
Humans ; Multivariate Analysis ; Retrospective Studies ; Thyroglobulin ; Thyroid Gland ; Thyroid Neoplasms ; Thyroidectomy ; Thyrotropin ; Thyrotropin Alfa

PURPOSE: This study is to evaluate rib fractures on bone scan in breast cancer patients treated with breast cancer surgery and radiation therapy and to evaluate its relation with radiation therapy and operation modality. MATERIALS AND METHODS: Two hundred seventy cases that underwent serial bone scan after breast cancer surgery and radiation therapy were enrolled. Bone scan and chest CT findings of rib fracture were analyzed. RESULTS: The rib uptake was seen in 74 of 270 cases (27.4%) on bone scan and 50 cases (18.5%) were confirmed to have rib fracture by chest CT. The rate of modified radical mastectomy in patients with rib fracture was significantly higher than that in patients without rib fracture (66.0% vs. 27.0%, p=0.000). The rate of additional radiation therapy to axillar or supraclavicular regions in patients with rib fracture was significantly higher than that in patients without rib fracture (62.0% vs. 28.6%, p=0.000). Rib fracture was seen most frequently at 1-2 years after radiation therapy (51.9%) and single rib fracture was seen most frequently (55.2%). Of total 106 rib fractures, focal rib uptake was seen in 94 ribs (88.7%) and diffuse rib uptake was seen in 12 ribs (11.3%). On one year follow-up bone scan, complete resolution of rib uptake was seen in 15 ribs (14.2%). On chest CT, the rate of fracture line in ribs with intense uptake was significantly higher than that in ribs with mild or moderate uptake (p=0.000). The rate of presence of fracture line in ribs with focal uptake was significantly higher than that in ribs with diffuse uptake (p=0.001). CONCLUSION: Rib fracture in breast cancer patients after radiation therapy was related to radiation portal and operation modality. It should be interpreted carefully as a differential diagnosis of bone metastasis.
Breast ; Breast Neoplasms ; Diagnosis, Differential ; Follow-Up Studies ; Humans ; Mastectomy, Modified Radical ; Rib Fractures ; Ribs ; Thorax

PURPOSE: The aim of this study was to evaluate the hemodynamic changes after endovascular stenting in patients with unilateral middle cerebral artery (MCA) stenosis using statistical probabilistic anatomical mapping (SPAM) analysis of basal/acetazolamide (ACZ) Tc-99m ECD brain perfusion SPECT. MATERIALS AND METHODS: Eight patients (3 men and 5 women, 64.8+/-10.5 years) who underwent endovascular stenting for unilateral MCA stenosis were enrolled. Basal/ACZ Tc-99m ECD brain perfusion SPECT studies were performed by one-day protocol before and after stenting. Using SPAM analysis, we compared basal cerebral perfusion (BCP) counts and cerebrovascular reserve (CVR) index of the MCA territory before stenting with those after stenting. RESULTS: After stenting, no patient had any complication nor additional stroke. In SPAM analysis, 7 out of the 8 patients had improved BCP counts of the MCA territory and 7 out of the 8 patients had improved CVR index of the MCA territory after stenting. Before stenting, the mean BCP counts and CVR index in the affected MCA territory were 47.1+/-2.2 ml/min/100 g and -2.1+/-2.9%, respectively. After stenting, the mean BCP counts and CVR index in the affected MCA territory were improved significantly (48.3+/-2.9 ml/min/100 g, p=0.025 and 0.1+/-1.3%, p=0.036). CONCLUSION: This study revealed that SPAM analysis of basal/ACZ brain perfusion SPECT would be helpful to evaluate hemodynamic efficacy of endovascular stenting in unilateral MCA stenosis.
Brain ; Constriction, Pathologic ; Cysteine ; Female ; Hemodynamics ; Humans ; Male ; Middle Cerebral Artery ; Organotechnetium Compounds ; Perfusion ; Stents ; Stroke ; Tomography, Emission-Computed, Single-Photon

Radioiodine ablation therapy has been considered to be a standard treatment for patient with differentiated thyroid cancer after total thyroidectomy. Patients may need to be hospitalized to reduce radiation exposure of other people and relatives from radioactive patients receiving radioiodine therapy. Medical staffs, nursing staffs and technologists sometimes hesitate to contact patients in radioiodine therapy ward. The purpose of this paper is to introduce radiation dosimetry, estimate radiation dose from patients and emphasize the safety of radiation exposure from patients treated with high dose radioiodine in therapy ward. The major component of radiation dose from patient is external exposure. However external radiation dose from these patients treated with typical therapeutic dose of 4 to 8 GBq have a very low risk of cancer induction compared with other various risks occurring in daily life. The typical annual radiation dose without shielding received by patient is estimated to be 5 to 10 mSv, which is comparable with 100 to 200 times effective dose received by chest PA examination. Therefore, when we should keep in mind the general principle of radiation protection, the risks of radiation exposure from patients are low and the medical personnel are considered to be safe from radiation exposure.
Humans ; Medical Staff ; Nursing Staff ; Radiation Protection ; Radiometry ; Thorax ; Thyroid Neoplasms ; Thyroidectomy

Bone scintigraphy using 99mTc-labeled phosphate agents has long been the standard evaluation method for whole skeletal system. However, recent shortage of 99mTc supply and advanced positron emission tomography (PET) technology evoked the attention to surrogate radiopharmaceuticals and imaging modalities for bone. Actually, fluorine-18 (18F) was the first bone seeking radiotracer before the introduction of 99mTc-labeled agents even though its clinical application failed to become pervasive anymore after the rapid spread of Anger type gamma camera systems in early 1970s. However, rapidly developed PET technology made us refocus on the usefulness of 18F as a PET tracer. Early study comparing 18F-Na PET scan and planar bone scintigraphy reported that PET has higher sensitivity and specificity in the diagnosis of metastatic bone lesions than planar bone scan. Subsequent reports comparing between PET and both planar and SPECT bone image also revealed better results of PET scan in similar study groups. Rapid clinical application of PET/CT also accumulated considerable amount of experiences in skeletal evaluation and this modality is known to have better diagnostic power than stand alone PET system as well as bone scan. Furthermore 18F-Na PET/CT revealed better or at least equal results in detection of primary and metastatic bone lesions compared with CT and MRI. Therefore, it is obvious that 18F-Na PET/CT has potential to become new imaging modality for practical skeletal evaluation so continuous and careful evaluation of this modality and radiopharmaceutical must be required.
Anger ; Gamma Cameras ; Positron-Emission Tomography ; Radiopharmaceuticals ; Sensitivity and Specificity ; Tomography, Emission-Computed, Single-Photon

No abstract available.
Diagnosis* ; Necrosis*