Poisoning ; drug therapy ; Thallium ; toxicity

Graphite ; Humans ; Spectrophotometry, Atomic ; methods ; Thallium ; urine

Adult ; Heavy Metal Poisoning ; Humans ; Male ; Poisoning ; Thallium ; poisoning

Adult ; Autopsy ; Female ; Hair ; metabolism ; Humans ; Liver ; pathology ; Thallium ; poisoning

PURPOSE: The current study was designed to evaluate the ability of thallium-201 scintigraphy to predict the response to preoperative chemotherapy in osteosarcoma, by comparing changes in thallium uptake ratio after chemotherapy to the tumor necrosis ratio. MATERIALS AND METHODS: Twelve osteosarcoma patients were included in this study. Thallium-201 scintigraphy was performed before and after preoperative chemotherapy, and the degree of tumor necrosis was estimated by histologic mapping postoperatively. To quantitatively determine thallium uptake, we drew a region of interest on the tumor side and on the contralateral normal side as a mirror image, and calculated the uptake ratio with dividing the gamma count in the tumor side by that of the normal side. We calculated these percent changes of thallium uptake ratio in the early and delayed phases, and compared these to the corresponding tumor necrosis ratio. RESULTS: Percent changes in the thallium uptake ratio were found to be correlated with the tumor necrosis ratio (p<0.03). This correlation was found in both the early (p<0.03) and delayed phase (p<0.03); moreover the correlation coefficient in early phase (0.79) was greater than that in the delayed phase (0.67). CONCLUSION: Thallium-201 scintigraphy could be effective at predicting the response to preoperative chemotherapy in osteosarcoma.
Drug Therapy* ; Humans ; Necrosis ; Osteosarcoma* ; Radionuclide Imaging* ; Thallium

BACKGROUND: Coronary microcirculation impairment with sequential decrease in cardiac function is reflected by abnormal left ventricular ejection fraction reserve (LVEFR),which precedes diagnostic evidence of myocardial insult. However, prognostic utility of LVEFR is less, if not least explored. The aim of this study was to evaluate the clinical utility of LVEFR in predicting major cardiac events (MACE) among patients with and suspected coronary artery disease (CAD).
MATERIALS AND METHODS: A retrospective cohort study of 245 patients who underwent stress thallium-201 myocardial perfusion scan (MPS) was conducted. The patients were categorized as having normal or abnormal perfusion scan. Each group was subdivided into normal and abnormal LVEFR groups. All subjects were followed up for any major adverse cardiac events 36 months after MPS through review of hospital records.
RESULTS: There was an overall increase in the likelihood of cardiac events with abnormal LVEFR (i.e., odds ratio of 2.99,p=<0.01). Majority of subjects with abnormal MPS also had abnormal LVEFR showing a significantly lower mean LVEFR (1.17± 7.30 vs. 3.02 ± 7.36p =<0.01).
CONCLUSION: Abnormal LVEFR can be used as an independent predictor of cardiac events which can be observed in subjects with normal and abnormal perfusion scans alike.

Human ; Male ; Female ; Middle Aged ; Adult ; Coronary Artery Disease ; Thallium ; Omega-chloroacetophenone ; Microcirculation ; Stroke Volume ; Heart ; Thallium Radioisotopes ; Myocardium ; Perfusion Imaging

BACKGROUND: Serum thyroglobulin assays and I-131 imaging and routinely employed for the detection of remaining functioning thyroid tissue after surgery and radioiodine therapy. However, the sensitivity of I-131 is suboptimal resulting in cases of positive thyroglobulin test but negative I-131 imaging, potentially creating a dilemma in subsequent therapeutic management. Other radiopharmaceuticals, such as TI-201 may offer better sensitivity, although it is not clear whether this contributes to the decision-making for subsequent I-131therapy. This prospective cohort study aimed to determine if Tl-201 imaging identified thyroid tissues that will take up therapeutic I-131, and to help define its clinical utility.
METHODS: Fourteen consecutive patients who underwent surgery for well-differentiated thyroid cancer, had I-131 therapy at least eight months previously, and with elevated thyroglobulin (>10 ng/mL) but negative pre-therapy (111 MBq) I-131 whole body scan (WBS), were enrolled in the study. WBS was done using 56.74 MBq of Tl-201. All patients had repeat I-131 ablation (3.7-7.4GBq) one to two months after Tl-201 imaging. Post-therapy WBS was done four to seven days after.
RESULTS: All 14 patients had papillary thyroid carcinoma. Ten patients had a positive Tl-201 scan. Of the 14 subjects, only two had a positive post-therapy I-131 WBS, both whom had a positive Tl-201 scan. Thallium-201 scanning showed a fairly high sensitivity (71%) in demonstrating thyroid remnants or metastases using a thyroglobulin level of >10 ng/mL as standard. However, a positivel Tl-201 scan only has a predictive value of 20% for subsequent uptake of therapeutic I-131 as shown in the post-therapy scan.
CONCLUSION: Thallium-201 uptake correlates poorly with therapeutic I-131 uptake in thyroglobulin-positive, but I-131 scan-negative, differentiated thyroid cancer patients. Results of this study suggest that the presence of thyroid remnants and metastases on Tl-201 imaging is inappropriate as a basis for subsequent I-131 therapy.

Human ; Male ; Female ; Middle Aged ; Adult ; Thyroglobulin ; Thyroid Cancer, Papillary ; Radiopharmaceuticals ; Iodine Radioisotopes ; Thallium ; Thyroid Neoplasms ; Carcinoma ; Neoplasms, Second Primary ; Thallium Radioisotopes

BACKGROUND: Serum thyroglobulin assays and I-131 imaging and routinely employed for the detection of remaining functioning thyroid tissue after surgery and radioiodine therapy. However, the sensitivity of I-131 is suboptimal resulting in cases of positive thyroglobulin test but negative I-131 imaging, potentially creating a dilemma in subsequent therapeutic management. Other radiopharmaceuticals, such as TI-201 may offer better sensitivity, although it is not clear whether this contributes to the decision-making for subsequent I-131therapy. This prospective cohort study aimed to determine if Tl-201 imaging identified thyroid tissues that will take up therapeutic I-131, and to help define its clinical utility.
METHODS: Fourteen consecutive patients who underwent surgery for well-differentiated thyroid cancer, had I-131 therapy at least eight months previously, and with elevated thyroglobulin (>10 ng/mL) but negative pre-therapy (111 MBq) I-131 whole body scan (WBS), were enrolled in the study. WBS was done using 56.74 MBq of Tl-201. All patients had repeat I-131 ablation (3.7-7.4GBq) one to two months after Tl-201 imaging. Post-therapy WBS was done four to seven days after.
RESULTS: All 14 patients had papillary thyroid carcinoma. Ten patients had a positive Tl-201 scan. Of the 14 subjects, only two had a positive post-therapy I-131 WBS, both whom had a positive Tl-201 scan. Thallium-201 scanning showed a fairly high sensitivity (71%) in demonstrating thyroid remnants or metastases using a thyroglobulin level of >10 ng/mL as standard. However, a positivel Tl-201 scan only has a predictive value of 20% for subsequent uptake of therapeutic I-131 as shown in the post-therapy scan.
CONCLUSION: Thallium-201 uptake correlates poorly with therapeutic I-131 uptake in thyroglobulin-positive, but I-131 scan-negative, differentiated thyroid cancer patients. Results of this study suggest that the presence of thyroid remnants and metastases on Tl-201 imaging is inappropriate as a basis for subsequent I-131 therapy.

Human ; Male ; Female ; Middle Aged ; Adult ; Thyroglobulin ; Thyroid Cancer, Papillary ; Radiopharmaceuticals ; Iodine Radioisotopes ; Thallium ; Thyroid Neoplasms ; Carcinoma ; Neoplasms, Second Primary ; Thallium Radioisotopes

BACKGROUND: Coronary microcirculation impairment with sequential decrease in cardiac function is reflected by abnormal left ventricular ejection fraction reserve (LVEFR),which precedes diagnostic evidence of myocardial insult. However, prognostic utility of LVEFR is less, if not least explored. The aim of this study was to evaluate the clinical utility of LVEFR in predicting major cardiac events (MACE) among patients with and suspected coronary artery disease (CAD).
MATERIALS AND METHODS: A retrospective cohort study of 245 patients who underwent stress thallium-201 myocardial perfusion scan (MPS) was conducted. The patients were categorized as having normal or abnormal perfusion scan. Each group was subdivided into normal and abnormal LVEFR groups. All subjects were followed up for any major adverse cardiac events 36 months after MPS through review of hospital records.
RESULTS: There was an overall increase in the likelihood of cardiac events with abnormal LVEFR (i.e., odds ratio of 2.99,p=<0.01). Majority of subjects with abnormal MPS also had abnormal LVEFR showing a significantly lower mean LVEFR (1.17± 7.30 vs. 3.02 ± 7.36p =<0.01).
CONCLUSION: Abnormal LVEFR can be used as an independent predictor of cardiac events which can be observed in subjects with normal and abnormal perfusion scans alike.

Human ; Male ; Female ; Middle Aged ; Adult ; Coronary Artery Disease ; Thallium ; Omega-chloroacetophenone ; Microcirculation ; Stroke Volume ; Heart ; Thallium Radioisotopes ; Myocardium ; Perfusion Imaging

To evaluate the diagnostic value of thallium-201 stress myocardial scintigraphic imaging and stress electrocardiography, sensitity, specificity and predicitive value of thallium-201 stress myocardial scintigraphic imaging were compared to simultaneously recorded 12 lead electrocardiography in 17 normal subjects and 30 patients with coronary artery disease who proved by coronary arteriography. The following results were obtained. 1) The mean age was 49.5+/-10.7 years(mean+/-SD)in subjects with normal coronary arteries and 53.1+/-8.8 years in patients with stenotic coronary arteries. 2) Fourteen patients had one-vessel disease, 10 two-vessel disease and 6 three-vessel disease. 3) Sensitivity of thallium myocardial scintigraphic imaging was higher than that of stress electrocardiography(86.7% vs 76.7%). 4) Specificity of both tests was same(70.6% vs 70.6%). 5) Sensitivity of thllium-201 stress myocardial scintigraphic imaging and stress electrocardigraphy in relation to the extent of coronary artery disease showed 78.6% vs 64.3% in one vessel disease, 90% vs 80% in two-vessel disease and 100% vs 100% in three-vessel disease. 6) Predictive value of thallium-201 stress myocardial scintigraphic imaging and stress electrocardiography revealed 83.9% vs 82% in the postive test and 75% vs 63.2% in the negative test. In conclusion, even though thallium-201 stress myocardial scintigraphic imaging was superior to stress electrocardiography in diagnosing coronary artery disease, scintigraphic defects were noted in 5 subjects with normal coronary arteries which could mislead to erroneous diagnosis of coronary artery disease. This point should be taken into consideration in the interpretation of thallium-201 stress myocardial scintigraphic imaging.
Angiography ; Coronary Artery Disease* ; Coronary Vessels* ; Diagnosis ; Electrocardiography* ; Humans ; Sensitivity and Specificity ; Thallium