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PubMed1993

Technetium-99m(V)dimercaptosuccinic acid uptake in intra-abdominal massive deposit of amyloid protein.

Technetium-99m(V)dimercaptosuccinic acid (DMSA) scintigraphy was performed in two patients with pathologically confirmed primary amyloidosis. Both patients had tumor-like deposits of AL-type amyloid in the abdomen. Marked uptake of the tracer by the amyloid deposits was noted. Technetium-99m-(V)DMSA scintigraphy appears to be useful in detecting the distribution of amyloid deposits and in determining the appropriate site for biopsy.

Abdomen↗
PubMed1993

Scintigraphic evaluation of tenosynovial giant-cell tumor using technetium-99m(V)-dimercaptosuccinic acid.

Technetium-99m(V) dimercaptosuccinic acid (DMSA) and 67Ga-citrate scintigraphy were performed in three patients with primary and recurrent tenosynovial giant-cell tumor (one localized type and two diffuse type). In all cases, 99mTc(V)DMSA showed marked accumulation in all primary and recurrent tumors; however, 67Ga-citrate showed no accumulation in any of the tumors. Technetium-99m(V)-DMSA scintigraphy was useful in detecting tenosynovial giant-cell tumor and in diagnosing recurrence of this tumor.

Adult↗
PubMed1993

Quick diagnosis of hyperthyroidism with semiquantitative 30-minute technetium-99m-methoxy-isobutyl-isonitrile thyroid uptake.

Ten normal volunteers and 14 patients with hyperthyroidism had pinhole thyroid imaging 30 min after an intravenous injection of 10 mCi 99mTc-MIBI. Technetium-99m-MIBI thyroid uptake was calculated by the formula: [total counts with a region of interest (ROI) over the whole thyroid gland] divided by [(mean counts of every pixel in the neck soft tissue) x (total number of pixels in ROI over the whole thyroid gland)]. The results showed that the 30 min 99mTc-MIBI thyroid uptake ratios had positive relationships with the 24 hr 131I-thyroid uptake (r = 0.79), and that the patients with hyperthyroidism had significantly higher 30 min 99mTc-MIBI thyroid uptake than the normal volunteers (5.31 +/- 0.78 s.e.m. versus 2.35 +/- 0.14 s.e.m., p < 0.005 using the Mann-Whitney U-test). Technetium-99m-MIBI thyroid uptake may be useful for the rapid diagnosis of hyperthyroidism.

Adult↗
PubMed1996

Technetium-99m-HMPAO SPECT in Sturge-Weber syndrome.

UNLABELLED: Technetium-99m-HMPAO interictal SPECT was performed on three pediatric patients with Sturge-Weber syndrome (SWS). RESULTS: Brain SPECT of all three patients demonstrated markedly diminished tracer localization in the affected hemisphere. In one patient, the SPECT abnormality was more extensive than the associated abnormalities on CT and MRI. CONCLUSION: Technetium-99m-HMPAO brain SPECT can detect cerebral perfusion abnormalities associated with SWS and deserves consideration in the imaging evaluation of SWS patients.

Brain↗
PubMed1977

Technetium-99m phytate as a bone-marrow imaging agent: biodistribution studies in animals: concise communication.

Technetium-99m phytate has been suggested as a bone-marrow imaging agent. This article compares the biodistribution of Tc-99m labeled "bone marrow" phytate, sulfur colloid, and diphosphonate in young rats and rabbits. Autoclaved bone marrow phytate revealed significant long-base depositon, but 96% of this activity was associated with compact bone and only 4% with bone marrow. This distribution is similar to that of diphosphonate, but significantly different from that of sulfur colloid. Technetium-99m-phytate is not recommended as a bone-marrow imaging agent.

Animals↗
PubMed1996

Parathyroid localization with technetium-99m-sestamibi: a prospective evaluation.

BACKGROUND: The purpose of this study was to prospectively evaluate parathyroid localization using technetium-99m-sestamibi (MIBI). STUDY DESIGN: Technetium-99m-sestamibi scintigraphy was performed in 124 patients with hyperparathyroidism and the results were correlated with serum calcium and parathyroid hormone (PTH) levels, weight, location, and pathology of parathyroid tissue, and associated thyroid abnormalities. RESULTS: Hyperparathyroidism was primary in 118 patients, secondary in four patients, and tertiary in two patients. The parathyroid pathology was a solitary adenoma in 95 patients (77 percent), double adenoma in five (4 percent), hyperplasia in 14 (11 percent), carcinoma in one (1 percent), and unconfirmed in nine (7 percent) who underwent noncurative parathyroidectomy. Associated thyroid disease was present in 29 (23 percent) patients. Fourteen patients (11 percent) had undergone previous parathyroid exploration. The mean calcium level was 11.4 +/- 0.8 mg/dL (range, 8.3 to 13.7 mg/dL) and the mean adjusted PTH level was 395 +/- 702 (range, 70 to 4,331). The sensitivity and positive predictive value of MIBI scintigraphy were 81 and 89 percent, respectively, in patients with a solitary adenoma and 37 and 100 percent, respectively, in patients with multiglandular disease. The mean adjusted PTH level was higher in patients with true-positive scans compared with false-negative scans (440 +/- 628 compared with 243 +/- 499, p > 0.05). The mean adenoma weight was 1,877 +/- 3,212 mg in patients with a true-positive scan compared with 485 +/- 296 mg with a false-negative scan (p > 0.05). CONCLUSIONS: The sensitivity and positive predictive value of MIBI scintigraphy is comparable to or better than the results reported for other localization procedures. Its lack of sensitivity for detection of multiglandular disease precludes its use in lieu of routine bilateral neck exploration in the management of patients with hyperparathyroidism.

Adolescent↗
PubMed1996

Technetium-99m-sulfur colloid for lymphoscintigraphy: effects of preparation parameters.

UNLABELLED: There has been a resurgence in the use of lymphoscintigraphy for the external detection of lymph nodes for metastatic melanoma and breast tumors. Technetium-99m-antimony trisulfide colloid was the radiopharmaceutical developed for this procedure and was found to have a narrow distribution of small particles, 0.003-0.03 microns, but it was never approved by the FDA. Technetium-99m-sulfur colloid also forms particles and this article reports on the effects different preparation parameters have on its particle size distribution and stability. METHODS: Four groups of kits were evaluated, kits which utilized: (a) a reduced heating protocol with a new 99mTc-elution, (b) a reduced heating protocol with an old 99mTc-elution, (c) a prolonged heating protocol with a new 99mTc-elution and (d) a prolonged heating protocol with an old 99mTc-elution. The particle size distribution and the stability of the different 99mTc-sulfur colloid kit preparations were evaluated over 6 hr utilizing polycarbonate filters ranging from 0.03 to 10 microns. RESULTS: In vitro studies demonstrated no significant change in the particle size distribution over a 6-hr period and all 99mTc-sulfur colloid preparations had a bimodal particle size distribution pattern. Importantly, heating the kit for shorter periods of times utilizing [99mTc]pertechnetate, which had a longer ingrowth of [99mTc]pertechnetate, produced a formulation which had the largest percentage of particles smaller than 0.03 microns. CONCLUSION: In our clinical setting, 99mTc-sulfur colloid prepared with the reduced heating protocol and utilizing [99mTc]pertechnetate, which has the highest ingrowth of [99mTc]pertechnetate has proved to be an excellent agent for lymphoscintigraphy studies. This preparation has demonstrated rapid movement of the particles from the primary site to the lymph nodes in over 97% (106/109) of the patients we have studied.

Humans↗
PubMed1995

Technetium-99m (Tc-99m) diphosphono-propanedicarboxylic acid bone tracer uptake and Tc-99m sestamibi distribution in cardiac amyloidosis--a case report.

It has long been recognised that significant bone tracer localisation in the myocardium is a good indicator for amyloid involvement of the heart in the clinical context of systemic amyloidosis. In this case report, although myocardial tissue diagnosis of amyloidosis was not made, the massive myocardial uptake of bone tracer strongly suggested the presence of amyloid infiltration in the heart, and this finding eventually led to the histological diagnosis of familial amyloid polyneuropathy by skin and sural nerve biopsy. Interesting findings were noted in the single photon emission computerised tomography (SPECT) studies of the myocardium with Technetium-99m diphosphono-propanedicarboxylic acid bone agent and Technetium-99m sestamibi myocardial perfusion agent. Such findings suggest that there is a lack of correlation between the intensity of myocardial uptake of bone tracer and viability of the myocardium, and that amyloid will not deposit in infarcted myocardial tissue.

Amyloid Neuropathies↗
PubMed1996

Comparison of technetium-99m-HMPAO and xenon-133 measurements of regional cerebral blood flow by SPECT.

UNLABELLED: This study compares 99mTc-HMPAO count ratios and derived regional cerebral blood flow (rCBF) to 133Xe rCBF ratios and true rCBF (ml/min/100 g), respectively. METHODS: Technetium-99m-HMPAO distribution was evaluated in 14 patients and 5 normal control subjects. Immediately after 133Xe SPECT, subjects received 22 +/- 4mCi 99mTc-HMPAO, and images were acquired 15 min after injection. rCBF (ml/min/100 g, 133Xe) or regional count density (99mTc-HMPAO) were extracted from 24 ROI located 6 cm above the cantho-meatal line. These data were also normalized to global cerebral blood flow (gCBF) for 133Xe or to global count density (gCD) for 99mTc-HMPAO. Technetium-99m-HMPAO ROI data also were expressed in units of ml/min/100 g by relating gCD to gCBF. Comparisons between 133Xe and 99mTc-HMPAO were evaluated using a Bonferroni-corrected paired t-test and by linear regression analysis. RESULTS: Profile plots demonstrated agreement in the pattern of relative distribution between rCBF ratios (133Xe) and count density ratios (99mTc-HMPAO). Regression analysis indicated a significant correlation (r = 0.78), with a modest slope (0.52) and a large intercept (0.48). A closer correlation (r = 0.92) was found for the comparison between rCBF (133Xe) and derived 99mTc-HMPAO rCBF. The slope was closer to one (0.82) and the intercept closer to zero. This relationship was also examined during high rCBF after a subset of these subjects (n = 7) was injected intravenously with 1 g acetazolamide. Again, profile plots and regression analysis demonstrated agreement in the pattern of distribution (ratios) between 133Xe and 99mTc-HMPAO (r = 0.66). However, the slope was reduced and the intercept increased relative to resting data. Absolute flow correlations showed some improvement relative to the ratio data (r = 0.77). CONCLUSION: The distribution of 99mTc-HMPAO is linearly related to rCBF measured by 133Xe SPECT, although our data suggest that 99mTc-HMPAO mildly underestimates rCBF above 80 ml/min/100 g. These results are similar to our previous comparison of 99mTc-ECD and 133Xe.

Adult↗
PubMed1977

Technetium-99m stannous citrate brain-tumor uptake in mice: concise communication.

The pharmacodynamics of technetium-99m stannous citrate were studies in Yale-Swiss mice bearing a sarcoma-like transplantable brain tumor, and the renal kinetics were determined in normal mice. Using a rating system based on tumor uptake and tumor-to-brain, tumor-to-blood, and tumor-to-skin ratios, the data obtained with this compound were compared with similar data obtained previously in the same model with Tc-99m Fe-(ascorbic acid), Tc-99m Fe-(ascorbic acid)-DTPA, Tc-99m Sn-DTPA, [99mTc] pertechnetate, and [99mTc] pertechnetate with perchlorate predose. Technetium-99m stannous citrate does not appear to achieve tumor localization by a mode different from these other Tc-99m-labeled compounds, nor does it show any potential advantage as a scanning agent in the tumor model.

Animals↗
PubMed1977

Technetium-99m-labeled n-(2,6-dimethylphenylcarbamoylmethyl) iminodiacetic acid (tc-99m HIDA): a new radiopharmaceutical for hepatobiliary imaging studies.

An easily formulated, stable kit preparation of technetium-99m HIDA, suitable for use in humans, was developed and tested in mice and dogs. The tracer was cleared rapidly from the blood and excreted predominantly by the liver in both species. In dogs, the hepatobiliary clearance of Tc-99m HIDA was significantly greater than that of C-14 HIDA and Sn-113 HIDA. The LD50 for HIDA in mice, 168 mg/kg, exceeded the average human dose by a factor of 1000 on a per-weight basis. Blood clearance curves for Tc-99m HIDA in 12 normal subjects were biexponential with half-times of 4.6 +/- 1.0 min and 31.5 +/- 7.0 min, and cumulative 90-min urine samples contained 14.2 +/- 1.8% of the injected dose. Images in normal subjects and nonjaundiced patients showed rapid concentration of tracer by the liver and activity was present within the biliary system in 10-20 min. In jaundiced patients, the tracer blood clearance was delayed and urinary excretion increased, but intestinal activity, indicating biliary patency, was imaged in those patients without complete focal obstruction of the common duct. Technetium-99m HIDA is a nontoxic radiopharmaceutical useful for clinical evaluation of hepatobiliary disorders in humans.

Acetanilides↗
PubMed1997

Evaluation of technetium-99m-MIBI scintigraphy in metastatic differentiated thyroid carcinoma.

UNLABELLED: Technetium-99m-methoxyisobutyl isonitrile (99mTc-MIBI) was evaluated for its ability to detect metastases from thyroid carcinoma. METHODS: Twenty-seven thyroidectomized patients with metastatic differentiated thyroid carcinoma, of whom 20, 9 and 12 had lung, lymph node and bone metastases, respectively, were examined with 99mTc-MIBI. The scan results were compared with those of 201TI and 131I whole-body scans. RESULTS: Increased accumulation of 99mTc-MIBI was observed in lung metastases of 15 patients (75.0%), 12 lymph node metastases (100.0%) and 29 of 31 bone metastases (93.5%). Increased accumulations of 201TI and 131I scans were seen in, respectively, 16 (80.0%) and 17 (85.0%) of the 20 patients with lung metastases, 12 (100.0%) and 5 (41.7%) of the 12 lymph node metastases and 28 (90.3%) and 27 (85.1%) bone metastases. Because of its better image quality, 99mTc-MIBI detected more lesions in the lung (n = 38) than 201TI did (n = 17). CONCLUSION: Technetium-99m-MIBI is clinically useful for detecting metastases from differentiated thyroid carcinoma and deserves clinical application in the postoperative follow-up of such patients.

Adult↗
PubMedDate not supplied

Development of a stable single-vial formulation for a new technetium complex using bilayer lyophilization.

The interaction between different components used in the preparation of a new radiodiagnostic agent, BMS-181321, was overcome by its lyophilization as a bilayered product. BMS-181321 is composed of a nitroimidazole ligand BMS-181032, that is complexed with technetium-99m just before it is used in radionuclide imaging studies. Stannous chloride is required to reduce technetium from the +7 to the +5 oxidation state before it can be complexed by the ligand. Because BMS-181032 is unstable in the presence of stannous chloride (when mixed in the liquid or solid state), the two components must be contained in separate vials. A bilayered lyophile was manufactured, containing the ligand and stannous chloride in separate layers in a single vial. The bilayered product was manufactured by first filling a solution of the ligand into a vial and freezing the solution. A solution containing stannous chloride was then filled into the same vial on top of the frozen layer of ligand, and this second layer was also frozen. The two frozen layers were then lyophilized to a dry solid cake. The resulting bilayered product showed stability comparable to that seen when the ligand and the reducing agent were contained in separate vials. The separation provided by the layering was sufficient to prevent any significant interaction between the reducing agent and the ligand.

Chemistry, Pharmaceutical↗
PubMed1996

Significance of radioisotope bone marrow uptake on 99m technetium sulphocolloid scan in portal hypertension.

A prospective study of 101 consecutive patients of portal hypertension was carried out to study the possible relationships between bone marrow activity on 99m technetium labelled sulphocolloid scan and severity of liver disease, etiology of portal hypertension and cirrhosis, as well as presence and extent of collateral circulation, including esophageal varices. The patients were divided into 4 etiological groups: alcoholic cirrhosis (ALD), (38) non-alcoholic cirrhosis (NALD) (35) non-cirrhotic portal fibrosis (NCPF) (14) and extrahepatic portal vein obstruction (EHPVO) (14). Patients of cirrhosis were categorised according to modified Child-Pugh's classification. Esophageal varices were graded endoscopically as (1) no varix (2) small varices (< 5mm) (3) large varices (> 5mm). All patients underwent radionuclide imaging using 99m Technetium labelled sulphocolloid and bone marrow activity was studied. Evaluation of portasystemic collaterals was done ultrasonically. We found that 16.6%, 44.6% and 72.72% patients with Child A, B and C cirrhosis respectively, had increased marrow activity (p < 0.05). There was no significant difference between marrow activity of patients with ALD (52.6%) and NALD (40%). None of the non-cirrhotic patients demonstrated bone marrow uptake of radioisotope. There was no significant difference between bone marrow uptake presence of lienorenal collaterals and presence or size of esophageal varices. We thus conclude the bone marrow activity on radioisotope scanning depends only on the severity of liver disease and does not vary a according to the etiology of cirrhosis, or presence and extent of portasystemic collaterals, including esophageal varices.

Adult↗
PubMed1997

Technetium-99m(V)-DMSA and thallium-201 in brain tumor imaging: correlation with histology and malignant grade.

UNLABELLED: This study was performed to compare imaging ability between pentavalent 99mTc-DMSA and 201TlCl in primary and metastatic brain tumors and to evaluate the relationship between retention and histologic malignancy. METHODS: Patients with a brain tumor were selected by MRI and/or CT. Dynamic, early and delayed static SPECT images of the brain were obtained immediately, 30 min and 3 hr after intravenous administration of approximately 555 MBq 99mTc(V)-DMSA and 111 MBq 201Tl-Cl, respectively. Both studies were performed on separate days within a week. Uptake ratios, retention ratio and retention index were calculated and compared with tumor histology and malignancy grade. RESULTS: One-hundred six studies were performed on 100 patients and 118 lesions were demonstrated: 16 glioblastomas, 13 anaplastic astrocytomas (Grade III), 19 astrocytomas (Grade II), 29 meningiomas, 11 schwannomas and 14 metastases. Approximately 93% and 88%, respectively, of primary and metastatic brain tumors were demonstrated by 99mTc(V)-DMSA and 201TlCl. The early uptake ratios were closely related to the tumor vascularity, but had no statistically significant difference in the tumor histology or histologic malignancy on either radiopharmaceuticals. The delayed uptake ratio, retention ratio and retention index were higher in malignant tumors than benign ones on 99mTc(V)-DMSA, however, there was no statistically significant difference between benign and malignant tumors on 201TlCl. CONCLUSION: Technetium-99m(V)-DMSA washout from the tumor was highly dependent upon its histology and histologic malignancy. The delayed uptake ratio, retention ratio and retention index significantly reflected tumor histology and clearly distinguished between benign and malignant tumors with a statistically significant difference. There was no statistically significant difference in 201TlCl uptake or washout among the brain tumors. Technetium-99m-DMSA is superior to 201TlCl in imaging quality, sensitivity to brain tumors and specificity for differentiating benign tumors from malignant ones. These results could suggest the clinical utility of 99mTc(V)-DMSA in imaging primary and metastatic brain tumors and differentiating their histological malignancy grade noninvasively.

Brain Neoplasms↗
PubMed1997

[Use of photoactivation in the preparation of radiopharmaceuticals. II. Dialysate of human leukocytes labelled with technetium (99mTc)].

The paper evaluates the effect of photoactivation on dialysate of human leukocytes, on their labelling with technetium(99mTc), and on biodistribution in rats. Dialysate of human leukocytes was irradiated with UV light at 254 nm and labelled with technetium(99mTc) by reduction of pertechnetate(99mTc) with stannous chloride. Radiochemical purity was evaluated using paper chromatography. The biodistribution of labelled dialysate of human leukocytes in rats with experimentally induced inflammation was determined by counting the activity of isolated organs or by planar gamma camera imaging 4 hours after administration. Photoactivation mildly raises the number of free SH groups in leukocyte dialysate. A high labelling efficacy (97%) and stability 8 hours after labelling (94%) was achieved. An effect of radiation on labelling efficacy and stability was not demonstrated. Photoactivation has a beneficial effect on the distribution of 99mTc dialysate of human leukocytes into experimental inflammation as measured in isolated organs of rats; however, deposition into inflammatory lesions is not quite sufficient for scintigraphic imaging.

Animals↗
PubMed1997

Technetium-99m-MIBI scintigraphy in the assessment of neoadjuvant chemotherapy in breast carcinoma.

UNLABELLED: Presurgical neoadjuvant chemotherapy (PSNC) is the treatment of choice for patients with locally advanced breast carcinoma (LABC). Accurate assessment of tumor response is important in planning subsequent treatments. Conventional response assessment by mammography and clinical evaluation is not fully reliable. This study evaluates the diagnostic yield of serial 99mTc-MIBI scintigraphy in the assessment of LABC response to PSNC. METHODS: Twenty-nine patients affected by LABC underwent clinical, mammographic and 99mTc-MIBI scintigraphy before and after 3 cycles of FEC (500 mg/m2 5-fluorouracil, 50 mg/m2 epirubicin and 400 mg/m2 cyclophosphamide) on Days 1 and 8. Surgery was planned for 15 days after the third cycle of chemotherapy. Pathological status was obtained after surgery in all patients. RESULTS: Sensitivities (i.e., true-positive ratios) for a correct prediction of tumor presence after PSNC were 65% for scintigraphy, 35% for clinical evaluation and 69% for mammography. Specificities (i.e., true-negative ratios) for a correct prediction of tumor absence after PSNC were 100% for scintigraphy, 67% for clinical evaluation and 33% for mammography. Technetium-99m-MIBI uptake in this series did not correlate with P-170 expression, proliferating cell nuclear antigen, Her-2/neu oncogene protein, antihuman endothelial cell CD31 antigen and estrogenic and progestinic receptor status. CONCLUSION: Technetium-99m-MIBI scintigraphy is effective in monitoring the response to PSNC in LABC patients. Its diagnostic yield is clearly superior to clinical evaluation alone. Scintigraphy performs as does mammography in patients with negative response, but it is clearly superior in patients with positive response.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1997

Hyperventilation technetium-99m-HMPAO brain SPECT in moyamoya disease to assess risk of natural childbirth.

We report a pregnant 19-yr-old patient with moyamoya disease who had undergone bilateral superficial temporal artery to middle cerebral artery anastomosis and encephalomyosynangiosis at 8 yr with an uneventful postoperative course and who desired natural delivery after becoming pregnant at 18 yr. We determined her cerebral vascular reserve since natural delivery can result in decreased cerebral blood flow during labor. Technetium-99m-HMPAO brain SPECT, with hyperventilation challenge, was performed to assess cerebral vascular reserve since the stress of hyperventilation was thought likely to rehearse that of labor. The brain SPECT images, obtained using 333 MBq 99mTc-HMPAO, revealed maintenance of cerebral vascular reserve. In addition, whole-body images including the 27-wk-old fetus were obtained. These images demonstrated accumulation in the fetal liver. Natural delivery was, thus, considered indicated for this patient, who subsequently delivered a healthy baby girl. Technetium-99m-HMPAO brain SPECT with hyperventilation challenge was useful for estimating cerebral vascular reserve and for determining whether natural delivery was indicated for this patient with moyamoya disease.

Adult↗