99mTc Uptake Research Articles

Chronic biliary obstruction induces pulmonary intravascular phagocytosis and endotoxin sensitivity in rats.

Endotoxin sensitivity varies among animal species and appears to correlate with the presence of pulmonary intravascular macrophage (PIM). In rats, which lack PIM, we investigated the hypothesis that chronic cholestatic liver injury leads to induction of PIM and endotoxin sensitivity. Rats were randomized to either common bile duct ligation (BDL) or sham-surgery and studied at 1 wk (acute cholestasis), 2 wk (cholestasis, early cirrhosis), and 4 wk (cholestasis, established cirrhosis) after surgery. Intravascularly injected fluorescent latex microspheres (1 micron diameter) were taken up by large phagocytic cells in lung parenchyma of BDL rats (at 2 and 4 wk), while no uptake was observed in lungs from control rats. Electronmicroscopy revealed accumulation of large, mononuclear, macrophage-like cells containing ingested latex particles within the pulmonary capillaries. Pulmonary intravascular phagocytosis, as reflected in lung uptake of 99mTc microaggregated albumin (Microlite, mean particle diameter = 1 micron), averaged 0.7 +/- 0.1% (mean +/- SEM) of total injected dose in 13 control rats and progressively increased with time after BDL (1 wk, 1.7 +/- 0.2%; 2 wk, 10.0 +/- 3.0%; 4 wk 35.1 +/- 5.9%). Rats with biliary cirrhosis were markedly sensitive to the lethal effects of low dose endotoxin and demonstrated marked lung edema at the time of death. Furthermore, the lung uptake of intravascular 125I-lipopolysaccharide was increased five-fold in cirrhotic rats. We conclude that chronic biliary obstruction leads to the induction of pulmonary intravascular phagocytes and enhances endotoxin sensitivity in rats. Pulmonary intravascular phagocytosis in patients with advanced cirrhosis may account for their increased susceptibility to sepsis-induced adult respiratory distress syndrome.

Scintigraphic findings of the thyroid in hypothyroid patients with blocking-type TSH-receptor antibodies

The present study was designed to analyse the scintigraphic appearance of the thyroid in hypothyroid patients with blocking-type TSH receptor antibodies (TRAbs). Eleven hypothyroid patients with autoimmune thyroiditis positive for TSH binding inhibitor immunoglobulins (TBII) [80% +/- 12 (SD)%; normal < 11%] and for thyroid stimulation-blocking antibodies (TSBAbs) (90% +/- 9%: normal < 32%) were studied. Thyroid scanning was performed using technetium-99m or iodine-123, when the patients were hypothyroid. Analysis of the scan images revealed the presence of localized functioning areas in six patients (group 1), and no visualization of the thyroid in the remaining five patients (group 2). Patients in group 1 showed significantly higher uptake of 99mTc than those in group 2 (P < 0.05). Interestingly, three patients in group 1 were positive for thyroid-stimulating antibodies (TSAbs) (249% +/- 17%; normal < 145%), which were not detected in the remaining eight patients. Antibodies against thyroglobulin and microsomal antigens were detected in nine nine (81.8%) and 11 (100%) patients, respectively, but neither of these titres correlated with the scan image. Three patients in group 1 underwent scintigraphy again after treatment with thyroxine, at which time the functioning lesion was not noted. Fourteen hypothyroid patients with negative TBII displayed no such scintigraphic findings. Chronic stimulation of the thyroid by TSAbs and/or TSH might be responsible for the presence of the functioning lesion, but clarification of the mechanism requires further studies. In summary (1) TSAbs were detected in three (27.3%) of 11 hypothyroid patients with blocking TRAbs; (2) thyroid scintigraphy revealed the presence of localized functioning area(s) in approximately half of these cases.

Effect of interleukin-2 on the biodistribution of technetium-99m-labelled anti-CEA monoclonal antibody in mice bearing human tumour xenografts

We have evaluated whether interleukin-2 (IL-2) at low doses can enhance delivery of radionuclides to tumour sites by improving the access of the radio-labelled antibody. The effects of 1000 or 2000 units of IL-2 on the biodistribution of technetium-99m-labelled anticarcinoembryonic antigen (CEA) monoclonal antibody, ZCE025, in athymic mice bearing human CEA-positive tumour (MKN45) xenografts were investigated. Treatment with IL-2 resulted in a significantly higher tumour uptake (1.2-1.5-fold) compared with the control group. Some normal organs, such as heart, lung, liver, spleen and kidneys, showed increased 99mTc uptake following the IL-2 treatment. Pretreatment with IL-2 also induced an enhancement of the permeability index for mouse IgG in tumours and in normal organs, whereas the blood flow in both normal organs and tumours remained at control levels. The effects of IL-2 were found to be dose-dependent. The IL-2 treatment increased the plasma CEA levels but not the CEA content in tumour tissues, suggesting that IL-2 enhanced the leakage of CEA from tumour to blood. The enhancement ratios of the tumour 99mTc-ZCE025 uptake following treatment with IL-2 were 1.4 and 1.8 in mice bearing small and large tumours, respectively. Our experimental results indicated that the low dose of IL-2 enhanced the vascular permeability sufficiently to increase the amount of antibody delivered to the tumour target. Administration of IL-2 would render radioimmunotherapy more effective, especially in patients with large tumour burdens.

Scintigraphic assessment of salivary function and excretion response in radiation-induced injury of the major salivary glands.

Both loss of the secretory function and impairment of the excretion may play a role in radiation-induced injury of the major salivary glands after radiotherapy for head and neck malignancies. Therefore, quantitative 99mTc-pertechnetate (99mTc) salivary scintigraphy to assess trapping, secretion, and excretion, was used to analyze irradiation-induced changes in relation to the radiation dose and the time interval after radiotherapy. Salivary scintigraphy was performed on 25 patients who had been irradiated to the neck and head for various malignancies with irradiation of the major salivary glands and in 6 nonirradiated patients. Excretion was induced by stimulation with carbachol (Carbacholum, Pharmachemie BV, Haarlem, The Netherlands). As a parameter for salivary glandular trapping and secretion, the cumulative 99mTc-pertechnetate glandular uptake in the first 12 minutes was used. Scintigraphic data were analyzed for each patient and for each individual gland at three radiation dose levels (range, 5-70 Gy), and at short (range, 2-7 months) and long (range, 10-50 months) intervals after radiotherapy. The excretion response to the stimulant carbachol was totally or partially disturbed in 84% of the irradiated patients. For individual glands, excretion was maintained in all glands irradiated with 25 Gy or less, in nearly half of the glands at doses of 25-45 Gy, and was almost invariably impaired at doses higher than 45 Gy, regardless of the time interval after radiotherapy. Although cumulative 99mTc glandular uptake tended to decrease at higher radiation dose levels (z = -3.059, P < 0.0022), at 45 Gy or more, cumulative 99mTc uptake was considerably higher in glands examined at a short postirradiation interval compared with glands examined after a long time interval (P = 0.0001). This tendency, seen for both parotid and submandibular glands, was not observed at doses lower than 45 Gy. These data suggest that in the first period after high dose irradiation, xerostomia is based predominantly on the failure of the gland to excrete saliva, whereas in the later period, a decreased trapping ability together with loss of secretory function play an additional role. Salivary scintigraphy using 99mTc-pertechnetate is a suitable method to assess radiation-induced salivary gland injury. The test is able to detect salivary glandular dysfunction in an early phase and may be useful to predict which patients will respond symptomatically to salivary stimulants.

Uptake of 99mTc by epoxy resin adhesives

The observation that [ 99mTc]technetium pertechnetate is taken up by an epoxy adhesive, lead to investigations of the uptake process. Parameters such as the concentration and soaking time in 99mTc, and the curing and mixing time of the epoxy adhesive were correlated with uptake. The effects of a blocking agent, polymer cements used for fixing prosthesis and glues used for joing PVC drainage pipes were also investigated. The uptake process appears to be primarily due to polar surface bonding, although other mechanisms cannot be ruled out.

Soft-tissue tumors: diagnosis with Tc-99m (V) dimercaptosuccinic acid scintigraphy.

To assess the potential of technetium-99m (V) dimercaptosuccinic acid (DMSA) scintigraphy for diagnosis of soft-tissue tumors. Tc-99m (V) DMSA scintigraphy was performed in 76 patients with histologic proof of soft-tissue tumors. In 57 of these patients, gallium-67 citrate scintigraphy was performed within 2 weeks after Tc-99m (V) DMSA scintigraphy. Uptake of Tc-99m (V) DMSA was clearly detected in almost all sarcomas, metastatic carcinomas, highly recurrent benign tumors (ie, extra-abdominal desmoids and tenosynovial giant cell tumors), superficial and deep hemangiomas, and granulomatous soft-tissue lesions but was not found in other benign solid tumors of soft tissue. Uptake of Ga-67 citrate was clearly detected in all inflammatory lesions and metastatic carcinomas, eight of 14 sarcomas (57%), and two of 10 highly recurrent benign tumors (20%) but was not found in hemangiomas or benign soft-tissue tumors. Low-grade malignant and highly recurrent benign lesions, which often recur after surgery, were detected more accurately with Tc-99m (V) DMSA scintigraphy than with Ga-67 citrate scintigraphy.

The Detection of Nasopharynx Carcinoma in Technetium-99m (V) Dimercaptosuccinic Acid SPECT imaging

Twenty-seven patients (24 men, 3 women; ages: 39-74 years) were diagnosed as having squamous cell carcinoma of the nasopharynx (NPC) as confirmed by pathologic findings of biopsies. In addition, three of the 27 patients had metastases to neck lymph nodes. The results of 2-4-hour SPECT images of the head and neck after intravenous injection of 15-20 mCi of Tc-99m (V) DMSA were compared with normal Tc-99m (V) DMSA images and CT of heads and necks. The results showed that of the 27 NPC cases, none of the patients had a significant uptake of Tc-99m (V) DMSA. However, in the three cases complicated with metastases of neck lymph nodes, the metastatic lesions could be detected by Tc-99m (V) DMSA. Our results challenge previous reports in which carcinomas of the head and neck were detected by Tc-99m (V) DMSA. The tumor-seeking agent Tc-99m (V) DMSA is not a good choice for the detection of NPC among malignancies of the head and neck.

Using technetium-99m (V) dimercaptosuccinic acid to detect malignancies from single solid masses in the lungs.

Fifty patients (43 male, 7 female, age 31-77 years) with single solid masses in their lungs based on the findings of a chest X-radiograph [40 malignancies: 5 small cell carcinoma (Ca), 17 epidermoid Ca, 12 adeno Ca, 6 undifferentiated large cell Ca] and 10 benign lesions underwent technetium-99m (V) dimercaptosuccinic acid [99m-(V)DMSA] scans to evaluate the usefulness of 99mTc-(V)DMSA in the detection of lung Ca with different cell types and benign lesions. Only 43% (17/40) of the malignancies in the lungs were detected by 99mTc-(V)DMSA, including 29% (5/17) epidermoid Ca, 50% (6/12) adeno Ca and 17% (1/6) undifferentiated large cell Ca of the lungs. However, all 5 cases of small cell Ca and 11 cases combined with bone metastasis were revealed by 99mTc-(V)DMSA. In addition, 3 of the 10 benign lesions (2 organizing pneumonias, 1 benign tumor) presented with an uptake of 99mTc-(V)DMSA. The diagnostic sensitivity, specificity and accuracy were 43%, 70% and 48%, respectively, in differentiating malignant from benign lesions for the single solid mass in the lungs. In conclusion, 99mTc-(V)DMSA is of little or no use in the differentiation of lung Ca from single solid masses in the lungs.

Biolocalization and cell labeling properties of neutral-lipophilic 99mTc-amine-phenol chelates

99mTc-diamine-diphenol chelates are neutral lipophilic chelates exhibiting good stability in aqueous solutions. The cell labeling and biolocalization properties of four different 99mTc-amine-phenol complexes were determined. All four chelates readily labeled leukocytes and RCBs in high yields. Even though 99mTc was retained by the cells, the elution rate of 99mTc from the labeled cells in plasma at 37 °C was unacceptably high for potential utility in scintigraphic imaging. The uptake of 99mTc in brain or heart following i.v. injection of the chelates in rats was low and clearance of activity from the blood was slow.

Onset of Subacute Aggravation of Chronic Thyroiditis Followed Immediately by Transient Hypothyroidism during Antithyroid Drug Therapy for Graves&amp;rsquo; Hyperthyroidism

A 56-year-old man presented with clinical and biochemical hyperthyroidism with high thyroid 99mTc uptake, positive result for antimicrosomal antibody (MCHA; 1:8,100) and markedly high activities of thyrotropin-binding inhibitory immunoglobulin (TBII; 90.0%) and thyroid-stimulating antibody (TSAb; 2,400%). Fifty days after the initiation of antithyroid drug therapy, he developed a painful tender enlarged thyroid and an accelerated erythrocyte sedimentation rate (ESR), which were followed immediately by hypothyroidism with a transient increase in MCHA titer (peak; 1:218,700) despite of maintenance of high TBII and TSAb activities. Two and a half months after the recovery from hypothyroidism, recurrent hyperfunction was observed with further elevation of TSAb activity (4,643%). After about 2 weeks, recurrences of a painful tender enlarged thyroid and an accelerated ESR, which were followed by abrupt progression to hypothyroidism, were found. Specimens obtained when he had still slightly tender goiter after the first and second episodes of neck pain showed microscopically extremely extended interstitial fibrosis with collapsed follicles and moderate lymphocytic infiltration. Thyroid-stimulation-blocking antibody was not detected at either onset of hypothyroidism. Thus, it is possible that Graves' disease, subacute aggravation of chronic thyroiditis and hypothyroidism coexist in the same individual. In such patients, thyroid status may be determined by the degree of each of the stimulating factors (TSH, TSAb and/or unknown factors) and suppressive or destructive factors (humoral and/or cellular) and may be changed in a very short interval.

術前治療と手術による口腔癌治療に伴う舌および唾液腺障害について

Speech intelligibility, salivary gland functions and gustation were examined in 74 patients who received chemo/radiotherapy and surgical excision of oral squarnous carcinoma. The results are surnmarized as follows.1. Among 52 patients who received glossoectorny, mild, moderate and severe impairment of single sound speech was found in 6, 5 and 2 cases, respectively. Sentence-reading tests revealed more restrictive impairment of speech intelligibility as class 11.(slightly difficult in understanding the spoken content) in 11 cases, class jll (understandable only when the speech content is already known) in 4 cases and class If impairment (hardly understandable) in one case.2. Speech impairment rarely resulted when the resection was limited to 1/3 of the tongue, and the impairment was greater in cases who received a glossoectorny over that limit. Speech intelligibility was related to tongue mobilit, and conservation of the tongue tip appeared important.3. Decrease in salivary flow rate (SFR) irreversibly occurred after treatment. SFR in the chemotherapy group decreased to 87% of the original value, and SFR in the cherno/radiotherapy group finally decreased to about 50% of the original. Viscosity increased grandually showing a reverse relation vi di SFR. Secretory IgA in saliva decreased during treatments, but an increase of s-IgA occurred 3 months after treatments.4. 99mTc uptake of the parotid and subrnandibular glands dec lined. Isotope activity in the submandibular glands decreased to about 70% of the initial value. Isotope elimination rate (IER) of the glands also decreased from an initial 26% to about 10% at one year after 60Co therapy. These results show that scintigraphy and SFR are useful for evaluation of salivary gland damage due to cancer therapies.5. Original taste thresholds in T1 and T2 cases did not significantly differ from healthy person values, but taste thresholds, especially for sugar were originally high in T3 and T4. Elevation of taste thresholds with chemotherapy was slight, but the chemo/radiotherapy group showed lemarkable threshold elevation. Recovery, to almost original levels, however, took place within a year.It was concluded from these results that taste impairment is temporary, while damage to the salivary glands is perrnanent, and that speech' impairment depends on excised tongue volume. Aggressive induction therapy made conservative surgery possible. Therefore, mini-mizing adverse effects to the salivary glands and tongue is essential for oral cancer treatments.

Gustatory impairment and salivary gland pathophysiology in relation to oral cancer treatment

Gustation and salivation were evaluated in 41 patients with oral carcinoma who were treated preoperatively with Peplomycin (PLM) or PLM + 5-FU+ 60CO- radiation. Thresholds for sweet, salt, sour and bitter were originally elevated in many patients. Gustatory impairment increased especially with chemoand radiotherapy. Recovery, however, took place within a year to almost original levels. Salivation was originally not impaired. Resting salivary flow rate (SFR) of the combined therapy group was decreased to half the initial rate, and a 20% decrease of SFR was seen in the PLM group. Corresponding to SFR, 99mTc uptake of the submandibular glands had declined, and salivary viscosity had increased. Salivary gland damage persisted during the study, and appeared irreversible. It was concluded from these results that taste impairment by oral cancer treatment is temporary, while damage to the salivary glands is permanent.

Thyrotoxic graves’ disease with normal thyroidal technetium-99m pertechnetate uptake

We saw 24 thyrotoxic Graves' patients with normal thyroidal uptake of technetium-99m pertechnetate (99mTc) out of 201 untreated thyrotoxic Graves' patients seen over 4 years. The clinical and laboratory findings for these patients were studied and analysed. Thyroid uptake and scintigraphic examinations by means of 99mTc, TBII and TSab activity measurement clearly distinguished these patients from other thyrotoxic disorders (destruction-induced thyrotoxicosis and autonomously functioning thyroid lesions). Different from other disorders, these patients had not lower but normal thyroid uptake and also showed diffuse and discrete trapping into the enlarged glands. These patients had significantly smaller goiters, a lower serum thyroid hormone level, and lower TBII and TSab activity, when compared with other high 99mTc uptake groups with Graves' disease, and their condition could be easily controlled with small amounts of antithyroid drugs. Our study indicates that thyrotoxic Graves' disease with normal 99mTc uptake exists and 99mTc uptake study and TBII activity measurement is very useful for the diagnosis. The normal 99mTc uptake thyrotoxic Graves' patient might be early stage patients with general Graves' disease and their early discrimination from general Graves' patients is very advantageous for treatment and prognosis.

Increased Focal Uptake of Tc-99m Stannous Phytate in an Irregular Fatty Liver Demonstrated by SPECT Imaging

An area of focally increased uptake of Tc-99m colloid (hot spot) in the liver has been reported in superior vena cava syndrome, Budd-Chiari syndrome, and focal nodular hyperplasia. A case of irregular fatty infiltration in which SPECT imaging clearly demonstrated an area of focally increased uptake in the left lobe of the liver, which was not well visualized by planar imaging, is presented. There have been a few previous reports of this finding on SPECT imaging in patients with irregular fatty infiltration of the liver.

Breast Uptake of Technetium-99m MDP During Radionuclide Angiography

A 31-year-old woman who developed congestive heart failure during her first pregnancy was scheduled for a resting, gated cardiac blood pool scan two weeks after delivery. She had not breast-fed her infant. High-quality RBC tagging was obtained, together with in vivo labeling and Tc-99m MDP. In this case, intense breast uptake of the radionuclide was seen, which confirms reports of uptake of Tc-99m and its excretion in breast milk and breast tissue in mothers given bone imaging agents.

TcU-Abhängigkeit von Akquisitionszeitpunkt, ROI und Untergrundsubtraktion

Thyroid uptake of 99mTc was compared using different modes of acquisition and evaluation. The starting time of acquisition, 5 min or 20 min after injection, did not make any difference. Comparison of the rectangular standard ROI and an irregular thyroid-shaped ROI showed a slight overestimation by 0.26% for the rectangular ROI. The results demonstrate that certain differences in acquisition and evaluation of TcU are clinically not important; however, if normal values are to be defined, they have to be taken into account.

Analogy between Tumor Uptake of Technetium(V)-99m Dimercaptosuccinic Acid (DMSA) and Technetium-99m-MDP

Sixty patients with a variety of malignant tumors were examined with Tc-99m(V) dimercaptosuccinic acid (DMSA) prepared by modification of a commercially available DMSA kit. Significant uptake of Tc-99m(V)-DMSA was observed in a number of tumors, offering additional clinically useful information. In the majority of cases in this study, however, the benefit of the Tc-99m(V)-DMSA image was limited because of low sensitivity. The most striking observation was the similarity between the tumor concentration of Tc-99m(V)-DMSA and the Tc-99m-MDP uptake in the tumor on the regular bone image. Therefore, patients with Tc-99m-MDP uptake in nonosseous tumor sites on the bone scan may be suitable candidates for tumor imaging with Tc-99m(V)-DMSA.

Elevated blood pressure and heart rate in rats exposed to a coal‐derived complex organic mixture

The susceptibility of the cardiovascular system to exposure to a high-boiling coal liquid (heavy distillate, HD) was studied in the rat using an isoproterenol (ISO) myocardial infarction model. Male Fischer rats were exposed to HD by inhalation (0.7 mg/l), 6 h/day, 5 days/week, for 6 weeks. After a 10-day recovery period, sham-exposed and HD-exposed rats were injected subcutaneously with 0, 20, 40 or 60 mg ISO/kg body weight. Blood pressure, heart rate, electrocardiogram and 99mTc uptake by the heart were measured 1 day later. A dose-related increase was observed in the uptake of 99mTc by the hearts of both sham-exposed and HD-exposed animals after ISO injection; however, uptake by the sham-exposed group was significantly greater than that of exposed groups. The most striking observation was a 20% elevation in arterial blood pressure of HD-exposed rats over that of sham-exposed animals when no ISO was injected. These results suggest that the cardiovascular system could be detrimentally affected by exposure to coal-derived complex mixtures and, possibly, to other complex organic mixtures.

Combined bone marrow and gallium imaging. Differentiation of osteomyelitis and infarction in sickle hemoglobinopathy.

The clinical records and scintigrams of patients with sickle hemoglobinopathy who underwent combined Tc-99m bone marrow imaging and Ga-67 imaging to differentiate osteomyelitis from bony infarction were reviewed. Of 18 paired examinations in 15 patients, osteomyelitis was diagnosed correctly in six cases; in all six, gallium uptake at the symptomatic site was incongruently increased relative to the bone marrow activity. Of the 12 episodes of infarction, 11 showed congruent activity on both Tc-99m and Ga-67 images. The remaining study was interpreted incorrectly as osteomyelitis due to incongruent Tc-99m and Ga-67 uptake. The use of sequential Tc-99m bone marrow and Ga-67 imaging is an effective means of distinguishing osteomyelitis from bony infarction in patients with sickle hemoglobinopathy.

Uptake of 99mTc - DISDA in Primary Hepatocellular Carcinoma and Metastatic Nodule in the Lung

Recently, several reports of extrahepatic hepatocellular carcinoma metastasis demonstrated by technetium- 99mTc-IDAs scan have shown that 99mTc-IDA s can be used to detect extrahepatic metastasis in hepatocellular carcinoma. We report here a case of hepatocellular carcinoma with pulmonary nodules that were demonstrated as metastasis in nature by the use of the 99mTc-DISIDA. The findings in this case and several reports reviewed here suggest that the 99mTc-DISIDA scan may be a useful diagnostic agent that can detect the extrahepatic metastasis of hepatocellular carcinoma and stage the disease. But more clinical study in needed to establish the position of 99mTc-DISIDA in the field of diagnosis of extrahepatic hepatocellular carcinoma.