99mTc-human Serum Albumin Research Articles

99mTc-Phytate Is Better than 99mTc-Human Serum Albumin as a Radioactive Tracer for Sentinel Lymph Node Biopsy in Breast Cancer

Several radioactive agents are used for sentinel lymph node biopsy (SLNB) in breast cancer, but we are still unsure which of these is best. We retrospectively compared the effectiveness of two radioactive agents, 99mTc-phytate and 99mTc-human serum albumin (HSA), when used in combination with blue dye. A consecutive series of 533 clinically node-negative patients with a collective 539 breast carcinomas were divided into two groups for treatment with SLNB. The HSA-group consisted of 264 patients (with a collective 266 breast cancers) and the P-group consisted of 269 patients (with a collective 273 breast cancers) treated with 99mTc-HSA and 99mTc-phytate, respectively, in combination with blue dye. We analyzed the identification and radioactivity of SLNs in the two groups. The identification rate of SLN was significantly higher in the P-group than in the HSA-group. The same results were produced by analysis using the radioactive agent alone, but not by using the blue dye alone. Most importantly, the highest radioactivity of SLNs per case was more than five times higher in the P-group than in the HSA-group, and this difference was significant. Our historical analysis of the two radioactive agents used in different periods could not exclude the influence of the improved skill of the surgeons. However, because the specific accumulation of phytate in SLNs was greater than that of HSA, phytate might result in a higher SLN identification rate. Thus, 99mTc-phytate is better than 99mTc-HSA as a radioactive agent for SLNB in breast cancer.

A Systemic Lupus Erythematosus Patient with Protein Losing Enteropathy

Protein-losing enteropathy (PLE) is a rare manifestation of systemic lupus erythematosus (SLE), and it is an uncommon cause of hypoalbuminemia without proteinuria. We describe a case of an 11 year-old girl who had diarrhea and periorbital edema as the initial symptoms of SLE. PLE was diagnosed by 24-hour stool alpha-1 antitrypsin clearance and (99m)Tc-human serum albumin scintigraphy.

Nuclear gastroenterology

Application of nuclear medicine for gastroenterology, especially the liver, portal circulation and alimentary tract was described. In the liver, radiocolloid scintigraphy is useful for the diagnosis and follow-up study of chronic liver diseases. 99mTc-GSA scintigraphy plays a role for the evaluation of hepatic functional reserve. 99mTc-PMT used for hepatobiliary imaging, is also useful for the diagnosis of hepatic tumor and extra-hepatic metastasis of hepatocellular carcinoma. In the study of portal circulation, various administration sites such as intrasplenic, rectal, oral, and intravenous have been reported. In the evaluation of motility function of alimentary tract, estimation of gastric emptying time is well known. Condensed image created from serial esophageal scintigrams using computer processing is also useful for the quantitative and qualitative evaluation of esophageal motility function and gastro-esophageal reflux. Abdominal scintigraphy with 99mTc-human serum albumin enables imaging diagnosis of protein-loosing gastroenteropathy.

Significance of lymphoscintigraphic mapping with Tc-99m human serum albumin and tin colloid in sentinel lymph node biopsy in breast cancer.

Sentinel lymph node biopsy (SLNB) in breast cancer is considered in order to spare node-negative patients from axillary lymph node dissection. To assess the clinical significance of lymphoscintigraphic mapping in SLNB, we analyzed the lymphatic drain to the sentinel lymph nodes (SLNs) in terms of the pattern and direction of the hot spot. Twenty-three breast cancer patients were enrolled for SLNB. Before surgery, lymphoscintigraphic mapping of SLN was performed using Tc-99m human serum albumin (HSA) and tin colloids, and the hot spot was marked. The Tc-99m HSA and tin colloids were subcutaneously injected above the tumor and peritumor sites, respectively, and lymphoscintigraphic scanning was monitored every 5 to 10 min, for up to 2 h after injection. The SLN was identified using a combination of a blue dye, indigocalmine, and a gamma probe during surgery. The hot spot pattern and direction of the lymphatic drains were evaluated in 21 of 23 cases. Two cases did not have a hot spot. Single, double, and multiple hot spots were observed in 12 cases (52.1%), 8 cases (34.7%), and 1 case (4.3%), respectively. The positions of the hot spots were: axillary (n=17, 80.9%), axillary and sternal (n=3, 14.2%), and phrenic (n=1, 4.7%). The sensitivity and specificity rates in SLNB were 66.6% and 100%, respectively, and the overall predictive rate was 85.7%. Lymphoscintigraphy produced false negatives in three cases (33.3%), including one on the phrenic side. Lymphoscintigraphic mapping with Tc-99m HSA and tin colloids is useful for determining the SLN, and avoiding a false negative. The pattern and direction of the lymphatic drain to the SLN in scintigraphy need to be considered for the elimination of axillary lymph node dissection in node-negative patients with breast cancer.

Radionuclide venography and labeled platelets in deep venous thrombosis

99mTc-labeled macroaggregated albumin, 99mTc-labeled red blood cell, and 99mTc human serum albumin blood pool venography are simple, noninvasive imaging procedures that provide indirect evidence of deep vein thrombosis. These techniques rely on alterations in the normal venous anatomy. They do not determine the cause of venous obstruction and/or altered anatomy and cannot differentiate between acute and chronic deep venous thrombosis. In vitro labeled platelet scintigraphy provides direct evidence of active or acute thrombosis. Unfortunately, this technique requires a labor-intensive, lengthy labeling process and has a high number of false-negative results in patients who receive heparin therapy.

Intestinal protein loss in patients with haemorrhagic fever with renal syndrome.

In haemorrhagic fever with renal syndrome (HFRS) vascular dysfunction has been observed in various organs, but the involvement of the intestine has not yet been reported. This study was performed to evaluate the association of intestinal protein loss in this disease with other clinical parameters reflecting vascular permeability or disease severity. Twenty patients with HFRS were included in this study. Intestinal protein loss was measured by (99m)Tc-human serum albumin ((99m)Tc-HSA) scintigraphy in the acute stage, and quantitative analysis of protein loss was measured by the faecal clearance of alpha 1-antitrypsin (C(AT)) in the acute and the recovery stages. C(AT) was then compared with clinical parameters reflecting disease activity and vascular permeability. (99m)Tc-HSA scintigraphy was positive in 13 (65%) patients, and C(AT) in the acute stage was significantly increased as compared with C(AT) in the recovery stage (40.5+/-24.1 vs 9.2+/-4.2 ml/day, P<0.001). C(AT) was associated with serum albumin levels, frequency of hypotensive episodes, severity of acute renal failure, and degree of thrombocytopenia. Our data suggest that the increased vascular permeability of HFRS is associated with the increased intestinal loss of plasma proteins, which might represent one of the parameters of disease severity in HFRS.

Sentinel lymph node and breast cancer staging: final results of the Turin Multicenter Study.

Validation of the sentinel node (SN) technique in breast cancer by means of lymphoscintigraphy. From December 1996 to January 1999 102 T1-T2 breast carcinoma cases were recruited in Turin. 99mTc-human serum albumin colloids were injected subdermally the day before surgery (mean activity, 5.2 +/- 2.5 MBq). Scintigraphic imaging was performed after injection. After identification of the SN during surgery by a hand-held gamma probe, the SN was excised and sent for histologic examination. SN histology was compared with that of other axillary nodes. The SN detection rate was 86.3%; among 88 cases with an identified SN, 37 (42%) had axillary metastases; the SN was metastatic in 35 cases (sensitivity, 94.6%); in 51.3% of pN+ cases (19/37) the SN was the only metastatic site. In two of the 53 negative SNs, SN histology did not match with that of the remaining axilla (negative predictive value, 96.2%; staging accuracy, 97.7%). Our results agree with those reported in the literature; however, except in clinical trials and experienced structures axillary lymph node dissection should not be abandoned when mandatory for prognostic purposes, considering that at present SN biopsy alone is not completely accurate for axillary staging, especially in the absence of an adequate learning period.

Radionuclide lymphangioscintigraphy in the evaluation of peripheral lymphedema.

The primary difficulty in evaluating and treating peripheral lymphedema is visualization of the lymphatics. Functional lymphatic studies have been performed on patients with peripheral edema to diagnose lymphedema, to determine its severity, and to understand the varied drainage patterns. After intradermal injection in the hands or feet, initial flow and whole-body images were taken using Tc-99m human serum albumin in more than 700 patients with possible lymphedema. Clear images of truncal lymph transport and draining lymph nodes were obtained, and pattern differences between primary and secondary lymphedema were seen. Follow-up studies showed any functional change in lymphatic dynamics. Peripheral lymphatics can now be easily visualized. Because lymphangioscintigraphy can be performed before and after medical treatment, follow-up evaluation of patients with lymphedema is possible. The procedure is noninvasive, repeatable, easy to perform, and harmless to the lymphatic endothelium.

Measurement of plasma volume using 99Tc(m)-labelled DMP-HSA.

Red cell volume (RCV) and plasma volume (PV) measurements are performed routinely in nuclear medicine departments to diagnose a number of haematological disorders. Currently, 125I-HSA is used as a plasma tracer and 99Tcm-labelled red cells to determine red cell volume. 125I-HSA is not always readily available, leading to inconvenience for patients and medical practitioners. Due to the availability of 99Tcm in nuclear medicine departments, the use of albumin labelled with 99Tcm was investigated. A new 99Tcm-human serum albumin labelling kit (99Tcm-DMP-HSA) was developed by Verbeke and supplied for use in this study. The main aim of the study was to investigate the use of 99Tcm-DMP-HSA for PV determination. Secondly, the feasibility to determine red cell and plasma volume simultaneously using 99Tcm as radionuclide in both instances was investigated. Fourteen healthy volunteers were enrolled in the dual-phase study. During the first study, 99Tcm-DMP-HSA was used as tracer to calculate PV (PV1a) after intravenous administration. Subsequently, 99Tcm-labelled red cells were administered and the PV (PV1b) and RCV (RCV1) were calculated. The second study was repeated within 2 weeks using the conventional method. 125I-HSA and 99Tcm-labelled red cells were administered simultaneously. The PV (PV2) and RCV (RCV2) were calculated. We found that the redistribution of 99Tcm-DMP-HSA is faster than that of 125I-HSA; therefore, the plasma counts obtained at different times were back-extrapolated to time zero for plasma volume calculations. The mean values for the different calculated PVs were 2964+/-470 ml for PV1a, 3006+/-623 ml for PV1b and 3001+/-530 ml for PV2, the reference PV. The confidence intervals indicate no significant differences between plasma volumes PV1a and PV2 and plasma volumes PV1a and PV1b. The mean calculated RCV1 was 2130+/-322 ml; that of RCV2 was 2128+/-353 ml. The difference between RCV1 and RCV2 was not significant. Our results indicate that 99Tcm-DMP-HSA could be used for plasma volume calculation. Red cell and plasma volumes can be calculated simultaneously using 99Tcm as radionuclide in both cases.

Scintigraphy for evaluating early aspiration after oral feeding in patients receiving prolonged ventilation via tracheostomy.

In tracheotomised patients the incidence of aspiration is difficult to determine because investigators often apply different criteria. In this study a scintigraphic method was used to visualise feeding aspiration directly and the results were compared with clinical evidence of aspiration. Prospective study in difficult-to-wean patients with tracheostomy. Respiratory ICU. The study population consisted of 62 consecutive patients (16 females, age: 64.1+/-11.1 years). All patients were tracheotomised and had previously been long-term ventilated in other ICUs due to weaning failure. The scintigraphic test was performed during spontaneous breathing. The standard nutrition consisted of a liquid, semi-liquid and solid meal which was labelled with 100 MBq 99mTc-human serum albumin. Scintigraphic aspiration (SA) was defined as positive if radioactivity was detected in the bronchial system using a scintillation camera. Furthermore, aspiration was proven clinically (CA). CA and SA yielded identical results in 54 of the 62 patients [10 positive (16%) and in 44 negative (71%)]. CA, but not SA, was seen in 4/62 (6.5%) and SA, but not CA, was found in 4/62 (6.5%) patients. Our data re-emphasise that aspiration in tracheotomised patients is common (in our study approximately 30%). The scintigraphic method failed to identify all tracheotomised patients with clinically significant aspiration; however, it did suggest that some patients had subclinical aspiration.

Ruptured Lymphocele as a Cause of Chylous Ascites: Demonstration by Lymphoscintigraphy

A 20-year-old woman who reported progressive abdominal distention was admitted to the hospital. CTs of the abdomen and pelvis showed a large amount of ascites, soft tissue density masses in the paraaortic region, and a cystic mass in the pelvis that was thought to be an ovarian tumor. Because the ascites were chylous in nature by abdominal paracentesis, lymphoscintigraphy was performed by injecting Tc-99m human serum albumin subcutaneously into the webbing between the first and second toes. Serial whole-body images suggested that the paraaortic and the cystic masses were lymphoceles extending from the pelvis to the paraaortic region. A gradual increase in abdominal activity was also observed, indicating leakage of lymph into the peritoneal cavity. On laparoscopy, normal ovaries were observed and a fluid leak was located in the pelvic cystic mass. Based on these findings, a ruptured lymphocele was thought to be the cause of the chylous ascites.

Pharmacokinetics of dacarbazine in the regional perfusion of extremities with melanoma.

The pharmacokinetics of dacarbazine (DTIC), which has been shown to be an effective therapeutic agent against metastatic melanoma, has not been extensively studied. However, to improve the clinical use of the drug, more information on the kinetics is required. A pharmacokinetic study was undertaken in six patients with melanoma of an extremity who were undergoing hyperthermic isolation perfusion with DTIC in order to understand better its clinical pharmacokinetics. Plasma was sampled from the arterial and venous lines of an extracorporeal pump during the perfusion with the systemic vein and urine sampled postperfusion. Samples were analyzed for DTIC. 2-azahypoxanthine (2-AZA), and aminoimidazole carboxamide (AIC). 99(m)Tc (Technetium) human serum albumin (HSA) was used in the perfusion circuit to monitor the crossover of the perfusate into the systemic circulation during the procedure. The data were analyzed using a compartmental model of sampled body compartments incorporating the isolated extremity. High tissue DTIC levels were maintained throughout the perfusion, whereas in the systemic circulation, plasma DTIC concentrations, when observed, were 40-100-fold less than those in the perfusate. Almost 70% of the DTIC administered was not recovered in the perfusate after the washout of the extremity. High levels of DTIC can be maintained in an extremity (i.e., arm or leg) during perfusion.

Pulmonary 99mTc-human serum albumin clearance and effects of surfactant replacement after lung lavage in rabbits.

Pulmonary clearance of technetium-labeled human serum albumin was measured in order to investigate whether the surfactant layer is a rate-limiting factor for the permeability of the alveolar-capillary membrane for 99mTc-labeled albumin. Prospective, randomized, controlled trial. Research laboratory. Nineteen white New Zealand adult rabbits. Three groups of rabbits were studied: group 1 animals received natural surfactant after lung lavage; group 2 animals underwent lung lavage only; and group 3 animals were not lavaged and served as an untreated, healthy control group. All animals were ventilated with high pressures. 99mTc-labeled albumin was nebulized into the inspiratory line of the breathing circuit with an air jet nebulizer. The clearance measurements were then immediately started. Gamma camera images were obtained in 1-min frames for 120 mins and stored in a 64 x 64 image matrix in a computer. In group 1 animals, surfactant restored blood gases to near normal, and all animals except one had bi-exponential clearance curves. The half-life of the fast compartment was 35.9 +/- 6.4 mins, and the half-life of the slow compartment was 847.5 +/- 143.5 mins. All group 2 animals also had bi-exponential clearance curves of the tracer (the half-lives of the fast and slow compartments were 14.6 +/- 6.7 and 459.8 +/- 167 mins, respectively). The half-lives of both the fast (p < .01) and slow (p < .01) components were significantly different between groups 1 and 2. Group 3 had a mono-exponential half-life of 580 +/- 225 mins. The use of 99mTc-human serum albumin as a tracer molecule is possible and feasible. The clearance of this tracer is, in part, determined by the integrity of the pulmonary surfactant system, as it is with 99mTc-diethylenetriamine pentaacetate.

Incidental detection of arterial aneurysms with Tc-99m human serum albumin.

Tc-99m human serum albumin gastrointestinal bleeding imaging was performed on a 66-year-old man with vascular Behcet disease, and small-bowel bleeding was demonstrated at 20 minutes after the administration of Tc-99m human serum albumin. Unexpected aneurysms, vascular complications of Behcet disease, were also detected.

201Tl and 99Tcm-human serum albumin for assessment of the effect of hypertensive treatment with angiotensin II infusion on tumour circulation.

The biodistribution of 201Tl and of 99Tcm-human serum albumin (99Tcm-HSA) was observed in tumour-bearing mice to investigate if tissue blood circulation could be evaluated in groups of mice infused with angiotensin II at a rate of 0.5 micrograms kg-1 min-1 (L) or 1 microgram kg-1 min-1 (H). Ten minutes after tracer injection, tumour uptake of 201Tl in the angiotensin II infused group showed a 2.20- and a 3.18-fold increase in the L and H groups, respectively, when compared to a group of mice infused with saline (P = 0.0478 and 0.0029, respectively). The effect of angiotensin II infusion on 201Tl uptake was minimal in normal organs. Decreased normal organ uptake of simultaneously injected 99Tcm-HSA in the L and H groups indicated the contraction of normal organ vessels, while increased tumour uptake of the tracer indicated mechanical dilatation of tumour vessels. We conclude that the effect of angiotensin II or other vasoactive agents can be non-invasively assessed by 201Tl and 99Tcm-HSA scintigraphy.

Scintigraphic Diagnosis of Protein Losing Enteropathy Using Tc-99m Dextran

The authors performed abdominal scintigraphy using intravenously administered Tc-99m dextran in a patient with protein losing enteropathy. The study revealed abnormal leakage of the radiotracer in the left lumber area that moved over time in a pattern suggestive of small intestinal transit. Besides being a nonprotein and having long stay in intravascular compartment, the macromolecule may have many advantages over Tc-99m human serum albumin, the current radiotracer of choice for imaging intestinal protein loss.

Scintigraphy in Assessment of the Feasibility of Separation of a Set of Xipho-Omphalopagous Conjoined Twins

An account is given of the assessment of a set of xipho-omphalopagous twins by means of Tc-99m microcolloid human serum albumin (HSA) and Tc-99m HIDA scintigraphy before their successful separation. The Tc-99m HSA examination showed the absence of connections between the two hearts and major vessels, as well as the independent vascularization of each liver parenchyma and absence of substantial intrahepatic shunts. Tc-99m HIDA disclosed bile secretion and the existence of intrahepatic ducts in both twins. In one, there was excretion into the intestine and the gallbladder and common bile duct were visualized, whereas in the other excretion was slow, either because of duct hypoplasia or as a result of the connections with the other twin. On separation, it was found that the liver parenchyma was composed of two fused parts (the livers of each twin). In one twin, cholangiography showed the gallbladder and intrahepatic and extrahepatic bile ducts with normal excretion into the intestine and excellent drainage, whereas in the other twin the gallbladder was absent, the common bile duct was hypoplastic, and excretion was poor. The two scintigraphic techniques employed provided evidence of bile duct function and enabled the separation to be planned, while intraoperative cholangiography gave a clear picture of the anatomical details before the reconstruction procedure.

The change in the distribution of Tc-99m human serum albumin radioaerosols in asthma after a 1-week course of corticosteroid inhalation treatment.

This study evaluated the effects of corticosteroid inhalation on the deposition pattern of Tc-99m HSA radioaerosols in 24 patients with asthma. The homogeneous degree of depositing radioaerosol was quantitatively evaluated using a modified standard score system over both lungs. The baseline scores were calculated before inhalation therapy of 0.05 mg beclomethasone dipropionate four times daily for 1 week. The studies were then repeated after treatment to evaluate the effects of inhalation therapy. After treatment, the scores decreased in 16 of 24 cases (67%), which means that the degree of the bronchial obstruction decreased. The statistical results revealed significant differences in the total homogeneity score (P < 0.001) before and after therapy. Thus, a 1-week course of beclomethasone dipropionate inhalation therapy improves the bronchial obstruction in asthma patients as shown by the quantitative homogeneity score system of the Tc-99m HSA radioaerosol inhalation lung scintigraphy.

Comparison of jet and ultrasonic nebulizers for alveolar targeting of methylprednisolone

The secondary systemic effects of oral corticosteroid therapy in chronic lung disease indicate the possible benefits of local therapy. The aim of this study was to show if alveolar targeting of a corticosteroid, methylprednisolone (MP), is possible, and to determine which type of nebulizer allows the most selective deposition into the alveoli. A jet nebulizer (Respirgard II) with 2 ml volume fill (R2), and an ultrasonic nebulizer (Ultraneb 99) with 4 ml volume fill (U4), were compared using a 40-mg dose of MP labelled 99Tcm human serum albumin. Particle size and MP-to-albumin binding were measured in the aerosol cloud. Each nebulizer was used in random order in five healthy volunteers. A dynamic posterior scan of 68 images of 15 s each was performed with a Gammatome II gamma camera during inhalation. Peripheral and central regions of interest were automatically defined with reproducible methods, and the peripheral-to-central ratio was used as a penetration index. Stomach and oropharynx activities were estimated on static anterior and static left lateral views, respectively, at the end of the examination. The mass median aerodynamic diameter (MMAD) was lower for R2 when unlabelled MP was used. The MMAD of MP+HSA was compatible with alveolar targeting. In the aerosol cloud, MP-albumin binding was 75% for R2 and 79% for U4. Peripheral and central activities at equilibrium (13-16 min) were higher with U4, but the penetration index was significantly higher with R2. Moreover, the stomach and oropharynx activities were significantly lower with R2.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of corticosteroid inhalation therapy on the deposition pattern of Tc-99m human serum albumin radioaerosols in asthma.

This study evaluated the effects of steroid inhalation on the deposition pattern of Tc-99m human serum albumin (Tc-99m HSA) radioaerosols in 25 asthma patients. A total of 12 normal controls also underwent the same examination. The pattern of radioaerosol deposition was quantitatively evaluated as the percentage of total deposition (PTD) in the central, intermediate, and peripheral regions of the right lung. The baseline PTD was calculated before and after the administration of a 1-week course of inhalation therapy of 0.05 mg beclomethasone dipropionate four times daily. There were significant differences in PTD between normal controls and asthma patients. Significant differences were also found before and after corticosteroid inhalation therapy in asthma patients. In conclusion, a week-long course of beclomethasone dipropionate inhalation therapy does influence the deposition patterns of aerosols in asthma patients, based on the findings of Tc-99m HSA radioaerosol inhalation lung scintigraphy.