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PubMed1995

Filtered technetium-99m-sulfur colloid evaluated for lymphoscintigraphy.

UNLABELLED: Several 99mTc-labeled radiopharmaceuticals have been developed for lymphoscintigraphy of the extremities. In the United States, however, these agents are not widely used clinically. This study evaluates the use of smaller particle sizes ( < 0.1 micron) of 99mTc-sulfur colloid (99mTc-SC) for lymphoscintigraphy. METHODS: The 99mTc-SC was prepared by kit, and the final preparation was filtered through a sterile 0.1-micron filter. The radiochemical purity (RCP) of the filtered 99mTc-SC was determined before administration. Nineteen patients with suspected lymphedema were injected with 18.5 MBq (500 muCi) filtered 99mTc-SC intradermally in each foot, and whole-body images were obtained immediately and 1, 3, 6 and 24 hr later. Local views over the inguinal or axillary lymph nodes were also obtained every 5 min for the first hour. RESULTS: The average RCP value was 93.4% +/- 4.2% (n = 19), and the RCP difference pre- and postfiltration of the 99mTc-SC preparation was -1.7% +/- 1.4% (n = 40). Evaluation of the particle size with the polycarbonate filter showed that 89.9% +/- 4.5% (n = 28) of particles were less than 50 nm, and the particle size was further determined by electron microscopy to be 38.0 +/- 3.3 nm (n = 202). The mean particle sizes of two peaks measured by laser light scattering techniques were 7.5 and 53.9 nm (major peak). Clinical studies with filtered 99mTc-SC demonstrated similar lymphoscintigrams compared with those obtained with 99mTc antimony sulfide colloid (99mTc-ATC). Filtered 99mTc-SC showed a faster transport rate to the inguinal lymph nodes and lower radiation dosimetry for liver, spleen and whole body compared with 99mTc-ATC. CONCLUSION: Filtered 99mTc-SC can be easily prepared and is readily available for routine clinical use in lymphoscintigraphic studies.

Antimony↗
PubMedDate not supplied

The diagnosis of internal mammary node metastases of breast cancer.

It is important to know the status of internal mammary lymph node (IMN) in estimating the prognosis in patients with breast cancer and/or planning the treatment. In the first series of this study, the diagnostic value of internal mammary lymphoscintigraphy (IMLS) and that of parasternal sonography (PS) were evaluated in 57 patients. The overall diagnostic accuracy of IMLS was 72% and that of PS, 84%, compared with IMN metastases confirmed on a biopsy. In the second series, 23 patients who underwent extended radical mastectomy and were found to have IMN metastases, were examined for the sizes and locations of metastatic IMN. Minute metastatic lymph nodes not detectable by IMLS or PS were found in 9 (39%) of the patients. However, the incidence of metastases to the first and/or second intercostal spaces was 97% for the patients. We concluded that a biopsy of the first and second intercostal spaces is useful in providing the information of IMN status.

Adult↗
PubMed1996

Intestinal leakage of technetium-99m-MDP in primary intestinal lymphangiectasia.

We present a case in which a patient with primary intestinal lymphangiectasia demonstrated abnormal intestinal accumulation of tracer during 99mTc-methylene diphosphonate (MDP) skeletal scintigraphy. Early intestinal leakage with gradual colonic migration and concentration was confirmed by repeat bone scan with serial acquisitions. The mechanism for the intestinal localization of 99mTc-MDP seen in this patient is not clear. Thus, intestinal lymphangiectasia can be a cause for extra-osseous localization of bone scan agents in the intestine.

Adult↗
PubMed1998

Optimized sentinel node scintigraphy in breast cancer.

INTRODUCTION: Axillary lymph node dissection (ALND) represents an important staging procedure in the surgical treatment of breast cancer. However, it may result necessary in tumors of little dimensions because of low percentage of metastatic axillary lymph node (ALN). If a non invasive technique predicted the status of ALN, ALND procedures could be avoided. We carried out this study i) to establish the best technique to perform the lymphoscintigraphy for detecting the sentinel node in breast cancer and ii) to determine whether a clear sentinel node reliably predicts a disease free axilla. METHODS: 215 patients were submitted to the lymphoscintigraphy before surgery. Three different colloidal radiotracers with particle size ranging between < 50 and 1000 nm were injected sudermically or peritumorally. Early and late images were recorded in anterior and oblique projections and the SN was marked on the skin and biopsied using a gamma detection probe (GDP) during surgery. RESULTS: The SN was identified in 210/215 cases (97.6%). The SN accurately predicted axillary ALN status in 204/210 (97.1%) patients in whom a sentinel node was identified and in all the cases (45 patients) with tumor < 1.5 cm in diameter. In 38/101 cases with metastatic axillary nodes (37.7%) the only positive node was the SN. CONCLUSIONS: Lymphoscintigraphy can easily locate the SN in breast cancer. SN detection resulted easier when large size microcolloids were used. Subdermally administration appeared the best way of injection for palpable lesions. Breast cancer patients without clinical involvement of the axilla should undergo SN biopsy routinely and this may allow sparing complete axillary dissection when the SN is free of disease.

Antimony↗
PubMed1998

Lymphoscintigraphy and radioguided biopsy of the sentinel axillary node in breast cancer.

UNLABELLED: Lymphoscintigraphy associated with radioguided biopsy of the sentinel node (SN) is well established in clinical practice for melanoma. In breast cancer, the SN concept is similarly valid, and lymphoscintigraphy is a useful method for localizing the axillary SN. The aim of this study was to optimize the lymphoscintigraphy technique in association with a gamma ray detecting probe (GDP) for identifying and removing the SN in breast cancer patients. METHODS: Two-hundred fifty patients with operable breast tumor underwent lymphoscintigraphy before surgery. Three different size ranges of 99mTc-labeled colloid particles (<50, <80 and 200-1000 nm) were used, with either subdermal (above tumor) or peritumoral injection. Early and late scintigraphic images were obtained in anterior and oblique projections, and the skin projection of the detected SN was marked. Sentinel nodes were identified and removed with the aid of the GDP during breast surgery; they were tagged separately. Complete axillary dissection followed. In 40 patients, a blue dye was also administered in addition to subdermal radiolabeled colloid to compare blue dye mapping with lymphoscintigraphy localization. RESULTS: Lymphoscintigraphy successfully revealed lymphatic drainage in 245 of 250 patients (98%). The axillary SN was identified in 240 patients (96%). SN biopsy correctly predicted axillary node status in 234 of 240 patients (97.5%). Lymphoscintigraphy and GDP detected the SN most easily and consistently when 200-1000 nm colloid was administered subdermally in an injection volume of 0.4 ml. Blue dye mapping was successful in 30 of 40 patients (75%). In 26 of these patients, the dye and lymphoscintigraphy identified the same node; in 4 cases different nodes were identified. None of these four patients had axillary disease. CONCLUSION: Lymphoscintigraphy is a simple procedure that is well tolerated by patients. Sentinel node identification is more reliable when large-size radiolabeled colloids are injected in a relatively small injection volume (0.4 ml). Use of a GDP greatly facilitates precise pinpointing and rapid removal of the SN.

Antimony↗
PubMed1977

Pancreatic scanning using retrograde injection of technetium-99m-labeled compounds.

With increased clinical availability of endoscopic retrograde pancreatography, a method for retrograde injection of radionuclides into the pancreas became available. A dog model was developed to evaluate resolution and toxicity of retrograde imaging prior to human use. Two groups of technetium-99m-labeled compounds were used. The first included ionic carriers--pertechnetate and pyrophosphate--and the second included particulate carriers--sulfur colloid and albumin microspheres. Parenchymal visualization, absorption patterns, and toxicity in dogs were studied. The results suggest that pyrophosphate, sulfur colloid, and albumin microspheres would all be feasible technetium carriers for use in humans.

Animals↗
PubMed1978

Factors influencing paper chromatographic analysis of technetium-99m phosphorus compounds: concise communication.

A single-paper chromatographic system has been developed, capable of resolving Tc-99m dioxide, [99mTc] pertechnetate and Tc-99m phosphorus compounds. The best separations are obtained with CM82 paper developed in 0.5 m naCl, and 3MM or ashless No. 40 paper developed in 1 M sodium acetate buffer. In these systems, 99TcO2 remains at the origin, while 99mTcO4--and Tc-99m phosphorus compounds move with Rf values of 0.56--0.75 and 0.80--1.0, respectively.

Chromatography, Paper↗
PubMed1988

Lung uptake of technetium-99m phosphate compounds after liver transplantation.

Pulmonary calcification can be detected easily using Tc-99m phosphate compounds. Lung uptake of Tc-99m bone imaging agents was observed in two patients after liver transplantation. Transient hypercalcemia due to calcium infusion during hepatic transplantation may be responsible for the pulmonary calcification.

Calcinosis↗
PubMed1988

Discordant hepatic uptake of Tc-99m HIDA and Tc-99m colloid in a patient with segmental biliary obstruction.

Discordant hepatic uptake between Tc-99m HIDA and Tc-99m colloid occurred in a 63-year-old female with segmental biliary obstruction due to cholangioma. Radiographic CT and a percutaneous transhepatic cholangiogram revealed the obstructed right hepatic duct as well as the dilated intrahepatic duct in the right lobe. At surgery this was confirmed, and a 2 cm mass encasing the right hepatic duct was identified. It should be included in the gamut of discordant hepatic uptake of Tc-99m IDA and Tc-99m colloid.

Adenoma, Bile Duct↗
PubMed1997

Dissociation of 99mTc-ECD and 99mTc-HMPAO distributions in herpes simplex encephalitis.

In herpes simplex encephalitis (HSE), the authors noted an evident dissociation between the 99mTc-ethyl cysteinate dimer (ECD) and 99mTc-d,l-hexamethyl-propylene-amine oxime (HMPAO) single photon emission computed tomographies (SPECTs). The patient was a 5-year-old boy with diffuse type of pontine glioma, which was treated with hyperfractionated radiotherapy. Two weeks after the completion of radiation therapy, a lesion suggesting that of HSE was noted in the right fronto-temporal region on magnetic resonance images. 99mTc-HMPAO SPECT showed an increased accumulation of the tracer in this lesion. On the 99mTc-ECD dynamic SPECT, an exaggerated accumulation of the tracer was noted within 80 s of administration, followed by a rapid drop in the accumulation, resulting in a low accumulation in 10 min. It was assumed that this dissociation was due to the different mechanisms to trap HMPAO and ECD in the brain tissue.

Brain↗
PubMed1984

Calcification and uptake of Tc-99m diphosphonates in neuroblastomas: concise communication.

Sixty-six percent of 54 patients with neuroblastoma demonstrated uptake of bone-seeking radioagents by the primary tumor. This is a higher incidence than previously reported. Uptake was slightly more common in abdominal than thoracic tumors. There was a significant correlation between the size of the tumor and tracer uptake. Calcification was demonstrated in the primary tumor in almost 90% of the 54 patients. This is a much higher incidence of calcification than previously reported. Microscopy shows that the calcification is not always due to tumor necrosis; it also occurs in areas of viable tumor cells. Tracer uptake is believed to be related to calcium metabolism. The rate of metabolic activity rather than the total amount of calcium present within the tumor may be the most important factor in determining the amount of uptake. No significant relationship was found between tracer uptake and tumor stage or homovanillic acid and vanillylmandelic acid metabolic activity.

Abdominal Neoplasms↗
PubMed1999

99Tcm-citrate: a new bone imaging radiopharmaceutical.

99Tcm-citrate has been shown to incorporate irreversibly in the skeleton with a biodistribution different to that on a conventional bone scan. The aims of this study were to confirm the bone-imaging properties of 99Tcm-citrate, to identify the variabilities influencing its skeletal uptake, to compare its uptake in bone with that of 99Tcm-MDP and to assess its possible role in bone scintigraphy. Appropriate animal and human studies (n = 45) were conducted. The 3 h lesion-to-bone ratio of 99Tcm-citrate was compared with that of 99Tcm-MDP in more than 150 lesions, including osteoblastic sites (Group A), lesions undergoing treatment or healing (Group B), and degenerative or old healed lesions (Group C). The uptake ratio was classified as concordant (< 20% variation), mildly discordant (20-50% variation) or significantly discordant (> 50% variation). Animal experiments showed most bone uptake of 99Tcm-citrate when prepared at a pH of 6.0-6.5. The two radiopharmaceuticals appeared to compete for bone uptake, suggesting related but different sites of bone accumulation. The 99Tcm-citrate/99Tcm-MDP uptake ratio in Group A was concordant (mean +/- S.D. = 0.92 +/- 0.15), while Group C lesions had a significantly lower 99Tcm-citrate/99Tcm-MDP uptake ratio (0.34 +/- 0.24, P < 0.01). A comparison of Group B lesions showed wide variation in intensity and area of involvement in many lesions (uptake ratio < 0.5 or > 1.5 in 13 of 30 sites). We conclude that 99Tcm-citrate has a different site of bone localization than phosphonates, possibly in the organic matrix. Although its skeletal uptake is lower than that of 99Tcm-MDP, it may have better specificity in differentiating osteoblastic from degenerated or healed bony lesions, and therefore be useful in predicting healing of bone secondaries, fractures or osteomyelitic lesions.

Adult↗