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PubMedDate not supplied

Optimal sentinel node examination and a new strategy for axillary control in breast cancer.

The sentinel lymph nodes (SLNs) have been reported to reflect the other nodal status in breast cancer, and it is thought that axillary dissection can be avoided in SLN-negative patients, whereas an additional axillary dissection must be performed for SLN-positive patients. To avoid any unnecessary dissection, non-SLN-negative patients should be distinguished among SLN-positive patients. In this study, an optimal histological examination of SLNs was investigated for a precise indication of additional axillary clearance. A modified radical mastectomy with an axillary dissection was performed for 61 patients. Technetium-labeled tin colloids were used to identify the SLNs. In all lymph nodes that were diagnosed as negative at one section by hematoxylin and eosin (H&E) examination, another additional slice was produced for each lymph node. We evaluated how minute areas of cancer in the SLNs can indicate the non-SLNs to be negative. Among 1,092 lymph nodes previously diagnosed by H&E examination as negative at one section, 3 nodes were revealed to be positive in 46 SLNs (6.52%), whereas in additional slices, only 3 nodes out of 1,046 non-SLNs were positive (0.29%). The mean ratio of the cancer cell area to the whole area of SLN on the slice was 15.6% (10-18%) in 12 non-SLN-negative patients and 45.6% (30-83%) in 16 non-SLN-positive patients. It is possible that additional axillary clearance is not needed for patients with a cancer area of less than approximately 20% in the SLN slice, based on an H&E staining evaluation of two slices. SLNs identified with radiolabeled tin colloids could reflect the other nodal status in breast cancer. There is a possibility that additional axillary clearance is not needed for patients with a cancer area of less than approximately 20% in the SLN slice.

Axilla↗
PubMed2001

Functional magnetic stimulation facilitates colonic transit in rats.

OBJECTIVE: To investigate the effect of functional magnetic stimulation (FMS) on colonic transit in rats. DESIGN: Experimental. SETTING: Functional magnetic stimulation laboratory in a Veterans Administration health care system. ANIMALS: Twenty-four female Wistar rats, divided into an experimental group and a control group. INTERVENTIONS: All rats had technetium 99m (Tc 99m) infused through a cecal catheter to assess colonic transit times. FMS was performed over the cervical region; a figure of 8 magnetic coil was used in the experimental group. The colon was removed and sectioned into 10 segments, and a stool sample was taken in both groups. MAIN OUTCOME MEASURES: Distribution of radioactivity within the large intestine and stool were measured. RESULTS: Geometric center calculations showed significant differences (p <.001) between the control group and the experimental group when the distribution of radioactivity along the colon was measured. The percentage of Tc 99m recovered from the stool in the experimental group was significantly higher than the percentage recovered from the control group. CONCLUSION: FMS facilitates colonic transit in a rat model.

Animals↗
PubMed2001

The effect of vascular endothelial growth factor on angiogenesis: an experimental study.

OBJECTIVE: to evaluate the effects of exogenous vascular endothelial growth factor (VEGF) on angiogenesis in a rabbit model of persistent hind limb ischaemia. MATERIALS AND METHODS: ischaemia was induced in the hind limbs of 42 New Zealand white rabbits divided into six groups, each of 7 animals. Group 1a and 1b received intramuscular injections of 1 and 2 mg VEGF/day, respectively, into the ischaemic hind limb for 10 days beginning on postoperative 11th day, and group 1c received IM injections of saline only. Group 2a and 2b received similar regimen of VEGF, but administered intra-arterially. Group 2c served as controls. Perfusion of the ischaemic limb was evaluated by thigh blood pressure and thigh circumference at 10, 25 and 40 days following limb ischaemia in all animals and by digital subtraction angiography, perfusion scans, histological examination of capillary density in 2 animals from each group. RESULTS: thigh pressure index and thigh circumference improved significantly in the VEGF treated animals (Groups 1a,b and 2a,b). Collateral formation, as assessed by angiography, scintigraphy and by histological examination, indicated marked formation of collaterals in the VEGF treated animals as compared with the controls. This was most pronounced in groups receiving the highest dose of VEGF. CONCLUSION: these data suggest that VEGF promotes angiogenesis, that the route of administration is unimportant, but that a dose-response relationship is present in this experimental ischaemic hind limb model.

Angiography, Digital Subtraction↗
PubMedDate not supplied

Pulmonary embolism associated with canine total hip replacement.

OBJECTIVE: To determine by pulmonary perfusion scans and ultrasonography if embolemia occurs during total hip replacement (THR) surgery in dogs. STUDY DESIGN: Prospective clinical study. ANIMALS: Forty client-owned dogs that had THR surgery. METHODS: Thoracic radiographs were taken immediately after THR and immediately after completion of (99m)Tc-MAA lung scans. Scintigraphy was performed in 28 dogs, 48 hours after THR. Intraoperative ultrasonography (intercostal or transesophageal) was performed in another 12 dogs that had THR. The right atrium and ventricle and pulmonary outflow tract were observed during and for 5 to 8 minutes after femoral component insertion into medullary canals prepared by reaming, and lavage and aspiration of debris before filling with polymethylmethacrylate in dough stage. A modified Prospective Investigation of Pulmonary Embolism Diagnosis (PIOPED) classification system was used to evaluate lung scans. RESULTS: No pulmonary radiographic abnormalities were identified. Segmental and subsegmental perfusion defects occurred in 23 (82%) dogs and were classified as severe in 9 (32%) dogs, moderate in 11, and mild in 3. There was no particular lobe predilection. Patchy mulberry-appearing defects, indicative of fat embolism, were most common. Embolemia was observed by ultrasound in 10 dogs. Variable-sized particles occurred in 8 dogs, particles and bubbles in 2 dogs, and no emboli were observed in 2 dogs. Embolemia was observed within 10 seconds after femoral stem insertion and lasted < 1 minute. Pneumoemboli remained in the right atrium for > 8 minutes before dislodgement. CONCLUSIONS: Embolemia of either air, particles, or both occurs in most dogs during THR surgery. CLINICAL RELEVANCE: Most dogs seemingly spontaneously recover from pulmonary embolism that occurs during THR. The risk of clinical complications from this pulmonary embolism should be taken seriously, even though the exact morbidity and mortality rates are unknown.

Animals↗
PubMed2001

Newer methods of labeling diagnostic agents with Tc-99m.

The past several years have seen marked advances in technetium/rhenium chemistry applicable to the preparation of new 99mTc-labeled radiopharmaceuticals. This article focuses on recent developments in technetium chemistry, including the preparation of "3 + 1" complexes, the preparation and use of (99mTc[CO]3)+ complexes for labeling biomolecules, the preparation of rhenium steroid inclusion complexes, improvements in both hydrazinonicotinamide labeling chemistry and in the preformed 99mTc complex method of labeling biomolecules, and new solid-phase separation techniques that may allow the isolation of high specific-activity radiopharmaceuticals in a clinical setting.

Isotope Labeling↗
PubMed2001

Imaging hypoxia in tumors.

For many years, it has been known that hypoxia affects the response to radiotherapy in human cancers. Hypoxic regions can develop as a tumor grows beyond the ability of its blood supply to deliver oxygen to the full extent of the tumor, exacerbated by vascular spasm or compression caused by increased interstitial fluid pressure. However, hypoxia is heterogeneous, and tumors that appear identical by clinical and radiographic criteria can vary greatly in their extent of hypoxia. Several invasive procedures to measure hypoxia in tumors have been developed and are predictive of response to therapy, but none of these is in routine clinical use because of technical complexity, inconvenience, and inability to obtain repeated measures. Noninvasive imaging with a hypoxia-directed radiopharmaceutical could be of great clinical utility. Most such radiopharmaceuticals under development use 2-nitroimidazole as the targeting moiety. 2-Nitroimidazole, which is selectively reduced and bound in hypoxic tissues, has been labeled with F-18, Cu-64/67, I-123, and Tc-99m. Of these, F-18-fluoromisonidazole and I-123-iodoazomycin arabinoside (IAZA) have been most widely studied clinically. Non-nitro-containing bioreductive complexes, such as the Cu-60/62/64 thiosemicarbazone ATSM and Tc-99m butylene amineoxime (BnAO or HL91), have also been evaluated. In particular, 1-123-IAZA and Cu-60-ATSM have shown correlation with response to radiotherapy in preliminary clinical studies. However, more preclinical studies comparing imaging with validated invasive methods and clinical studies with outcome measures are required. Nuclear medicine is poised to play an important role in optimizing the therapy of patients with hypoxic tumors.

Animals↗
PubMed1996

[The value of colloid scintigraphy and erythrocyte scintigraphy in detecting acute or intermittent gastrointestinal hemorrhages].

PURPOSE: In a retrospective analysis the diagnostic value of two scintigraphic methods was compared with each other. METHOD: 104 patients with acute or intermittent gastrointestinal haemorrhage were examined with 121 scintigraphic studies. We compared scintigraphic results with surgical findings, endoscopic results or final clinical diagnosis. We used two scintigraphic methods, colloid scintigraphy and in vivo/vitro red blood cell scintigraphy. RESULTS: Our scintigraphic findings reached a sensitivity of 72% and a specificity of 100%. We calculated a sensitivity of 68% for colloid scintigraphy and a sensitivity of 79% for red blood cell scintigraphy. The correct localisation of bleeding was successful in 52 (98%) cases. CONCLUSIONS: Our results demonstrate that red blood cell scintigraphy is the method of choice in detecting intermittent gastrointestinal hemorrhage. We believe that with new preparation kits for in vivo labelling red blood cell scintigraphy will become seriously competitive for the colloid scintigraphic method.

Acute Disease↗
PubMedDate not supplied

[Nuclear medicine prediction of histologic tumor response of osteosarcoma].

The prediction of histologic tumor response to preoperative chemotherapy was assessed by quantitative scintigraphic follow-up examinations of 54 osteosarcomas. Tumor/non-tumor scintimetry using 99mTc labeled diphosphonates allowed accurate prediction of tumor response in 28 of 30 tumors (accuracy = 93%) after completion and in 10 of 12 osteosarcomas (accuracy = 83%) at the half-way stage of preoperative chemotherapy evaluating only those tumors which showed convergent changes of tumor/non-tumor ratios in the perfusion and the mineral phase. At the half-way stage, however, evaluation of chemotherapy effects was complicated in 12 of 23 osteosarcomas by diverging T/NT ratios. In contrast, quantification and mapping of the tumor plasma volume and 99mTc MDP plasma clearance predicted the histologic tumor response to chemotherapy in 12 of 13 tumors (accuracy = 92%) after completion and in all 11 cases (accuracy = 100%) at the half-way stage.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1983

[Intraoperative lymphoscintigraphy in radical surgery of cancer].

The use of a gamma-camera operating table and the intraoperative lymphoscintigraphy using 99mTc-Antimony sulfide in radical surgery of carcinoma of the breast allows a better control of axillary lymphadenectomy. Remained lymph nodes are localized by an indicator filled with technetium and removed secondarily. Due to this technique it is possible to control and increase the extent of the axillary lymphadenectomy. Since the introduction of intraoperative axillary lymphoscintigraphy 83 patients were treated by mastectomy and axillary lymphadenectomy. In 48 cases complete lymphadenectomy could be obtained.

Antimony↗
PubMedDate not supplied

[Femur head necrosis. Diagnosis and morphologic analysis using roentgen, scintigraphy, computerized tomography and magnetic resonance tomography].

35 patients with a total number of 53 AVN were examined with conventional radiographs (n = 53), radionuclide scans (n = 37), CT (n = 19) and MRI (n = 53). Findings were classified according to FICAT (stage 0-IV). With a sensitivity of 96.2% and a specificity of 98.1% MRI proved to be the most accurate imaging modality especially in early stages. CT proved to be a reliable technique, too, although accuracy was less compared with MRI. Radionuclide scanning was of minor value with a sensitivity of 62.1% and a specificity of 59.5%. Typical findings with plain radiographs, radionuclide scans, CT and MRI in different stages of AVN are described.

Adult↗
PubMedDate not supplied

[Results of scintigraphy with labeled leukocytes for the diagnosis of infectious hip prosthesis loosening].

The present paper reports on the results of a specific scintigraphic examination method for diagnosing infections in cases of loosening of hip prostheses by means of labeled granulocytes. In 103 patients the result of the examination was compared with the result of the bacteriological and/or histological investigation following removal or replacement of the implant. Where there was an infectious loosening of the prosthesis the findings were in agreement with the results of the scintigraphic examination in 83.1% of the cases. It was possible to rule out infectious loosening of the prosthesis in 93% of the cases thus investigated.

Adult↗
PubMed1990

[NMR tomography compared to skeletal scintigraphy after traumatic vertebral body fractures].

MRI and scintigraphy were compared in 73 patients with 104 vertebral fractures aged between three days and 64 months. MRI was performed at 0.5 Tesla and 1.5 Tesla using T1- and T2-weighted spin-echo sequences. Isotope uptake was divided into four grades (normal, mild, moderate and marked increase). 92% of cases aged 0-6 months showed increased signal intensity on T2 sequences. This finding reflects edema in the bone. All these cases showed moderate or markedly increased uptake in 86%. The increased signal intensity in T2 spin-echo images provides a criterion for differentiating new from old fractures. The identification of normal fatty marrow in 91% of fractured vertebrae provides an important means for distinguishing traumatic from neoplastic fractures. One can also demonstrate bleeding, fatty change and sclerotic bone. MRI is less sensitive than scintigraphy, but more specific in following the posttraumatic healing process.

Adolescent↗
PubMed1987

[99mTc tin colloid scintigraphy in the diagnosis of acute rejection reactions in kidney transplants].

Quantitative measurements of 99MTc-tin colloid uptake in renal transplants permits differentiation of acute rejection from other causes of deteriorating renal function, such as acute tubular necrosis, cyclosporin A nephrotoxicity or chronic rejection. 144 99mTc-tin colloid scintigrams were performed on 71 renal transplants; the results were compared with clinical, biochemical and histological findings. Sensitivity of colloid scintigraphy is 97.4% and specificity is 80%. Compared with other isotope methods, this has the advantage that it does not depend on comparison with repeated examinations.

Cyclosporins↗
PubMed1984

[Appearance of fresh vertebral body fractures on the bone scintigram].

Based on observations on 27 patients technetium-99m-diphosphonate scintigram is recommended as two-stage-investigation. During the first 12 hours no activity and up to 48 hours only slight activity can be seen in contrast to a marked take-up of the tracer after 6 to 8 days. This enables a timing of the fracture, which can be of importance in compensation and legal disputes.

Adolescent↗