A comparison of iodine-123 meta-iodobenzylguanidine scintigraphy and single bone marrow aspiration biopsy in the diagnosis and follow-up of 26 children with neuroblastoma.

In staging neuroblastomas, the demonstration of tumoural invasion of the bone marrow is an important criterion with regard to the therapeutic prospects and the prognosis. Iliac crest aspiration sampling has been used routinely for the detection of bone marrow metastases in neuroblastoma. However, due to the limited character of the sampling, it sometimes leads to false-negative results. Another procedure which is used to determine the extent of neuroblastoma is metaiodobenzylguanidine (mIBG) scintigraphy. In order to establish the respective merits of both diagnostic techniques retrospectively, 148 iodine-123 mIBG scans of 26 children with neuroblastoma have been re-evaluated and compared with the results of routine bone marrow samples obtained within a 4-week period before or after scanning. Three types of mIBG uptake in the bone/bone marrow could be differentiated: (1) no visualization of the skeleton; (2) diffuse uptake in the skeleton with or without focally increased uptake, which indicates massive, diffuse bone marrow invasion by the tumour; and (3) focal tracer accumulation in one or several bones. No tracer uptake was observed in the skeleton in 91 scans. In 89 of the 91 the bone marrow biopsy was negative. Twenty-four scans showed diffuse skeletal uptake with or without foci. The bone marrow biopsies were negative for eight of those 24 scans. Hyperactive foci in one or more bones without diffuse tracer accumulation in the skeleton were detected in 33 scans. In only 7 of these 33 scans did bone marrow biopsy specimens from the iliac MDP crest contain neuroblastoma cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Visualization of a parathyroid adenoma with Tc-99m MIBI in a case with iodine saturation and impaired thallium uptake.

A case of a parathyroid adenoma is presented in which the conventional Tl-201 minus Tc-99m subtraction technique failed to localize the adenoma because of prior iodide administration and a low Tl-201 uptake. Ultrasonography and CT could not provide useful data either. However, a Tc-99m methoxylisobutylisonitrile (MIBI) scintigram clearly delineated the adenoma and the thyroid tissue.

Lymphocyte labeling with technetium-99m-HMPAO: a radiotoxicity study using the micronucleus assay.

The cytogenetic radiation damage to lymphocytes after in-vitro labeling of mixed leukocytes and isolated lymphocytes with 99mTc-hexamethylpropyleneamine oxime (HMPAO) was evaluated using the cytokinesis-blocked micronucleus assay. A direct assessment of the radiation damage to the lymphocytes after a labeling procedure of leukocytes separated from 46 ml blood with 740 MBq of 99mTc-HMPAO was not possible due to an almost complete impairment of the proliferative capacity. By starting with isolated lymphocytes, the number of micronuclei was studied versus the intracellular activity concentration in the range 0-3 MBq/10(7) lymphocytes for three donors. A comparison of these results with the dose response of the micronucleus incidence in lymphocytes after in-vitro irradiation with x-rays allowed an individual assessment of the x-ray dose, inducing the equivalent amount of clastogenic damage as the intracellular activity after 99mTc-HMPAO labeling. Based on an extrapolation of these data, the radiation damage of the lymphocytes due to self-irradiation in a labeling procedure of leukocytes with 740 MBq of 99mTc-HMPAO was estimated to be equivalent to 26 Gy of x-rays. Due to the observed almost complete inhibition of the proliferative capacity at this high dose level, the increased risk for a lymphoid malignancy after administration of isolated lymphocytes or mixed leukocytes labeled with 99mTc-HMPAO activities sufficient for scintigraphy can be regarded as small.

Measurement of short-term 11C-thymidine activity in human head and neck tumours using positron emission tomography (PET).

Tumour uptake of 11C-thymidine labeled in the methyl position was assessed after intravenous injection in 13 patients with head and neck tumours. This activity was compared to other tracers such as C15O, 13NH3 and C15O2. In every single case a 'positive' tumour image after injection of 11C-thymidine was obtained. Time-activity curves showed the initial activity to be followed by a rapid decrease over the first 10-15 min with an apparent plateau thereafter. A similar level of uptake was found in normal salivary gland regions and myocardium, while higher activities were noted in liver and kidney parenchyma. It is suggested that both blood flow and cellular metabolism can influence 11C-thymidine imaging in this class of human tumours.

Technetium-99m-diphosphonate, gallium-67 and labeled leukocyte scanning techniques in tibial nonunion.

On the technetium-99m bone scan the vast majority of nonunion cases show an intense tracer uptake at the fracture site, as do fractures undergoing normal healing. Therefore static bone scintigraphy usually does not contribute to the diagnosis of nonunion. One of the main causes of delayed fracture healing is infection. Increased blood flow and blood pool as demonstrated during the first and second phases of a 3-phase bone scan are consistent with an inflammatory reaction but are not pathognomonic for infection. A gallium-67 scan is indicative of infection if Ga-67 uptake exceeds Tc-99m uptake on the bone scan. The most specific tracers for infection however are leukocytes labeled with indium-111 or technetium-99m.

Intestinal mucosal permeability in inflammatory rheumatic diseases. I. Role of antiinflammatory drugs.

Using the 51Cr-EDTA resorption test, gut permeability was measured in 129 patients with inflammatory joint diseases and in 97 control patients (42 patients with no inflammatory rheumatic disorders taking antiinflammatory medication and 55 healthy controls). Thirty-two patients (30 arthritis and 2 control patients) taking nonsteroidal antiinflammatory drugs (NSAID) as well as corticosteroids were excluded from statistical analysis. The intake of NSAID significantly increased gut permeability in controls but not in the arthritis groups. The same applied to corticosteroid intake. This could be due to the restricted number of arthritis patients who had never taken antiinflammatory drugs or to a disease related increased permeability. There was no statistically significant difference in altered gut permeability between patients taking NSAID and patients taking corticosteroids. Our findings suggest that drug induced alteration of gut permeability may not only be accounted for by an inhibition of mucosal cyclooxygenase activity, but that other enzymatic pathways in the arachidonic cascade might be implicated.

Intestinal mucosal permeability in inflammatory rheumatic diseases. II. Role of disease.

Gut permeability as measured by the 51Cr-EDTA resorption test was determined in 56 patients with rheumatoid arthritis (RA), 73 patients with spondyloarthropathies (SpA), 18 patients with inflammatory bowel disease (IBD) and 97 controls (42 patients with no inflammatory rheumatic diseases and 55 healthy controls). Gut permeability was found to be increased in the 3 patient groups, partially due to the intake of antiinflammatory drugs. When only patients not taking these drugs were considered, an increased gut permeability was found in patients with SpA and IBD. In patients with RA gut permeability could not be evaluated as they were all taking antiinflammatory medication. Ileocolonoscopy with biopsies of the gut was performed in 62 of the 73 patients with SpA and disclosed subclinical gut inflammation in 21. No difference in gut permeability was found between patients with or without gut inflammation. However, when the type of gut inflammation was considered, a significant increase of gut permeability was found in patients with chronic gut inflammation compared with patients presenting acute lesions. Our findings again suggest that the chronic gut inflammation seen in SpA is fundamentally different from acute gut inflammation and possibly related to the gut inflammation of IBD.

Scintigraphic, spirometric, and roentgenologic effects of radiotherapy on normal lung tissue. Short-term observations in 14 consecutive patients with breast cancer.

The effects of radiotherapy on lung function, ventilation/perfusion scans, and chest radiography were studied prospectively in 15 patients who underwent either modified radical mastectomy or tumorectomy, followed by radiotherapy for breast cancer. In all patients, pulmonary function studies, chest x-ray films, and lung scintigraphic studies were performed prior to and at the end of radiotherapy as well as three months later. No consistent or significant alteration in either parameter was detected. No patient developed clinical symptoms suggestive of radiation-induced lung changes, although in one of them, major radiologic features were found that were consistent with radiation pneumonitis; those changes disappeared completely in the course of the subsequent months. It is concluded that the tangential beam technique for postoperative irradiation as used in these patients is largely safe as regards pulmonary function, perfusion, and ventilation.