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H Ahlström

Publications and source records attributed to H Ahlström.

At least 73 records · Page 4Linked to original sources
PubMed1994

Computed tomography of experimental liver metastases using an iodinated hepatocyte-specific lipid emulsion. A correlative study in the nude rat.

RATIONALE AND OBJECTIVES: A hepatocyte-specific iodinated lipid emulsion, NRI 757, was used for detection of experimental hepatic metastases. MATERIALS AND METHODS: The study was performed in a correlative model of multiple hepatic metastases from a human colonic cancer implanted in the nude rat. RESULTS: After intravenous injection, normal liver parenchyma remained enhanced for several hours, whereas the uptake in hepatic metastases was negligible. A liver-to-lesion contrast of 45 Hounsfield units (HU) was obtained at a dose of 1 mL NRI 757/kg body weight (BW). In a lesion-by-lesion analysis of 177 metastases ranging in size from 1 to 32 mm, the mean +/- standard deviation overall detection rate for native scanning and contrast-enhanced scanning in vivo and post mortem, 20 +/- 0.4%, 53 +/- 5.2%, and 55 +/- 4.0%, respectively and 28%, 84%, and 82%, retrospectively. When metastatic size also was considered, for native scanning the maximum detection rate of 61% was reached for 8- to 10-mm lesions, whereas for contrast-enhanced computed tomography scanning, 100% of the 5- to 7-mm lesions and 42% of the 1- to 2-mm nodules were detected. CONCLUSION: The use of NRI 757 improved the diagnostic yield considerably.

Adenocarcinoma↗
PubMed1994

Positron emission tomography with L-methyl-11C-methionine in the monitoring of therapy response in muscle-invasive transitional cell carcinoma of the urinary bladder.

OBJECTIVE: To investigate whether positron emission tomography (PET) with L-methyl-11C-methionine as a tracer could be used for diagnostic purposes and for evaluation of therapy in patients with varying stages of urinary bladder cancer treated with chemotherapy. PATIENTS AND METHODS: PET was employed in 44 separate examinations involving 29 patients (24 men and five women with a median age of 68 years [mean 66, range 47-78]) with localized or metastatic transitional cell carcinoma of the urinary bladder. In four patients PET examinations were performed prior to the commencement of chemotherapy, and after one course and after three courses. RESULTS: The diagnostic accuracy of PET was poor. The technique did not monitor the therapeutic effect of neoadjuvant chemotherapy, producing results that correlated with therapy outcome. PET identified those patients who responded less successfully to therapy. CONCLUSION: PET with L-methyl-11C-methionine demonstrates alterations in tumour metabolism long before visible changes appear on computed tomography or magnetic resonance imaging. Further work is required to develop more specific tracers.

Aged↗
PubMed1994

[111In-DTPA-D-Phe1]octreotide scintigraphy in patients with carcinoid tumours: the predictive value for somatostatin analogue treatment.

This study was performed to evaluate whether the presence or absence of somatostatin receptors in malignant carcinoid tumours detected by [111In-DTPA-D-Phe1]octreotide scintigraphy can be used to predict response to somatostatin analogue treatment. Thirty patients were investigated, 28 with midgut carcinoid tumours and two with foregut carcinoid tumours. Twenty-seven patients showed pathological uptake in tumour lesions at scintigraphy; of these, 22 responded to somatostatin analogue treatment using octreotide, somatuline or octastatin, while five patients failed to respond. None of the three patients displaying negative scintigraphic investigations responded to treatment with somatostatin analogues. These results show a good correlation between the somatostatin receptor status and the patients' ability to respond to somatostatin analogue treatment (p = 0.014). We conclude that somatostatin receptor scintigraphy using [111In-DTPA-D-Phe1]octreotide can be used to select patients with malignant carcinoid tumours suitable for somatostatin analogue treatment and exclude those that will not benefit from such medication.

Aged↗
PubMed1994

Positron emission tomography with 11C-methionine in hyperparathyroidism.

BACKGROUND: Positron emission tomography (PET) has not been evaluated for preoperative localization and functional characterization of the parathyroid tissue in hyperparathyroidism. METHODS: Images of the neck and upper mediastinum of 23 patients with hyperparathyroidism were obtained by PET after intravenous administration of 400 to 800 MBq L-[methyl-11C]-methionine. The investigation was repeated in six patients after Na2-ethylenediamine tetraacetic acid infusion, whereby stable 65% to 157% rise in intact serum parathyroid hormone values was attained. RESULTS: Parathyroid surgical procedure revealed single (21 patients) or two enlarged parathyroid glands (two patients) that were characterized as chief cell adenoma (n = 13), hyperplasia (n = 10), or carcinoma (n = 2) and weighed 80 to 6000 mg. Twenty (80%) of these glands were localized by PET. The remaining examinations (20%) were false negative and mainly encompassed small parathyroids in juxtathyroid position. Among 15 patients undergoing parathyroid reoperation true-positive localizations were obtained for 87% of the glands. The images displayed lower tracer uptake in residual thyroid lobes (n = 40), esophagus, and cervical vertebrae. Na2-ethylenediamine tetraacetic acid infusion failed to enhance parathyroid uptake values. Ultrasonography, computed tomography, technetium-thallium scintigraphy, and venous sampling revealed 25% to 53% of the pathologic parathyroid tissues of the patients undergoing reoperation and was largely complementary to PET. CONCLUSIONS: The results suggest that PET may provide novel possibilities for the imaging of pathologic parathyroid glands in hyperparathyroidism.

Adult↗
PubMed1993

Three-dimensional OctreoScan111 SPECT of abdominal manifestation of neuroendocrine tumours.

In the present study we have investigated the three-dimensional (3D) reconstruction of OctreoScan111 SPECT (single photon emission tomography) images in 20 patients with neuroendocrine tumours. All patients had at least 2 tumour lesions as assessed from computerized tomography (CT) and SPECT. The 3D rendering was performed using a software, which produces images by implementing direct rendering from voxels without an intermediate surface data structure. The software has options for a free choice of thresholding and possibilities of clipping in coronal, transversal and sagittal planes. The results obtained showed that 3D reconstruction with volume rendering (3Dvr) gave a superior topographical localization of tumour uptakes when compared with SPECT. The 3Dvr technique was also combined with transversal clipping in rendered volumes (3Dvr+c). The major advantage with the 3Dvr+c technique was found to be an improved visualization of anatomical references as well as improved diagnostic information in a particular, selected, transversal slice, thus facilitating the identification and comparison of individual tumour lesions.

Abdominal Neoplasms↗
PubMed1993

Positron emission tomography (PET) in neuroendocrine gastrointestinal tumors.

Positron emission tomography (PET) makes it possible to study effects of medical treatment in vivo. Carcinoid tumors with liver metastases, especially those of midgut origin, produce serotonin via the precursors tryptophan and 5-hydroxytryptophan (5-HTP) and this overproduction contributes to the clinical symptoms of the carcinoid syndrome. Seven patients with histopathologically verified neuroendocrine tumors and liver metastases, five of whom with ileal carcinoids, one a lung carcinoid and one an endocrine pancreatic tumor, were included in the study. All patients had elevation of urinary 5-HIAA with the exception of one patient with a solitary liver metastasis of midgut origin. After an intravenous injection of 11C-5-HTP, PET was performed and the uptake of radioactivity in tumor tissue, normal liver and plasma were compared. All patients with elevated urinary 5-HIAA and also the patient with a solitary liver metastasis and normal urinary 5-HIAA had high accumulation and signs of a high rate of binding of 5-HTP in the liver metastases. The uptake was relatively homogeneous in midgut carcinoid liver metastases but in large necrotic metastases the radioactivity was localized to the periphery. In three patients PET examination was repeated after 3 months of interferon treatment and in agreement with circulating tumor markers and ultrasonography the uptake of 5-HTP was unchanged. Another patient who received the somatostatin analog somatuline progressed on treatment and accordingly the uptake of 5-HTP also increased. The experience with PET in neuroendocrine gastrointestinal tumors is very limited. Our results so far indicate that 5-HTP can be used to visualize serotonin-producing neuroendocrine tumors and furthermore it might prove to be of value to monitor the effects of treatment, possibly also as an early predictive test of the outcome of treatment.

5-Hydroxytryptophan↗
PubMed1993

Somatostatin receptor scintigraphy of carcinoid tumours using the [111In-DTPA-D-Phe1]-octreotide.

Somatostatin-receptor scintigraphy using the 111In-labelled somatostatin-analogue octreotide ([111In-DTPA-D-Phe1]-octreotide) was performed in 40 patients with carcinoid tumours. In 31/40 patients, this scintigraphy proved positive compared with the 33/40 patients whose tumours were disclosed on CT scans. In addition, 18 previously unidentified lesions were detected with this scintigraphy. Two of these lesions represented previously undetectable primary tumours. It is concluded that somatostatin receptor scintigraphy using [111In-DTPA-D-Phe1]-octreotide has a future role in the staging of patients with carcinoid disease.

Adult↗
PubMed1993

Radioimmunolocalization of hepatic metastases and subcutaneous xenografts from a human colonic cancer in the nude rat. Aspects of tumour implantation site and mode of antibody administration.

Antibody localization was analyzed following intraperitoneal (i.p.) or intravenous (i.v.) injection of the 125I-labelled anti-CEA-MAb I-38S1 in 44 nude rats, in order to evaluate the influence of tumour implantation site and the route of MAb administration. The animals were xenografted with a human colonic cancer (LS 174 T), either in the form of hepatic metastases, subcutaneous (s.c.) tumours or both. Tissue measurements, 4 days after MAb injection, showed better uptake for hepatic than for s.c. tumours, irrespective of the route of antibody administration. Antibody accumulation per g liver metastases was not size dependent for noduli weighing between 4 and 1,110 mg. MAb excretion evaluated in 20 animals and blood activity studied in 11 rats were equivalent 24-96 h following i.p. and i.v. injection. Dissimilar autoradiographic patterns were seen in hepatic metastases with predominantly peripherally located clusters following i.p. and more homogeneously distributed grains after i.v. MAb administration. The results indicate that tumour implantation site has a quantitative, and the route of administration at least a qualitative impact on the tumour accretion of anti-CEA MAb I-38S1 in the present xenograft model.

Animals↗
PubMed1993

Oral contrast media in CT of the abdomen. A double-blind randomized study comparing an aqueous solution of amidotrizoate, an aqueous solution of iohexol and a viscous solution of iohexol.

In a double-blind randomized study 3 different preparations of oral contrast media for bowel opacification at CT of the abdomen have been compared. Plain aqueous solutions of amidotrizoate (9 mg I/ml) and iohexol (9 mg I/ml) were used as well as a preparation of iohexol (9 mg I/ml) to which a viscosity-increasing agent had been added. The distribution of the contrast media in the intestine, transit time and patient tolerance were evaluated. No significant differences were found regarding the distribution between the 3 preparations of contrast media, while there was a tendency for the transit time to be increased when the viscous preparation of iohexol was used. The aqueous solution of iohexol had the best taste, while the viscous preparation was markedly more difficult to drink. Aqueous solutions of iohexol and amidotrizoate were equal for bowel opacification and the addition of the viscosity-increasing agent did not improve the distribution of the contrast medium in the intestine.

Administration, Oral↗
PubMed1992

Octreotide and interferon alfa: a new combination for the treatment of malignant carcinoid tumours.

24 patients with malignant carcinoid tumours received octreotide and interferon alfa (IFN-alpha). All the patients initially received octreotide 50-100 micrograms, twice daily. When progressive symptoms or increasing biochemical markers were observed, the daily dose was raised to a median 300 micrograms. If the initial dose proved ineffective or if no improvement was seen after escalation, IFN-alpha was added (median 9 MU subcutaneously per week). After the addition of IFN-alpha, 17 of the 22 patients (77%) with elevated urinary 5-hydroxyindoleacetic acid showed a significant (> 50%) reduction. Only 1 patient progressed and 4 had continuously stable biochemical disease. No significant reduction in tumour size was noted; in 5 patients, the tumour continued to grow despite decreasing hormone levels. 18 patients had carcinoid syndrome when IFN-alpha was added in 10 (56%) symptoms ameliorated. Thus, the addition of IFN-alpha is beneficial for patients with malignant carcinoid tumours that progress and/or who do not respond to octreotide.

Adult↗
PubMed1992

Treatment with alpha-interferon versus alpha-interferon in combination with streptozocin and doxorubicin in patients with malignant carcinoid tumors: a randomized trial.

An open randomized trial was performed to compare the effect of recombinant interferon-alpha 2a (rIFN-alpha 2a) (group A, n = 12) versus rIFN-alpha 2a in combination with chemotherapy (group B, n = 11) in patients with malignant carcinoid tumors. Both groups received rIFN-alpha 2a at a dose of 3 MU/m2 s.c. three times weekly during the first 6 months. IFN was discontinued every third week in group B, followed by an i.v. injection of 2 g streptozocin and 40 mg/m2 doxorubicin. After 6 months group A showed one complete biochemical response (CR), 9 patients with stable disease (SD) and 2 who progressed (PD). Two patients had a partial reduction (PR) of tumor size, 9 showed SD and one PD. All patients in group B demonstrated SD. Chemotherapy was withdrawn after 6 months and all patients continued with rIFN-alpha 2a at an increased dose of 3 MU/m2 five days/week for a further 6 months. After 12 months 6 patients showed PR, 12 SD and one PD biochemically. Tumor size showed SD in 18 patients and PD in one. One patient died from cardiomyopathy, probably induced by doxorubicin. Antibodies against rIFN-alpha 2a developed in 41% of the patients. In conclusion, we detected no difference in response rates between the two treatment groups. Adverse reactions from the combination were considerable. The frequent development of IFN antibodies might have interfered with the therapeutic results.

Aged↗
PubMed1992

Induction and quantification of hepatic metastases from a human colonic cancer in the nude rat.

Nude rats were injected with human colonic cancer cells (LS 174 T) in the superior mesenteric vein and the extent of hepatic metastases at sacrifice was estimated by visual inspection and computer-based area calculation. After 3 weeks, 5.0 x 10(6) cells caused hepatic metastases in 14/14 rats whereas 0.5 x 10(6) cells failed to produce liver metastases in 4/4 rats (P < 0.001). Injection of 1.0 x 10(7) cells caused portal vein occlusion in 3/5 rats. Extrahepatic tumour growth was rare; lung metastases were observed in four rats, and three rats had local tumour in the abdomen. The average extent of hepatic tumour replacement was 20.2 +/- 4.0%. Injection of embolies or single cells did not affect the incidence or extent of hepatic metastases. The incidence of hepatic metastases was similar in male and female rats, but the extent of hepatic tumour was larger in males (24.6%) than in females (3.2%) (P = 0.005). The pathophysiological similarities to human disease should make this model suitable for diagnostic and therapeutic studies with clinical application.

Animals↗
PubMed1992

Contrast-enhanced CT scanning in vivo for the quantification of hepatic metastases from a human colonic cancer in the nude rat.

Hepatic metastases were induced in nude rats by intraportal injection of 2.5-5.0 x 10(6) cells from the human colonic cancer cell line LS 174 T. Quantification of tumour burden, expressed as relative metastatic area, was performed by contrast-enhanced computed tomography (CT) scanning in vivo (n = 14), contrast enhanced CT scanning post mortem (n = 21) and computer-based area calculation (CBAC) (n = 21). To determine the false-positive contribution to the estimated tumour burden by the evaluation procedures themselves, six rats without metastases were assessed. The quantification in the three different assessment groups was in close accordance in animals with an intermediate or extensive metastatic burden, but not in rats with a minor (< 4%) tumour burden. The results indicate that contrast-enhanced CT scanning can be used in this model to quantify hepatic metastases, except in animals with few and small lesions. Furthermore, the results suggest a potential for the assessment of therapeutic response by repeated contrast-enhanced CT scanning in vivo, as well as prospects for a corresponding evaluation in man.

Animals↗
PubMed1991

Radioimmunolocalization of human colonic cancer xenografts; aspects of extensive purification of monoclonal anti-CEA-antibodies.

Tumour-to-normal tissue ratios of i.p. injected 125I-labelled monoclonal antibodies (MAbs), reacting with CEA were determined in nude rats xenografted with human colonic cancer cells (LS 174 T). Two MAbs, I-38S1 and II-16, reactive with the GOLD 1-epitope on CEA were tested. MAb I-38S1 was also tested after additional purification using anion exchange chromatography (thereafter named AEC 38). In the external activity measurements, MAb AEC 38 showed significantly better tumour-to-liver ratios than did MAb II-16 on all 4 days after injection. MAb I-38S1 gave intermediate ratios but was significantly better than II-16 only on day 3. The mean tumour-to-blood ratios were 3.0, 2.6 and 1.5 and the mean tumour-to-liver ratios were 6.6, 4.8 and 3.5 for MAbs AEC 38, I-38S1 and II-16 respectively. Gamma camera registrations in 3 animals on 4 days showed good imaging properties for all three MAbs and the patterns of tissue uptake were consistent with those seen in the external measurements. Furthermore, histopathological and immunohistochemical determinations were performed, showing that MAb II-16 gave about the same spatial binding as the previously analysed MAb I-38S1. The results indicate that additional purification of MAbs using anion exchange chromatography may potentiate tumour uptake in this model.

Carcinoembryonic Antigen↗
PubMed1991

Calcified leiomyosarcoma simulating uterine myoma in a patient with long-standing anaemia.

A case of small bowel leiomyosarcoma in a 75-year-old woman is reviewed. The patient had an unexplained anaemia with occult blood in the faeces for at least 15 years. The value of different radiological investigations in patients with suspected gastrointestinal bleeding is discussed. The possible significance of calcifications visible on plain abdominal films is emphasized.

Aged↗