Biomedical subjects

C Hoefnagel

Publications and source records attributed to C Hoefnagel.

7 recordsLinked to original sources

PubMed2000

Improved effect of 131I-MIBG treatment by predosing with non-radiolabeled MIBG in carcinoid patients, and studies in xenografted mice.

BACKGROUND: 131I-meta-iodobenzylguanidine (MIBG) has been used with success for the palliation of metastatic carcinoid. To qualify more patients for this treatment, we evaluated the effect of predosing with non-radiolabeled MIBG on 131I-MIBG tumour targeting in carcinoid patients and in mice with BON human carcinoid xenografts. PATIENTS AND METHODS: Ten carcinoid patients with a faint tumour imaging on a diagnostic 131I-MIBG scan (1 mCi = 37 MBq, 5 mg MIBG) received non-radiolabeled MIBG prior to a second scintigraphy. In case of improved tumour targeting patients were treated with 200 mCi (7.4 GBq) 131I-MIBG following a pharmacological predose of 20-40 mg/m2 MIBG. RESULTS: In six patients. highly increased 'tumour/non-tumour' ratios were seen due to reduced levels in normal tissues and increased tumour accumulation. The combined treatment applied in five patients, considerably improved symptoms in all (duration 6-12 months), accompanied by biochemical response in three. In BON carcinoid xenografted mice, MIBG was injected intraperitoneally followed by intravenous 125I-MIBG with similar findings: increased 'tumour/non-tumour' radioactivity ratios by 1.5-3-fold. CONCLUSION: Predosing with non-radiolabeled MIBG resulted in improved 131I-MIBG tumour targeting, prolonged palliation and encouragingly often biochemical responses in carcinoid.

3-Iodobenzylguanidine↗

PubMed1999

Carcinoid tumors.

Explore the source record for details and available documents.

3-Iodobenzylguanidine↗

PubMed1999

[Carcinoid tumors of the intestines: developments in the Netherlands for diagnosis and palliative treatment].

Carcinoid tumours in the intestine are slowly growing neuroendocrine tumours. Patients as a rule report symptoms of the carcinoid syndrome: attacks of diarrhoea and of flushing. When the earliest symptoms manifest themselves, metastases are already present, virtually always localized in the liver. At a late stage, heart failure may occur, difficult to treat and caused by fibrosis of the tricuspid valve in the presence of protractedly raised blood serotonin levels. To diagnose carcinoid tumours, use is made of radioactive substances binding to hormone receptors such as 131I-MIBG and 111-In-octreotide. When multiple metastases exist, only palliative treatment is possible. The drugs used are the somatostatin analog octreotide, interferon alpha, radioactive MIBG and non-radioactive MIBG; these drugs may also be used in combination. The therapies mentioned have approximately the same effect: symptoms improve in 60-80%, while 30-50% show a biochemical response, i.e. decrease of the number of breakdown products in the urine of the hormones produced by the tumour; tumour size decreases in 0-12%.

Carcinoid Heart Disease↗

PubMed1999

Long-term palliation in metastatic carcinoid tumours with various applications of meta-iodobenzylguanidin (MIBG): pharmacological MIBG, 131I-labelled MIBG and the combination.

Carcinoid tumours are rare, but well known for their characteristic presentation with diarrhoea and flushes due to overproduction of serotonin in the case of liver metastases. Treatment is mainly based on the reduction of vasoactive peptide hypersecretion and symptomatic improvement Octreotide and interferon are widely applied and effective treatment options to induce symptomatic improvement and, to a lesser extent, biochemical response. The main drawbacks, however, are the need for frequent injections and/or the occurrence of side effects. A rather new approach is the application of meta-iodobenzylguanidine (MIBG), which resembles noradrenalin and serotonin. In carcinoid patients, MIBG is taken up in the tumour cells and stored in the neurosecretory granules. When labelled with 131 iodine, radionuclide imaging is positive in up to 70% of the patients. In these patients, two cycles of a therapeutic dose of radioactive MIBG may induce long-lasting palliation (8 months) by internal irradiation. Also, the non-radioactive MIBG compound may be effective in palliation, even in patients with a negative scan. The mode of action is based on specific tumour acidification as found in animal models, and/or based on its effect as a false neurotransmittor. Three case reports demonstrate different therapeutic possibilities of MIBG: 1) symptomatic relief with unlabelled MIBG, which is a safe and simple treatment; 2) the longterm palliation following radioactive treatment; and 3) an additional new aspect of predosing with unlabelled MIBG followed by radioactive MIBG led to improved tumour targeting and impressive clinical response.

3-Iodobenzylguanidine↗

PubMed1991

Imaging and retention measurements of selenium 75 homocholic acid conjugated with taurine, and the carbon 14 glycochol breath test to document ileal dysfunction due to late radiation damage.

In order to assess ileal dysfunction in patients with complaints after pelvic radiation therapy, retention measurements and scintigraphic imaging with selenium 75 homocholic acid conjugated with taurine (75Se-HCAT), combined with the carbon 14 glycochol breath test, were evaluated in 39 patients. In 22 patients without ileal resection the results of the 75Se-HCAT test and the breath test differentiated between a normal functioning ileum (both tests negative) and ileal dysfunction as a cause of complaints (one or both tests positive). Among the patients with ileal dysfunction, the combination of both tests permitted those with bacterial overgrowth (breath test positive, 75Se-HCAT negative) to be separated from patients with evidence of bile acid malabsorption (75Se-HCAT positive, breath test positive or negative). In 17 patients with small-bowel resection, the 75Se-HCAT test helped to estimate the severity of bile acid malabsorption with implications for therapy. In this group the breath test was false-negative in 7 cases with abnormal 75Se-HCAT. Additional systematically performed scintigraphic imaging improved the accuracy of the 75Se-HCAT test, revealing cases with prolonged colonic accumulation of the radiopharmaceutical, causing spurious retention values. In conclusion, assessment of ileal dysfunction by nuclear medicine techniques in post-irradiation conditions provides information about the aetiology and therefore the possibility of adjustment in the clinical management.

Aged↗

PubMed1991

Effect of loperamide and delay of bowel motility on bile acid malabsorption caused by late radiation damage and ileal resection.

Selenium-75 homocholic acid conjugated with taurine (75Se-HCAT) was used during loperamide administration in seven patients suspected of having bile acid malabsorption due to late radiation damage and small-bowel resection in order to document the aetiology of ileal dysfunction and to adjust therapeutic management. In two patients with ileal resection up to 50 cm and in one patient without resection, a reduction of bowel motility by loperamide resulted in marked normalization of the 75Se-HCAT retention measurements. Sequential scintigraphic 75Se-HCAT imaging demonstrated a significant improvement in the 75Se-HCAT reabsorption and recirculation, accompanied in one case by prolongation of colonic retention of the radiopharmaceutical. In four patients with more than 80 cm resection, the 75Se-HCAT test was abnormal during loperamide administration. In two of these patients for whom baseline values were available, no improvement in the pattern of 75Se-HCAT absorption was observed. In conclusion, the first results of loperamide 75Se-HCAT in patients suspected of having bile acid malabsorption and abnormal baseline 75Se-HCAT are promising. Intervention with loperamide is easy and seems to improve the clinical value of the test with direct therapeutic implications. Sequential 75Se-HCAT imaging is essential for interpreting changes in the 75Se-HCAT retention measurements.

Abdomen↗

PubMed1984

Comparison of reliability of tests to distinguish upper from lower urinary tract infection.

The results of scintiphotography with gallium-67 (67Ga), renography with technetium-99m diethylene triamine penta-acetic acid, immunofluorescence of antibody coated bacteria, and determination of renal beta 2 microglobulin excretion were compared in 19 patients with upper and 15 patients with lower urinary tract infection. All patients with acute pyelonephritis showed an appreciable unilateral or bilateral uptake of 67Ga and an increased excretion of beta 2 microglobulin, whereas immunofluorescence of antibody coated bacteria yielded positive results in only 10. In patients with lower urinary tract infections excretion of beta 2 microglobulin and uptake of 67Ga were always normal, whereas immunofluorescence of antibody coated bacteria was positive in three cases. Scintiphotography with 67Ga and determination of renal beta 2 microglobulin excretion are currently the most reliable non-invasive methods of detecting acute pyelonephritis.

Adult↗