Biomedical subjects

K Kletter

Publications and source records attributed to K Kletter.

At least 37 records · Page 2Linked to original sources

PubMed2001

Comparative somatostatin receptor scintigraphy using in-111-DOTA-lanreotide and in-111-DOTA-Tyr3-octreotide versus F-18-FDG-PET for evaluation of somatostatin receptor-mediated radionuclide therapy.

BACKGROUND: Based on the high number of somatostatin (SST) receptors expressed by neuroendocrine tumors, long-acting SST analogs have been successfully used for tumor detection. New developments point to the potential use of these types of radioligands for tumor-specific radionuclide therapy. PATIENTS AND METHODS: We have comparatively investigated the diagnostic capacity of the SST analog. 111In-DOTA-lanreotide (LAN), as opposed to 111ln-DOTA-DPhe1-Tyr3-octreotide (TOCT) in tumor patients. This article gives an overview of recent scintigraphic results compared to CT/MRI, 18F-FDG-PET, endoscopy and/or surgery in a threshold of 218 tumor patients. RESULTS: As opposed to radiology, previously unknown tumor lesions were demonstrable by either SST radioligand in about one third of patients. In carcinoid patients, the SST scan sensitivity was 64% for LAN (18 of 28) and 87% (34 of 39) for TOCT, whereas the sensitivity was 100% in patients with (radioiodine-negative) thyroid cancer (17 of 17) for LAN and 95% for TOCT (20 of 21). Discordant scintigraphic results between LAN and TOCT (higher tumor uptake and/or visualisation of different lesions in the same patient) were also seen in patients with lymphoma, lung cancer and intestinal adenocarcinoma. In a direct comparison of both SST tracers in 38 tumor patients, LAN gave positive results in 35 of 38, TOCT in 36 of 38 and 18F-FDG-PET in 14 of 22 of the same patients. SST scan results obtained by both tracers were equivocal in 23 of 38 patients, but were better in 10 patients withTOCTand in 5 patients with LAN. CONCLUSIONS: We conclude that both SST radioligands are suitable tracers for tumor imaging, but may give significantly different uptake results for different tumor types. Since the uptake is most important for tumor therapy, using either longacting SSTanalogs, and/or 90Y-labeled analogs, careful evaluation should be made prior to therapy.

Adenocarcinoma↗

PubMed2001

FDG positron emission tomographic, radioiodine, and MIBI imaging in a patient with poorly differentiated insular thyroid carcinoma.

Poorly differentiated insular thyroid carcinoma is now classified as a separate entity among other tumors of the thyroid gland. Its histologic pattern and its clinical course are regarded as intermediate between well differentiated and anaplastic thyroid cancer. Insular carcinoma accumulates I-131, but no data exist regarding its fluorodeoxyglucose (FDG) positron emission tomographic (PET) uptake. The authors report F-18 FDG PET, Tc-99m MIBI, and radioiodine imaging features in a 63-year-old patient with metastatic insular thyroid carcinoma. After total thyroidectomy (for poorly differentiated insular carcinoma pT3a), the patient was referred for radioiodine ablation. No signs of recurrence were present until 16 months later, when thyroglobulin levels increased. An I-131 scan showed a single lesion in the right lung, and further radioiodine treatment was administered (cumulative dose [530 mCi], 19,610 MBq I-131). Three years after the initial diagnosis, FDG-PET and Tc-99m MIBI scans were performed within 5 days during thyroxine treatment. After that, thyroxine substitution was withdrawn; 6 weeks later, an I-131 whole-body scan was performed. Both radioiodine and MIBI images showed increased tracer uptake in the known lung lesion. However, FDG PET showed a normal tracer distribution. Magnetic resonance and computed tomographic imaging confirmed a 12-mm lesion in the right upper lobe. These findings support the concept of the "flip-flop phenomenon" in insular thyroid carcinoma, an alternating pattern of metastases with either I-131 or FDG-uptake. Despite poorly differentiated histologic findings, glucose metabolism was not increased in this patient with an insular tumor.

Carcinoma↗

PubMed2001

Effect of near physiologic insulin therapy on hypoglycemia counterregulation in type-1 diabetes.

OBJECTIVES: The aim of this study was to examine hormonal counterregulation during insulin-induced hypoglycemia in type-1 diabetic patients during long-term near normoglycemic insulin therapy and intensive clinical care. METHODS: Type-1 diabetic patients (age 35.3 +/- 2 years, body mass index 22.8 +/- 1 kg x m(-2), mean diabetes duration 13.6 (11-17 years), mean HbA1c during the last year 6.6 +/- 0.1%) and nondiabetic subjects were studied during (0-120 min) and after (120-240 min) hypoglycemic (3.05 mmol/l) hyperinsulinemic (approximately 330 pmol/l) clamp tests. RESULTS: During hypoglycemia peak plasma concentrations of glucagon (199 +/- 16 vs. 155 +/- 11 ng/l, p < 0.05), epinephrine (4,514 +/- 644 vs. 1,676 +/- 513 pmol/l, p < 0.001), norepinephrine (2.21 +/- 0.14 vs. 1.35 +/- 0.19 nmol/l, p < 0.01) and cortisol (532 +/- 44 vs. 334 +/- 61 nmol/l) were reduced in the diabetic patients. Plasma lactate did not change from baseline values (0.51 +/- 0.06 mmol/l) in diabetic but doubled in healthy subjects (1.13 +/- 0.111 mmol/l, p < 0.001 vs. control). During the posthypoglycemic recovery period plasma concentrations of free fatty acids were higher in diabetic patients at 240 min (1.34 +/- 0.12 vs. 2.01 +/- 0.23 mmol/l, p < 0.05). CONCLUSION: Despite long-term near physiologic insulin substitution and the low incidence of hypoglycemia, hormonal hypoglycemia counterregulation was impaired in type-1 diabetic patients after a diabetes duration of more than 10 years.

3-Hydroxybutyric Acid↗

PubMed2000

18F-fluorodeoxyglucose (FDG)-PET features of focal nodular hyperplasia (FNH) of the liver.

AIM: The aim of this paper is to describe the imaging pattern of focal nodular hyperplasia (FNH) by l8F-fluorodeoxyglucose (18F-FDG) positron emission tomography (PET). METHODS: Eight consecutive asymptomatic patients with histologic proof of FNH underwent 18F-FDG PET imaging. The lesions were found incidentally. The 18F-FDG PET imaging was performed with a dedicated PET tomograph after intravenous injection of 300-370 MBq 18F-FDG. The 18F-FDG accumulation in the lesions was (semi)quantified by calculating the standardized uptake value (SUV) and SUV has been corrected for the lean body mass (LBM). Eight patients with liver metastases spread from melanoma (n=2) and colorectal carcinoma (n=6) served as controls. The size of the FNH lesions and of the control group ranged from 2.0 to 8.5 cm (mean 4.83 cm +/- 2.37) and from 1.5 to 6 cm (mean 3.28 +/- 1.52), respectively. RESULTS: While in malignant liver lesions the accumulation of 18F-FDG was significantly increased, all FNH lesions showed normal or even decreased accumulation of 18F-FDG. In FNH lesions, SUV ranged between 1.5 and 2.6 (mean 2.12 +/- 0.38), whereas all liver metastases showed an increased SUV ranging between 6.20 and 16.00 (mean 10.07 +/- 3.79). The SUV corrected for LMB (SUVLBM) was similar to the SUV and ranged between 0.9 and 2.2 (mean 1.81 +/- 0.41) for FNH and between 5.9 and 16.3 (mean 9.15 +/- 4.03), respectively. CONCLUSION: In contrast to liver metastases, there is no increased glucose metabolism in FNH in vivo. The imaging feature of FNH by 18F-FDG-PET imaging is not specific for FNH; however, it may be helpful to differentiate FNH from liver metastases in cancer patients if radiological methods are not diagnostic.

Adult↗

PubMed2000

Hormonal and metabolic counterregulation during and after high-dose insulin-induced hypoglycemia in diabetes mellitus type 2.

Non-obese type 2 diabetic subjects in good metabolic control (n=6, HbA1c 7.0 +/- 0.3%, mean diabetes duration: 5.7 +/- 1 years) and matched non-diabetic subjects (control; n = 6) were studied during hyperinsulinemic (approximately 3 nmol/l)-hypoglycemic (approximately 3.1 mmol/l) clamp tests (0-120 min) and the subsequent recovery period (120-240 min). Plasma glucagon rose gradually but not significantly, whereas norepinephrine and epinephrine similarly increased approximately 2 and approximately 25-fold in both groups. Islet amyloid polypeptide (IAPP) decreased to approximately 41% and approximately 24% of basal values during hypoglycemia and rapidly rose approximately 4.7-fold during the recovery period, while plasma C-peptide remained suppressed in both groups. Within 140 min, plasma free fatty acids similarly decreased to approximately 70 micromol/l (p < 0.05), but then rose to values being approximately 50% higher in diabetic than in control subjects (240 min: 907 +/- 93 vs. 602 +/- 90 micromol/l; p < 0.05). Glucose infusion rates were comparable during hypoglycemia, but approximately 40% lower during recovery in diabetic patients (1.88 +/- 0.27 vs. 3.44 +/- 0.27 mg x kg(-1) x min(-1), p < 0.001). These results demonstrate that (i) hypoglycemia induced by high-dose insulin largely abolishes the counterregulatory response of glucagon, but not of catecholamines in nondiabetic and well-controlled type 2 diabetic subjects, (ii) the rapid posthypoglycemic increase of plasma IAPP occurs independently of plasma insulin, and (iii) the superior rise in plasma free fatty acids may account at least in part for the posthypoglycemic insulin resistance of type 2 diabetic patients.

Adult↗

PubMed1999

[FDG-PET in oncology. Methodological principles and clinical applications].

Clinical PET is now primarily used in oncological indications. Fluorine-18-fluorodeoxyglucose (FDG) shows a high uptake in a variety of malignancies and accounts for approximately 95% of the oncological PET studies. The first part of this review deals with theoretical and methodological aspects of FDG-PET. Possible sources of errors for the method are discussed briefly. Oncological indications for FDG-PET are highlighted according to the results of consensus meetings of experts from nuclear medicine and oncology, organized by the German Society of Nuclear Medicine. FDG-PET is mainly used in staging and restaging, demonstrating of tumour recurrence and therapy control. Main benefits of the method are functional imaging, better spatial resolution than conventional scintigraphy and the possibility to perform whole-body imaging easily. A brief outlook on future prospects for the application of PET in oncology is given.

Fluorodeoxyglucose F18↗

PubMed1999

Positron emission tomography with fluorine-18-2-fluoro-2-deoxy-D-glucose (F18-FDG) does not visualize extranodal B-cell lymphoma of the mucosa-associated lymphoid tissue (MALT)-type.

BACKGROUND: On the basis of promising data on the use of fluorine-18-2-fluoro-2-deoxy-D-glucose (F18-FDG) whole body positron emission tomography (WB-FDG-PET) in the staging of patients with lymphoma, we initiated a pilot series to evaluate the role of WB-FDG-PET in the staging of extranodal B-cell lymphoma of the mucosa-associated lymphoid tissue (MALT) type. PATIENTS AND METHODS: We examined ten consecutive patients with histologically-verified MALT-type lymphomas of various origin before initiation of therapy. Nine patients had low-grade lymphomas (five cases of gastric lymphoma, two patients with lymphoma arising in the lung, one parotid and one lacrimal gland lymphoma), while one patient had a high-grade gastric lymphoma arising from a low-grade background. Two patients had stage EI, seven had stage EII disease, and one presented with stage EIII. WB-FDG-PET scans were performed 40 min following the injection of 300-380 MBq of F18-FDG. The PET scans were correlated with extensive conventional staging including ophthalmologic investigation, otolaryngologic examination, gastroscopy, endosonography, enteroclysis, colonoscopy, CT of thorax and abdomen, and bone marrow biopsy. RESULTS: WB-FDG-PET documented no lymphoma in any of the 10 patients studied, as no focal tracer uptake was demonstrated in either gastric or extragastric lesions or in involved lymph nodes, irrespective of histologic grading. In three patients the scan showed a false negative result with respect to the MALT lesions but showed focal tracer uptake indicating tumor spread, which, however, was ruled out by further follow-up and biopsy, respectively, and was thus rated false positive. Due to these results, the study was discontinued prematurely after the first ten patients. CONCLUSIONS: These discouraging results indicated that WB-FDG-PET is not useful for staging and follow-up of MALT-type lymphoma, and should therefore not be included in the clinical decision making process.

Aged↗

PubMed1998

Accelerated right colonic emptying after simulated upper gut hemorrhage.

OBJECTIVE: Upper gastrointestinal hemorrhage delays gastric emptying. Our aim was to evaluate the effect of gastrointestinal hemorrhage on small intestinal, ileocecal, and proximal colonic transit. METHODS: Healthy volunteers were randomized to receive either a duodenal infusion of heparinized autologous blood (n = 7) or egg white, acting as a control substance with similar composition; 1.5 mCi99mTc-DTPA was added to the infused substances. We infused 30 ml at an infusion rate of 1 ml/min. Gamma-camera images were taken for 4 h or until all radioactivity had entered the colon. Arrival of radiolabels in the colon and also counts in the ascending and transverse colon were quantified. RESULTS: Small intestinal and ileocecal transit were not significantly different between blood and egg white infusions. However, ascending colonic emptying was significantly faster after blood infusion compared to egg white. Four hours after the start of blood infusion a median of 30% of counts were in the transverse colon (11-50%; 25th-75th percentile) versus 0% (0-7%) after egg white infusion (p < 0.001). CONCLUSION: We concluded that simulated upper gastrointestinal bleeding hastens proximal colonic transit, but does not alter small intestinal transit and colonic filling.

Adult↗

PubMed1998

Lipids infused into the jejunum accelerate small intestinal transit but delay ileocolonic transit of solids and liquids.

BACKGROUND: Various nutrients are known to alter small intestinal motility patterns although their effect on transit of fluids and solids in man is not clear. AIMS: To determine small intestinal transit of solids and liquids during perfusion with lipids, protein, and non-energy solutions. METHODS: Twenty eight healthy volunteers received a jejunal infusion (1 ml/minute for 30 minutes) of one of four solutions: a lipid or a protein solution (4.18 J/ml), a non-absorbable electrolyte solution containing polyethylene glycol, or 0.9% sodium chloride. As solid phase marker 1 g of amberlite resin pellets labelled with 111InCl3 was added; 99mTc DTPA was used as a fluid phase marker. Images were obtained on a gamma camera at 10 minute intervals for four hours or until all radiolabel was detected in the colon. RESULTS: Intestinal transit of solids and liquids from the duodenojejunal junction to the caecum was simultaneous, and independent of the energy content of the solution infused. Lipid infusion accelerated transit through the small intestine but delayed transport of chyme along the ileocolonic junction. After protein small intestinal transit was slowest; ileocolonic transit on the other hand was fastest with protein. Transit of the non-energy solutions was in between that of the nutrient solutions. CONCLUSIONS: Transit times through the small intestine and the ileocolonic junction were influenced by the luminal contents. In the small intestine fat induced significantly faster transit compared with proteins, but delayed ileocolonic transit. Once in the small intestine, solids and liquids transit the small bowel together, independent of the luminal content.

Adolescent↗

PubMed1998

Indium-111-DOTA-lanreotide: biodistribution, safety and radiation absorbed dose in tumor patients.

UNLABELLED: Imaging with radiolabeled somatostatin/vasoactive intestinal peptide analogs has recently been established for the localization diagnosis of a variety of human tumors including neuroendocrine tumors, intestinal adenocarcinomas and lymphomas. This study reports on the biodistribution, safety and radiation absorbed dose of 111In-1,4,7,10-tetraazacyclododecane-N,N',N",N'''-tetraacetic acid (DOTA)-lanreotide, a novel peptide tracer, which identifies hSST receptor (R) subtypes 2 through 5 with high affinity, and hSSTR1 with low affinity. METHODS: The tumor localizing capacity of 111In-DOTA-lanreotide was initially investigated in 10 patients (3 lymphomas, 5 carcinoids and 2 intestinal adenocarcinomas). Indium-111 -DOTA-lanreotide was then administered to 14 cancer patients evaluated for possible radiotherapy with 90Y-DOTA-lanreotide (8 neuroendocrine tumors, 4 intestinal adenocarcinomas, 1 Hodgkin lymphoma and 1 prostate cancer). After intravenous administration of 111In-DOTA-lanreotide (approximately = 150 MBq; 10 nmol/patient), sequential images over one-known tumor site were recorded during the initial 30 min after peptide application. Thereafter, whole-body images were acquired in anterior and posterior views up to 72 hr postinjection. Dosimetry calculations were performed on the basis of scintigraphic data, urine, feces and blood activities. A comparison with 111In-DTPA-D-Phe1-octreotide (111In-OCT) scintigraphy was performed in 8 of the patients. RESULTS: After an initial rapid blood clearance [results of biexponential fits: T(eff1) 0.4 min (fraction a1 80%) and T(eff2) 13 min (fraction a2 14%)], the radioactivity was excreted into the urine and amounted to 42% +/- 3% of the injected dose (%ID) within 24 hr and 62% +/- 6%ID within 72 hr after injection of 111In-DOTA-lanreotide. In all patients, tumor sites were visualized during the initial minutes after injection of 111In-DOTA-lanreotide. The mean radiation absorbed dose amounted to 1.2 (range 0.21-5.8) mGy/MBq for primary tumors and/or metastases. The effective half-lives of 111In-DOTA-lanreotide in the tumors were T(eff1) 4.9 +/- 2.2 and T(eff2) 37.6 +/- 6.6 hr, and the mean residence time tau was 1.8 hr. The highest radiation absorbed doses were calculated for the spleen (0.39 +/- 0.13 mGy/MBq), kidneys (0.34 +/- 0.08 mGy/MBq), urinary bladder (0.21 +/- 0.03 mGy/MBq) and liver (0.16 +/- 0.04 mGy/MBq). The effective dose was 0.11 +/- 0.01 (range 0.09-0.12) mSv/MBq. During the observation period of 72 hr, no side effects were noted after 111In-DOTA-lanreotide application. The 111In-DOTA-lanreotide radiation absorbed tumor dose was significantly higher (ratio 2.25 +/- 0.60, p < 0.01) when directly compared with 111In-OCT. CONCLUSION: Indium-111 -DOTA-lanreotide shows a high tumor uptake for a variety of different human tumor types, has a favorable dosimetry over 111In-OCT and is clinically safe.

Adenocarcinoma↗

PubMed1997

Comparison and histopathological correlation of three parathyroid imaging methods in a population with a high prevalence of concomitant thyroid diseases.

The aim of this prospective study was to evaluate the diagnostic utility of a technetium-99m sestamibi dual-phase protocol enhanced by single-photon emission tomography (SPET) and semiquantitative analysis in comparison to established preoperative staging procedures in patients with primary hyperparathyroidism. Twenty-eight (50%) out of 56 patients had superimposed thyroid disease, and 12 patients had previously undergone neck surgery. Visual and semiquantitative analysis of planar 99mTc-sestamibi dual-phase imaging, SPET of the delayed phase, ultrasonography, and thallium-201 chloride-technetium-99m pertechnetate subtraction scintigraphy was further correlated with the histopathological examination of the surgical specimens. 99mTc-sestamibi dual-phase imaging achieved the highest sensitivity for side localization and precise localization compared with 201Tl-99mTc subtraction scintigraphy and ultrasonography, but the differences reached statistical significance only in comparison to ultrasonsography. Semiquantitative analysis did not enhance sensitivity. Adenoma detection by 99mTc-sestamibi dual-phase imaging was only correlated to serum calcium levels and osteocalcin, not to cell density or oxyphil cell count (SPET yielded additional information for the exact topographical localization of the parathyroid tumour in 22 (39%) patients with superimposed thyroid disease or previous neck surgery but did not enhance the overall detection rate.

Female↗

PubMed1997

Cisplatin-induced renal effects and thromboxane A2 receptor blockade.

The aim of this study was to evaluate the renal protective effect of linotroban, a thromboxane A2 receptor antagonist, in 25 patients with malignant tumours scheduled for cisplatin therapy. Cisplatin was administered 1 h after the start of a 24-h continuous infusion of linotroban or placebo. Glomerular filtration rate and effective renal plasma flow were measured. Infusions of cisplatin decreased glomerular filtration rate by 17 +/- 25 mL min-1 (P = 0.049 vs. baseline) and effective renal plasma flow by 94 +/- 150 mL min-1 (P = 0.049 vs. baseline) in the placebo group. In the linotroban group a decrease in glomerular filtration rate by 11 +/- 18 mL min-1 (P = 0.050 vs. baseline) and in effective renal plasma flow by 26 +/- 63 mL min-1 (P = 0.2 vs. baseline) was noted. However, no difference was noted between groups in response to treatment. Our findings indicate that linotroban may not be useful for prevention of cisplatin's acute nephrotoxic effects.

Adult↗

PubMed1997

The diagnostic value of planar and SPET scintimammography in different age groups.

Planar scintimammography (SMM) with 99Tcm-sestamibi (99Tcm-MIBI) has proved to be a useful method in the evaluation of breast lesions. The aim of our study was to determine the diagnostic value of planar and single photon emission tomograpic (SPET) SMM in different age group. We investigated women with breast lesions for which the surgeon recommended biopsy or careful follow-up. Seventy consecutive patients underwent supine planar SMM, while supine SPET was performed in 68 of the patients. Twenty-seven carcinomas in 23 patients and 35 benign lesions in 31 patients were confirmed histologically. In the remaining 16 patients, the findings were classified as benign at follow-up. The carcinomas and benign lesions had a mean (+/- S.D.) diameter of 25 +/- 17 and 17 +/- 11 mm respectively (P < 0.05). A sensitivity/specificity of 67/96% and 88/91% was obtained with the planar and SPET techniques respectively. The accuracy of both techniques was 90%. In patients aged 40 years or less, SPET increased the sensitivity from 50 to 100% (P < 0.01), whereas it decreased the specificity and accuracy from 94 to 81% and 91 to 81% respectively (N.S.). In patients aged 41-50 years, the sensitivity increased from 63 to 100% (P < 0.01), whereas there was a small decrease in specificity and an increase in accuracy (from 91 to 89% and 86 to 91% respectively, N.S.) We conclude that, in younger patients, a negative SPET SMM study indicates the need for careful follow-up rather than biopsy. However, the addition of SPET in supine scintimammography does-not change the overall accuracy significantly.

Adult↗

PubMed1997

The distal colon provides reserve storage capacity during colonic fluid overload.

BACKGROUND: In addition to its absorptive function the capacity of the colon to retain fluid might be relevant in compensating for increased fluid loads and prevention of diarrhoea. The distal colon is considered to be mainly a conduit without extensive storage function. AIMS: To evaluate colonic volume capacity in a model of pure osmotic diarrhoea. METHODS: A non-absorbable, iso-osmotic solution (OS) containing polyethylene glycol (500 ml) was infused into the caecum of nine healthy volunteers; the control group (n = 5) received an equal amount of an easily absorbable electrolyte solution (ES). Fluids were radiolabelled with technetium-99m and gamma camera images were obtained for 48 hours. Counts in the proximal and distal colon were measured and regional and overall colonic transit and stool output were quantified. RESULTS: After OS, in contrast to ES, faecal output was increased significantly (p < 0.05), but colonic transit after OS was not different from transit after ES (p > 0.05). This indicates storage of OS in the colon: after OS infusion, counts in the proximal colon decreased linearly while the distal colon stored approximately 30% of radioactivity for the whole 48 hour study period. After OS, stool output correlated with distal (p < 0.01), but not with proximal (p > 0.05), colonic transit. In contrast, after ES, stool output was determined by proximal colonic transit (p < 0.05) but not by transit through the distal colon (p > 0.05). CONCLUSION: The distal colon retains non-absorbable fluid volumes extensively. In our model transit through the distal colon--but not the proximal colon--determined the time at which diarrhoea occurred.

Adult↗

PubMed1997

Inhalation scintigraphy with iodine-123-labeled interferon gamma-1b: pulmonary deposition and dose escalation study in healthy volunteers.

UNLABELLED: Recent studies have suggested that recombinant interferon gamma (IFNg) may be useful in the treatment of various respiratory diseases, such as chronic inflammatory disease. This study was undertaken to investigate the dose response of escalating doses of inhaled 123I-labeled IFNg (123I-IFNg) and its safety, biodistribution and radiation absorbed doses in healthy volunteers. METHODS: IFNg was labeled with 123I to produce a specific activity of 1800 MBq/mg of IFNg. The biological activities of 123I-IFNg, nebulized 123I-IFNg and unlabeled IFNg were evaluated in various functional in vitro tests. Ten healthy volunteers were enrolled in the in vivo dose escalation study (180 MBq of 123I-IFNg diluted with 0.1-2 mg of INFg). Inhalation scintigraphy, using a Pari-Master nebulizer, was performed for up to 37 min, during which dynamic posterior images of the lungs were obtained. Whole-body scanning was performed at various time points up to 24 hr postinjection, for biodistribution and dosimetry purposes. Blood, urine and feces were also collected over this 24-hr period. Lung perfusion scintigraphy with 99mTc-microspheres was performed at the end of the study for attenuation correction. RESULTS: Inhaled nebulized IFNg showed a uniform deposition pattern in the lungs with deposition ratios of 0.74 (central-to-peripheral) and 0.78 (upper-to-lower). The lung deposition of IFNg was time-dependent, with a deposition half-time between 1 and 5 min. Despite a large interindividual variation, the total lung deposition was proportional to the nebulizer charge and was 53 +/- 12% of the inhaled dose and 19 +/- 7% of the initial nebulizer charge (between 0.1 and 2 mg of IFNg). The biological half-life in the lung could be fitted to a biexponential function, with resultant half-lives of 1 and 11 hr. Blood activity was maximal at 3.5 hr after inhalation and was due to free iodine. The radioactivity was excreted through both the urinary and intestinal tracts. Plasma IFNg levels did not significantly increase over time, and no significant HLA-DR induction on peripheral blood cells was detected. The highest radiation absorbed doses of 0.14 and 0.19 mGy/MBq were determined for the trachea and the lower intestines, respectively. The effective dose equivalent was 0.05 mSv/MBq. CONCLUSION: After inhalation with the Pari-Master nebulizer, IFNg deposits normally in the lungs and shows no systemic effects in healthy volunteers.

Administration, Inhalation↗

PubMed1996

Distinction between obstructive and nonobstructive hydronephrosis: value of diuresis duplex Doppler sonography.

OBJECTIVE: The purpose of this study was to determine the diagnostic accuracy of diuresis duplex Doppler sonography in distinguishing between obstructive and nonobstructive hydronephrosis by calculating the resistive indexes before and after administration of furosemide. SUBJECTS AND METHODS: We prospectively studied 48 kidneys in 26 patients with suspected chronic renal obstruction. All patients underwent diuretic renography and duplex Doppler sonography before and after administration of furosemide. According to the findings at diuretic renography, kidneys were classified as nonobstructed (n = 12), indeterminate (n =9), obstructed (n = 8), or normal (n = 19). The mean resistive index of each kidney and the difference between the mean resistive indexes of both kidneys were calculated before and after administration of 0.5 mg furosemide per kilogram of body weight. A receiver operating characteristic curve was generated to determine the discriminatory resistive index value for diagnosing obstruction. RESULTS: Resistive indexes were not significantly different between kidneys with nonobstructive dilatation and normal kidneys before and after diuresis. Significant differences in resistive indexes before and after diuresis were seen between kidneys with obstructive dilatation and kidneys with nonobstructive dilatation, and between normal kidneys. Kidneys with obstructive dilatation showed a significant increase in resistive index after administration of furosemide. In the indeterminate kidneys, furosemide had a heterogeneous effect on the resistive indexes, indicating obstructive resistive indexes in five kidneys and nonobstructive resistive indexes in four kidneys. Receiver operating characteristic analysis revealed a diuresis resistive index of 0.75, which resulted in an accuracy rate of 95% in diagnosing renal obstruction. CONCLUSION: Diuresis duplex Doppler sonography is accurate in the differentiation of obstructed from nonobstructed kidneys and may facilitate the distinction between obstructive and nonobstructive hydronephrosis, notably in kidneys classified as indeterminate according to diuretic renography.

Diuresis↗

PubMed1996

Comparison of iodine-123-vasoactive intestinal peptide receptor scintigraphy and indium-111-CYT-103 immunoscintigraphy.

UNLABELLED: Recently, we have shown that the expression of receptors for vasoactive intestinal peptide (VIP) on intestinal adenocarcinomas can be used for in vivo targeting of primary or metastatic tumor sites using 123I-labeled VIP. Several other receptors and antigens including the TAG-72 protein have also been implemented for in vivo localization purposes. In this study, we have compared the in vitro and in vivo binding of 123I-VIP and of the 111In-labeled monoclonal antibody (MAb) directed against TAG-72 (OncoScint; 111In-CR-103) in patients with intestinal adenocarcinomas in a single-blinded, prospectively randomized trial. METHODS: Twenty patients were administered either 123I-VIP (150-200 MBq; 1 microgram) or 111In-CYT-103 (150 MBq; 1 mg) for one imaging study. After interim analysis demonstrated superior imaging with 123I-VIP, the next 10 patients (accounting for a total of 50 patients) enrolled in this trial underwent both studies in random order to allow for a direct comparison. RESULTS: In total, 123I-VIP scans were true-positive in 28 of 30 patients (93%) versus 17 of 30 patients administered 111In-CYT-103 (56%). In the subgroup of 10 patients enrolled in the second part of the study, primary intestinal adenocarcinomas were imaged in five of five patients with 123I-VIP and in only two of these patients with 111In-CYT-103. Liver metastases were visualized in five of six patients by 123I-VIP receptor scanning and in four of these patients with 111In-CYT-103. The in vitro results indicated significant binding of 123I-VIP to primary colorectal tumors as well as to HT29 and COLO320 adenocarcinoma cells. In vitro, adenocarcinoma cells also expressed abundant numbers of the TAG-72 antigen. CONCLUSION: Intestinal adenocarcinomas co-express VIP receptors and the IAG-72 antigen. Despite significant in vitro binding of both agents, however, the VIP receptor scan is more sensitive in localizing intestinal adenocarcinomas and metastatic spread.

Adenocarcinoma↗

PubMed1996

Consensus on diuresis renography for investigating the dilated upper urinary tract. Radionuclides in Nephrourology Group. Consensus Committee on Diuresis Renography.

UNLABELLED: There is great variation in technique and interpretation of diuresis renography between different establishments. METHODS: To address this problem, an International Consensus Committee was appointed by the Ninth International Symposium on Radionuclides in Nephrourology in 1994. RESULTS: The final document was produced and addressed: objectives, equipment, data acquisition, choice of radiopharmaceutical, patient preparation, position, dosage of furosemide, timing of furosemide, role of bladder catheter, duration of study, pediatric considerations, evaluation of the furosemide response, interpretation, and conclusion. CONCLUSION: The report presents a standardized approach to diuresis renography that, if adopted, will improve reproducibility between centers, discourage unacceptable practice and stimulate further discussion between nuclear medicine and urology health care professionals who treat patients with dilated and obstructed upper urinary tracts.

Adolescent↗