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I Virgolini

Publications and source records attributed to I Virgolini.

At least 37 records · Page 2Linked to original sources

Successful treatment of an advanced hepatocellular carcinoma with the long-acting somatostatin analog lanreotide.

Treatment options for hepatocellular cancer apart from surgical resection are limited because of the drug-refractory nature of this disease. Little is known about the role of somatostatin-receptors in hepatocellular cancer, and somatostatin analogs have not been investigated for treatment of this malignancy. We present the case of a 68-yr-old male, who was successfully treated with the long-acting somatostatin analog lanreotide.

Aged↗

DOTA-lanreotide: a novel somatostatin analog for tumor diagnosis and therapy.

Long acting somatostatin-14 (SST) analogs are used clinically to inhibit tumor growth and proliferation of various tumor types via binding to specific receptors (R). We have developed a 111In-/90Y-labeled SST analog, DOTA-(D)betaNal1-lanreotide (DOTALAN), for tumor diagnosis and therapy. 111In-/90Y-DOTALAN bound with high affinity (dissociation constant, Kd, 1-12 nM) to a number of primary human tumors (n = 31) such as intestinal adenocarcinoma (n = 17; 150-4000 fmol/mg protein) or breast cancer (n = 4; 250-9000 fmol/mg protein). 111In-/90Y-DOTALAN exhibited a similar high binding affinity (Kd, 1-15 nM) for the human breast cancer cell lines T47D and ZR75-1, the prostate cancer cell lines PC3 and DU145, the colonic adenocarcinoma cell line HT29, the pancreatic adenocarcinoma cell line PANC1, and the melanoma cell line 518A2. When expressed in COS7 cells, 111In-DOTALAN bound with high affinity to hsst2 (Kd, 4.3 nM), hsst3 (Kd, 5.1 nM), hsst4 (Kd, 3.8 nM), and hsst5 (Kd, 10 nM) and with lower affinity to hsst1 (Kd, approximately 200 nM). The rank order of displacement of [125I]Tyr11-SST binding to hsst1 was: SST (IC50, 0.5 nM) >> DOTALAN (IC50, 154 nM) > lanreotide (LAN) approximate to Tyr3-octreotide (TOCT) approximate to DOTA-Tyr3-octreotide (DOTATOCT) approximate to DOTA-vapreotide (DOTAVAP; IC50, >1000 nM); that to hsst2 was: DOTATOCT approximate to TOCT approximate to DOTALAN approximate to SST approximately LAN approximate to DOTAVAP (IC50, 1.4 nM); that to hsst3 was: SST (IC50, 1.2 nM) > DOTALAN = LAN (IC50, 15 nM) approximate to TOCT (IC50, 20 nM) approximate to DOTAVAP (IC50, 28 nM) > DOTATOCT (IC50, 73 nM); that to hsst4 was: SST (IC50, 1.8 nM) approximate to DOTALAN (IC50, 2.5 nM) > LAN (IC50, 22 nM) >> DOTATOCT approximate to DOTAVAP approximate to TOCT (IC50, >500 nM); and that to hsst5 was: DOTALAN (IC50, 0.45 nM) > SST (IC50, 0.9 nM) > TOCT (IC50, 1.5 nM) > DOTAVAP (IC50, 5.4 nM) >> LAN (IC50, 21 nM) > DOTATOCT (IC50 260 nM). In Sprague Dawley rats (n = 10), 90Y-DOTALAN was rapidly cleared from the circulation and concentrated in hsst-positive tissues such as pancreas or pituitary. Taken together, our results indicate that 111In-/90Y-DOTALAN binds to a broad range of primary human tumors and tumor cell lines, probably via binding to hsst2-5. We conclude that this radiolabeled peptide can be used for hsst-mediated diagnosis (111In-DOTALAN) as well as systemic radiotherapy (90Y-DOTALAN) of human tumors.

Adenocarcinoma↗

Current applications and perspectives of diagnostic nuclear medicine in oncology. Task Group of Oncology.

The characteristic of nuclear medicine is that it gives images of organs, structures and physiological or pathological processes, detecting the distribution of several radio-pharmaceuticals according to their uptake and metabolism. Its imaging can provide morphological information while at the same time containing data on cellular activity and functions. Such molecular imaging fulfils the modern orientations of oncology, where there is a need to define the presence of a malignancy in the earliest and most effective way, to characterise the neoplasm in terms of biological characteristics (e. g., proliferation, aggressiveness, differentiation, receptor status) and to obtain fundamental issues in patient management such as evaluation of disease extent, monitoring of therapies and study of treatment-induced side effects. The aim of this position paper is to discuss the main indications of nuclear medicine in diagnostic oncology reporting the most recent developments in nuclear medicine, and an extensive list of the major indications for nuclear medicine procedures. The techniques have been labelled as when considered essential in the diagnostic process, when they can give useful additional or information in combination with other instrumental diagnostic approaches, and alternative when they may be performed instead of other tests. These indications were derived by a general consensus within the Task Group of Oncology of the World Federation of Nuclear Medicine and Biology, and it should be stressed that only the current role of nuclear medicine was considered. The Task Group does not claim to have covered the entire range of nuclear medicine indications; in fact it was agreed to include only the most widely used techniques. The highly specific or very exceptionally used applications, or those still in development or under evaluation in clinical trials were not taken into consideration. The conclusion is that the current relationship between nuclear medicine and oncology can be defined not only as satisfactory but also as extremely promising, as nuclear medicine has the potential to compete with the most advanced radiological techniques of imaging, perhaps not so much in terms of sensitivity but more so in terms of specificity and biological characterisation. Several novel diagnostic procedures are able to solve clinical problems for which traditional radiology has shown clear limitations. Nuclear medicine remains today a dynamic medical specialty because it includes a combination of advances in basic science research, technology, cell biology and medical practice and it cannot be excluded that the new lines of research both towards new radiopharmaceuticals and advanced instrumentation will offer in the future new stimulating opportunities.

Forecasting↗

"MAURITIUS": tumour dose in patients with advanced carcinoma.

Radioimaging of various human tumours by means of somatostatin analogues and vasoactive intestinal peptide has been introduced into clinical practice in recent years. The finding that human tumours express various subtypes of somatostatin receptors has led to the development and characterization of a novel peptide tracer, termed MAURITIUS. MAURITIUS identifies a broad range of somatostatin receptors with high binding affinity, and somatostatin receptor 1 with low binding affinity. In order to evaluate patients for tumour radiotherapy with 90Y-MAURITIUS, tumour dose calculation is performed with 111In-MAURITIUS [111In-DOTA-lanreotide]. Treatment is initiated in patients presenting a tumour uptake of > or = 10 Gy/GBq (i.e., standard dose for 1 treatment cycle with 90Y-MAURITIUS). In 25 patients with advanced cancer refractory to conventional antineoplastic treatment 111In-MAURITIUS (approximately 150 MBq; 10 nmol/patient), scintigraphy and dosimetry was performed. Dosimetry data were calculated based on scintigraphic results as well as urine, faeces and blood data. In all patients, at least one tumour site was visualized during the initial few minutes of application. Additional tumour sites not seen on conventional imaging (computerized tomography, magnetic resonance imaging bone scan) could be detected in 6 patients with carcinoids, one patient with prostate cancer and one patient with lymphoma. Liver metastases were visualized in all patients with gastrointestinal cancers, while the primary tumour was not detected in 2 patients with pancreatic, and in 1 patient with rectal, cancer. The calculated radiation dose for tumours and/or metastases ranged between 3-60 Gy/GBq for 90Y-MAURITIUS. MAURITIUS is a universal receptor ligand for a large variety of different human tumours, and is suitable for treatment when labelled with 90Y.

Dose-Response Relationship, Radiation↗

Somatostatin receptor subtype specificity and in vivo binding of a novel tumor tracer, 99mTc-P829.

Recent data suggest that somatostatin receptors (SSTRs) are expressed on various tumor cells. High-level expression of SSTR on the tumor cell surface provides the basis for the successful clinical use of radiolabeled ligands for the in vivo localization of tumor sites. We have characterized the in vitro binding properties of the novel SSTR ligand 99mTc-P829 using primary human tumors (carcinoids, breast cancers, intestinal adenocarcinomas, pheochromocytomas, small cell and non-small cell lung cancer, and melanomas; n = 28), various tumor cell lines, and COS7 cells transfected with the human SSTR (hSSTR) subtypes 1, 2, 3, 4, and 5. 99mTc-P829 bound to primary tumor cells and tumor cell lines with high affinity and high capacity. The dissociation constants (Kd) ranged between 1 and 20 nM. 99mTc-P829 also bound with high affinity to the transfected hSSTR2 (Kd, 2.5 nM), hSSTR5 (Kd, 2 nM), and hSSTR3 (Kd, 1.5 nM). Binding of 99mTc-P829 to hSSTR3 was found to be displaceable by unlabeled P829/([ReO]-P829), SST-14, and vasoactive intestinal peptide (VIP; IC50, 2 nM) and, less effectively, by Tyr3-octreotide (IC50, 20 nM). In contrast, the binding of 99mTc-P829 to hSSTR2 and hSSTR5 could be displaced by P829/([ReO]-P829) and Tyr3-octreotide but not by VIP. 99mTc-P829 scintigraphy revealed in vivo binding to primary or metastatic tumor sites in seven of eight patients with breast cancer and six of six patients with melanoma. In summary, our data show that 99mTc-P829 binds with high affinity to many different types of primary and cloned tumor cells. Furthermore, our data identify hSSTR2, the VIP acceptor hSSTR3, and hSSTR5 as the respective target receptors. Because these receptors are frequently expressed at high levels on primary tumor cells, 99mTc-P829 appears to be a promising novel peptide tracer for tumor imaging.

Animals↗

123I-labelled vasoactive intestinal peptide receptor scintigraphy in patients with colorectal cancer.

Recent studies have shown that various gastrointestinal tumours express substantial amounts of vasoactive intestinal peptide (VIP) receptors. Based on these observations, we have developed a receptor scintigraphy using [123I]VIP as a radioligand. An initial series performed at our institution showed promising potential for visualization of various gastrointestinal adenocarcinomas by means of [123I]VIP. In this article, we now report the results obtained in 80 consecutive patients with colorectal adenocarcinoma. Eighty consecutive patients with histologically verified colorectal cancer underwent scanning by means of [123I]VIP (1 microg, approximately 150 MBq). Thirteen patients were free of tumour after complete resection of Dukes' C cancer, eight patients presented with primary and 14 with locally recurrent tumours but were free of metastases. Ten patients had locally recurrent disease and liver, lung or lymph node metastases. Disease confined to organ metastases (i.e. liver, lung or lymph nodes) was present in 35 patients. The size of the primary or recurrent tumours ranged between 3 and 6 cm, and the size of metastases was between 1 and 13 cm in diameter. Scan results were evaluated independently by two nuclear medicine physicians in a blinded way, and results were then compared with computerized tomography (CT)scans not older than 4 weeks. Seven out of eight primary (87%) and 21 out of 24 (82%) locally relapsing cancers were imaged with [123I]VIP. Negative VIP scans were obtained in all 13 patients in whom the cancers had been curatively resected. All patients with lymph node metastases showed positive VIP scans (four out of four), and positive scans were obtained in 25 out of 28 (89%) patients with liver metastases and in two out of three cases with lung metastases. In four patients with relapsing cancer, the VIP scan indicated the presence of disease before CT, and in two patients the diagnosis of scar tissue instead of a local recurrence of rectal cancer as suggested by CT could be established. We conclude that [123I]VIP receptor scanning is a sensitive method for radioimaging of colorectal cancer with the potential to provide valuable additional information to conventional radiological methods.

Adult↗

Visualization of intestinal splenosis by somatostatin receptor scintigraphy.

A case of intestinal splenosis in a splenectomized patient is presented. (111)In-DTPA-D-Phe-1-octreotide ((111)In-OCT) scintigraphy, computed tomography, as well as magnetic resonance imaging suggested a tumor in the small intestine. The histopathological finding after operation revealed an intestinal splenosis. This case illustrates that intestinal splenosis may mimic a tumor by (111)In-OCT scan. In a splenectomized patient, a splenosis should therefore be considered.

Adult↗

Iodine-123-vasoactive intestinal peptide receptor scanning in patients with pancreatic cancer.

UNLABELLED: Recent data demonstrated a high sensitivity (>90%) in the visualization of primary/recurrent pancreatic cancer as well as metastases by means of 123I-labeled vasoactive intestinal peptide (VIP). The aim of this study was to investigate the diagnostic value of radioiodinated VIP in patients suffering from adenocarcinoma of the exocrine pancreas. METHODS: Sixty consecutive patients (26 women, 34 men; mean age 59 yr) with histologically verified pancreatic cancer were investigated in this study. Twenty-one patients presented with organ-confined malignancy (19 at study entry and 2 during follow-up after initial surgery developed tumor recurrence), while 25 patients had distant metastases along with the local malignancy, and 7 patients had liver metastases after resection of the primary lesion (6 on study entry and 1 during follow-up showed tumor development). In 5 of these patients, abdominal lymph node metastases were present at the time of scanning. Of 10 patients, who had undergone potentially curative surgery for their cancer, 7 remained free of disease during follow-up until death or for at least 6 mo. Iodine-123-VIP (150-200 MBq; approximately 1 microg VIP) was administered to all patients. Scintigraphic results were evaluated as compared to conventional radiologic imaging methods and surgical exploration. RESULTS: Primary pancreatic tumors were visualized by 123I-VIP in 19/21 patients (90%) with disease confined to the pancreas and in 8/25 patients (32%) suffering both from locoregional and disease metastatic to the liver. The overall 123I-VIP scan sensitivity for primary pancreatic adenocarcinomas was 58% (27/46 scans). Liver metastases were imaged in 29/32 patients (scan sensitivity 90%) and abdominal lymph node metastases in 4/5 patients. In 5 patients, the VIP receptor scan indicated the malignant lesion before CT. In vitro results confirmed specific binding of 123I-VIP to primary pancreatic tumor cells as well as to PANC1 adenocarcinoma cells. CONCLUSION: Iodine-123-VIP receptor scanning has the potential to offer additional information to augment diagnostic standard methods and could influence the decision-making process in the treatment of pancreatic cancer.

Adenocarcinoma↗

Location of a VIPoma by iodine-123-vasoactive intestinal peptide scintigraphy.

A major problem in patients with small endocrine tumors is the difficulty in localizing the primary tumor site. Many endocrine tumors possess larger amounts of high affinity vasoactive intestinal peptide (VIP) binding sites compared with normal tissue or blood cells. We used radiolabeled VIP to localize the tumor site in a patient with Verner-Morrison syndrome (VMS). Under octreotide therapy, the VIP levels had declined in this patient, but a tumor site could not be detected by conventional techniques or by radiolabeled octreotide. However, using 123I-VIP, the tumor was detectable in the pancreatic tail. Surgical resection of the tumor was followed by complete remission of the VMS. Expression of VIP binding sites in the tumor was confirmed by a radioreceptor assay and showed cross-competition between VIP and octreotide. The identity of the VIP binding site in the tumor was analyzed by Northern blotting and revealed the expression of somatostatin receptor subtype 3, which binds both somatostatin-14 and VIP with higher affinity than octreotide. Iodine-123-VIP scintigraphy would be an effective tracer to identity the tumor site in VMS patients.

Adult↗

Indium-111-DTPA-D-Phe-1-octreotide and technetium-99m-(V)-dimercaptosuccinic acid scanning in the preoperative staging of medullary thyroid carcinoma.

UNLABELLED: The early detection of all tumor sites in patients with medullary thyroid carcinoma (MTC) before primary surgery is important, because MTC tends to metastasize to regional lymph nodes of the neck and mediastinum early during the course of the disease. METHODS: In an approach to localize the primary tumor sites and to detect additional tumor involvement, we have performed in 22 patients with MTC either 99mTc(V)-dimercaptosuccinic acid (DMSA) and/or 111In-diethylenetriamine pentaacetic acid-D-Phe-1-octreotide scintigraphy. RESULTS: Indium-111-octreotide (150-200 MBq) identified the primary tumor in 10 of 14 patients (71%), whereas the primary tumor was visualized by 99mTc-DMSA (300-370 MBq) in 10 of 17 patients (58%). In 8 of 22 patients (36%), lymph node metastases were present at the time of diagnosis, as confirmed by histopathology and histochemistry after surgery (all <2 mm). Preoperatively, neither scan was able to detect lymph node involvement in these patients (0/8). CONCLUSION: Both 99mTc-DMSA and 111In-octreotide studies have similar sensitivity to localize primary MTC; however, these scans are not able to detect small lymph node involvement (micrometastases) before initial surgery. Unfortunately, both scans have no clinical implication for preoperative staging in patients with MTC.

Carcinoma, Medullary↗

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↗

Response to treatment with yttrium 90-DOTA-lanreotide of a patient with metastatic gastrinoma.

1,4,7,10-tetraazacyclododecane-N,N',N",N'''-tetraacetic acid (DOTA)-lanreotide is a universal somatostatin (SST) receptor subtype ligand that binds to a large variety of human tumors. We report the case of a patient with metastatic gastrinoma who was treated with 90Y-DOTA-lanreotide. Before treatment, dosimetry with 111In-DOTA-lanreotide (150 MBq, 10 nmol) indicated a dose of 5.8 mGy/MBq for the recurrent abdominal gastrinoma, and a mean dose of approximately 1.0 mGy/MBq for liver metastases (i.e., 56 and approximately 10 mGy/MBq for 90Y-DOTA-lanreotide, respectively). After four infusions of 90Y-DOTA-lanreotide (each 1 GBq, approximately 30 nmol) over a 6-mo period, the 111In-DOTA-lanreotide scintigraphy of the liver had returned to a nearly normal condition and a remarkably decreased uptake by the recurrent gastrinoma was calculated (approximately 5 mGy/MBq for 90Y-DOTA-lanreotide). The imaging results were well-correlated with a 25% regression of the liver metastases as indicated by CT. Blood, urine and whole-body clearances of 111In-DOTA-lanreotide and 90Y-DOTA-lanreotide were very similar. The DOTA-lanreotide promises to be useful for functional tumor diagnosis (111In-DOTA-lanreotide) and receptor-mediated tumor radiotherapy (90Y-DOTA-lanreotide).

Gastrinoma↗

Molecular and functional characterization of the urokinase receptor on human mast cells.

The urokinase receptor system is involved in several biological processes including extracellular proteolysis, cell invasion, and chemotaxis. Mast cells are multifunctional perivascular cells that play an important role in the regulation of microenvironmental events. We report that primary human mast cells and the human mast cell line HMC-1 express the receptor for urokinase. As assessed by Northern blotting and reverse transcription polymerase chain reaction technique, purified human lung mast cells and HMC-1 cells expressed urokinase receptor mRNA in a constitutive manner. Using a toluidine blue/immunofluorescence double staining technique and monoclonal antibodies, surface expression of urokinase receptor was demonstrable in lung, skin, uterus, heart, and tonsil mast cells, whereas the low density lipoprotein receptor-related protein was not detectable. Binding of monoclonal antibody VIM5 (recognizing the urokinase binding domain of urokinase receptor) to HMC-1 could be blocked by high molecular weight but not low molecular weight urokinase. Binding analyses performed with 123I-urokinase revealed expression of 271,000 +/- 55,000 high affinity urokinase binding sites per HMC-1 cell, with a calculated dissociation constant of 1. 29 +/- 0.3 nM. Purified urokinase induced dose-dependent migration of primary mast cells and HMC-1 in a chemotaxis assay without inducing release of histamine. The mast cell agonist stem cell factor also induced migration of HMC-1 and caused up-regulation of expression of urokinase receptor mRNA. Together, our data show that human mast cells express functional receptors for urokinase. Expression of urokinase receptors on mast cells may have implications for mast cell-dependent microvascular processes associated with fibrinolysis, migration, or local tissue repair.

Binding Sites↗

Prostaglandin E1 decreases human arterial accumulation of radiolabeled apo B-containing lipoproteins in vivo.

OBJECTIVE: An increased apo B-containing lipoprotein influx and cholesterol ester accumulation in arteries are well-known events in human atherogenesis. In vitro and experimental animal studies have provided evidence of a beneficial effect of PGE1 on both vascular apo B-containing lipoprotein accumulation and cholesterol ester content. METHODS: We examined the effect of PGE1 (administered via an intravenous portable infusion pump at a rate of 5 ng PGE1 kg-1.min-1 for 5 days a week, 6 h daily, over a total of 5 weeks) in ten patients (eight males, two females) on 123I-apo B-containing lipoprotein accumulation into the large arteries in vivo. Apo B-containing lipoprotein isolation was carried out by immunoaffinity chromatography and radiolabeling with the iodine monochloride method. 123I-apo B-containing lipoprotein accumulation was imaged and quantified by means of special computer software before and after 5 weeks of PGE1 therapy. RESULTS: PGE1 led to a significant decrease in maximal arterial apo B-containing lipoprotein retention. The mean decrease in the carotid and femoral arteries in type I lesions amounted to between 16.9% and 30.4%, and in type II lesions between 22.4% and 30.7%, 20 h after injection of radiolabeled apo B-containing lipoprotein. The type of arterial apo B-containing lipoprotein kinetic curves, however, remained unchanged. CONCLUSION: These findings indicate that PGE1 decreases the apo B-containing lipoprotein influx in the large arteries and the vascular cholesterol content, suggesting that PGE1 may lead to regression of lipid-rich lesions in human in vivo.

Alprostadil↗

Radiation doses deriving from patients undergoing 111In-DTPA-D-phe-1-octreotide scintigraphy.

The purpose of this study was to estimate the radiation doses to nursing staff, other patients, accompanying persons and family members deriving from patients undergoing 111In-DTPA-d-Phe-1-octreotide (111In-OCT) scintigraphy. Dose rates were measured from 16 patients who had received an intravenous injection of 140+/-40 MBq 111In-OCT. The measurements were performed at three different distances (0.5, 1 and 2 m) at 10-20 min, 5-7 h and 24 h (and in some cases, up to 48 h) after administration of 111In-OCT. The effective half-lives of the biexponential decrease of the dose rates were estimated to be 2.94+/-0.27 h (T1) and 65.17+/-0. 58 h (T2). The calculated maximum dose to other persons in the waiting area was 27.2 microSv, to family members 61.5 microSv, to nursing staff in a ward 24.1 microSv and to neighbouring patients in the ward 69.5 microSv. Our results clearly demonstrate that the calculated maximum radiation exposure to accompanying persons, personnel, family members and other patients is well below the maximum annual dose limit for non-professionally exposed persons.

Air Pollutants, Radioactive↗