| 311. |
- Öberg, Kjell, et al.
(author)
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The role of interferons in the management of carcinoid tumors
- 1991
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In: Acta Oncologica. - 0284-186X .- 1651-226X. ; 30:4, s. 519-522
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Journal article (peer-reviewed)abstract
- Malignant carcinoid tumors with the carcinoid syndrome has over the years presented a therapeutic challenge. Surgery is the treatment of choice in local disease but when liver metastases have developed other treatment procedures must be considered. Conventional chemotherapy has been of little benefit, whereas a new somatostatin analogue octreotide gives a good control of clinical symptoms but not of tumor progression. Interferon treatment was introduced in 1982 by our group and we are now presenting results of medical treatment in 130 patients with histologically verified malignant carcinoid tumors and liver metastases. One hundred and eleven patients were treated with alpha-interferon, whereas 19 patients received conventional chemotherapy. Forty-seven out of 111 patients (42%) treated with alpha-interferon demonstrated a significant biochemical response and 15% also more than 50% reduction of tumor size. In another 43 (39%) patients stabilization of the carcinoid disease was noted whereas 21 (19%) showed progressive disease. The median duration of response was 34 months. Subjective response with improvement of diarrheas, flush and/or bronchoconstriction was noticed in 76 patients (68%). Among the 19 patients treated with conventional chemotherapy only 2 showed biochemical response and it lasted only for 3-5 months. The patients treated with chemotherapy had a median survival of only 8 months compared with 80+ months in the group treated with alpha-interferon. The adverse reactions of alpha-interferon are manageable and consist mainly of fatigue, weight reduction and reduction of blood cell counts. Neutralizing interferon antibodies might occur in patients treated with recombinant alpha-interferons (5-15%).
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| 312. |
- Öhrvall, Ulf, et al.
(author)
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Method for dissection of mesenteric metastases in mid-gut carcinoid tumors
- 2000
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In: World Journal of Surgery. - : Springer Science and Business Media LLC. - 0364-2313 .- 1432-2323. ; 24:11, s. 1402-1408
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Journal article (peer-reviewed)abstract
- With adequate medical management the midgut carcinoid tumor generally is an indolent malignancy associated with substantial life expectancy and appreciable life quality, even in the presence of liver metastases and significant tumor burden. Abdominal complications may occur in this entity of carcinoids owing to entrapment of intestines and encasement of mesenteric vessels by mesenteric metastases and associated marked mesenteric fibrosis. This may be the cause of abdominal pain, disabling diarrhea, weight loss to the extent of malnutrition, and eventually the risk of death with acute or chronic intestinal obstruction or intestinal gangrene. Operative removal of the mesentericointestinal lesion is often indicated to prevent or treat these complications but may be technically difficult when mesenteric metastases extend in the vicinity of major vessels in the mesenteric root. At laparotomy 56 patients with advanced midgut carcinoids underwent removal of the mesenteric tumor with a method for preserving the mesenteric vessels. This was feasible by mobilizing and releasing the right colon and mesenteric root from posterior adhesions, identifying the mesenteric artery below the pancreas, and free-dissecting this artery on the tumor capsule in the mobilized mesentery. Dissection was successful even with tumors initially judged inoperable unless tumor growth completely surrounded the mesenteric vessels or extended retroperitoneally. One patient was subjected to distal intestinal artery bypass. Symptom relief was been substantial and often of long duration after mesenteric tumor removal in patients who prior to surgery often had threatening intestinal ischemia. Patients with advanced midgut carcinoids may benefit markedly from dissectional removal of mesenteric tumors, which (conceivably better than conventional wedge resection) preserves the length of the remaining intestine.
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| 313. |
- Örlefors, Håkan, et al.
(author)
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Carbidopa pretreatment improves image interpretation and visualisation of carcinoid tumours with 11C-5-hydroxytryptophan positron emission tomography
- 2006
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In: European Journal of Nuclear Medicine and Molecular Imaging. - : Springer Science and Business Media LLC. - 1619-7070 .- 1619-7089. ; 33:1, s. 60-65
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Journal article (peer-reviewed)abstract
- PURPOSE: Positron emission tomography (PET) with 11C-5-hydroxytryptophan (5-HTP) as tracer is a promising imaging instrument in the management of patients with neuroendocrine tumours (NETs). However, high radioactivity concentrations in the urinary collecting system sometimes produce image reconstruction artefacts that can make detection of small NETs difficult. As a means to decrease urinary excretion of radioactivity and thereby improve image quality, we examined the effect of pretreatment with carbidopa (CD), a peripheral inhibitor of aromatic amino acid decarboxylase (AADC), which converts 5-HTP to serotonin (5-hydroxytryptamine, 5-HT). METHODS: Six patients with midgut carcinoid metastases were examined with 11C-5-HTP PET before and 1 h after oral administration of 100 or 200 mg of CD. RESULTS: There was a fourfold significant reduction of tracer uptake in the urinary collecting system after CD administration (p=0.0277, n=6), with a mean standard uptake value (SUV) of 155+/-195 before CD and 39+/-14 after CD. In tumour lesions there was a significant increase in SUV after CD administration (p<0. 0001, n=18), with a mean SUV of 11+/-3 before CD and 14+/-3 after CD. There was no difference between the doses (100 and 200 mg) of CD in this respect. In all patients, image interpretation and tumour detection were markedly improved after CD administration. CONCLUSION: We conclude that CD premedication improves 11C-5-HTP PET image quality and facilitates detection of NET lesions. Because of the similarity of metabolic pathways, this method could probably be applied to improve PET imaging using other tracers like 18F-DOPA and 11C-DOPA.
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| 314. |
- Örlefors, Håkan, et al.
(author)
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Demonstration of high monoamineoxidase-A levels in neuroendocrine gastroenteropancreatic tumors in vitro and in vivo : tumor visualization using positron emission tomography with 11C-harmine
- 2003
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In: Nuclear Medicine and Biology. - 0969-8051 .- 1872-9614. ; 30:6, s. 669-679
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Journal article (peer-reviewed)abstract
- Background and Aims: A majority of neuroendocrine gastroenteropancreatic (GEP) tumors can be detected by conventional radiological methods and scintigraphic techniques. Still there are problems to visualize small tumor lesions and non-functioning tumors. The aim of this study was to investigate some of the monoamine processing pathways of neuroendocrine GEP-tumors and try to find a new tracer substance for in vivo characterization and visualization by Positron Emission Tomography (PET). Subjects and Methods: Autoradiography of tumor sections from 8 midgut carcinoids (MGC) and 8 endocrine pancreatic tumors (EPT) was performed with C-11-labeled tracers for serotonin and dopamine transporters, serotonin HT2A-, dopamine D1- and muscarinic receptors and for monoamine oxidase A (MAO-A). The in vitro results initiated PET studies with C-11-Harmine in 4 patients with MGC and 7 patients with EPT (one insulinoma, two glucagonomas and four non-functioning EPT). Results: The MAO-A-ligand Harmine expressed specific in vitro binding of 87 +/- 21% for MGC and 125 +/- 50% for EPT, compared to reference tissue (rat brain, 100%). All other substances showed relatively low specific binding. C-11-harmine-PET could visualize tumors in all patients. The mean standardized uptake value (SUV) for MGC was 7.5 +/- 3.9 and for EPT 12.9 +/- 2.7, whereas the SUV of normal liver, intestine and pancreas were 3.1 +/- 0.5, 3.4 +/- 1.2 and 8.9 +/- 3.0 respectively. Conclusions: This study demonstrates in vitro and in vivo that neuroendocrine GEP-tumors are characterized by a high MAO-A-expression, thereby adding to the similarities of neuronal and neuroendocrine tissue. It also indicates a possible application for C-11-harmine as a new PET-tracer for neuroendocrine GEP-tumors with the potential to visualize also non-functioning EPT's.
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| 315. |
- Örlefors, Håkan, et al.
(author)
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PET-Guided Surgery : High Correlation between Positron Emission Tomography with 11C-5-Hydroxytryptophane (5-HTP) and Surgical Findings in Abdominal Neuroendocrine Tumours
- 2012
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In: Cancers. - : MDPI AG. - 2072-6694. ; 4:1, s. 100-112
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Journal article (other academic/artistic)abstract
- Positron emission tomography (PET) with 11C-labeled 5-hydroxytryptophane (5-HTP) is a sensitive technique to visualize neuroendocrine tumours (NETs), due to high intracellular uptake of amine-precursors like L-dihydroxyphenylalanine (L-DOPA) and 5-HTP. NETs are often small and difficult to localize in spite of overt clinical symptoms due to hormonal excess. In our study, 38 consecutive NET patients underwent 11C-5-HTP-PET and morphological imaging by CT within 12 weeks prior to surgery. Surgical, histopathological and 5-HTP PET findings were correlated. 11C-5-HTP-PET corresponded to the surgical findings in 31 cases, was false negative in six, and true negative in one case resulting in 83.8% sensitivity and 100% specificity. Positive predicted value was 100%. In 11 patients 11C-5-HTP-PET was the only imaging method applied to localize the tumour. Thus, we could demonstrate that functional imaging by 11C-5-HTP-PET in many cases adds vital preoperative diagnostic information and in more than every fourth patient was the only imaging method that will guide the surgeon in finding the NET-lesion. Although the present results demonstrates that 11C-5-HTP may be used as an universal NET tracer, the sensitivity to visualize benign insulinomas and non functioning pancreatic NETs was lower.
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| 316. |
- Örlefors, Håkan
(author)
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Positron Emission Tomography in the Management of Neuroendocrine Tumors
- 2003
-
Doctoral thesis (other academic/artistic)abstract
- Neuroendocrine tumors (NET´s) are often characterized by overproduction of peptide hormones. In spite of pronounced clinical symptoms, the tumor lesions can be small and difficult to detect. The general aim of this thesis was to investigate, in vitro and in vivo, some of the potential monoamine pathways present in NET´s, using radiolabeled tracers for positron emission tomography (PET), with the intention to explore the value of PET-imaging in the management of NET´s. We used the 11C-labeled serotonin precursor 5-hydroxy tryptophan (HTP) as the tracer for imaging of NET´s. More than 95% of the subjects displayed a high tracer uptake on PET and tumor detection rate with PET was higher in >50% of the patients compared both to computed tomography (CT) and somatostatin receptor scintigraphy (SRS). The primary tumor was imaged by PET in 84% (16/19), compared to 47% and 42% for SRS and CT, respectively. Tumor visibility was better with PET due to a higher tumor-to-background ratio and a better spatial resolution. There was a strong correlation (r = .907) between changes in urinary-5-hydroxy indole acetic acid and changes in transport rate of 11C-5-HTP during treatment, indicating the use of PET in treatment monitoring of NET´s. Pretreatment with carbidopa decreased the urinary radioactivity concentration four-fold and significantly (p<0.001) increased the tumor tracer uptake. This greatly improved image interpretation and tumor lesion detection. A screening for expression of monoamine pathways in NET´s revealed a high in vitro binding of the monoamineoxidase-A ligand harmine to tumor sections. PET examinations with 11C-harmine could visualize tumors in all patients, including non-functioning endocrine pancreatic tumors (EPT´s). Finally, the in vitro turnover and in vivo distribution of the amino acids glutamate, glutamine and aspartate was investigated. Limited uptake in vivo indicates the lack of utility for these substances as PET-tracers for imaging and characterization of NET´s.
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| 317. |
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| 318. |
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| 319. |
- Örlefors, Håkan, et al.
(author)
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Whole-body 11C-5-hydroxytryptophan positron emission tomography as a universal imaging technique for neuroendocrine tumors : Comparison with somatostatin receptor scintigraphy and computed tomography
- 2005
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In: Journal of Clinical Endocrinology and Metabolism. - : The Endocrine Society. - 0021-972X .- 1945-7197. ; 90:6, s. 3392-3400
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Journal article (peer-reviewed)abstract
- Neuroendocrine tumors (NETs) can be small and situated almost anywhere throughout the body. Our objective was to investigate whether whole-body (WB) positron emission tomography (PET) with 11C-5-hydroxytryptophan (5-HTP) can be used as a universal imaging technique for NETs and to compare this technique with established imaging methods. Forty-two consecutive patients with evidence of NET and a detected lesion on any conventional imaging (six bronchial, two foregut, 16 midgut, and two thymic carcinoids; one ectopic Cushing’s syndrome; four gastrinomas; one insulinoma; six nonfunctioning endocrine pancreatic tumors; one gastric carcinoid, one paraganglioma; and two endocrine-differentiated pancreatic carcinomas) were studied. The WB-11C-5-HTP-PET examinations were compared with WB-computed tomography (CT) and somatostatin receptor scintigraphy (SRS). Tumor lesions were imaged with PET in 95% of the patients. In 58% of the patients, PET could detect more lesions than SRS and CT and equal numbers in 34%, whereas in three cases, SRS or CT showed more lesions. In 84% (16 of 19 patients), PET could visualize the primary tumor compared with 47 and 42% for SRS and CT, respectively. The surgically removed PET-positive primary tumor sizes were 6–30 mm. To conclude, this study indicates that WB-11C-5-HTP-PET can be used as a universal imaging method for detection of NETs. This study also shows that WB-11C-HTP-PET is sensitive in imaging small NET lesions, such as primary tumors, and can in a majority of cases image significantly more tumor lesions than SRS and CT.
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