(dtpa-phe(1))-octreotide and Paraganglioma

This paper is a critical review of the literature on NET radionuclide therapy with (111)In-DTPA(0)-octreotide (Octreoscan) and (131)I-MIBG, focusing on efficacy and toxicity. Some potential future applications and new candidate therapeutic agents are also mentioned. Octreoscan has been a pioneering agent for somatostatin receptor radionuclide therapy. It has achieved symptomatic responses and disease stabilization, but it is now outperformed by the corresponding β-emitter agents (177)Lu-DOTATATE and (90)Y-DOTATOC. (131)I-MIBG is the radionuclide therapy of choice for inoperable or metastatic phaeochromocytomas/paragangliomas, which avidly concentrate this tracer via the noradrenaline transporter. Symptomatic, biochemical and tumour morphological response rates of 50-89%, 45-74% and 27-47%, respectively, have been reported. (131)I-MIBG is a second-line radiopharmaceutical for treatment of enterochromaffin carcinoids, mainly offering the benefit of amelioration of hormone-induced symptoms. High specific activity, non-carrier-added (131)I-MIBG and meta-astato((211)At)-benzylguanidine (MABG) are tracers with potential for enhanced therapeutic efficacy, yet their integration into clinical practice awaits further exploration. Amongst other promising agents, radiolabelled exendin analogues show potential for imaging and possibly therapy of insulinomas, while preclinical studies are currently evaluating DOTA peptides targeting the CCK-2/gastrin receptors that are overexpressed by medullary thyroid carcinoma cells.

Topics: 3-Iodobenzylguanidine; Carcinoid Tumor; Carcinoma, Neuroendocrine; Humans; Iodine Radioisotopes; Neuroendocrine Tumors; Octreotide; Paraganglioma; Pentetic Acid; Pheochromocytoma; Radiopharmaceuticals; Receptors, Somatostatin; Thyroid Neoplasms

The aim of the present study was to prospectively evaluate the add value provided by [(111)In]DTPA-octreotide single-photon emission computed tomography/computed tomography (Octreo-SPECT/CT) with respect to [(111)In]DTPA-octreotide SPECT (Octreo-SPECT) in terms of diagnostic accuracy and localization of neuroendocrine tumors (NETs).. Eighty-one consecutive patients with known or suspected NET underwent [(111)In]DTPA-octreotide scintigraphy using an integrated SPECT/low-energy-CT system (Infinia & Hawkeye; GE Medical Systems, Milwaukee, WI, USA). SPECT and fused SPECT/CT images were interpreted separately and a lesion-by-lesion analysis was performed with regard to classification (probability of NET graded on a 5-point scale) and localization of each abnormal focal tracer uptake. A subgroup analysis, distinguishing between abdominal and thoracic lesions, and a patient-by-patient analysis for likelihood of NET in each patient was also performed. Standard of reference for confirming presence or absence of NET was either histopathology or clinical/imaging follow-up data. The value of SPECT/CT imaging was assessed by ROC analysis and McNemar test.. A final diagnosis of NET was achieved in 43 out of 81 patients and a total of 169 areas (138 NET and 31 benign/physiological) with focal tracer uptake were included in the final lesion-by-lesion analysis. SPECT/CT imaging led to a significantly higher proportion of patients (75/81=92.6% vs 64/81=79%) and lesions (163/169=96.4% vs 138/169=81.1%) correctly classified vs SPECT alone. ROC analysis confirmed that Octreo-SPECT/CT performed significantly better than Octreo-SPECT for the detection of NET on both patient- and lesion-based analysis, improving especially evaluation of abnormal tracer uptake in the abdomen. Moreover, Octreo-SPECT/CT accurately localized 160/169 (94.7%) lesions, significantly higher than SPECT alone (77/169= 45.6%).. Octreo-SPECT/CT allows more accurate detection and localization of NETs than simple Octreo-SPECT, with major benefits for lesions located in the abdomen.

Topics: Abdomen; Adult; Aged; Aged, 80 and over; False Positive Reactions; Female; Humans; Male; Middle Aged; Neuroendocrine Tumors; Octreotide; Paraganglioma; Pentetic Acid; Radiography, Abdominal; Radiography, Thoracic; Recurrence; ROC Curve; Sensitivity and Specificity; Thorax; Time Factors; Tomography, Emission-Computed, Single-Photon; Tomography, X-Ray Computed

A Tc MDP bone superscan occurs when osseous activity is extremely intense and genitourinary and soft tissue activity is not identified. A similar phenomenon has been described with metaiodobenzylguanidine (MIBG) in metastatic pheochromocytoma and neuroblastoma. We present a case of metastatic paraganglioma resulting in an MIBG superscan. Neuroendocrine bone metastasis alters the biodistribution of MIBG such that the liver, heart, and urinary bladder are not well visualized. Our case occurred in association with neurofibromatosis type 1 and in the absence of an identified primary tumor.

Topics: 3-Iodobenzylguanidine; Female; Humans; Middle Aged; Neurofibromatosis 1; Octreotide; Paraganglioma; Pentetic Acid; Radionuclide Imaging; Tomography, X-Ray Computed; Whole Body Imaging

Gastrin receptor scintigraphy (GRS) is a new imaging method primarily developed for the detection of metastases of medullary thyroid carcinoma (MTC). As gastrin-binding CCK(2) receptors are also expressed on a variety of other neuroendocrine tumours (NET), we compared GRS to somatostatin receptor scintigraphy (SRS) in patients with NET. SRS and GRS were performed within 21 days in a series of 60 consecutive patients with NET. GRS was directly compared with SRS. If lesions were visible on GRS but not detectable by SRS, other imaging modalities (MRI, CT) and follow-up were used for verification. Of the 60 evaluable patients, 51 had carcinoid tumours, 3 gastrinomas, 2 glucagonomas, 1 insulinoma and 3 paragangliomas. The overall tumour-detection rate was 73.7% for GRS and 82.1% for SRS. In the 11 patients with negative SRS, GRS was positive in 6 (54.5%). Based on the number of tumour sites detected and the degree of uptake, GRS performed better than SRS in 13 patients (21.7%), equivalent images were obtained in 18 cases (30.0%) and SRS performed better in 24 (40.0%) cases. In six of the SRS positive patients, 18 additional sites of tumour involvement could be detected. Overall, GRS detected additional tumour sites in 20% of the patients. Localisation of the primary tumours or their functional status had no influence on the outcome of imaging. GRS should be performed in selected patients as it may provide additional information in patients with NET with equivocal or absent somatostatin uptake.

Topics: Adult; Aged; Carcinoid Tumor; Diagnosis, Differential; Female; Glucagonoma; Humans; Indium Radioisotopes; Insulinoma; Male; Middle Aged; Neuroendocrine Tumors; Octreotide; Paraganglioma; Pentetic Acid; Prognosis; Radionuclide Imaging; Radiopharmaceuticals; Receptor, Cholecystokinin B; Receptors, Somatostatin

We analyzed the results of conventional imaging and somatostatin receptor scintigraphy in 150 patients with neuroendocrine tumors.. The outcomes of combinations of imaging modalities were compared in terms of tumor localization, effect on patient management and financial costs.. In patients with carcinoids, a combination of somatostatin receptor scintigraphy, chest radiograph and ultrasound of the upper abdomen had a high sensitivity for tumor localization, and detected lesions in patients in whom no tumor was found with conventional imaging, justifying the greater cost. In patients with medullary thyroid carcinoma, somatostatin receptor scintigraphy adds little to the information obtained with conventional imaging and therefore should not be used as a screening method. In patients with paraganglioma, CT scanning of the region where a paraganglioma is suspected, followed by somatostatin receptor scintigraphy to detect multicentricity has the best cost effectiveness ratio. In patients with gastrinomas, the combination of somatostatin receptor scintigraphy and CT scanning of the upper abdomen had the highest sensitivity. The relatively high cost of this process is outweighed by its demonstrating a resectable tumor. In patients with insulinomas, the highest yield against the lowest cost is obtained if somatostatin receptor scintigraphy is only performed if CT scanning fails to demonstrate the tumor.. Somatostatin receptor scintigraphy should be performed in patients with small-cell lung carcinoma because it can lead to a change of stage and may demonstrate otherwise undetected brain metastases. The cost increase is outweighed by the omission of unnecessary treatment for some of the patients and by the possibility of irradiating brain metastases at an early stage, which may lead to a better quality of life.

Topics: Carcinoid Tumor; Carcinoma, Medullary; Carcinoma, Small Cell; Cost-Benefit Analysis; Costs and Cost Analysis; Humans; Indium Radioisotopes; Lung Neoplasms; Netherlands; Neuroendocrine Tumors; Octreotide; Pancreatic Neoplasms; Paraganglioma; Pentetic Acid; Radionuclide Imaging; Receptors, Somatostatin; Sensitivity and Specificity; Thyroid Neoplasms; Tomography, X-Ray Computed

The results of in vivo somatostatin scintigraphy were correlated with those of MIBG from 14 patients, aged 22-66 yr, with metastatic pheochromocytoma (10 patients), malignant paraganglioma (3 patients) and metastatic ganglioneuroblastoma (1 patient). Twelve patients had elevated catecholamine excretion. A dynamic study and serial whole-body scans (4-48 hr) were obtained after injection of 130-187 MBq of 111In-DTPA-Phe-1-octreotide. When indicated, SPECT imaging was done. The results were compared to MIBG scans obtained after a diagnostic or a therapeutic dose.. Three patients with more than 20 tumor sites on MIBG scans had only 1-9 sites on 111In-octreotide scintigraphy. Two patients had no MIBG uptake but one had lung uptake on octreotide scintigraphy. In the other 9 patients with a total of 41 foci of MIBG uptake, 33 sites of 111In-octreotide uptake are found. All positive images with octreotide scintigraphy were seen at or before 4 hr, but the contrast improved at 24 hr. Uptake intensity was lower with 111In-octreotide than MIBG and the number of tumor sites was higher with MIBG. However, seven foci were positive only on octreotide scintigraphy and six of them could not be confirmed by other imaging modalities.. Use of octreotide to identify somatostatin receptors seems promising, especially when results from MIBG scans are negative. Moreover octreotide images could aid in determining a treatment regimen as well as establishing the extent of disease and prognosis.

Topics: 3-Iodobenzylguanidine; Adrenal Gland Neoplasms; Adult; Aged; Female; Ganglioneuroblastoma; Humans; Indium Radioisotopes; Iodine Radioisotopes; Iodobenzenes; Magnetic Resonance Imaging; Male; Middle Aged; Neoplasm Metastasis; Octreotide; Paraganglioma; Pentetic Acid; Pheochromocytoma; Radionuclide Imaging; Tomography, X-Ray Computed