Disease relevance of DTPA-SMS

• CONCLUSIONS: 111In-pentetreotide scintigraphy is a practical, safe, and sensitive procedure for in vivo imaging of gastroenteropancreatic neuroendocrine tumors [1].
• The smallest duodenal gastrinoma detected by Octreoscan scintigraphy measured 3 mm [2].
• METHODS: Results of Octreoscan scintigraphy in 21 consecutive patients with Zollinger-Ellison syndrome were compared with those of conventional imaging techniques, including endoscopic ultrasonography, and with the surgical findings [2].
• Our findings suggest that 111In-pentetreotide imaging effectively detects occult mesenchymal tumours and facilitates surgical treatment of oncogenic osteomalacia [3].
• In 30 of 31 patients (94%), at least one metastasis was positive at OctreoScan scintigraphy [4].

Psychiatry related information on DTPA-SMS

• Furthermore, Octreoscan imaging in this case proved useful in clinical decision making [5].

High impact information on DTPA-SMS

• Biochemical diagnosis is established by elevation of plasma chromogranin A (CgA), serotonin, or urinary 5-hydroxyindoleacetic acid (5-HIAA), while topographic localization is by Octreoscan, computerized axial tomography (CAT) scan, or endoscopy/ultrasound [6].
• Comparative imaging by computerized tomography, magnetic resonance imaging, and transabdominal ultrasonography yielded false-negative results for somatostatin-receptor scintigraphy in 8 of 40 patients; however, in 16 patients, tumor tissue that had escaped conventional imaging techniques was detected by 111In-pentetreotide scintigraphy [1].
• Thirty-one patients with metastatic hormone-refractory prostatic adenocarcinoma were investigated scintigraphically with the 111In-labeled somatostatin analogue [DTPA-D-Phe1]-octreotide (OctreoScan) and with 99mTc-labeled HDP [4].
• A 29-yr-old woman presented with acromegaly, pituitary gland enlargement, and an isolated pulmonary mass of 3.3 cm in diameter, which displayed a very high tracer uptake after OctreoScan [7].
• Cells infected with the SSTR2-expressing VV or controls were incubated with the somatostatin analog 111In-pentetreotide with or without an excess of nonradiolabeled pentetreotide [8].

Chemical compound and disease context of DTPA-SMS

• Thallium-201 SPECT showed similar findings to those of 111In-pentetreotide scintigraphy except in two patients with glioblastoma multiforme: One with 201TL negative scan showed increased uptake of 111In-pentetreotide and the other showed increased thallium uptake but minimal uptake of 111In-pentetreotide [9].
• OBJECTIVES: Scintigraphy with radiolabelled octreotide (octreoscan) is useful for imaging various neuroendocrine tumours, especially in patients with midgut carcinoids [10].
• Several of these, including Indium-III-DTPA Pentetreotide (Octreoscan [Mallinckrodt Medical, St. Louis, MO]), which was approved for clinical use by the Food and Drug Administration in June 1994, have been of considerable value in scintigraphically identifying various neuroendocrine tumors [11].
• OBJECTIVES: To estimate the diagnostic value of indium (111) -octreotide scintigraphy (Octreoscan in detecting metastases [12].
• A metastatic neuroendocrine anaplastic small cell tumor in a patient with multiple endocrine neoplasia type 1 syndrome. Assessment of disease status and response to doxorubicin, cyclophosphamide, etoposide chemotherapy through scintigraphic imaging with 111In-pentetreotide [13].

Biological context of DTPA-SMS

• Because we demonstrated that in 26 NB patients the density of sst2 is strongly related to survival (P < 0.0005) and apparently independent from N-myc oncogene amplification (P < 0.05), we propose that NB tumor imaging with 111In-pentetreotide may have not only a diagnostic but also a prognostic value [14].
• All patients with positive 111In-pentetreotide imaging results had elevated urinary catecholamine levels, and the two most 111In-pentetreotide-positive metastases were found in neuroblastomas from children with an aneuploid primary tumor [15].
• A marked improvement of sst2 affinity was found for Ga-DOTA-[Tyr3]-octreotide (IC50 2.5 nM) compared with the Y-labelled compound and Octreoscan [16].
• CONCLUSIONS: While Octreoscan 111 has been shown to localize the majority of amine precursor uptake and decarboxylation system (APUD) cell tumors as well as various other somatostatin-positive tumors, this technique may also be useful in a number of other circumstances [17].
• METHODS: Somatostatin receptor scintigraphy using 111In-pentetreotide (Octreoscan) was performed in all patients and the results correlated with histology, ultrasonography, computerized tomography, magnetic resonance imaging, plain radiography, bone scintigraphy and selective venous catheterization [18].

Anatomical context of DTPA-SMS

• Finally, no relationship was found between the levels of the above-mentioned parameters and clinical activity scores, octreoscan scores, and thyroid hormones [19].
• Lymphocyte infiltration of retrobulbar tissue in Graves' ophthalmopathy is the rationale of receptor imaging with radionuclide-coupled 111In-pentetreotide [20].
• The 111In-pentetreotide and MIBG results were only partly correlated with bone marrow status, as assessed by immunocytological and histological studies at the time of scanning [15].
• We investigated the distribution of 111In-pentetreotide (Octreoscan, Mallinckrodt) in nude mice xenografted with a human neuroblastoma cell line (SKLAN, derived from the LAN1 line) [21].
• In the patients with multifocal disease, increased 111In-pentetreotide uptake was found in disease-related areas such as the salivary glands, the skin, the soft tissues, and the bones [22].

Associations of DTPA-SMS with other chemical compounds

• Because sst2 binds with high-affinity octreotide and its scintigraphic derivative, 111In-pentetreotide, we tested the hypothesis of whether NB tumor imaging with 111In-pentetreotide gives similar information to ex vivo measurement of sst2 expression [14].
• Thallium-201 and 111In-pentetreotide brain SPECT were performed with a 3- to 4-day interval before surgery [9].
• METHODS: In 20 (16 hyperthyroid) Graves' patients with active eye disease, planar (thyroid) and SPECT (orbit) images were performed 4 and 24 hr after injection of 111In-pentetreotide (222 MBq) before and 3 mo after starting antithyroid and combined steroid and orbital radiotherapy [23].
• Indium- 111 labelled DTPA-D-Phe1-octreotide (DTPA-OC, OctreoScan) has been introduced into clinical routine for the detection of somatostatin receptor (SSTR)-positive tumours, which are predominantly of neuroendocrine origin [24].
• Indeed, successful immunosuppression with prednisone, orbital irradiation, or very recently with somatostatin analogues, has been demonstrated in patients with TAO and positive octreoscan [25].

Gene context of DTPA-SMS

• The most frequently used peptides in the clinic are analogs of somatostatin (SRIF), e.g. OctreoScan, which contain chelators for the radioisotopes 111In, 86Y, 90Y, 67Ga, 68Ga and 64Cu or for 99mTc and 188Re. and were labelled with the halogens 123I and 18F [26].
• Oncolytic vaccinia virus expressing the human somatostatin receptor SSTR2: molecular imaging after systemic delivery using 111In-pentetreotide [8].
• SSTR2-infected tumors were visible on imaging 6 days after VV injection and could be visualized for up to 3 weeks post-viral injection using repeat injections of 111In-pentetreotide [8].
• Nevertheless, DOTATOC was clearly superior to the other DOTA-somatostatin analogs tested, as well as OctreoScan, as indicated by the highest tumor-to-nontarget-tissue ratio, including the tumor-to-SSTR-positive-tissue ratios [27].
• In agreement with reports showing somatostatin receptors on the cell membrane of ectopically secreting ACTH tumours, scintigraphy was performed after intravenous injection of 111 MBq 111In-pentetreotide (OCT) [28].

Analytical, diagnostic and therapeutic context of DTPA-SMS

• Octreoscan scintigraphy was the only positive preoperative technique in 32% of the patients [2].
• Endoscopic ultrasonography detected all the tumors visualized by any other conventional technique and was considered falsely positive, as was Octreoscan scintigraphy, in 1 patient [2].
• We, therefore, studied simultaneously nine NB tumors with 111In-pentetreotide single photon emission computed tomography and competitive reverse transcription-PCR for sst2, along with other prognostic markers [14].
• The aim of this retrospective study was to evaluate which test, if any, among acute testing, short-term (1 month) administration, and 111In-pentetreotide (111In-DTPA-Phe-D-OCT) scintigraphy, is best in predicting response to long-term OCT treatment [29].
• METHODS: Seventy-one whole-body scintigrams in 24 patients with known breast cancer and 24 whole-body scintigrams in 8 controls were obtained at 0.5, 5 and 24 hr after intravenous injection of 110 MBq 111In-pentetreotide [30].

References