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

Radioiodine scintigraphy is the gold standard exploration for imaging metastases of differentiated thyroid cancer and enables the decision of therapy with 131 radioactive iodine to be made. However, other approaches may be of use for diagnosis when there is no visible uptake after the administration of 131I, while elevated thyroblobulin levels suggest the presence of metastatic tissue in one third of metastatic patients. In order to detect recurrences or metastases, in conjunction with conventional imaging techniques (cervical and hepatic ultrasonography, lung CT scan..), other scintigraphic explorations with various radiopharmaceutics may be used, although none of them has any specificity towards thyroid cancer. Tl201 and MIBI which are used as perfusion tracers for myocardial explorations, are also used for detection of various tumors and for metastatic thyroid cancer. The performances of both radiopharmaceutics in imaging metastases are differently evaluated between investigators with a sensitivity ranging from 45 to 94% while the specificity varies less (82-97%). 18-Fluoro-deoxyglucose is retained in malignant tissue depending on the grade of malignancy. It has been shown to accumulate in thyroid cancer and metastases. Its detection by whole body PETscan represents a limitation for use which will be modified by new techniques. 111In-octreotide which binds to somatostatin receptors located on tumor cell membranes is able to show thyroid cancer metastases in some instances. We report on the very preliminary results of these combined scintigraphic approaches, performed in a limited number of patients who had no radioiodine uptake and elevated Tg levels, in order to determine the most appropriate exploration in terms of performance and cost.

Topics: Adenocarcinoma; Carcinoma, Papillary; Deoxyglucose; Fluorodeoxyglucose F18; Humans; Iodine Radioisotopes; Neoplasm Metastasis; Octreotide; Pentetic Acid; Radionuclide Imaging; Radiopharmaceuticals; Technetium Tc 99m Sestamibi; Thallium; Thyroid Neoplasms

The authors report their preliminary experience and results of the use of 111In-DTPA-octreotide scintigraphy (octreoscan) in the staging of neuroendocrine and non-neuroendocrine tumors of the lung.. From July 1995 to May 1996 twenty-six scintigraphic studies were performed in patients affected by lung cancer at the Department of Thoracic Surgery and at the Service of Nuclear Medicine of the University of Turin.. Scintigraphy made it possible to detect the lesion in all the patients affected by neuroendocrine tumors and in 63.2% of the patients affected by non-neuroendocrine neoplasm of the lung. Scintigraphy also revealed mediastinal lymphnodal metastases in patients in which thoracic CT scan was negative: this result was confirmed by postoperative TNM.. The authors stress the importance of 111In-DTPA-octreotide scintigraphy in a correct procedure of staging of neuroendocrine and non-neuroendocrine tumors of the lung and in the follow-up of neoplastic patients.

Topics: Adenocarcinoma; Carcinoma, Large Cell; Carcinoma, Squamous Cell; Humans; Lung Neoplasms; Neoplasm Staging; Neuroendocrine Tumors; Octreotide; Pentetic Acid; Preoperative Care; Radionuclide Imaging; Radiopharmaceuticals; Reproducibility of Results; Sensitivity and Specificity

The somatostatin analogue octreotide is effective in the treatment of neuroendocrine and other tumours. 111-In-labelled DTPA-octreotide scintigraphy is successful in localizing primary neuroendocrine tumours and metastases and other tumours containing somatostatin receptors. An antiproliferative effect of octreotide was also demonstrated for colorectal carcinoma. Since only about 40% of colorectal carcinomas express somatostatin receptors, we tried to establish whether 111-In-labelled DTPA-octreotide scintigraphy is able to reveal the receptor status of liver metastases in patients with colorectal liver metastases. This would be useful in selecting patients for adjuvant therapy studies with octreotide. We performed 111-In-labelled DTPA-octreotide scintigraphy in ten patients with nonresectable liver metasoffes of colorectal origin and curatively resected primary. In nine of ten patients the liver metastases were somatostatin receptor negative, in one patient somatostatin receptor positive. In the patient with somatostatin receptor-positive liver metastases after resection of a rectal carcinoma, the histological examination of the biopsies from the liver metastases showed a solid tumour of neuroendocrinal differentiation. In the repeated histological examination of the specimen of the rectal primary, a small solid tumour with neuroendocrinal differentiation was found between formations of adenocarcinoma (adenoendocrine carcinoma). In our study 111-In-labelled DTPA-octreotide scintigraphy did not indicate the receptor status of liver metastases from colorectal carcinoma and was not useful in the planning of therapeutic regimens. For the diagnosis of the receptor status of colorectal liver metastases autoradiographic investigation on tissue biopsies are still necessary. In patients with adenoendocrine carcinomas 111-In-labelled DTPA-octreotide scintigraphy may help to histologically differentiate the metastases.

Topics: Adenocarcinoma; Adult; Aged; Antineoplastic Agents, Hormonal; Chemotherapy, Adjuvant; Colorectal Neoplasms; Female; Humans; Indium Radioisotopes; Liver Neoplasms; Male; Middle Aged; Octreotide; Pentetic Acid; Prognosis; Radionuclide Imaging; Receptors, Somatostatin

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. In vitro somatostatin receptor autoradiography was performed on biopsies obtained from eight patients with hormone-refractory prostatic adenocarcinoma. In 30 of 31 patients (94%), at least one metastasis was positive at OctreoScan scintigraphy. Of the 346 lesions detected with 99mTc-labeled HDP bone scintigraphy, 128 were visualized with the OctreoScan technique, thus accounting for a 37% detection rate. Two uptakes on OctreoScan could not be identified on bone scintigraphy and were, thus, assessed as false positive. The biopsies of the eight patients disclosed a low density of receptors, localized on the tumor cells, as demonstrated with receptor autoradiography. Two patients with untreated metastatic prostatic adenocarcinoma were investigated in vivo before the start of endocrine therapy. However, none of the lesions detected by bone scintigraphy in these patients could be visualized with the OctreoScan technique. Positron emission tomography using [11C] methionine showed a decreased uptake in a metastatic index lesion in a patient treated with octreotide. It is concluded that hormone-refractory prostatic adenocarcinoma expresses somatostain receptors both in vitro and in vivo. The results obtained form the basis for the development of a new tool for in vivo characterization and of a new treatment strategy in patients with hormone-refractory prostatic adenocarcinoma.

Topics: Adenocarcinoma; Aged; Aged, 80 and over; Animals; Bone Neoplasms; Humans; Indium Radioisotopes; Male; Middle Aged; Octreotide; Pentetic Acid; Prostatic Neoplasms; Receptors, Somatostatin; Tomography, Emission-Computed; Tomography, Emission-Computed, Single-Photon

The aim of this study was to use compartmental analysis as a theoretical tool to provide quantitative and unitary data for a more precise determination of 111In-OCT concentrations in a tumour site and various body organs. Five subjects (3 male and 2 female) with neoplasias were studied. Structural and parametric identification of the model was based on the plasma, urine, total body and ROI (soft tissue, spleen, kidney and tumour) activity values. The model was of the mammillary type with 5 compartments (blood, soft tissue, spleen, kidneys and urine) for the 4 patients with a negative scintiscan and 6 (blood, soft tissue, spleen, kidneys, urine and tumour) for the adenocarcinoma patient. Numerical constants were determined by running a best-fit procedure with the MINUIT minimisation program (CERN library) using a microVAX 3800 computer. The reliability of the models was also tested. 111In-OCT accumulates in the kidneys and spleen, from which it is slowly released into the blood. Elimination is via the urine at first rapidly, then more slowly. The maximum concentration in the tumour compartment is reached at 12-14 hours and remains almost constant.

Topics: Adenocarcinoma; Carcinoma, Small Cell; Computer Simulation; Female; Humans; Indium Radioisotopes; Kidney; Lung Neoplasms; Male; Metabolic Clearance Rate; Models, Biological; Models, Chemical; Neuroblastoma; Neuroectodermal Tumors; Octreotide; Pentetic Acid; Radiopharmaceuticals; Reproducibility of Results; Spleen; Tissue Distribution

Twenty-one patients with small cell lung cancer (SCLC) were investigated with 111in-octreotide (111-In-OCT) scintigraphs, 5 hours after the i.v. injection of 111 MBq of the radiotracer. Whole-body and planar scintigraphy as well as SPECT of the thorax were required. The scintigraphic results were compared to those of other conventional diagnostic procedures used for the staging and follow-up of SCLC patients. 111In-OCT detected 86% (48/56) of the lesions already known at the time of scintigraphy, being positive for all 20 SCLC lesions and negative for one lung adenocarcinoma. 111In-OCT showed a high sensitivity for mediastinal metastases (94%) and good sensitivity for bone (75%) and abdominal lymph node metastases (71%). It did not detect 2 liver metastases but revealed 5 unknown lesions which were then confirmed by other diagnostic examinations. 111In-OCT was also effective in patients with low levels of NSE. Three patients received cold octreotide for seven days to investigate whether this treatment might affect SCLC imaging. Scans were performed before and after treatment. The 111In-OCT uptake increased in the cancer lesions while the fixation in normal tissues decreased, demonstrating enhancement of SCLC imaging following cold octreotide administration.

Topics: Adenocarcinoma; Aged; Antineoplastic Agents, Hormonal; Bone Neoplasms; Carcinoma, Small Cell; Diagnostic Imaging; Female; Follow-Up Studies; Humans; Indium Radioisotopes; Injections, Intravenous; Liver Neoplasms; Lung Neoplasms; Lymphatic Metastasis; Male; Mediastinal Neoplasms; Middle Aged; Neoplasm Staging; Octreotide; Pentetic Acid; Phosphopyruvate Hydratase; Radiopharmaceuticals; Sensitivity and Specificity; Tomography, Emission-Computed, Single-Photon