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Query: UMLS:C0027651 (tumor)
 685,946 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Various tumors of neuroendocrine origin that have amine precursor uptake and decarboxylation (APUD) characteristics can be visualized in vivo after intravenous (IV) injection of the somatostatin analogue, [123I-Tyr3]-octreotide. However, the relatively short effective half-life of this compound and the high background of radioactivity in the abdomen are drawbacks to its application. Therefore, an 111In-coupled somatostatin analogue ([111In-DTPA-D-Phe1]- octreotide) was developed. This analogue is excreted mainly via the kidneys, with 90% of the dose being present in the urine 24 hours after injection. Using 111In-octreotide scintigraphy, seven of seven gastrinomas, four of seven insulinomas, one of one glucagonomas, three of three unclassified APUDomas, and none of 18 exocrine pancreatic carcinomas were visualized. Also, 19 of 19 carcinoids, 15 of 15 glomus tumors, eight of 12 medullary thyroid carcinomas, six of six small-cell lung carcinomas, four of four growth hormone-producing and six of nine clinically nonfunctioning pituitary adenomas were visualized. Apart from APUD cell-derived tumors, 111In-octreotide scintigraphy was also successfully applied in visualizing breast cancer, lymphomas, and granulomas. In 39 of 50 patients with breast carcinoma, 10 of 11 patients with non-Hodgkin's lymphomas, three of three patients with Hodgkin's disease, and eight of eight patients with sarcoidosis, tumor sites accumulated radioactivity during octreotide scintigraphy. In a considerable number of patients with carcinoids and glomus tumors, and also in patients with granulomas and lymphomas, 111In-octreotide scintigraphy showed more tumor sites than did conventional imaging techniques. The results of imaging in vivo correlated with the somatostatin-receptor status on the tumors in vitro.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:111In-octreotide scintigraphy in oncology. 135 91

Extracerebral cavernous hemangioma is a rare entity, only 51 cases have been reported up to 1991. Most of the extracerebral cavernous angiomas occur in the parasellar region and easily extend to the sella; with CT and MRI views entirely different from those of intracerebral cavernous hemangiomas. The CT scan shows a good, homogeneous enhanced tumor, similar to a meningioma, yet lacking calcification or bony hyperostosis. In MRI, the characteristic findings of extracerebral cavernous hemangioma are the very high signal intensity in the T2 weighted image, and strong homogeneous enhancement by Gadolinium-DTPA. Here we report two cases of parasellar cavernous hemangioma. A 68-year-old male patient shown to have a dumbbell tumor in the parasellar and sellar regions by CT scan, showed a high density before contrast, and good enhancement by an iodine contained contrast medium. The tumor had a very high signal intensity in the T2 weighted image of MRI and a good, homogeneous enhancement by Gadolinium-DTPA, yet a carotid angiogram showed it was avascular. Surgical removal was abandoned in view of the probability of massive bleeding. The second case was a 34-year-old man, who had had a skin hemangioma on the right side of the face since his childhood. For the past 3 months, he had suffered from ptosis, and limitation of eye movement which was found to be due to 3rd and 4th cranial nerve palsy. CT showed a good enhanced tumor mass in the left side of the parasellar region with sellar extension. MRI also showed a high intensity in T2WI and good, homogeneous enhancement by Gadolinium-DTPA. A carotid angiogram revealed some tumor stain. Surgical removal. in this case, was also impossible due to its intracavernous sinus location and the probability of massive bleeding.
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PMID:[CT and MRI of parasellar cavernous hemangioma in two cases]. 135 66

The immune response of 56 colorectal cancer patients to a single infusion of 1 mg of radiolabeled (111In) mouse B72.3-GYK-DTPA immunoconjugate was examined using a double-antigen radiometric assay system. The incidence of antibody response was 48% to polyclonal mouse IgG, 71% to mouse B72.3, and 62% to chimeric B72.3. Twelve patients (23%) had an antibody response to B72.3 V region in the absence of binding to polyclonal mouse IgG. An antiidiotype response was demonstrated in sera from 36% of 25 patients examined and correlated well with chimeric B72.3-GYK-DTPA immunoconjugate binding (r = 0.72, moderately well with mouse B72.3 binding (r = 0.56), and not at all with polyclonal mouse IgG binding (r = 0.28). The peak antibody response occurred most frequently 2 weeks postinfusion, although a "delayed" peak response to chimeric B72.2 occurred in 29% of patients. This study suggests that mouse B72.3 causes an immune response in the majority of patients and that antibody response to the V region is common. Understanding the physiological significance of these antibody responses will require correlation with the kinetics and tumor localization of repeat infusions of such immunoconjugates.
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PMID:Frequent anti-V-region immune response to mouse B72.3 monoclonal antibody. 137 50

Pleomorphic xanthoastrocytomas (PXA) are classically supratentorial, peripherally located, well-circumscribed, partially cystic neoplasms, which can enhance on CT following the administration of intravenous contrast agents. Focal calcification may also be seen. Although the CT appearance has been described, we report the MR findings in two cases of histologically documented temporal lobe PXA. The two well-circumscribed lesions were predominantly cystic and both contained a Gd-DTPA enhancing mural nodule. The latter was isointense with gray matter on T1-weighted images and hyperintense on T2-weighted scans. Minimal surrounding edema was present. Histologically, PXA may be confused with glioblastoma multiforme (GBM) due to the pronounced cellular pleomorphism. Because of their potentially more indolent behavior compared with GBM, it is important to recognize the gross morphologic characteristics of this rare tumor on MR. The MR pattern of a cystic lesion with enhancing mural nodule is characteristic of PXA, but not diagnostic, and other lower grade gliomas such as ganglioglioma and pilocytic astrocytoma need to be considered. The MR and CT appearance of PXA can provide critical information for the pathologist, especially when only a small amount of tissue is obtained for histologic evaluation.
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PMID:MRI of temporal lobe pleomorphic xanthoastrocytoma. 138 98

1493 patients with various lesions in the head and neck region were prospectively evaluated with MR imaging (MRI) and other imaging modalities. The findings of MRI and conventional imaging techniques were correlated with histological findings. All MRI examinations were carried out on a 1.0 and 1.5 Tesla superconducting MR unit employing combined T1 and T2 weighed spin-echo sequences. Dynamic MRI with fast gradient-echo sequences and application of a paramagnetic contrast agent (Gd-DTPA) was additionally performed in 120 patients. 250 patients were examined with non-invasive MR angiography. Appropriate saturation enabled the visualization of either arterial or venous vascular structures. Analysis of metabolic parameters and tumor proliferation was possible through in-vivo spectroscopy in 60 patients. Highest values for specificity and sensitivity of MRI were achieved in the area of the skull base and petrous bone. In comparison to other imaging modalities, the exact differentiation of pathological alterations such as neurinoma, meningioma and glomus tumors succeeded with high accuracy. In the region of the naso- and oropharynx, plain MRI revealed in 77% of the cases adequate diagnostic information, which could be significantly increased with application of the paramagnetic contrast agent Gd-DTPA. Due to multiplanar slice orientation and improved soft tissue differentiation MRI proved to be superior to other imaging techniques in salivary glands and in the region of the neck. As a conclusion, the advantages of MRI are the depiction and visualization of small infiltrations as well as the high sensitivity and specificity of this imaging modality.
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PMID:[Magnetic resonance tomography in questionable lesions of the ENT area. Examination technique and results of a prospective study of 1,493 patients]. 138 73

Tissue diagnosis is necessary for optimal treatment of pineal region tumors in children. Preoperative staging should include craniospinal MR imaging with and without gadolinium DTPA enhancement, CSF sampling for cytology, and measurement of biologic tumor markers in serum and CSF. Surgical approach is determined by results of preoperative MR imaging and the extent of resection by the results of staging and intraoperative frozen-section histopathologic evaluation. There is no longer a role for the radiation test dose (2000 cGy) in the management of these tumors. Postoperative treatment is based on histopathology and extent of disease. Benign tumors are treated with surgery only, and nondisseminating focal tumors with surgery and focal radiation therapy. Non-germinoma malignant germ cell tumors are best treated with neoadjuvant chemotherapy followed by radiation therapy given focally for focal disease; craniospinal radiation therapy is reserved for patients with evidence of disseminated disease at the completion of induction chemotherapy.
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PMID:Pineal tumors. 139 80

The dura mater adjacent to the attachment of meningiomas was enhanced on MR imaging with intravenous Gd-DTPA infusion. It was examined histologically in four patients with intracranial globoid meningiomas. Histological examination revealed that there was no tumor cell invasion within the dura mater enhanced on MR imaging, except at the point of their attachment. A layer of tumor cells was occasionally observed on the surface of the dura mater, but this was limited to within 5 mm of the tumor margin. Our electronmicroscopic observation indicated that enhancement of the dura mater adjacent to the attachment of meningiomas was caused by increased vascular permeability of the dural vessels and extended extravascular space.
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PMID:[The dura mater adjacent to the attachment of meningiomas: its enhanced MR imaging and histological findings]. 140 40

When radiation therapy is performed on a patient with malignant tumor, vertebral spines are sometimes included in the irradiation field. In the present study, 99mTc-HMDP uptake was examined in 102 cases of malignant tumors treated with radiation therapy (irradiated total doses from 10 to 70 Gy) in order to clarify the time course of accumulation. The scintigram on the film was transformed with a film digitizer into objective data, and the Accumulation Decreasing Index (ADI) was calculated each month after irradiation. In the group receiving less than 30 Gy, recovery of 99mTc-HMDP accumulation was seen after a mild decrease in the ADI. However, in the group that received more than 40 Gy, no recovery of accumulation was seen, and a large decrease in the ADI followed. Vertebral MRI was performed with and without Gd-DTPA enhancement to calculate the vertebral Signal Intensity Ratio (SIR), and decreased blood flow in the irradiated bone marrow was estimated from the changes in SIR values. In the irradiated area, no definite abnormal accumulation of 99mTc-HMDP was observed against the new metastatic bone tumor. In such cases, MRI should be performed soon after bone scintigraphy in order to detect the tumor.
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PMID:[A study of irradiated spines in radiotherapy--using 99mTc-HMDP bone scintigraphy & MR imaging]. 140 80

A localization technique, based on three-dimensional CT and MR imaging data for precision radiotherapy of basal meningiomas, is presented. Indications for radiotherapy included unresected tumors, gross disease remaining despite surgery, and recurrences. The patient's head was fixed in a stereotactic localization system which is usable at the CT, MR and the linear accelerator installations. The geometrical distortion of MR imaging data was evaluated in three dimensions by phantom measurements. The geometrical distortion was "corrected" (reducing displacements to the size of a pixel) by calculations based on modelling the distortion as a fourth order two-dimensional polynomial. The target volume was defined in three-dimensional MR imaging data after application of 0.1 mmol/kg b.w. Gd-DTPA solution and transferred precisely from MR onto CT data to provide a map of the radiation attenuation coefficient for dose calculation. The superior soft tissue contrast of MR showed an excellent tumor delineation especially when the bony base of the skull obscured the target in CT images. Target volume, calculated dose distribution, and critical structures could be transferred between CT and MR imaging data and displayed as three-dimensional shaded structures for better assessment for matching of target volume and dose distribution. With the described planning system a more precise target definition of basal meningiomas was possible by integration of the superior tumor delineation in MR compared with CT.
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PMID:Radiotherapy treatment planning of basal meningiomas: improved tumor localization by correlation of CT and MR imaging data. 141 May 91

The feasibility of diagnosing the malignancy and viability of intraparenchymal brain tumours using Gd-DTPA, enhanced and unenhanced T1-weighted MRIs was investigated. The relationship between the Gd-DTPA enhancement pattern, the growth fraction (GF) determined by using the anti-bromide-oxyuridine (BrdU) monoclonal antibody, the clinical condition, the proliferative potential and the change of Gd-DTPA enhancement over time was studied. Forty-five patients with intracranial tumours were studied with the static method of Gd-DTPA MRI. The enhanced effect in Gd-DTPA MRIs was dependent on tumour-cell density, vascularization, necrosis, and dilatation of vascular lumen. Tumour-cells were observed in eighty-seven of eighty-nine specimens taken from areas with Gd-DTPA enhanced MRIs. Seventy-four percent of these specimens (64 of 87) showed a malignancy of more than 5% growth fraction. On the other hand, tumour cells were observed in twenty-seven of fifty-six specimens taken from areas with Gd-DTPA unenhanced MRIs. Eighty-five percent of these specimens (23 of 27) showed a malignancy value of less than 5% GF. However, fifteen percent of these specimen showed values between 5 and 15% GF. In the kinetic study of Gd-MRIs five patients who were in a clinically stable condition and one patient who had radionecrosis showed a constant pattern of enhancement or slightly increased enhancement 30 min after injection compared to 4 min after injection. Therefore, GD-DTPA MRI can be used effectively in the diagnosis of tumour viability and malignancy after treatment.
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PMID:Malignancy and viability of intraparenchymal brain tumours: correlation between Gd-DTPA contrast MR images and proliferative potentials. 141 20


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