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C L Maini

Publications and source records attributed to C L Maini.

At least 37 records · Page 2Linked to original sources
PubMed1995

111In-octreotide scintigraphy in pituitary adenomas.

This study reports on 111In-octreotide scintigraphy in 20 patients affected with pituitary adenomas, including tracer uptake ratios and in vitro immunohistochemical characterization of the matostatin receptor state. 111In-octreotide uptake was already observed at 4 hours in 7/8 GH-secreting adenomas, in 5/7 non-secreting adenomas and in 1/5 prolactinomas. Concordance between the scan and the histochemical results was observed in all cases. The uptake ratios evaluated at 24 hours ranged from 2.3 to 4.2. The following conclusions were drawn: 1) 111In-octreotide is a suitable tracer to evaluate the somatostatin receptor state of pituitary adenomas; 2) Semi-quantitative measures of tracer uptake can be easily obtained with static planar scanning, but more refined techniques are needed for receptor kinetics evaluation; 3) This nuclear technique is a promising non-invasive tool to identify patients with somatostatin receptor positive pituitary adenomas who might potentially benefit from pre- and/or post-surgery cold octreotide medical treatment.

Adenoma↗
PubMed1995

Clinical relevance of 111In-octreotide scans in CNS tumors.

Sixty-six patients with a clinical and neuroradiological diagnosis of CNS tumors were evaluated by 111In-octreotide scintigraphy. Planar images were acquired at 2-4 and 24 hours after the injection of 111-185 MBq of 111In-octreotide (Octreoscan, Byk-Gulden). In the positive scans the tumor/non-tumor ratio was evaluated using a standard ROI method, and an uptake index (U.I.) of the lesion was determined. In vitro binding assays were performed on frozen sections from surgical specimens from 17 patients. All 32 meningiomas demonstrated a positive 111In-octreotide scan with a high U.I. Only 13 of 21 gliomas showed a positive scan, but the U.I. was significantly lower (p < 0.001 by "t"-test); one lymphoma showed a faint tracer uptake. All the other histotypes evaluated yielded negative scans. In all cases the receptorial pattern shown by the immunohistochemical staining technique was concordant with the scintigraphic results. 111In-octreotide scintigraphy allowed a differential diagnosis of meningioma versus other CNS tumors in 6 patients (4 neurinomas, 1 brain metastasis of melanoma, 1 lymphoma). In conclusion, 111In-octreotide scintigraphy is a promising tool to evaluate the SS receptorial pattern of CNS tumors and to increase the diagnostic specificity of conventional imaging providing useful information in selected cases for the therapeutic strategy.

Brain Neoplasms↗
PubMed1995

111In-octreotide scintigraphy in small cell lung cancer.

Somatostatin receptors have been identified on the cellular surface of a subset of patients with small cell lung cancer (SCLC) and may be associated with a less aggressive evolution of the tumor. Moreover, medical therapy with somatostatin analogues holds promise for neoplastic growth control. We performed planar imaging in 22 patients with histologically proven SCLC at 2-4 and 24 hours after the injection of 111-185 MBq of 111In-DTPA-octreotide (Octreoscan, Byk-Gulden). Tumor uptake was observed in 19 patients in both early and late scans, while 2 patients previously treated with chemotherapy showed negative early and late scans. One patient had a positive early scan and a negative late scan. All the scintigraphic studies showed more extensive disease than expected by CT. No significant modification in tumor uptake of radiooctreotide was observed in three patients studied before and after chemotherapy. In conclusion, 111In-octreotide is a suitable radiopharmaceutical for the in vivo evaluation of the somatostatin receptors of small lung cancer. The prognostic and therapeutical implications of this nuclear technique must be further investigated, however.

Aged↗
PubMed1994

Thallium-201 scintigraphy and chemotherapeutic response in rhabdomyosarcoma.

Thallium-201 scintigraphy was used to evaluate chemotherapeutic response in a case of rhabdomyosarcoma treated with epirubicin. A scintigraphic semiquantitative index of tumor viability was correlated with MRI and clinical assessment. Both imaging studies were performed before therapy and after treatment involving a cumulative dose of 640 mg/m2 of epirubicin. A very good inverse correlation was observed between Tl-201 uptake and tumor necrosis evaluated by MRI, leading to the conclusion that sequential Tl-201 scintigraphy may have a role not only in delineating the extent of the tumor, but in objectively assessing tumor response to therapeutic interventions. The proposed scintigraphic method is much simpler to perform and less expensive than MRI-derived semiquantitative measurement of tumor necrosis.

Adult↗
PubMed1994

TSH suppression by octreotide in differentiated thyroid carcinoma.

OBJECTIVE: This study evaluates the addition of octreotide and L-thyroxine to shorten the period of exposure to unduly elevated TSH levels in patients with differentiated thyroid carcinoma undergoing total body scan with 131I. DESIGN: Fourteen thyroidectomized patients were studied after total body scan and the restarting of different doses of thyroxine. After one year a second total body scan and a schedule of the same dose of thyroxine combined with octreotide were performed in each subject. PATIENTS: Patients were divided into four groups according to the treatment: seven patients received initially 100 micrograms of L-thyroxine (Group 1) and after 1 year 100 micrograms of L-thyroxine plus 300 micrograms of octreotide/day (Group 3); the other seven received initially 150 micrograms of L-thyroxine (Group 2) and then 150 micrograms of L-thyroxine plus 300 micrograms of octreotide/day (Group 4). MEASUREMENTS: Serum TSH, T3 and T4 were measured on the day of radioiodine administration (day 0) and after 14, 21, 30, 45, 60 and 90 days. RESULTS: Mean basal TSH levels were elevated in all four groups ranging from 104 to 91 mU/I without significant differences. The patterns of TSH inhibition were however different in the four groups studied. TSH remained very elevated for a long time in Group 1 patients: at day 90 the TSH value was still 2.1 +/- 1.2 mU/I (mean +/- SEM). Patients in Groups 2 and 3 showed a similar pattern: TSH was suppressed in 45 days. The most rapid TSH inhibition was observed in Group 4 patients with a mean decrease of 88% in 14 days and complete suppression in 30 days. CONCLUSIONS: TSH suppression by L-thyroxine is very slow and it can be significantly enhanced by combined octreotide administration. Combined therapy is safe and offers an alternative choice when high dosages of L-thyroxine are inappropriate or in conditions of advanced illness.

Adolescent↗
PubMed1994

[Quantitative scintigraphic detection of 111In sources].

This paper reports on a quantitative scintigraphic method for 111In sources using counts from isoboundary regions of interest of source images. Accordingly, total counts from regions of the image excluding the counts below a given percentage of the maximum are recorded and attenuation correction is implemented using the Depth Independent Buildup Factor method which corrects the effects of Compton scattering on the transmission function of the photon flux leaving the source. The transmission function of both the 172 and the 247 keV photons of 111In was determined for a set of circular flat sources of varying diameter (33 to 111 mm), using counts recorded in isoboundary regions of interest of images of the sources placed in air and at various depths in water. The images were acquired using a gamma camera equipped with a parallel hole medium energy collimator. The influence of the isoboundary value on the shape of the transmission function was investigated, and thus the chosen isoboundary value was set to no more than 20% of the maximum count on the image. Two parallel and dimetrically opposed views were acquired to determine the unknown activity of the sources placed in a water phantom. This counting geometry was chosen to operate in conditions of depth independent of the source in the phantom. Our results show a high degree of accuracy, the experimental estimate of the activity obtained by using the counts in the regions of interest with the lowest isoboundary value exhibiting 4% error rate. The error rate increases with the increase in the isoboundary values. The method proved to be simple, practical and accurate. Moreover, it overcomes the problem of accurate estimation of sources size, a variable usually not known with sufficient accuracy in clinical scintigraphic studies.

Indium Radioisotopes↗
PubMed1993

Somatostatin receptor imaging in small cell lung cancer using 111In-DTPA-octreotide: a preliminary study.

Small cell lung cancer is a common and aggressive disease. Combined multiagent chemotherapy and radiotherapy can improve short-term prognosis, but long-term prognosis remains dim. Somatostatin receptors have been identified on the cellular surface of subsets of this cancer and may be associated with less aggressive evolution. Moreover, medical therapy with somatostatin analogues holds promise for neoplastic growth control. Planar scintigraphy has been performed in 15 patients with histologically proven small cell lung cancer at 4 and 24 h after the intravenous (i.v.) injection of 185 MBq 111In-octreotide (Octreoscan, BYK-Gulden). No short-term adverse effects were recorded; tumour uptake of the radiopharmaceutical was observed in 13 patients at 4 h and in 12 patients at 24 h suggesting more extensive disease than apparent by computed tomography (CT). It is highly likely that the 24 h uptake reflects the presence of somatostatin receptors on the tumour. Previous chemotherapy does not seem to play a key role in tumour visualization. 111In-octreotide is a suitable radiopharmaceutical for in vivo evaluation of somatostatin receptor status of small cell lung cancer. Quantitative scintigraphic methods are needed to investigate nonspecific binding and receptor kinetics.

Aged↗
PubMed1993

Somatostatin receptors in meningiomas: a scintigraphic study using 111In-DTPA-D-Phe-1-octreotide.

111In-octreotide (Octreoscan) planar scintigraphy was performed in 12 patients with suspected meningioma. The scan was positive in 10 patients with meningioma and negative in two patients with acoustic neurinoma assisting in the differential diagnosis. Good quality images were obtained as early as 2 h after injection and there was no increase in diagnostic quality at 24 h. No adverse effects were observed to radiopharmaceutical administration. The following conclusions are drawn: 111In-octreotide is a safe and fast test which can increase the specificity of traditional neuroimaging procedures.

Adolescent↗
PubMed1992

Crossed cerebello-cerebral diaschisis: a SPECT study.

A scintigraphic single photon emission computed tomographic (SPECT) evaluation of frontal perfusion alteration was performed in five patients with known cerebellar lesions but with normal supratentorial computed tomographic (CT) or magnetic resonance (MR) scans. A clearly evident asymmetry was found in prefrontal areas in the four subjects with acquired cerebellar damage. The fifth subject, who had congenital left cerebellar hypoplasia, did not show any frontal flow asymmetry. The data support the growing clinical evidence that the cerebellum contributes to the cognitive processes of the frontal lobes and suggest a possible role for SPECT examination in the assessment of functional cognitive impairment in patients with acquired cerebellar lesions.

Adolescent↗
PubMed1991

Cerebral blood flow in AIDS-related neurotoxoplasmosis: a preliminary 99mTc-HMPAO SPECT study.

Cerebral blood flow (CBF) was evaluated by gamma camera 99mTc-HMPAO SPECT in 11 patients with AIDS-related neurotoxoplasmosis and correlated with neurological findings and the results of CT and MRI. Evident CBF abnormalities were observed in all patients with involvement of at least two cerebral lobes. In 10 patients the abnormalities were bilateral and in 8 patients basal ganglia were involved; no specific hypoperfusion pattern was however evident. Focal lesions were found in 7 patients by CT (sensitivity: 63.6%) and in 10 patients by MRI (sensitivity: 90.9%). It may be concluded that neurotoxoplasmosis in AIDS patients is associated with a high prevalence of focal cortical and subcortical hypoperfusion but that the scintigraphic findings are not specific; that HMPAO SPECT may show focal hypoperfusion in patients with normal CT studies and/or non-focal MRI abnormalities; that the hypoperfusion may be more extensive than the corresponding MRI lesion(s) and that it may be present even in areas with normal MRI signals; and that more experience and longitudinal studies are needed to assess the possible impact of HMPAO SPECT on follow-up and therapy monitoring.

Acquired Immunodeficiency Syndrome↗
PubMed1990

Cortical cerebral blood flow in HIV-1-related dementia complex.

Dementia complex is a syndrome that affects a high percentage of AIDS patients. Neuroradiological findings may be non-specific and the diagnosis can be difficult in its earlier stages. Preliminary radionuclide studies have recently reported derangements of regional cerebral blood flow (CBF) which may be present before overt anatomical injury. This study reports on cortical and cerebellar CBF changes in 26 patients studied with 99Tcm-HM-PAO and single photon emission computed tomography (SPECT). Extensive cortical CBF derangements were observed in all patients and an evident cerebellar hypoperfusion was also present in three. The prevalence of hypoperfusion was highest in the frontal and parietal lobes. The extension of the hypoperfusion showed a highly significant correlation with the severity of the dementia complex (P less than 0.01 by chi 2 test). The SPECT also showed hypoperfused areas in three patients with normal CT scans and in two patients with normal MRI scans. These results confirm previous preliminary reports on the high prevalence of cortical hypoperfusion in dementia complex and suggest the use of this radionuclide technique to assist in the early diagnosis and follow-up of AIDS patients, especially when CT and MRI are still normal.

AIDS Dementia Complex↗
PubMed1990

Cerebral blood flow and volume in symptom-free migraineurs: a SPECT study.

Both CBF and CBV were evaluated by gamma-camera SPECT in 14 patients with classic migraine, all studied while symptom-free. Nuclear data were correlated with CT and MRI. A decreased regional CBF was observed in 13 of the 14 patients. The decreased perfusion was localized in the frontal lobe in 6 patients, the temporal lobe in one, the parietal lobe in 11 and the occipital lobe in 5 patients. The parieto-occipital cortex was involved more often than the frontal cortex; the association of hypoperfusion with parieto-occipital cortex was quite high. The right parieto-occipital regions were affected more often than the left ones. Regional CBV was increased in 8 patients. There was good topographical concordance between decreased CBF and increased CBV, but the increase of CBV was in general more evident at the periphery of the hypoperfusion. It is of interest that the only patient with a normal CBF study had a pathological CBV study. Apparently, CBF derangements are very common in symptom-free patients with classic migraine, a CBF decrease being often accompanied by a CBV increase. In these patients both CT and MRI have a lower diagnostic yield than SPECT.

Adolescent↗
PubMed1989

Dynamic renal scanning using 99mTc-MAG-3 in man.

99mTc-labelled mercapto-acetyltriglycine (MAG-3) has recently been proposed as an ortho-iodohippurate (OIH) substitute for dynamic renal imaging. Experience with MAG-3 is, however, still limited and its biokinetics are not completely known. Moreover, most of the published studies have used HPLC purified MAG-3 which is inpractical for routine clinical work. In this study a commercially available kit of MAG-3 which does not require high performance liquid chromatography (HPLC) is used in 10 normal subjects and 15 patients with renal disease. The results obtained lead to the following conclusions: a. MAG-3 provided in kit form is suitable for renal imaging and semiquantitative analysis in routine clinical settings. b. There are significant differences between renal handling of MAG-3 and OIH, but the dynamic studies obtained with MAG-3 can be interpreted with the same criteria used for OIH studies. c. More information on MAG-3 kinetics is needed before this new radiopharmaceutical can be considered as an OIH substitute for truly quantitative studies such as effective renal plasma flow determinations.

Adult↗
PubMed1989

Effects of aging on mucociliary clearance.

Preliminary results from the relationship between aging and mucociliary clearance of inhaled 99-Tc human albumin particles (0.92-2.5 microns) are reported from two groups of healthy non-smokers: 1) 20-61-year-old (mean 42 years) and 2) 71-90-year-old (mean 79.5 years). The analytical procedure is presented, and on the basis of the analysis it is concluded that there is evidence for an age-related decline of the mucociliary clearance by a bi-phasic curve, similar to those reported in the literature for other physiological functions.

Adult↗
PubMed1988

The influence of age on the pulmonary clearance of 99Tcm-DTPA radioaerosol.

Age-dependent changes of 99Tcm-DTPA radioaerosol transpulmonary clearance have been investigated in 49 healthy volunteers with an age range of 21-63 years. The clearance was uniformly increased in all smokers irrespective of age, but it showed a highly significant (p less than 0.001) decrease in non-smoking patients over 50 years. Several age-related changes in the ageing lung can contribute to this decreased clearance, but the reduced alveolar-capillary surface area available for the transport is probably the key factor. The practical implication of the results is the need to use age-related normal ranges when interpreting 99Tcm-DTPA radioaerosol clearance studies.

Adult↗
PubMed1988

[Quantitative study of mucociliary clearance using static scintigraphy].

Mucociliary clearance can be evaluated by radionuclide techniques, but such approaches have been usually implemented only in research-oriented laboratories because of technical difficulties. A very practical radionuclide method is here presented which requires only three static acquisitions after the inhalation of a polydisperse radioaerosol produced by a commercial generator. Data processing is also very simple. The diagnostic performance of the method was tested on a study population of 10 healthy subjects and 10 patients with atrophic bronchitis; a highly significant difference between normal and pathological patients was found. Its simple implementation and diagnostic yield recommend this radionuclide method for the routine assessment of mucociliary clearance also in busy clinical-oriented laboratories.

Adult↗