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Biomedical subjects

P Peltier

Publications and source records attributed to P Peltier.

At least 37 records · Page 2Linked to original sources
PubMed1992

Comparison of technetium-99mC and phytate aerosol in ventilation studies.

The image quality obtained with technetium-99mC aerosol (Technegas) was evaluated and compared with that obtained with 99mTc-phytate aerosol generated by a jet nebulizer. Fifty patients underwent ventilation scanning after inhalation of each aerosol (mean interval of 3 days). Four views (anterior, posterior, left and right posterior oblique) were recorded with 200 k precounts. Both sets of images were blindly compared for (i) qualitative evaluation of images, (ii) quantitation of penetration (PI) and heterogeneity (HI) indices and (iii) assessment of ventilation state. Peripheral penetration was the same in 64% of cases, greater with 99mTc-C in 27% and greater with 99mTc-phytate in 9%. The use of 99mTc-C led to fewer and less intense foci of bronchial or gastric activity. The differences for 99mTc-C and 99mTc-phytate, respectively, between mean PI (0.78 vs. 0.70) and HI (15 vs. 18) were not significant. Consideration of all the parameters indicates the overall superiority of 99mTc-C. The final interpretation of the lung ventilation scans was, however, similar with both tracers.

Administration, Inhalation↗
PubMed1992

Correlative imaging study in the diagnosis of ovarian cancer recurrences. The INSERM Research Network (Nantes, Rennes, Reims, Villejuif, Saclay), France.

A correlative imaging study was carried out in 61 female patients previously treated for ovarian carcinoma. Upon suspicion of recurrence, abdominopelvic immunoscintigraphy (IS) using F(ab')2 fragments of indium-111-labelled OC 125 monoclonal antibody was performed in all patients, Ultrasonography (US) and computed tomography (CT) were performed 53 and 37 times, respectively. The diagnostic accuracy of the different imaging techniques was studied per site (abdomen and pelvis) and per patient. The diagnostic accuracy of planar scintigraphy (PS) was slightly lower than that of emission computed tomography (ECT): 66% vs 73% for abdomen, 65% vs 72% for pelvis, and 78% vs 84% in analysis per patient. The accuracy of IS (PS and ECT combined) was markedly better than that of US and CT for abdomen (IS = 73%; US = 30%; CT = 47%), pelvis (IS = 73%; US = 37%; CT = 52%) and analysis per patient (IS = 85%; US = 43%; CT = 59%). The results of IS and morphological imaging techniques (MIT: US and/or CT) were correlatively analysed with the frequency of recurrence. When IS and MIT were both negative, the frequency of non-recurrence was 14/23 for abdomen, 7/12 for pelvis and 8/13 in analysis per patient. On the other hand, when both IS and MIT were positive, the frequency of recurrence was high (9/9 for abdomen, 17/21 for pelvis and 24/26 for analysis per patient). It was also found that a positive IS associated with a negative MIT was still highly suggestive of recurrence (17/21 for abdomen, 16/22 for pelvis and 17/19 for analysis per patient).(ABSTRACT TRUNCATED AT 250 WORDS)

Antigens, Tumor-Associated, Carbohydrate↗
PubMed1992

MIBG scintigraphy of a patient with pheochromocytoma on labetalol therapy.

A patient with pheochromocytoma was studied by MIBG scintigraphy while on labetalol therapy, which has been reported to interfere with imaging. Serial imaging was performed at 2, 18, 25, and 90 hours to obtain time/activity curves. Blood samples were taken at each imaging study to determine activity counts. Tumor activity per gram of tissue (surgery 116 hours after injection) was compared with blood activity. Tumor and blood activity decreased concurrently, whereas the decrease in peritumoral activity was faster, thus providing transiently improved contrast on 18- and 25-hour images. The diagnostic implications of these results are discussed.

3-Iodobenzylguanidine↗
PubMed1992

Anti-beta HCG abdominopelvic immunoscintigraphy in patients with resistant gestational trophoblastic disease.

The clinical utility of abdominopelvic immunoscintigraphy (IS) using anti-beta HCG-labelled monoclonal antibodies was evaluated in six patients with resistant gestational trophoblastic disease and no common pathological site. Five patients with abnormal retrovesical uptake had persistence of uterine trophoblastic disease confirmed on hysterectomy. Four of these patients are now in remission. It is concluded that IS provides a useful indication for surgery when a single abnormal uptake site is found.

Abdomen↗
PubMed1992

Immunoscintigraphy using 111In-labeled F(ab')2 fragments of anticarcinoembryonic antigen monoclonal antibody for detecting recurrences of medullary thyroid carcinoma.

The only current possibility for curing medullary thyroid carcinoma (MTC), especially recurrences, is total surgical removal. Early positive diagnosis of recurrences is now possible by monitoring tumor markers such as thyrocalcitonin and carcinoembryonic antigen (CEA). However, preoperative topographic diagnosis of such recurrences remains an unresolved problem. Immunoscintigraphy (IS) using an anti-CEA monoclonal antibody is a new approach that complements morphological imaging, i.e. ultrasonography, computerized tomography, and magnetic resonance imaging. In this study, IS by means of an 111In-labeled anti-CEA monoclonal antibody F(ab')2 was performed nine times in eight patients. True positives were obtained five times (one case of cervical involvement confirmed by surgery, three cases of mediastinal involvement confirmed by computerized tomography, magnetic resonance imaging, and surgery, and one case of bone metastasis, one of them was revealed neither by x-ray nor by conventional bone scan). The remaining four tests gave a false positive, a true negative, a probably false negative, and one unconclusive result. We conclude that IS is helpful in diagnosing sites of MTC recurrence and should accompany other examinations in the evaluation of lesions.

Adult↗
PubMed1991

[Fixation of Indium111-labeled antifibrin monoclonal antibody on the vegetation in endocarditis: evaluation in a rabbit model].

The uptake of a 111In labelled antifibrin antibody was studied in left ventricle endocarditis on a rabbit model. The immunospecificity of the antibody for the cardiac vegetations is favorable, exhibiting an uptake at least 4 times that of blood, or myocardium. A planar scintigraphy of the opened left ventricle showed a radionuclide imaging of vegetations, according to anatomical lesions. The use of antifibrin monoclonal antibodies could prove helpful to improve the specificity of valvular lesions visualized by echocardiography, or to detect the small vegetations at the early stage of acute endocarditis.

Animals↗
PubMed1991

Reproducibility of image interpretation in immunoscintigraphy performed with indium-111- and iodine-131-labeled OC125 F(ab')2 antibody injected into the same patients.

An important criterion for the clinical use of a new imaging technique is the correct reproducibility of interpretation. Forty-six paired immunoscintigraphic examinations were performed on 43 patients with suspected ovarian carcinoma recurrence using F(ab')2 fragments of OC125 antibody labeled first with indium-111 and then with iodine-131. Planar scintigraphy (PS) and emission computed tomography (ECT) images were interpreted blindly and separately by three observers, and reproducibility was evaluated by a kappa concordance index. Intra- and interobserver reproducibility were generally satisfactory (kappa values of 0.6 and 0.7, respectively). Binomial analysis of kappa values for ECT showed the superiority of indium-111 for intraobserver (p = 0.035) and interobserver (p = 0.0039) study. However, for PS there was no significant difference in reproducibility with the two radionuclides.

Adult↗
PubMed1991

Evaluation of indium-111-labeled antifibrin monoclonal antibody for the diagnosis of venous thrombotic disease.

The potential advantage of using 111In-antifibrin (111In-AF) monoclonal antibody for the diagnosis of deep venous thrombosis (DVT) was studied in 44 patients with suspected DVT (27 underwent heparin therapy before 111In-AF injection). All patients had contrast venography (considered as the gold standard) and 111In-AF scintigraphy within 24 hr. Two to 3 mCi of 111In-AF were injected intravenously, and planar scintigraphy of the limbs was recorded within 10 min (17 times), 3 hr (44 times), and 18 hr (39 times). Indium-111-AF images were then interpreted without knowledge of the results of the other examinations. The DVT diagnostic accuracy of 111In-AF was greater when interpretation was based on images recorded at different time periods after injection. Indium-111-AF sensitivity for diagnosis of DVT was 85% (29/34) and was not apparently decreased by heparin therapy. None of the 10 patients with negative contrast venography had a positive 111In-AF scan. The results demonstrate the importance of recording serial images and the excellent accuracy of 111In-AF for diagnosing DVT.

Antibodies, Monoclonal↗
PubMed1990

Comparison of technetium-99m aerosol and krypton-81m in ventilation studies for the diagnosis of pulmonary embolism.

A new method of producing aerosols (technegas) in which 99Tcm is bound to carbon atoms (99Tcm-C) was evaluated by comparing 99Tcm-C images with those obtained with 81Krm in the same patients. Twenty-five patients with suspected pulmonary embolism (PE) were studied. Immediately after the last 99Tcm-C view, the patients remained in supine position and inhaled 81Krm at tidal volume. Immediately after the 81Krm ventilation views were recorded, 4-7 mCi of MAA were injected IV. The same four views (ant, lop, rop, post) were recorded after inhalation of 99Tcm-C and 81Krm (200 kcounts) and 99Tcm MAA injection (400 kcounts). The mean penetration index of 99Tcm-C (0.91) was lower than that of 81Krm (1.04) (P less than 0.03). The apex to base lung distribution of 99Tcm-C and 81Krm appeared to be similar. The mean heterogeneity of 99Tcm distribution was 23, greater than that of 81Krm (14) (P = 10(-4)). The 99Tcm-C ventilation image quality was considered very good for 16 patients and good for 6 others. Significant foci of high bronchial uptake were infrequent. Interpretation of the examinations performed after inhalation of 99Tcm-C and 81Krm was concordant in all cases. No patient had an 81Krm/99Tcm MAA examination suggestive of PE when 99Tcm-C/99Tcm MAA indicated a low probability of PE, and vice versa. 99Tcm-C aerosols enable good quality ventilation images to be obtained in nearly all cases. Thus 99Tcm-C aerosols could be used in preference to 81Krm in ventilation studies for the diagnosis of PE.

Administration, Inhalation↗
PubMed1990

[Role of imaging in the exploration of the adrenal glands].

Currently, the major method of adrenal gland imaging is computed tomography. This method allows demonstration of normal adrenals and the diagnosis of adrenal masses (if these are greater than 1 cm in diameter). The examination should be directed by clinical signs and known laboratory investigations. Computed tomography is therefore the first line investigation to perform. Certain lesions may be better demonstrated by other methods: MRI and MIBG scintigraphy offer a greater specificity in the investigation of pheochromocytomas. In addition, scintigraphy can identify possible ectopic tumours or recurrences. Selective catheterisation of the adrenal veins allows aldosterone and cortisone secretions to be assayed. There remains the problem of the incidental finding of adrenal masses in either an asymptomatic patient or in the context of investigation of spread of a know cancer. These lesions may benefit from diagnostic percutaneous guided biopsy.

Adrenal Gland Neoplasms↗
PubMed1989

Histological correlation of 17 prospective immunoscintigraphies of recurrences of colorectal carcinomas using indium-111-labeled anti-cea and(or) 19-9 monoclonal antibodies.

Seventeen patients (mean age 55 years) with suspected recurrence in previously operated and histologically confirmed colorectal adenocarcinomas were explored by immunoscintography (IS) associating planar and emission computed tomography (ECT) and using the 111In-labeled anti carcinoembryonic antigen (CEA) and(or) 19-9 monoclonal antibodies (MoAbs). The results of IS were compared blind with those of computed tomography (CT) and ultrasonography (US). The final diagnosis of recurrence and(or) metastasis was done in 16 cases by second-look surgery and in another patient by rectal biopsy. Overall per-patient sensitivity for the pelvis and extrahepatic abdomen was 69% for IS and 31% and 25% respectively for computed tomography and ultrasonography. No false positive of IS, as well as US and CT, for the pelvis and the extrahepatic abdomen was seen. Based on the number of anatomical sites tested, sensitivity of IS was 91% in the pelvis. In our series, scintigraphic computer subtraction did not allow adequate resolution of the problem of intense liver uptake of 111In-labeled MoAbs. It is concluded that IS using 111In-labeled anti CEA and(or) 19-9 MoAbs should be carried out prospectively in patients at high risk of recurrence of colorectal cancer.

Adenocarcinoma↗
PubMed1988

Aerosol-perfusion lung scintigraphy: value of ventilation subtraction.

99Tcm-labelled aerosol ventilation and 99Tcm-macroaggregate albumin (99Tcm-MAA) perfusion can be performed in the diagnosis of pulmonary embolism (PE). If both examinations are performed on the same day, the superposition of activity from the first scintigraphic examination might mask defects in the second. In this study, 106 examinations were carried out for suspected PE. Aerosol ventilation was performed first with 20 to 30 mCi 99Tcm-labelled rhenium sulphur (four views, 200,000 counts). Immediately afterwards, with the patient remaining in the same position, 5 to 7 mCi of 99Tcm-MAA were injected (four views, 400,000 counts). After normalization, aerosol activity was subtracted from perfusion images and unprocessed perfusion (UP) and ventilation subtraction perfusion (SP) images were compared. Interobserver diagnostic reproducibility between three readers was calculated both for UP and SP images. Intraobserver reproducibility between UP and SP images was calculated for each reader. Interobserver reproducibility was comparable for SP and UP images. Intraobserver reproducibility was good. Thus, whether ventilation was subtracted or not from perfusion images, there was no appreciable effect on perfusion defect detection. However, some perfusion abnormalities showed up more clearly on SP images. Perfusion can be performed immediately after aerosol ventilation; the images thus obtained are reliable for interpretation, and subtraction of ventilation is not necessary.

Aerosols↗
PubMed1987

[Microalbuminuria is not a marker of diabetic retinopathy].

Microalbuminuria is considered a good predictor of diabetic nephropathy. In this study over 50% of patients with retinopathy, whatever its severity, did not show microalbuminuria. However, among patients with microalbuminuria, the percentage of retinopathy was significantly increased (75%). It is concluded that with the exception of nephropathy, microalbuminuria is not a good parameter for the detection of other microangiopathic complications of diabetes.

Adult↗
PubMed1987

Immunoscintigraphy of recurrences of gynecologic carcinomas.

In a first, retrospective study, 15 patients with known ovarian carcinoma were injected with 131I-OC 125 F(ab')2 monoclonal antibody (MAb). The sensitivity of immunoscintigraphy based on the number of the tumor sites was 67% (12/18). In a second, prospective study, 29 patients with gynecologic carcinoma were injected with 131I-OC 125 F(ab')2 (24) or 131I-19-9 F(ab')2 (5) MAbs according to the histologic type. Based on the number of tested anatomic sites, sensitivity was 72% and specificity 86%. In two patients injected with both 131I-OC-125 F(ab')2 and 125I-NS F(ab')2 (nonspecific immunoglobulin) 1 and 4 days before tumor resection, tumor uptake of the specific antibody was 2.2 and 4.5 times greater than that of NS. Immunoscintigraphic results were complementary with those of ultrasonography and computed tomography. Finally, in one patient injected successively with 131I-OC 125 F(ab')2 and 111In-DTPA-OC 125 F(ab')2, the recurrent tumor was visualized with both radionuclides, with 111In providing better abdominal tumor contrast but causing much greater liver radioactivity than 131I.

Adenocarcinoma↗
PubMed1986

99mTc-DTPA and 99mTc-rhenium sulfur aerosol compared as adjuncts to perfusion scintigraphy in patients with suspected pulmonary embolism.

Two radiopharmaceuticals, 99mTc-DTPA (D) and 99mTc-rhenium sulfur (R), were evaluated with a nebulizer delivering submicronic particles. Seventy-seven patients were examined (42 D, 35 R). For all patients, the examination began with a ventilation study. Immediately after the last ventilation view, 99mTc MAA was injected. Aerosol performance was assessed in 37 D and 17 R. Nebulization yield was 8.98% for D and 9.31% for R. A lung clearance study was performed in 12 patients for D and in 12 different patients for R. The lung clearance was 0.22%/min for R and 2.35%/min for D. The quality of ventilation and the quantification of bronchial and gastric activity were evaluated; the difference between the two groups was not statistically significant. It may be concluded that radioaerosols allow good quality images to be obtained. The yield of the nebulizer is adequate, so that nebulization of 20 mCi delivers approximately 2 mCi of aerosol activity to the lung. When pulmonary embolism is being investigated, R, due to its slower lung clearance, would appear to be preferable to D for patients suspected of increased bronchoalveolar permeability, especially if the time between nebulization and recording is greater than 10 min.

Adult↗