[Comparison between PET(-FDG) and computed tomography in the staging of lung cancer. Consequences for operability in 94 patients]. / Comparaison entre TEP(-FDG) et scanner dans le bilan d'extension du cancer bronchopulmonaire, conséquences pour l'opérabilité chez 94 patients.

INTRODUCTION: Lung cancer, a major application of FDG/PET-CT, has recently been introduced in daily practice in France. The authors retrospectively studied its impact on the management of this disease. METHODS: The results of PET-CT and conventional assessment (brain imaging, chest and abdominal CT and possibly bone scintigraphy) were compared in 94 patients, referred for the staging of non-small cell lung cancer, or the assessment of a solitary lung lesion. The impact of thoracic lymph node involvement on the operability of patients was studied in 44 patients. RESULTS: PET-CT revealed metastases in 20% of the patients without metastases found by conventional imaging and modified the stage of the disease in 28% of the cases. It changed the indication of surgical treatment in 19% of the cases and led to induction chemotherapy in two patients. In addition, two synchronous cancers were discovered. Regarding lymph node involvement, PET-CT remains of diagnostic value regardless of the scanner results. CONCLUSION: The impact of PET-CT in assessing non-small cell lung cancer was confirmed in the authors' practice. Its interest and the consequences in some patients misclassified with conventional assessment have been demonstrated.

Gastric emptying is accelerated in obese type 2 diabetic patients without autonomic neuropathy.

OBJECTIVE: To clarify the impact of type 2 diabetes mellitus on the gastric emptying rate. MATERIAL AND METHODS: Using a double-isotope scintigraphic technique, we assessed the gastric emptying of a standard liquid-solid meal in 13 obese type 2 diabetic patients without autonomic neuropathy (age: 47.4 +/- 8.6 yr, body mass index: 33.9 +/- 4.8 kg/m(2), glycaemia: 9.1 +/- 2.6 mmol/l) and in 7 controls with similar sex ratio, age, BMI and body fat distribution. RESULTS: The half gastric emptying time for the liquid phase was not significantly different between diabetic patients and controls (respectively: 52.7 +/- 14.5 min and 63.1 +/- 15.2 min). However, the half gastric emptying time for the solid phase was significantly shortened in diabetic patients versus controls (respectively 88.8 +/- 23.2 min in diabetic patients and 113.6 +/- 26.9 min in controls; p<0.04). Furthermore, a negative relationship was highlighted between the half gastric emptying time for the solid phase and basal glycaemia (r=-0.65, p<0.02) in diabetic patients. No significant relationship was found between gastric emptying parameters and cardiac autonomic nerve function, insulin or gastrin levels. CONCLUSION: Solid gastric emptying is accelerated in obese type 2 diabetic patients without patent autonomic neuropathy when compared to obese non diabetic patients.

Detection of subclinical abdominal hernia by peritoneal scintigraphy.

This study investigated the incidence of subclinical abdominal hernia in patients starting peritoneal dialysis (PD). From April 1995 to August 1999, every new patient without clinical evidence of abdominal leakage underwent peritoneal scintigraphy. A total of 59 patients were enrolled in the study. Imaging of the peritoneal cavity was performed by mixing 74 MBq (2 mCi) of 99 m technetium sulfur colloid with 2 L of 1.36% dextrose peritoneal dialysis solution. Sequential gamma camera static images were obtained at 0 minutes, 60 minutes, and after drainage. Ten abdominal hernias (2 diaphragmatic leaks, 8 inguinal hernias) were observed in ten patients (6 males, 4 females; mean age: 65.1 years). One patient with diaphragmatic leak recovered partial renal function and stopped continuous ambulatory peritoneal dialysis (CAPD); the other was switched to automated peritoneal dialysis (APD). Among the eight patients with inguinal hernia, six had no clinical manifestations within eight months of follow-up. Two patients became symptomatic at 15 months and 25 months respectively. They underwent surgical repair. In CAPD patients without obvious abdominal hernias, peritoneal scintigraphy at onset of dialysis discovered 17% positive cases. The technique of scintigraphy is safe, with a low radiation exposure. Surgical repair for maintenance on CAPD is not always necessary, and a change in the PD strategy may be useful.

[Acoustic quantification of right ventricular dimensions and systolic function]. / Estimation par quantification acoustique des dimensions et de la fonction systolique du ventricule droit.

In view of the important prognostic significance of right ventricular systolic function, there have been many non-invasive studies of this subject. The majority of these studies have been limited by difficulties in modelisation of this geometrically complex cardiac chamber. Automatic border detection by acoustic quantification based on the back scatter of ultrasound provides a "direct" method of analysing right ventricular dimensions and functions. The authors undertook a prospective study of 34 patients to evaluate the reliability of this technique in measuring the surfaces and fractional shortening of the right ventricle. The feasibility was 92%. The correlation coefficients between the manual two-dimensional technique and automatic border detection were 0.81 for the end diastolic surface areas, 0.85 for the end systolic surface areas and 0.74 for the fractional shortening. Compared with the isotopic ejection fraction, the correlation coefficient was 0.73. The authors conclude that acoustic quantification is a feasible and reliable technique of measuring right ventricular dimensions and its contractile function.

Interest of direct radionuclide cystography in repeated urinary tract infection exploration in childhood.

108 children with repeated urinary tract infection were examined both with direct contrast cystography and radionuclide cystography. There was a good correlation between the two procedures in the majority of the cases (79), but in 21 cases, direct radionuclide cystography alone was positive and for 8 other children, direct contrast cystography showed a low-grade vesico-ureteric reflux even though radionuclide cystography was negative. When comparing the two procedures and taking into consideration the age of the patients we find that radionuclide cystography is more sensitive to detect vesico-ureteric reflux in the younger population (p < 0.02). This advantage is less clear for older children who more often present a low-grade reflux. Low radiation exposure is also a great advantage of radionuclide cystography, but anatomic definition is better with contrast cystography. It seems thus that the two procedures complement rather than rival each other. Their respective interest for evaluation of repeated urinary tract infection in children therefore depends on age, attain-ability of the procedure, and the possibility of a bladder or ureteral abnormality. Quite a few authors consider radionuclide cystography as at least as valid as contrast cystography, and even more sensitive. We have attempted to compare both procedures and to determine their respective role in repeated urinary tract infection exploration.

Thoracic and abdominal SPECT-CT image fusion without external markers in endocrine carcinomas. The Group of Thyroid Tumoral Pathology of Champagne-Ardenne.

UNLABELLED: Superimposition of SPECT and computed tomography (CT) slices from the thoracoabdominal region was achieved without the use of external markers for 14 studies in 13 patients with endocrine carcinoma. Technical feasibility and clinical validation of this retrospective fusion method were assessed. METHODS: Patients had a history of thyroid cancer or of carcinoid tumor. To detect tumor sites, CT scan and dual-isotope tomoscintigraphy were performed, with 99mTc-hydroxymethylene diphosphonate for bone scintigraphy and with 111In-pentetreotide, 131I or 131I-metaiodobenzylguanidine for tumor scintigraphy (TS). A superimposition method previously developed for the pelvic region was adapted to the nonrigid thoraco-abdominal region. CT-bone scintigraphy and CT-TS superimposed images were obtained. Clinical validation of the information obtained from the superimposed images was obtained from surgery or follow-up imaging studies performed after clinical evolution of the disease process. RESULTS: Reliable and reproducible registration was achieved in all patients. CT-TS superimposed images produced accurate localization of abnormal TS foci. Accuracy was limited primarily by variable relative displacements of the thoracoabdominal organs. For 10 sites in 8 patients, localization and/or characterization obtained from CT-TS images was confirmed by a reference technique. Superimposition enabled the localization of tumor sites that otherwise could not have been suspected from CT alone and allowed the characterization of CT suspicious masses and the confirmation of CT positive sites. Nonspecific tumor TS uptake sites were also localized. CONCLUSION: With standard CT and dual-isotope SPECT acquisitions, SPECT-CT fusion is feasible in the thoracoabdominal region without the use of external markers. Fused images were validated in 8 patients for 10 sites. The use of this technique could probably improve the management and care of patients with endocrine carcinoma.

Assessment of radioisotopic micturating cystography for the diagnosis of vesicoureteric reflux in renal transplant recipients with acute pyelonephritis.

BACKGROUND: The gold standard for documenting vesicoureteric reflux is direct (retrograde) micturating cystography (MC). In children, radioisotopic MC has been advocated for increased sensitivity and lesser radiation exposure. In renal transplant recipients, where reflux can induce acute pyelonephritis, this technique has not been evaluated. The aim of this study was to assess the radioisotopic technique in these patients. METHODS: Seventeen renal transplant recipients had developed acute pyelonephritis following the surgical grafting procedure. They were investigated using both MC techniques. Radioisotopic MC was performed using 99mTc-pertechnetate. RESULTS: Reflux was documented in nine patients by radioisotopic MC but in only seven with the conventional technique. All negative patients remained symptom free after the pyelonephritis was cured and it was assumed that they had no reflux. Consequently, using the radioisotopic MC as gold standard, the conventional X-ray technique had a sensitivity of 78% and a specificity of 100%. CONCLUSIONS: Direct radioisotopic MC allowing continuous cystogram recording is more accurate than conventional X-ray MC for the diagnosis of vesicoureteric reflux in transplanted patients with acute pyelonephritis.

Quantitative comparison of prone and supine myocardial SPECT MIBI images.

The myocardial count distribution and the stress/rest ratio distribution were compared between prone and supine Tc-99m MIBI myocardial SPECT acquisitions. Ninety-nine male patients with a low stress supine inferior wall count underwent stress and rest acquisitions in the supine and prone positions successively. For each study, values depicting the inferior, anterior, septal, and lateral wall counts were extracted from a medioventricular normalized circumferential profile and underwent a statistical analysis (Student's paired t-test). On prone imaging, when compared to supine imaging, counts showed a highly significant mean relative increase of 11% +/- 1% in the inferior wall and of 7% +/- 1% in the septum. Conversely, these counts showed a significant mean relative decrease of 4% +/- 1% in the anterior wall and of 3% +/- 1% in the lateral wall. Moreover, the inferior wall stress/rest ratio showed a highly significant mean relative increase (6% +/- 2%). The prone position is probably preferable for interpreting the inferior wall and septum, where relative counts are enhanced, as with TI-201, and because the inferior stress-rest discrepancies are reduced in that position. But the anterior and lateral wall information is impaired in the prone position. The authors suggest, in case of a low stress supine inferior count, the combination of both positions, which is feasible with Tc-99m MIBI, in order to prevent a misleading interpretation.

Visualization of myocardial infarction six hours after injection of 111 In-antimyosin antibodies using an image subtraction technique.

111 In-antimyosin antibodies are capable of visualizing acute myocardial infarction (MI). Because of slow blood clearance, images are usually recorded 24 or 48 h postinjection. This pilot study was aimed at validating a blood pool subtraction technique, which makes it possible to visualize MI 6 h postinjection. Twenty-five patients with proven MI (16 anterior, 9 inferior) were imaged 10 minutes, 6 and 24 h after an injection of 110 MBq 111 In-labelled antimyosin antibodies, with a mean delay of two weeks after infarction. Three planar views were obtained each time. Using software which performs geometric registration, grey level normalization and subtraction of images, the blood pool image (obtained 10 minutes postinjection) was subtracted from the 6 hour image. The resulting image was the blood pool corrected 6 h image. The 24 h images and the blood pool corrected 6 h images were interpreted blindly and the number of correct, incorrect and indeterminate MI localizations were tabulated. The number of correct localizations was 19/25 for the standard 24 h images and 22/25 for the blood pool corrected 6 h images. With this blood pool subtraction method it was possible to visualize MI 6 h postinjection. Theoretically, this method could be applied six hours after myocardial infarction.

Shape preserving three-dimensional display of myocardial scintigraphic data.

A three-dimensional display has been developed which is specifically suited to the visualization of myocardial single photon emission tomographic (SPET) data. A set of radial maxima voxels, representative of the whole left ventricle uptake and shape is first extracted by cylindrical and spherical sampling of the short axis slices. A three-dimensional representation of these voxels is then obtained, with hues depicting the uptake amount and shades (i.e. intensity and saturation) depicting the shape. This technique is suitable for 201Tl and 99TCm-hexakis-2-methoxyisobutyl isonitrile (99TCm-sestamibi) myocardial images. It is proposed as an aid to interpreting myocardial SPET as it enables the physician to distinguish simultaneously the actual shape, the extent and the severity of perfusion defects on a single frame.

[Value of renal scintigraphy in the diagnosis of vascular complications of renal transplantation]. / Intérêt de la scintigraphie rénale dans le diagnostic des complications vasculaires de la transplantation rénale.

Nuclear medicine can make an efficient contribution to the diagnosis and monitoring of renal disease and to the assessment of therapeutic interventions in the field of renal transplantation. The new radio pharmaceutical MAG 3 labelled with 99mTc provides renal imaging of quality in patients with impaired renal function and enables quantitative evaluation of renal function. We report on radionuclide evaluation, with special emphasis on the analysis of the vascular component of the scintigram, in the different clinical situations (i.e. renal failure) that may compromise the outcome of a successful renal transplant.

What factors determine indium-111 antimyosin monoclonal antibody uptake in patients with myocardial infarction?

The intensity of indium-111 antimyosin monoclonal antibody uptake for visualization of myocardial infarction seems partially dependent on the state of the infarct related coronary artery. The aim of this study is to determine the factors which could account for the monoclonal antibody uptake variability. For this purpose, we investigated 27 patients (mean age 52.7 +/- 9.6 years) with a first proven myocardial infarction, by monoclonal antibody scintigraphy and coronary arteriography within the same period of time (7.12 +/- 6 days). The monoclonal antibody uptake was quantified by the heart/lung ratio on images recorded 24 h after injection. The infarct size was quantitatively estimated on wall motion analysis of twelve segments in 30 degree right anterior-oblique view with a radial method. The infarct related coronary artery state was assessed by the Thrombosis in Myocardial Infarction grade and the functional characteristics of collateral vessels by Rentrop's classification. These three variables as well as location of myocardial infarction, left ventricular ejection fraction, administration of a thrombolytic therapy, delay between myocardial infarction and monoclonal antibody scintigraphy were studied using non parametric test, or by linear regression method in order to determine whether these factors would influence the heart/lung ratio. None of these parameters except infarct size was related to heart/lung ratio. Consequently, monoclonal antibody uptake is only dependent on the extent of infarcted myocardium and the intensity of uptake cannot predict the patency of an infarct related coronary artery.

111In-hyaluronectin, a new probe for radiodetection of tumours: biodistribution and imaging in grafted mice.

Hyaluronectin (HN), a glycoprotein which shows a strong specific affinity for Hyaluronic Acid (HA), a very high molecular weight glycosaminoglycan expressed in the stroma reaction of all tumours, was used to radiolocalize grafted autologous carcinomas (CB33 and CB03) in mice. After conjugation to DTPA (0.5-3.7 DTPA/HN) and radiolabelling with 111In (5 microCi/micrograms HN) HN retained 93% of its affinity for HA. Different preparations of HN purified from lamb brain were assayed. The best results were obtained when the HN molecules reactive with HA were selected by gel permeation to discard unreactive molecules which were unable to complex with HA. At 48 hours the tumour to blood ratio was 7.7 with a localization index of 2.2 in CB33; there was 2.8% uptake of the injected dose (ID) into CB33 and 1.6% into CB03. 111In-HN uptake per gram of tumour was tumour-size dependent: the smaller masses had the higher uptake. Tumours were visualized and either early images of 111In-HN distribution or simultaneous distribution images of 99mTc-phytate or 201Tl-DTPA were used for the subtraction treatments.

Usefulness of imaging ovarian cancer recurrence with In-111-labeled monoclonal antibody (OC 125) specific for CA 125 antigen. The INSERM Research Network (Nantes, Rennes, Reims, Vuillejuif, Saclay.

BACKGROUND: A progressive rise in serum CA 125 concentration during follow-up monitoring of ovarian cancer after treatment of primary tumor is suggestive of a recurrence. PATIENTS AND METHODS: A study was carried out in 19 patients with suspected recurrence of a previously treated ovarian carcinoma. All patients underwent ultrasonography (US), computed tomography (CT) and immunoscintigraphy (IS) using F(ab')2 fragments of indium-111-labeled OC 125 monoclonal antibody (specific for CA 125 antigen). The definitive diagnosis of recurrence was made on the basis of histological data obtained at surgery. RESULTS: In all 15 of the patients with recurrence, all three of the imaging methods had false negative results once. In 7 patients, only the IS method had positive results; six of these 7 benefited from a macroscopically total resection of the recurrence. IS was positive and concordant with US and/or CT in 7 further patients. Two of them benefited from a total resection of their recurrence. The usefulness of IS was more evident when serum CA 125 concentration was below 500 U/ml. The absence of recurrence was correctly indicated by IS and CT in 1 case and by IS associated with negative US and CT in 2 other cases. IS and CT were falsely positive in 1 case. CONCLUSION: Thus, immunoscintigraphy would appear to be an efficient method for detecting a recurrence early when limited involvement can make it possible for the surgeon to achieve total resection.

A multivariate analysis of the diagnostic values of clinical examination, exercise testing and exercise radionuclide angiography in coronary artery disease.

Data of clinical examination, exercise testing and exercise radionuclide angiography in 102 patients referred for assessment of chest pain was included in a logistic regression to optimize the diagnosis of coronary artery disease with coronary arteriography as the reference investigation. None of the patients had other cardiac problems or previous myocardial infarction. In the absence of symptoms, exercise testing was continued until at least 80% of the theoretical maximal heart rate was attained. Each patient was characterized by the value of the logistic function or probability of coronary artery disease. A threshold value corresponding to 80% sensitivity of ROC graphs was determined. The significant variables were: a clinical variable--the type of chest pain as assessed by the clinical history; two radionuclide angiographic variables--the ejection fraction at peak effort and the corrected variation of ejection fraction between rest and stress, that is not taking into account possible decreases at the last increment of exercise. Coronary patients can be identified with an 80% sensitivity and 77% specificity on these criteria. This specificity is greater than that obtained by clinical examination and exercise testing alone (65%). Exercise radionuclide angiography may therefore reduce the number of unnecessary coronary arteriographies.

[Value of parathyroid scintigraphy in preoperative localization of parathyroid adenoma. Study apropos of 138 tests]. / Valeur de la scintigraphie parathyroïdienne dans le repérage pré-opératoire des adénomes parathyroïdiens. Etude à propos de 138 examens.

The authors have studied, about a total of 138 exams, the value of parathyroid nuclide scan. All the patients, who had primary hyper parathyroidism, have been operated upon. The results of parathyroid scintigraphy have been compared to the results of surgical exploration. Overall sensibility of the exam has been 80%, better with the MIBI (89%) than with the Thallium (78%). The specificity has also been better with the MIBI (95%) than with the Thallium (87%) with a global result of 88%). Computerized treatment of images with automatized subtraction especially studied in Institut Jean-Godinot, Rheims, explain the quality of these results.

Visualization of myocardial infarction 6 h after injection of 111In-antimyosin antibodies using a blood pool subtraction technique.

111In-antimyosin antibodies are capable of visualizing myocardial infarction (MI). Because of slow blood clearance, images are usually recorded 24 or 48 h postinjection. In this pilot study, a blood pool subtraction technique, which makes it possible to visualize MI 6 h postinjection, is validated. Twenty-five patients with proven MI (16 anterior, 9 inferior) were imaged a few minutes, 6 and 24 h after an injection of 111 MBq 111In-labelled antimyosin antibodies. Three planar views are obtained each time. Using software which performs the geometric registration, the grey level normalization and the subtraction of images, the blood pool image (obtained a few minutes postinjection) is subtracted from the 6 h image. The resulting image is the blood pool corrected 6 h image. The 24 h images and the blood pool corrected 6 h images were interpreted blindly and the number of correct, incorrect and impossible MI localizations was counted. The number of correct localizations is 19/25 for the standard 24 h images and 22/25 for the blood pool corrected 6 h images. Then, with this blood pool subtraction method, it is possible to visualize MI 6 h postinjection. This has to be taken into account when discussing the role of antimyosin scintigraphy in the management of patients with MI.