Value of linsidomin in assessing myocardial viability with thallium-201 SPECT.

Myocardial viability can be assessed with rest/24 h redistribution (201)Tl myocardial single photon emission computed tomography (SPECT). The intravenous injection of vasodilators induces an early redistribution of (201)Tl and shortens the total examination time. The aim of this study was to compare the images after injection of linsidomin with the 24 h images. We studied 51 consecutive patients (38 males, 13 females), aged 66+/-11 years, referred for assessment of myocardial viability after acute myocardial infarction. SPECT acquisition at rest (30 projections over 180 degrees, 30 s per projection) was performed 20 min after injection of (201)Tl. A second acquisition (same parameters) was performed 2 min after intravenous injection of linsidomin (2 mg). A delayed acquisition was performed on the following day (50 s per step). Myocardial perfusion at rest was normal in 111 of 255 segments. For the 144 other segments, 24 h images were similar to the images acquired after the injection of linsidomin in 94% of cases (136 of 144 segments). The 24 h images showed partial redistribution that was not present after linsidomin in only eight segments (6%). Injection of linsidomin after rest acquisition can provide a reliable and more rapid assessment of myocardial viability. This very simple protocol (rest/linsidomin (201)Tl myocardial SPECT) can be performed in less than 1 h.

Assessment of left ventricular function by 201Tl SPECT using left ventricular cavity-to-myocardium count ratio.

Equilibrium radionuclide angiography (ERNA) is the 'gold standard' for assessing left ventricular ejection fraction (LVEF). The aim of the study was to determine whether the left ventricular cavity-to-myocardium count ratio (LVCMR) from 201Tl myocardial single photon emission computed tomography (SPECT) correlated with LVEF assessed by ERNA. The study group included 159 consecutive patients (117 male, 42 female), aged 59+/-12 years, who underwent both 201Tl SPECT and ERNA at rest on the same day. The LVCMR was calculated from a mid-ventricular short axis slice on redistribution studies, using two regions of interest (ROIs). One ROI was placed in the centre of the left ventricular cavity (C) and the other was placed in the myocardium with maximum uptake (Mmax): LVCMR= (C/Mmax) x 100. The correlation between LVCMR and LVEF was r = 0.85 (y = 0.943x+5.002; P < 0.0001). The mean calculated values +/- 1 SD were LVCMR=54+/-16% and LVEF=52+/-15%. In conclusion, LVCMR from 201Tl SPECT studies was closely correlated with LVEF from ERNA studies and can be used to easily and rapidly estimate left ventricular function.

Impairment of cardiac neuronal function in childhood dilated cardiomyopathy: an 123I-MIBG scintigraphic study.

UNLABELLED: Abnormalities of norepinephrine uptake have been found to reflect impairment of cardiac adrenergic neuronal function in adults with heart failure. To our knowledge, no data on childhood dilated cardiomyopathy (DCM) are available. The aim of this study was to assess the cardiac neuronal function using 123I-metaiodobenzylguanidine (MIBG) scintigraphy in children with idiopathic DCM. METHODS: We studied 26 patients (mean age, 44+/-50 mo) with DCM and left ventricular dysfunction and 12 control subjects (mean age, 49+/-65 mo) with normal left ventricular function. All subjects underwent planar cardiac imaging after intravenous injection of 20-75 MBq 123I-MIBG. A static anterior view was acquired 4 h after injection. The heart-to-mediastinum count ratio was measured as described previously. RESULTS: On the basis of a reduction of the heart-to-mediastinum count ratio, cardiac neuronal uptake of 123I-MIBG was significantly decreased in patients with DCM compared with cardiac uptake in control subjects (172%+/-34% versus 277%+/-14%; P<0.0001). A significant correlation was found between left ventricular ejection fraction and 123I-MIBG cardiac uptake in patients with DCM (y = 2.5x + 113.3; r = 0.80; P<0.0001). CONCLUSION: Cardiac adrenergic neuronal function is impaired in children with idiopathic DCM. 1231-MIBG cardiac scintigraphy is a useful tool to assess cardiac neuronal function in childhood DCM.

Upper retropharyngeal node involvement in differentiated thyroid carcinoma demonstrated by 131I scintigraphy.

We report four patients with papillary thyroid cancer who had upper retropharyngeal node involvement demonstrated by 131I scintigraphy. Three patients presented with a thyroid nodule and enlarged jugular nodes. Total thyroidectomy was performed with node dissection. Pathology demonstrated papillary carcinoma with several metastatic nodes. 131I scanning 4 weeks after surgery demonstrated increased uptake in an upper retropharyngeal node. In one patient, thyroidectomy had been performed 21 years previously. Increased thyroglobulin level led to 131I scanning, which showed focal retropharyngeal uptake. All four patients had asymmetrical uptake at mouth level with focal uptake close to the sagittal plane. A lateral projection showed focal uptake between the base of the skull and the mandibular angle, behind the region of the mouth and nose. CT in all cases and MRI in one case confirmed the presence of an enlarged node. The mass was removed surgically in two patients and pathology confirmed the papillary nature of the metastatic node. Two patients were treated by 131I. Focal uptake of 131I in the region of the mouth is ambiguous, since salivary uptake of 131I is a common finding on scintigraphy. In cases of asymmetrical uptake in the region of the mouth, a lateral projection of the head therefore allows the correct diagnosis.

Decreased uptake of therapeutic doses of iodine-131 after 185-MBq iodine-131 diagnostic imaging for thyroid remnants in differentiated thyroid carcinoma.

We performed a prospective random study to assess possible thyroid stunning by a 185-MBq iodine-131 dose used to diagnose thyroid remnants. Patients with differentiated thyroid carcinoma were included after total or near-total thyroidectomy. They were randomly assigned to two groups. In group 0 (G0, 32 patients), iodine-123 administration only was used to diagnose thyroid remnants and/or metastasis, so that no thyroid stunning by 131I would occur. In group 1 (G1, 19 patients), diagnostic imaging was performed with 123I and 185 MBq 131I. 123I imaging was less sensitive than 131I imaging in identifying thyroid remnants in both groups (94%). Thyroid uptake of 123I was measured in both groups (at 2 h) and was not significantly different between the groups. Patients with thyroid remnants who remained in the study (28/32 in G0, 17/19 in G1) were treated with 370 MBq 131I, 5 weeks after treatment (mean time, range 12-84 days). In 12/17 G1 patients thyroid uptake measurement was repeated immediately before treatment. Uptake was equal to 1.97% +/- 0.71% and significantly lower (P < 0.05) than the previous measurement (3.76% +/- 1.50%). Patients were imaged 7 days after administration of the therapeutic dose and the images were compared with the diagnostic images. In 28/28 G0 patients thyroid remnants were unchanged and clearly seen. In 5/17 G1 patients, however the remnants were hardly identified, although they had been clearly seen at the time of diagnosis. We conclude the following: (1) a diagnostic dose of 185 MBq 131I decreases thyroid uptake for several weeks after administration and can impair immediate subsequent 131I therapy; (2) 123I is slightly less sensitive than 131I in identifying thyroid remnants; and (3) the need to scan for thyroid remnants remains to be confirmed, since only 2/51 patients enrolled in this study were not treated with 131I.

Effects of smoking on bronchial clearance of technetium-99m-DTPA and indium-113m-DTPA.

UNLABELLED: In asymptomatic smokers, epithelial permeability in the distal lung regions is increased. To date, the effect of smoking on the epithelial permeability in proximal lung regions is still debated. The measurement of bronchial clearance of inhaled radiolabeled diethylene-triaminepentaacetic acid (BC-DTPA) can be used to assess epithelial permeability of proximal bronchi, but there are two potential limitations to this method: in vivo breakdown of 99mTc-DTPA in smokers and mucociliary transport of DTPA. METHODS: Eight nonsmokers and eight asymptomatic smokers were studied. We used a spinning disk system to generate an aerosol of large particles of 99mTc-DTPA or 113mIn-DTPA (MMAD 6.3 microns). To measure the bronchial clearance of 99mTc-DTPA and 113mIn-DTPA, we analyzed the perihilar regions of the lung. To determine the contribution of mucociliary transport, we measured the activity over a tracheal region of interest (ROI) in eight nonsmokers. RESULTS: Technetium-99m-DTPA bronchial clearance did not differ in smokers (1.16 +/- 0.54%/min; mean +/- s.d.) or nonsmokers (1.29 +/- 0.51%/min; ns). The 113mIn-DTPA bronchial clearances in nonsmokers (1.24 +/- 0.51%/min) and in smokers (1.01 +/- 0.66%/min) were similar to the 99mTc-DTPA bronchial clearances (ns). In the tracheal ROI, we found no increase in activity. CONCLUSION: In smokers, BC-DTPA was not increased compared to nonsmokers. In contrast to distal lung regions, there was no evidence of breakdown of the 99mTc-DTPA complex in the proximal regions of smokers' lungs. Mucociliary clearance does not significantly contribute to BC-DTPA.

Comparison of jet and ultrasonic nebulizers for alveolar targeting of methylprednisolone.

The secondary systemic effects of oral corticosteroid therapy in chronic lung disease indicate the possible benefits of local therapy. The aim of this study was to show if alveolar targeting of a corticosteroid, methylprednisolone (MP), is possible, and to determine which type of nebulizer allows the most selective deposition into the alveoli. A jet nebulizer (Respirgard II) with 2 ml volume fill (R2), and an ultrasonic nebulizer (Ultraneb 99) with 4 ml volume fill (U4), were compared using a 40-mg dose of MP labelled 99Tcm human serum albumin. Particle size and MP-to-albumin binding were measured in the aerosol cloud. Each nebulizer was used in random order in five healthy volunteers. A dynamic posterior scan of 68 images of 15 s each was performed with a Gammatome II gamma camera during inhalation. Peripheral and central regions of interest were automatically defined with reproducible methods, and the peripheral-to-central ratio was used as a penetration index. Stomach and oropharynx activities were estimated on static anterior and static left lateral views, respectively, at the end of the examination. The mass median aerodynamic diameter (MMAD) was lower for R2 when unlabelled MP was used. The MMAD of MP+HSA was compatible with alveolar targeting. In the aerosol cloud, MP-albumin binding was 75% for R2 and 79% for U4. Peripheral and central activities at equilibrium (13-16 min) were higher with U4, but the penetration index was significantly higher with R2. Moreover, the stomach and oropharynx activities were significantly lower with R2.(ABSTRACT TRUNCATED AT 250 WORDS)

Radioiodine therapy of the autonomous thyroid nodule in patients with or without visible extranodular activity.

UNLABELLED: Patients with an autonomously functioning thyroid nodule (ATN) may be present with various clinical, biochemical and scintigraphic features. To optimize 131I dose planning and treatment timing in these patients, relationships between dosimetric data and clinical follow-up events must be established. METHODS: We retrospectively reviewed the records of 88 patients who received 131I (intended dose of 80 Gy) for an ATN, of whom 39 had evidence of extranodular activity (ENA) and 76 presented with overt thyrotoxicosis. In all of the patients, dosage calculation was monitored to estimate precisely both beta and gamma absorbed doses received by the ATN and the nodule-free lobe. The mean duration of follow-up was 75 mo (max 180) and always included biochemical thyroid tests. Finally, we compared the dosimetric profiles of four dosage schemes which had been normalized by simulation to ensure that the same absorbed dose threshold value was always delivered to the ATN. RESULTS: About 75% of the patients were cured at 6 mo for a mean 305 MBq administered. The absorbed doses delivered to the nodule-free lobe ranged from 12% (no ENA) to 86% (ENA) of the values delivered to the ATN, mainly in the form of beta irradiation. Life-table estimates for hypothyroidism and death were 9.6% and 22% at 75 mo, respectively. Hypothyroidism mainly developed in patients with nonsuppressed TSH levels but regardless of ENA, which often accounted for multifocal disease. CONCLUSION: We suggest that fixed doses bordering on 370 MBq are advizable in younger individuals and in patients with mild thyrotoxocosis, while 555 MBq-740 MBq can be administered in other patients and that ENA indicates multifocal autonomy in patients with toxic ATN and is a further indication for radioiodine treatment which should be begun as soon as possible to avoid the development of cardiac complications.

Respiratory epithelial permeability in complete Freund's adjuvant rat lung granulomatosis.

To investigate Freund's adjuvant-induced changes in respiratory epithelial permeability, we determined the respiratory epithelium clearance of 99mTc-DTPA (RC-DTPA) in rats and the localization of horseradish peroxidase (HRP) across the lung epithelium. RC-DTPA was determined before and after intravenous injection of saline (control) or complete Freund's adjuvant (CFA). Although the respiratory epithelium was not disrupted, RC-DTPA was increased 15 min after injection of CFA and was still high after 3 d but had returned to normal after 7 d, after which it again increased and stayed high from Day 42 through Day 112. Cell number obtained by bronchoalveolar lavage increased from 15 min to 3 d after injection of CFA. Lung granulomatosis was observed 14 to 112 d after injection of CFA; changes in RC-DTPA correlated with changes in alveolar cells. HRP was present in bronchiolar intercellular spaces only in the CFA group. We conclude that (1) RC-DTPA increases in rat lung CFA granulomatosis 15 min to 3 and 42 to 112 d following injection, (2) the increase in RC-DTPA is not related to a rupture of epithelium but (3) is proportional to the cell influx into the lung, and (4) is possibly caused by the opening of tight junctions in small airways.

Mechanisms of increased epithelial lung clearance of DTPA in diffuse fibrosing alveolitis.

The aim of this study was to elucidate possible mechanisms of increased epithelial lung clearance in diffuse fibrosing alveolitis (DFA). We investigated the relationships between epithelial lung clearance as assessed by the clearance of aerosolized 99mTc-diethylene-triamine-penta-acetic acid (RC-DTPA), luminal alveolitis as assessed by bronchoalveolar lavage, and pulmonary function, in 30 nonsmokers with DFA. In 14 of these patients, RC-DTPA and lung function were determined before and during therapy with prednisolone (0.5 mg.kg-1 daily). RC-DTPA was higher in patients with DFA (4.45 +/- 2.50%.min-1) than in normal subjects (1.18 +/- 0.31%.min-1). RC-DTPA did not correlate with the number of alveolar neutrophils, but correlated positively with the number of alveolar lymphocytes, and negatively with vital capacity (VC). RC-DTPA decreased from 6.1 +/- 2.8 to 3.8 +/- 1.9%.min-1 with prednisolone. RC-DTPA before prednisolone correlated positively with the prednisolone-associated improvement in VC. We conclude that in patient with DFA, RC-DTPA is increased, and decreases but does not return to normal with corticosteroid therapy. Our data suggest that in DFA the increase in RC-DTPA could be related to the recoil-induced stretch of the respiratory epithelium and to alveolar lymphocytic inflammation.

Influence of dose selection on absorbed dose profiles in radioiodine treatment of diffuse toxic goiters in patients receiving or not receiving carbimazole.

We retrospectively reviewed the records of 224 patients with diffuse goiters treated with radioiodine, half of which received carbimazole. In all the cases, we carefully monitored the calculation of dosage. A lower percentage of early hypothyroidism but a higher failure rate was observed in the carbimazole subgroup. Nevertheless, after one year, a constant (4.5%) incremental rate of hypothyroidism was found regardless of carbimazole administration. Since we were able to precisely estimate the absorbed doses in our series, we evaluated by simulation the dosimetric profiles of nine methods of dose selection (MDS). These MDS were calibrated in such a way that the same threshold value of absorbed dose would always be reached at the thyroid level. We showed that the more elaborate the MDS, the more accurate the irradiation at the thyroid level and the lower the radiation dose administered. In patients not receiving carbimazole, a rapid MDS using modified early uptake measurements to predict the 24-hr actual value was found to be advisable. With patients receiving carbimazole and if a goal is to delay the occurrence of hypothyroidism, we advise MDS based on either a 48-hr uptake or on the calculation of the individual half-life.

Influence of Pneumocystis carinii pneumonia on serum and tissue concentrations of pentamidine administered to rats by tracheal injections.

Pentamidine isethionate was administered by the tracheal route to control rats and immunodepressed rats with Pneumocystis carinii pneumonia (PCP). The serum concentration of pentamidine base 20 min after the administration was higher in the PCP rats (309 +/- 165 ng/ml) than in the control animals (71 +/- 36 mg/ml; p less than 0.001); 90 min after the injection the proportion of the pentamidine administered was lower in the right lung of the PCP rats (29 +/- 15%) than in the control rats (57 +/- 23%; p = 0.038); the proportion of pentamidine in the left kidney was higher in the PCP rats (14 +/- 4%) than in the control animals (4 +/- 2%; p less than 0.001). Respiratory clearance of 99mTc-DTPA, an index of the permeability of the respiratory epithelium, was higher in the PCP rats (1.84 +/- 0.42 %/min) than in the controls (0.44 +/- 0.11 %/min; p less than 0.001). We conclude that the more rapid diffusion of pentamidine from the alveolar lumen to the pulmonary circulation is explained by the increased alveolocapillary permeability as a result of pneumocystosis.

[Analgesic effect of transcutaneous cranial electrostimulation in patients treated by Nd:YAG laser for cancer of the rectum. A double-blind randomized trial]. / Efficacité de l'électrostimulation transcutanéo-crânienne dans l'analgésie de patients traités par le laser Nd:YAG pour cancer du rectum. Essai randomisé en double insu.

The aim of this double blind cross-over randomized trial was to assess if transcutaneous cranial electrical stimulation by Limoge current could decrease the dose of fentanyl required in patients with rectal cancer treated by Nd:YAG laser. Fifty patients, 29 women, 21 men, 78 +/- 10 years old (range: 53-96 years), were treated by 2 laser sessions with an interval of 48 hours between each session. Active and sham electrostimulation were given in random order for the 2 laser sessions. The major end point was the quantity of fentanyl injected when the score of pain was greater than or equal to 5 according to a visual analgesic scale. Age, sex, body weight, tumor location and length, tumor circumferential extent and luminal patency, duration of laser session, amount of energy delivered per session (watt-seconds), and number of patients with deep sedation did not differ between the 2 groups. There was no interaction between the order of treatments and the treatments. The mean quantity of fentanyl was 29 micrograms and 42 micrograms when sham electrostimulation was given. There was a decrease of 31 percent in the quantity of fentanyl with active electrostimulation (P less than 0.05). Results were not affected either by the treatment order nor by tumor location. There were no side effects in either group.

[Paracoccidioidomycosis assessed with 4 isotopic studies]. / La paracoccidioidomycose évaluée par quatre études isotopiques.

Paracoccidioidomycosis (south-american blastomycosis) is a consumptive granulomatous disease that is found in all Latin-America. The ethiological agent is a fungus (Paracoccidiosis brasiliensis) and mechanisms of disease transmission are not clear. Affection is frequent in the lungs, liver, spleen, ganglia, oropharynx and brain. Disease's response to therapy (Amphotericin, Ketoconazole) is good but recurrence is frequent. We have studied 12 patients with gallium-67, bone scintigraphy, bone marrow scintigraphy and lymph-scintigraphy. Six of these patients were re-studied after variable time of therapy. Gallium-67 accumulated in all patients's lungs. Other abnormal areas included ganglia, liver, spleen and bone. Bone scintigraphy was abnormal in all bone sites that were abnormal at the gallium study. Bone marrow scintigraphy showed expansion to the periphery in 6/12 cases and lymph nodes accumulated the radiopharmaceutical in 5 patients. Patients re-studied after the beginning of therapy presented decreased degrees or normalization of the radio-pharmaceutical's uptake (gallium and MDP), a regression of the bone marrow periphery expansion (bone marrow scintigraphy) and normalization of the lymph node aspects. These four radioisotopical studies may be useful for staging and for therapy follow-up. The sensitivity of the method is greater than the one noted for the conventional radiological studies.

[Keloid paracoccidioidomycosis assessed with gallium]. / La paracoccidioidomycose chéloïde étudiée avec le gallium.

This rare mycosis is caused by Paracoccidiodis loboii and is found mainly among indians of the Amazon forest. It is a cutaneous disease. No visceral affection was ever described, though generalized skin disease has been reported. One case of cheloid paracoccidioidomycosis was studied with gallium-67. The radiopharmaceutical has accumulated in the affected area and in a lymph node, although adenomegaly be rare. Degree of accumulation was discrete/moderate but the patient had been under irregular treatment for 10 years. As no laboratorial data are evaluable for this affection, gallium-67 may represent a means of disease extent and therapy efficacy evaluation.

Bronchial clearance of DTPA is increased in acute asthma but not in chronic asthma.

To investigate bronchial permeability in asthma, we measured the bronchial clearance of 113mIn-DTPA in seven asthmatics during and after an acute attack of asthma, seven asthmatics with chronic airflow limitation, and seven asthmatics without airflow limitation but with bronchial hyperresponsiveness to methacholine. We compared these results with those from seven normal subjects, seven patients with chronic bronchitis and bronchial infection, and seven patients with emphysema. An aerosol of 113mIn-DTPA was produced with a spinning disc to ensure a predominantly bronchial deposition of inhaled particles (6.3 microns MMAD). Radioactivity over the chest was recorded with a gamma-camera for 10 min after the subject inhaled the aerosol. Central regions of interest were selected, and the logarithm of the radioactivity was plotted against time; bronchial clearance of 113mIn-DTPA was calculated as the negative slope of the regression line. Clearance was substantially higher in asthmatics during their acute attacks than in all other groups (p less than 0.0001), and it decreased toward normal levels after recovery from the acute episode. The bronchial clearance of 113mIn-DTPA in all other groups did not differ from normal. We conclude that the bronchial clearance of 113mIn-DTPA is increased in asthmatics during attacks of asthma but in the stable state is not related either to bronchial hyperresponsiveness or to airflow limitation. Our findings are best explained by an increase in permeability of the bronchial mucosa of asthmatics during acute attacks.

[2 infectious granulomatous diseases (leprosy and cutaneous and mucous leishmaniasis) by scintigraphic methods]. / Contribution au début de l'étude de deux maladies infectieuses granulomateuses (la lèpre et la leishmaniose cutanée et muqueuse) par des méthodes scintigraphiques.

Leprosy is a multiform chronic infectious granulomatous disease caused by Mycobacterium leprae, that affects over 12 million people in the world. Cutaneous and mucous leishmaniasis (CML) is also a chronic granulomatous infectious disease, caused by Leishmania brasiliensis and transmitted to man by the mosquitoes of the Phlebotominae family. It is a worldwide spread disease. We studied one case of Borderline-wirchowian leprosy and 2 cases of CML with Gallium-67 (GA-67) scintigraphy. Ga-67 is a radiopharmaceutical known for its property of concentrating in inflammatory sites. In the leprosy patient, Ga-67 accumulated in the skin in a moderate, homogeneous and disseminated way (outlined skin); in the area of the face, the uptake was important and homogeneous (image in beard). Several internal organs accumulated Ga-67. As for the 2 CML patients, Ga-67 accumulated focally, in different degrees, in the affected anatomical areas. The leprosy patient was not under treatment and the 2 CML were under treatment (20 and 40 days, respectively). In the 3 cases, all affected areas accumulated Ga-67. Intensity differences of uptake may be explained both by different degrees of inflammatory processes (between leprosy and CML) and by treatment lasting. It is possible that Ga-67 scintigraphy may be useful for the evaluation of these 2 diseases extent and also for the therapy follow-up.