Comparison of [¹¹¹In]pentetreotide-SPECT and [¹8F]FDOPA-PET in the localization of extra-adrenal paragangliomas: the case for a patient-tailored use of nuclear imaging modalities.

AIMS AND METHODS: The aim of this prospective study was to compare the diagnostic value of [¹8F]FDOPA-PET and [¹¹¹In]pentetreotide-SPECT somatostatin receptor scintigraphy (SRS) in patients with nonmetastatic extra-adrenal paragangliomas (PGLs). Twenty-five consecutive unrelated patients who were known or suspected of having nonmetastatic extra-adrenal PGLs were prospectively evaluated with SRS and [¹8F]FDOPA-PET. ¹³¹I-MIBG and [¹8F]FDG-PET were added to the work-up in patients with a personal or familial history of PGL, predisposing mutations, abdominal PGLs, metanephrine hypersecretion and abdominal foci on SRS and/or [¹8F]FDOPA-PET. RESULTS: SRS correctly detected 23/45 lesions of which 20 were head or neck lesions (H&N) and 3 were abdominal lesions. [¹8F]FDOPA-PET detected significantly more lesions than SRS (39/45, P < 0·001). Both SRS and ¹8F-DOPA-PET detected significantly more H&N than abdominal lesions (66·7% vs 20%, P = 0·003 and 96·7% vs 67%, P = 0·012, respectively). In two patients with the succinate dehydrogenase D (SDHD) mutation, [¹8F]FDOPA-PET missed five abdominal PGLs which were detected by the combination of SRS, [¹³¹I]MIBG and [¹8F]FDG-PET. A lesion-based analysis using a forward stepwise logistic regression model demonstrates that size ≤ 10 mm (P = 0·002) and abdominal lesions (P = 0·031) were independently associated with "[¹8F]FDOPA-PET diagnosis only". In turn, a previous history of surgery and/or the presence of germline mutation was associated with lower lesion size (P = 0·001). CONCLUSIONS: The sensitivity of SRS for localizing parasympathetic PGLs is lower than originally reported, and [¹8F]FDOPA-PET is better than SRS for localizing small lesions. SRS should be replaced by [¹8F]FDOPA-PET as the first-line imaging procedure in H&N PGL, especially in patients at risk of multifocal disease (predisposing mutations and or previous history of surgery).

Performance in recognition memory is correlated with entorhinal/perirhinal interictal metabolism in temporal lobe epilepsy.

In addition to the hippocampus, the entorhinal/perirhinal cortices are often involved in temporal lobe epilepsy (TLE). It has been proposed that these anterior parahippocampal structures play a key role in recognition memory. We studied the voxel-based PET correlation between number of correctly recognized targets in a new recognition memory paradigm and interictal cerebral metabolic rate for glucose, in 15 patients with TLE with hippocampal sclerosis. In comparison to healthy subjects, patients had decreased recognition of targets (P<0.001) and ipsilateral hypometabolism (relative to side of hippocampal sclerosis) of the hippocampus, entorhinal/perirhinal cortices, medial temporal pole, and middle temporal gyrus (P<0.05, corrected by false discovery rate method). Performance correlated with interictal metabolism of ipsilateral entorhinal/perirhinal cortices (P<0.005, Spearman's rank test), but this relationship was not significant in the hippocampus itself (P>0.18, Spearman's rank test). These findings highlight the preferential involvement of entorhinal/perirhinal cortices in recognition memory in patients with TLE, and suggest that recognition memory paradigms may be useful in assessing anterior parahippocampal functional status in TLE.

Quality of life changes and clinical outcomes in thyroid cancer patients undergoing radioiodine remnant ablation (RRA) with recombinant human TSH (rhTSH): a randomized controlled study.

BACKGROUND: Recombinant human TSH (rhTSH) has become the modality of choice for radioiodine remnant ablation (RRA) in low-risk thyroid cancer patients. AIMS AND METHODS: The aims of the present prospective randomized study were to evaluate the impact of TSH stimulation procedure (hypothyroidism vs. rhTSH) on quality of life (QoL) of thyroid cancer patients undergoing RRA and to evaluate efficacy of both procedures. L-T4 was initiated in both groups after thyroidectomy. After randomization, L-T4 was discontinued in hypothyroid (hypo) group and continued in rhTSH group. A measure of 3.7 GBq of radioiodine was given to both groups. The functional assessment of chronic illness therapy-fatigue (FACIT-F) was administered from the early postoperative period to 9 months. Socio-demographic parameters, anxiety and depression scales were also evaluated (CES-D, BDI and Spielberger state-trait questionnaires). At 9 months, patients underwent an rhTSH stimulation test, diagnostic (131)I whole body scan (dxWBS) and neck ultrasonography. RESULTS: A total of 74 patients were enrolled for the study. There was a significant decrease in QoL from baseline (t0) to t1 (RRA period) in the hypothyroid group with significant differences in FACIT-F TOI (P < 10(-3)), FACT-G total score (P = 0.005) and FACIT-F total score (P = 0.003). By contrast, QoL was preserved in the rhTSH group. In the multivariate analysis, FACIT-TOI changes were only affected by the modality of TSH stimulation performed for RRA. From 3 to 9 months, changes of QoL scales and subscales were no longer statistically different in both groups of patients. Based on serum rhTSH-stimulated Tg alone (Tg < 0.8 microg/l, BRAHMS Tg Kryptor), no difference in ablation success was observed between rhTSH and hypothyroidism groups, 91.7% and 97.1%, respectively. A higher rate of persistent thyroid remnants was observed in the rhTSH arm, although in most cases uptake was < 0.1% and of no clinical significance. CONCLUSIONS: rhTSH preserves QoL of patients undergoing RRA with similar rates of ablation success compared to hypothyrodism. However, there is a wide heterogeneity in the clinical impact of hypothyroidism.

Management of cervical lymph node recurrence of melanoma of the head and neck.

OBJECTIVES: To compare the diagnostic accuracy between Positron emission tomography using 2-[fluorine-18] fluoro-2-deoxy-D-glucose (FDG-PET scan) and conventional work-up such as ultrasound (US) and/or Computed tomography (CT) in the detection of cervical lymph node recurrences of melanoma of the head and neck after initial cervical lymph node surgery. METHODS: A retrospective review was performed on patients who presented with clinical and/or radiological suspicion of isolated cervical lymph node recurrence after lymph node surgery from April 2004 to January 2007. All patients underwent CT and/or US of the neck, and FDG-PET scan before salvage neck dissection. None of included patients had clinical or radiological detectable distant metastases at the time of the lymph node dissection. Performances of conventional imaging and FDG-PET scan in detection of lymph node recurrence were calculated and compared by using the histopathological results of lymphadenectomy as gold standard with Fischer's exact test. RESULTS: Of the twelve cases in included in the study (9 patients, 3 of them had 2 consecutive lymph node redissection for a second lymph node recurrence), melanoma recurrence was found in 10 cases (83%). Sensitivity, specificity, positive predictive value and negative predictive values were 78.6%, 40%, 78.6%, and 40% respectively for conventional imaging and 85.7%, 40%, 80% and 50% for FDG-PET scan. No statistically significant difference was found between the 2 methods. CONCLUSION: This is the first study that compares the diagnostic accuracy between FDG-PET scan and conventional imaging in the detection of cervical lymph node recurrence of melanoma of the head and neck. Our results showed that FDG-PET scan is actually not better than conventional imaging to detect these cervical lymphatic recurrences.

The role of 18F-FDOPA and 18F-FDG-PET in the management of malignant and multifocal phaeochromocytomas.

BACKGROUND: (18)F-DOPA has emerged as a promising tool in the localization of chromaffin-tissue-derived tumours. Interestingly, phaeochromocytomas (PHEO) are also FDG avid. AIM AND METHODS: The aim of this study was to retrospectively evaluate the results of (18)F-FDOPA and/or (18)F-FDG-PET in patients with PHEO and paragangliomas (PGLs) and to compare the outcome of this approach with the traditional therapeutic work-up. Nine patients with non-MEN2 related PHEO or PGL were evaluated. At the time of the PET studies, the patients were classified into three groups based on their clinical history, conventional and SPECT imaging. The groups were malignant disease (n = 5, 1 VHL), apparently unique tumour site in patients with previous surgery (n = 1, SDHB) and multifocal tumours (n = 3, 1 VHL, 1 SDHD). (18)F-FDOPA and (18)F-FDG-PET PET/CT were then performed in all patients. RESULTS: PET successfully identified additional tumour sites in five out of five patients with metastatic disease that had not been identified with SPECT + CI. Whilst tumour tracer uptake varied between patients it exhibited a consistently favourable residence time for delayed acquisitions. (18)F-FDOPA uptake (SUVmax) was superior to (18)F-FDG uptake in cases of neck PGL (three patients, four tumours). If only metastatic forms and abdominal PGLs were considered, (18)F-FDG provided additional information in three cases (two metastatic forms, one multifocal disease with SDHD mutation) compared to (18)F-FDOPA. CONCLUSIONS: Our results suggest that tumour staging can be improved by combining (18)F-FDOPA and (18)F-FDG in the preoperative work-up of patients with abdominal and malignant PHEOs. (18)F-FDOPA is also an effective localization tool for neck PGLs. MIBG however, still has a role in these patients as MIBG and FDOPA images did not completely overlap.

Does 18F-FDG PET/CT add diagnostic accuracy in incidentally identified non-secreting adrenal tumours?

PURPOSE: The widespread use of high-resolution cross-sectional imaging such as computed tomography (CT) and magnetic resonance imaging (MRI) for the investigation of the abdomen is associated with an increasing detection of incidental adrenal masses. We evaluated the ability of (18)F-fluorodeoxyglucose positron emission tomography to distinguish benign from malignant adrenal masses when CT or MRI results had been inconclusive. METHODS: We included only patients with no evidence of hormonal hypersecretion and no personal history of cancer or in whom previously diagnosed cancer was in prolonged remission. PET/CT scans were acquired after 90 min (mean, range 60-140 min) after FDG injection. The visual interpretation, maximum standardised uptake values (SUVmax) and adrenal compared to liver uptake ratio were correlated with the final histological diagnosis or clinico-radiological follow-up when surgery had not been performed. RESULTS: Thirty-seven patients with 41 adrenal masses were prospectively evaluated. The final diagnosis was 12 malignant, 17 benign tumours, and 12 tumours classified as benign on follow-up. The visual interpretation was more accurate than SUVmax alone, tumour diameter or unenhanced density, with a sensitivity of 100% (12/12), a specificity of 86% (25/29) and a negative predictive value of 100% (25/25). The use of 1.8 as the threshold for tumour/liver SUVmax ratio, retrospectively established, demonstrated 100% sensitivity and specificity. CONCLUSION: FDG PET/CT accurately characterises adrenal tumours, with an excellent sensitivity and negative predictive values. Thus, a negative PET may predict a benign tumour that would potentially prevent the need for surgery of adrenal tumours with inconclusive conventional imaging.

[Radiography of scoliosis: comparative dosimetry between conventional technique and digital fluorography]. / Radiographie des scolioses: dosimétrie comparée entre la technique conventionnelle et la fluorographie numérique.

OBJECTIVE: Compare the irradiation delivered in conventional radiography and digital radiography by image intensifier during a scoliosis workup. PATIENTS AND METHODS: Our prospective randomized study included 105 patients, all of whom were identified according to sociodemographic parameters as well as criteria evaluating the quality of the full front spinal x-ray at PA incidence. The entry dose at the scapula and the exit dose in interorbital, thyroid, mammary, and hypogastric projection was measured by thermoluminescent dosimeters. RESULTS: The results of 71 girls and 28 boys, aged a mean 13.8 years with a mean weight of 47 kg were analyzed. At equal image quality, the entry dose was not significantly different between the two techniques; the mean exit dose reduction was 64% during digital acquisition. This reduction involved the interorbital (162%), mammary (43%), and thyroid (309%) regions. However, this system is more irradiating in the hypogastric region (34%). CONCLUSION: The dosimetric evaluation of the different imaging techniques used to explore the entirety of the spine should be part of radiologists' quality standard used to document their work and their choices.

[Role of [18]-FDG PET/CT in the initial staging of head and neck cancers]. / Apport de la [18F]-FDG TEP/TDM dans la stadification initiale des cancers de la tête et du cou.

OBJECTIVE: To evaluate the impact of fusion of positron emission tomography with computed tomography (FDG-PET/CT) in the initial staging of head and neck carcinomas. METHODS: This retrospective study included 44 patients with squamous cell carcinoma of the upper aerodigestive tract. Patients underwent a standard workup and a PET/CT image fusion during the initial staging. The standard workup included CT scan of the head, neck and chest, panendoscopy under general anaesthesia, oesophageal endoscopy and abdominal echography. Potential additional diagnostic value of PET/CT was evaluated. RESULTS: Findings between PET/CT and standard workup were concordant in 41/44 cases for primary tumour in 79/88 cases for lymph node staging, in 36/44 cases for distant metastases (or distant second primary) and in 41/44 cases for synchronous second primaries of the upper aero-digestive tract. PET/CT leads to a change of treatment for 6.8% of patients (1 for lymph node staging and 2 for distant metastases). 17.2% of pathological FDG uptake foci found by PET/CT were false-positives results. CONCLUSION: PET/CT enables to realise a whole body check-up in a single time. However, it cannot be used alone, due to its lack of spatial resolution: It must be used in complement of the standard workup. This high rate of false-positive findings, asking for further expensive diagnostic procedures, limits its usefulness.

Incidence of salivary side effects after radioiodine treatment using a new specifically-designed questionnaire.

Sialadenitis is one of the common complications of radioiodine treatment for thyroid malignancy. The aim of this study was to evaluate the prevalence of radioiodine-induced sialadenitis and other side effects by using a self-administered questionnaire. From 1 January 2011 to 31 December 2012 all consecutive patients with a newly-established diagnosis of thyroid cancer who were treated with adjuvant radioiodine at La Timone University Hospital were sent a self-administered questionnaire on salivary complaints that had been specifically designed for this study. A total of 413 patients sent the questionnaire back, of whom 100 (24%) had experienced pain, 116 (28%) discomfort or swelling, and 147 (36%) dry mouth or xerostomia. This survey has highlighted the number of side effects of radioiodine treatment in a large group of patients and corroborates previous observations. Our new self-administered questionnaire may be useful to others for follow-up and research.

Early sequential changes in serum thyroglobulin after radioiodine ablation for thyroid cancer: possible clinical implications for recombinant human thyrotropin-aided therapy.

TNM status and posttherapy whole-body scan findings aid in risk stratification of patients with thyroid cancer during initial therapy. Recently, the thyroglobulin (Tg) value measured during hypothyroidism just before 131I therapy (preablation Tg) has proved to be effective for predicting persistent/recurrent disease. In this study, we assessed the changes in serum Tg 48 hours after radioiodine ablative therapy performed in the hypothyroid state in order to evaluate if this parameter could be used in recombinant human thyrotropin (rhTSH)-treated patients. Because rhTSH-stimulated TG is traditionally measured 72 hours after the second injection of rhTSH corresponding to 48 hours post-131I therapy, the time course of serum Tg after radioiodine administration is an important clinical issue. To address this issue, we performed a prospective evaluation of 26 consecutive patients with low-risk differentiated thyroid cancer hypothyroidism for radioiodine ablation (3.7 GBq of 131I). Baseline Tg values were compared to posttherapy Tg values (at 24 and 48 hours). We found that Tg increased after 131I therapy because of the acute radiation effects on residual thyroid cells. Median values at each of the three time points were 1.8 ng/mL (baseline), 3 ng/mL (Tg-24), and 11.3 ng/mL (Tg-48) (Brahms Tg Kryptor assay, Brahms AG, Berlin, Germany). Tg-48 values were not statistically correlated with initial Tg values. Tg-48 remained below 15 ng/mL in 14 of 26 patients. In conclusion, the increase in Tg during the early post-131I therapy period means that first rhTSH-stimulated Tg cannot be used as a corresponding value for preablative hypo-Tg. We discussed whether rhTSH-stimulated Tg value might be useful in a subset of patients. In our opinion, this drawback does not outweight the expected benefits of rhTSH-aided therapy on quality of life of patients and overall cost of the therapy.

[Contribution of 18-F-FDG PET for detection of head and neck carcinomas with an unknown primary tumor]. / Apport du TEP scanner au [18F]-FDG dans les adénopathies cervicales primitives.

OBJECTIVES: To evaluate the usefulness of fusioning positron emission tomography with computed tomography (PET/CT) for the detection of head and neck carcinomas of unknown primary. METHODS: This prospective study included 20 patients with cervical lymph node of squamous cell carcinoma of unknown primary after standard initial workup (nasofibroscopy and CT scan of the chest and head and neck). Patients underwent PET/CT and panendoscopy of the upper airways and upper digestive tract with PET/CT directed biopsies. The follow-up was 6 months minimum in all patients. RESULTS: A potential primary tumor was found in 10 of the 20 cases and confirmed by histology in 7 cases (3 bases of tongue, 1 tonsillar pillar, 1 vallecula, 1 tonsillar fossa, 1 piriform sinus). Four of these seven patients presented a normal endoscopy (diagnosis was made with submucosal PET/CT directed biopsies). PET/CT was normal in 10 of 20 cases with 3 false negatives. The sensitivity of PET/CT was 70%, the specificity was 70% and the accuracy was 70%. CONCLUSION: PET/CT seems to be of interest in the detection of head and neck carcinoma of unknown primary. PET/CT detected 15% of unknown primary tumors with treatment-related implications.

[Contribution of 18FDG PET/CT post treatment surveillance of head and neck squamous cell carcinoma]. / Intérêt de la TEP au 18FDG couplée à la TDM dans la surveillance post-thérapeutique des carcinomes épidermoïdes des voies aérodigestives supérieures.

OBJECTIVE: To evaluate the contribution of 18FDG positron emission tomography for the post treatment surveillance of head and neck carcinomas. METHODS: : This prospective study included 61 patients with advanced squamous cell carcinoma of the upper airways and/or digestive tract and who underwent curative treatment. Patients underwent a standard workup (physical examination, CT scan and panendoscopy) and a PET/CT image fusion 3 months after the end of treatment. The follow-up was 6 months minimum in all patients after this workup. PET/CT was evaluated in terms of: primary tumor, cervical lymph nodes, metastases and overall patient assessment. RESULTS: : For diagnosis of the primary tumor, the sensitivity, specificity, positive predictive value, negative predictive value and accuracy of PET/CT were respectively 86.7%, 82.6%, 62%, 95% and 83.6%. Values for cervical lymph nodes were: 100%, 98.2%, 80%, 100% and 98.3%. Values for metastases were: 100%, 92.2%, 66.7%, 100% and 93.2%. Values for overall patient assessment were: 88.8%, 78.1%, 64%, 94.1% and 81.4%. Performances of PET/CT were better than standard workup in 22% of patients. CONCLUSION: PET/CT contributes useful information in this indication, particularly an excellent negative predictive value.

[Medico-surgical treatment of occlusion of the left pulmonary artery by extension of ductal tissue (pulmonary coarctation)]. / Traitement médico-chirurgical de l'occlusion de l'artère pulmonaire gauche par extension de tissu ductal (coarctation pulmonaire).

The authors report the results of surgical treatment completed by interventional catheterisation of occlusion of the left pulmonary artery by extension of ductal tissue. Since 2001, 7 patients operated for occlusive coarctation of the left pulmonary artery at an average age of 11 months (3 to 37 months) had a restenosis. The cardiac malformation was pulmonary atresia with ventricular septal defect (N=4), tetralofy of Fallot (N=2) and critical pulmonary valvular stenosis (N=1). Pulmonary artery surgery consisted of resection anastomosis in 4 cases and a plasty in 3 cases. A primary angioplasty was performed 5 to 170 months (median 12 months) later, at an average age and weight of 3.4 years (0.7 to 16.9 years) and 14 Kg (8 to 52 Kg) with implantation of 3 stents. The median diameter increased from 5 mm (1 to 9 mm) to 10 mm (6 to 16 mm). Tc-99m scintigraphy showed an increase in mean left pulmonary perfusion from 9% (6 to 28%) to 28% (18 to 42%). Secondarily, 3 repeat angioplasties were necessary with a total of 6 stents implanted in 7 patients. After an average of 2.9 years (0.8 to 6.3 years) follow-up, the patients were asymptomatic with normal right ventricular pressures and a mean left pulmonary perfusion of 33% (24 to 45%). The authors conclude that the treatment of left pulmonary occlusion by coarctation requires a medico-surgical approach in which angioplasty and stenting complete successfully the surgical revascularisation.

Effect of the energy density of a solid-liquid meal on gastric emptying and satiety.

The effect of the energy density of a meal on gastric emptying and satiety was assessed in nine volunteers. They ingested, in randomized order, a diluted (2671 kJ/L, 950 mL) and a concentrated (7452 kJ/L, 350 mL) test meal of 2500 kJ each (80% as solids). Half-emptying times of solids and liquids were not significantly different for the diluted and concentrated meal (solids: 145 +/- 18 and 156 +/- 16 min, respectively; liquids: 76 +/- 10 and 84 +/- 10 min, respectively), and consequently, pyloric outputs of energy were identical. Neither the intensity and duration of satiety, nor the amount of energy ingested, ad libitum, 6 h after the test meal, were significantly affected by energy density of the food ingested. Both the intensity and duration of satiety correlated significantly with the gastric emptying time for solids (r = 0.60 and 0.67, respectively, P < 0.01). These results show that satiety depends on gastric emptying of energy and is not affected by the energy density of food intake.

Advantages of SPECT in technetium-99m-sestamibi parathyroid scintigraphy.

UNLABELLED: We demonstrate several advantages of SPECT in parathyroid scintigraphy. METHODS: Forty-four parathyroid 99mTc-MIBI scintigrams were obtained before surgery in 43 patients suffering from hyperparathyroidism. For each patient, we obtained dynamic views and planar and SPECT images of the neck and thorax. For 15 patients, we also acquired a delayed static view of the neck 2 hr after tracer injection. Abnormal thyroid-area glands were detected with factor analysis of dynamic structure (FADS) of the initial dynamic acquisition. In the 15 patients with delayed views of the neck, we compared FADS and the double-phase study results to detect glands in the thyroid uptake area. Glands outside the thyroid area were demonstrated on planar views. The location of enlarged glands was more precisely defined on the tomographic slices. The anatomic and histologic findings and the evolution of hypercalcemia after surgery were taken as reference. RESULTS: Sixty-four abnormal glands were found during surgery, including 39 observed in patients who underwent reoperation for persistent or recurrent hyperparathyroidism. Twenty-two of these glands were in an abnormal location, including 10 in the mediastinum. SPECT allowed the detection of three glands not demonstrated on planar views or FADS. Fifty-eight glands were correctly localized scintigraphically, including 34 in patients who underwent reoperation. Therefore, SPECT raised the sensitivity from 86% to 90.5% and from 79.5% to 87% in the reoperated patients. Tracer uptake in the low mediastinal area was better analyzed on tomographic slices than on planar views. Only seven false-positive results were depicted by planar views or FADS; none were depicted on SPECT. CONCLUSION: A combination of FADS and SPECT permits detection of small glands, even in a posterior location, inside or outside the thyroid area. This scintigraphic method enables the surgeon to define more precisely details about the location of the enlarged gland and contributes to improved parathyroid surgery.

Somatostatin receptor scintigraphy in pituitary adenomas: a somatostatin receptor density index can predict hormonal and tumoral efficacy of octreotide in vivo.

UNLABELLED: Previous studies have failed to predict somatostatin analog response with somatostatin receptor scintigraphy in pituitary adenomas. In vitro studies have shown that the density of somatostatin receptors in pituitary tumors might be critical for octreotide response. METHODS: The density of somatostatin receptors was calculated in vivo combining the uptake index obtained from somatostatin receptor scintigraphy and the tumor volume obtained by MRI. The ratio of these two values, called density index (DI), was established in 32 of 37 consecutive patients with pituitary adenomas (11 had growth hormone-secreting adenomas, 4 thyroid-stimulating hormone-secreting and 17 nonfunctioning). It was compared with hormonal response, assessed in 15 secreting adenomas on growth hormone or thyroid stimulating hormone suppression (which was considered significant when it reached at least 50% of basal level), and with tumor shrinkage (which was considered significant when > or =20% of pretherapeutic value) in 12 secreting and 14 nonfunctioning adenomas. RESULTS: In agreement with previous reports, uptake index is not predictive of octreotide response. In contrast, DI predicts both hormonal suppression and tumor shrinkage (P = 0.009 and P = 0.0002, respectively) obtained with octreotide therapy. DI sensitivity, specificity and accuracy were 92% each, and a positive correlation was found between DI and the percentage of tumor shrinkage (r = 0.54, P = 0.004). CONCLUSION: The combination of scintigraphic and MRI data allows the computation of a DI for somatostatin receptors that points out patients who can profit from somatostatin analog treatment.

Mechanisms of postoperative prolonged plasma volume expansion with low molecular weight hydroxethy starch (HES 200/0.62, 6%).

OBJECTIVE: To define the mechanisms of the stable and prolonged post-operative plasma volume expansion observed with Hydroxyethyl Starches (HES) and to determine whether a partial intravascular hydrolysis of large molecules contribute to reinforce the colloid-osmotic effect. DESIGN: Prospective, pharmacologic study using single dose of drug. SETTING: University-based, post-anesthesia care unit. PATIENTS: The protocol was performed during the post-operative period, in 10 patients after stable recovery from general anesthesia for carotid endarterectomy. INTERVENTIONS: HES 200/0.62 (500 ml) was infused over 30 min. Standard hemodynamic and biological variables, HES concentration and colloid osmotic pressure were obtained at each measurement. Plasma volume was calculated using 51Cr-labelled RBCs. Patterns of changes in number average molecular weight (MWn) and weight average MW (MWw) were measured using gel permeation chromatography. Measurements were obtained at control, end of infusion, 1 h, 3 h, 6 h and 24 h after infusion. MEASUREMENTS AND MAIN RESULTS: Plasma volume increased by 693 ml (+21%) after the infusion of HES and remained constant over 24 h. HES concentration progressively decreased to reach a value of 35% of the peak at 24 h. MWn and MWw, initially decreased when compared with the dose solution and changed little in the 24 h study period. Diuresis significantly decreased at 3 h up to 24 h. Plasma albumin decreased after infusion and then progressively increased to reach a significantly higher value at 24 h than after infusion. CONCLUSION: Initial plasma volume expansion and decrease in HES concentration agree with previously-published data. Maintenance of plasma volume expansion over 24 h was not related to a partial intravascular hydrolysis. Low elimination rate of HES, extravascular mobilization of albumin and post-operative renal adaptations were possibly the 3 main mechanisms to explain a prolonged plasma volume expansion with HES 200/0.62, 6%.

Low molecular weight hydroxyethyl starch 6% compared to albumin 4% during intentional hemodilution.

Intentional normovolemic hemodilution was chosen as the model to compare a 6% low molecular weight hydroxyethyl starch (LMW HES) to 4% albumin. The study ran over the plasma exchange period for 24 h. Nine patients, scheduled for abdominal aortic surgery, were included in each group. After basal measurements, blood was withdrawn and simultaneously replaced by either 4% albumin (Group 1) or 6% LMW HES (Group 2) to achieve a final hematocrit of approximately 30%. Hemodynamic blood oxygen gas and hormonal plasma levels were determined before hemodilution then at 30 min, 1, 2, 3, and 24 h after the end of hemodilution. Basal value for total blood volume was 4377 +/- 162 ml in group 1 and 4138 +/- 315 ml in group 2. As in both groups the decrease in blood cell volume was exactly compensated by the increase in plasma volume, no significant change in total blood volume (respectively 4432 +/- 159 and 4305 +/- 267 ml) was observed. Throughout the study, in both groups, no significant change in mean arterial and right atrial pressures was observed. In group 2 (LMW HES), a significant increase of pulmonary capillary wedge pressure was noted 120 min after hemodilution. After hemodilution, despite a significant decrease in arterial oxygen O2 content, systemic oxygen transport did not significantly vary until 24 h in relation to the increased cardiac index. An increase in O2 extraction was observed after the exchange but no further increase was observed until the 24 h. No significant changes either in global O2 consumption or in lactate concentration were detected.(ABSTRACT TRUNCATED AT 250 WORDS)

A new quantitative D-dimer assay appropriate in emergency: reliability of the assay for pulmonary embolism exclusion diagnosis.

Plasma D-dimers, degradation products of cross-linked fibrin, are elevated in several thrombotic diseases. In the last decade, their measurement has been performed with specific monoclonal antibody based ELISA assay, with a high negative predictive value of such pathologies. However these methods have a low clinical impact since they cannot be used in emergency because they are time consuming and require series. Recently, rapid tests have been proposed with similar accuracy and are feasible for use in emergency conditions. The aim of our study was to evaluate the potential value of a new quantitative rapid assay, based on agglutination of latex microparticles coated with two monoclonal antibodies specific for D-dimers (Liatest D-Di, Diagnostica Stago), in the exclusion diagnosis of pulmonary embolism (PE). Eighty-five consecutive suspected PE patients were included in the study. D-dimer determination was performed with both standard ELISA and Liatest D-Di just before pulmonary scintigraphy. Sixty-nine patients were free of PE and 16 had PE. Our results confirm the excellent sensitivity and negative predictive values of the conventional D-dimer ELISA. Using a cut-off value of 500 ng/ml, the sensitivity and the negative predictive values of Liatest D-Di were 94% and 96%, respectively. Only one case of PE had a D-dimer value at 480 ng/ml, close to the cut-off value. This study demonstrates that the Liatest D-Di assay is sensitive enough to be used as the first step in the assessment of PE. However, the best cut-off value has to be determined to get an exclusion diagnosis with certainty.

Subcutaneous administration of recombinant human thyrotropin as an alternative to thyroid hormone withdrawal in patients with anticoagulated thyroid cancer: preliminary results.

For patients with thyroid cancer taking anticoagulants, because of hematoma risk at the injection site, intramuscular injections (IM) of recombinant human thyrotropin (rhTSH) are usually avoided and patients remain hypothyroid. The aim of the present study was to evaluate if subcutaneous injections (SC) of rhTSH are an alternative to IM. Five consecutive patients receiving anticoagulants were evaluated. The dose regimen was similar to the traditional follow-up protocol (2 x 0.9 mg, SC route). rhTSH administration elicited a sharp and prompt increase in serum TSH that peaked at day 3 (24 hours after the second rhTSH injection), with mean values of 246 +/- 68 mU/L. In one patient with a large thyroid remnant, thyroglobulin (Tg) rose from 18 ng/mL to 450 ng/mL. No adverse effects were observed. We conclude that SC injection of rhTSH represents a safe and efficient procedure in the monitoring of patients with thyroid cancer taking anticoagulants.