Percutaneous thermal ablation of primary and secondary lung tumors: Comparison between microwave and radiofrequency ablation.

PURPOSE: The purpose of this study was to retrospectively compare microwave (MWA) and radiofrequency (RFA) ablation in the percutaneous treatment of primary and secondary lung tumors. MATERIAL AND METHODS: A total of 115 patients with a total of 160 lung tumors (primary, n=41; secondary, n=119) were retrospectively included. There were 56 men and 59 women with a mean age of 67.8±12.7 (SD) years (range: 42-89 years) who underwent either MWA (61 patients; 79 tumors) or RFA (54 patients; 81 tumors). The primary study endpoints were local recurrence during follow-up and the incidence of complications during and following thermal ablation. The MWA and RFA groups were compared in terms of treatment efficacy and complication rates. RESULTS: Demographics were similar in the two groups. Mean tumor diameter was smaller in RFA group (13.1±5.1 [SD] mm; range: 4-27mm) than in MWA group (17.1±8.3 [SD] mm; range: 5-36mm) (P<0.001). Ablation volumes at one month were 24.1±21.7 (SD) cm3 (range: 2-97.8 cm3) in RFA group and 30.2±35.9 (SD) cm3 (range: 1.9-243.8 cm3) in MWA group (P=0.195). During a mean overall follow-up duration of 488±407 (SD) days (range: 30-1508 days), 9/160 tumors (5.6%) developed local recurrence: six (6/79; 7.6%) in the RFA group and three (3/81; 3.7%) in the MWA group (P=0.32). Pneumothoraces were more frequent in the RFA group (32/79; 40.5%) than in the MWA group (20/81; 24.7%) (P=0.049). The mean length of hospital stay was 4.5±3.7 (SD) days (range: 1-25 days) in the RFA group and 4.7±4.6 (SD) days (range: 2-25 days) in the MWA group (P=0.76). CONCLUSIONS: MWA favorably compares with RFA and can be considered as an effective and safe thermal ablation technique for lung tumors, especially in situations where RFA has limited efficacy.

Chart for renal tumor microwave ablation from human study.

PURPOSE: To define microwave ablation (MWA) charts according to time and power in human renal tumors and to compare them to the charts given by the HS AMICA manufacturer. MATERIALS AND METHODS: A total of 54 patients with 54 renal cancers who underwent MWA were included. There were 36 men and 18 women with a mean age of 72.5±10[SD] years (range: 40-91years). The system used for MWA was HS AMICA with the Amica-probe V4 applicator. The following variables (antero-posterior diameter, transverse diameter, cranio-caudal diameter and volume were measured on computed tomography examinations performed one month after MWA. The dimensions of the ablation zone were correlated with power (40 or 60W) and exposure time (5, 10 and 15min) used for MWA. Actual ablation dimensions were compared to the manufacturer's data. RESULTS: The variation of diameters, with a longer ablation time, was linear at 40W with a volume increase of 30% for each additional 5minutes. At 60W, a more pronounced variation (volume increase of 112%) was observed. Compared to the manufacturer's chart, significantly larger ablation zones were obtained (P<0.05), the differences being mainly marked for the antero-posterior diameter (≥1cm). CONCLUSION: MWA using AMICA generator produces reproducible ablation area for given time and power in renal tumor ablation. The charts presented here should be used instead of the manufacturer's chart, which is based on porcine liver and is significantly different.

Shear wave elastography: An accurate technique to stage liver fibrosis in chronic liver diseases.

OBJECTIVES: The goals of this study were to assess the diagnostic accuracy of shear wave elastography (SWE) using the results of histopathological analysis as a standard of reference and compare the results of SWE and those of transient elastography (TE) to the degree of fibrosis as evaluated by histomorphometry. PATIENTS AND METHODS: Adult patients who were scheduled to undergo liver biopsy were prospectively enrolled in the study. The diagnostic performances of SWE were assessed using AUROC curve analysis according to fibrosis thresholds defined by ≥F2 (significant fibrosis), ≥F3 (advanced fibrosis) and F4 (cirrhosis). Additional analyses using the Obuchowski measures for pairwise comparisons of fibrosis stages were performed. In a subgroup of 55 patients, the relationships between stiffness as measured using SWE and TE and the percentage of fibrosis were compared using Spearman's rank coefficient. RESULTS: Among the initially enrolled 170 patients, 148/170 (87%) had successful SWE acquisition and formed the study population. SWE sensitivity and specificity were respectively 85.1% and 82.7% (≥F2), 88.9% and 90.3% (≥F3), 93.3% and 98.3% (F4). The AUROC curves of SWE along with their 95% confidence intervals (CI) were respectively 0.904 (95%CI: 0.845-0.946) for fibrosis ≥F2; 0.958 (95%CI: 0.912-0.984) for fibrosis ≥F3 and 0.988 (95%CI: 0.955-0.999) for fibrosis=F4. The global Obuchowski measure was 0.953±0.007. In the subgroup study, a significant correlation was found between the percentage of fibrosis and stiffness as assessed by SWE (r=0.77; 95%CI: 0.63-0.86; P<0.0001) and by TE (r=0.65; 95%CI: 0.47-0.78; P<0.01). CONCLUSION: SWE is accurate to assess liver fibrosis in patients with chronic liver disease.

Treatment of hepatocellular carcinomas by thermal ablation and hepatic transarterial chemoembolization.

Local tumor recurrence after thermal ablation of hepatocellular carcinoma (HCC) can impact on overall survival and are very closely linked to partial treatment of the primary lesion or to potential microvascular invasion or satellite micronodules located close to the main lesion. The diagnosis of these liver metastases close to the primary lesion on CT and MRI is difficult and their incidence, number and spread throughout the liver correlates with diameter of primary tumor. Tumor diameter is currently the key factor to predict whether or not thermal ablation of HCC will be complete or not. It has now been shown for monopolar radiofrequency ablation that this therapy alone is sufficient to effectively treat single HCCs<3cm in diameter provided that liver micrometastases are not present. If the HCC is>3cm in size, multifocal or in the case of tumor recurrence, overall survival and recurrence-free survival results are better if monopolar radiofrequency ablation is combined with hepatic trans-arterial chemoembolization. The timing of this combination of treatments probably influences its effectiveness on tumor and tolerability and remains to be assessed.

[Disseminated nocardiosis in a child with acute lymphoblastic leukemia]. / Nocardiose viscérale disséminée chez un enfant atteint de leucémie aiguë lymphoblastique.

Nocardiosis is a rare infectious disease in children. We report here a disseminated nocardiosis in a child with acute lymphoblastic leukemia. The patient presented prolonged febrile neutropenia and nodular pneumopathy. Based on the amplification of a 16S rDNA, a PCR assay detected Nocardia sp. in the patient's bronchoalveolar lavage (BAL) fluid. Culture of BAL samples yielded Nocardia nova colonies after 2 weeks of incubation. Hepatic, splenic, renal and cerebral localisations were detected on extension checkup. trimethoprime-sulfamethoxazole and amikacine were started given the results of PCR assay, with a good response. Improvement of the patient's general condition led to complete chemotherapy under ciprofloxacine and ceftriaxone treatment, without nocardiosis reactivation. Nocardiosis is a rare complication in children with acute lymphoblastic leukemia. trimethoprime-sulfamethoxazole prophylaxis is widely used to prevent Pneumocystis jiroveci infection in children with haematologic malignancies. As Nocardia species are usually sensible, trimethoprime-sulfamethoxazole could play a role in Nocardia prophylaxis in such population. In our patient, compliance with trimethoprime-sulfamethoxazole had been low. Nocardia species are relatively fastidious growth bacteria and are difficult to isolate with classical bacteriological techniques. Molecular methods are now available, with a good sensitivity and fast results allowing to start an appropriate antibiotherapy before culture results, as early treatment is a major prognosis factor in nocardiosis. Nocardia infection should be suspected in case of nodular pneumopathy in immunocompromised children. An extension checkup should be performed to detect secondary localisations.

[HIV associated nephropathy syndrome: a case report in Dakar]. / Syndrome de néphropathie liée au VIH: une observation a Dakar.

HIV associated nephropathy syndrome ( HIVAN Syndrome ) is a recently identified entity and no study has been done in Senegal. So we report this observation. A 40 years old black patient was admitted for renal oedema syndrome and immunosuppressive signs. The biological investigations noticed a non-pur nephrotic syndrome and severe renal failure. Ultrasonography showed quite normal kidney sizes with hyper echogenicity and dediferenciation. HIV research was positive with 45 CD4 lymphocytes / mm3. This patient had no known causes of nephrotic syndrome ( diabetis, lupus ,amyloidosis.). So the diagnosis of HIVAN syndrome was determined with the clinical features and the bad outcome. We emphasize on the necessity to think about HIVAN in every black patient presenting a quickly progressive non-pur nephrotic syndrome. We expect prospectives studies to describe the clinical signs and the frequency of HIVAN syndrome in Senegal.

Dual energy X-ray absorptiometry of the hand and wrist--a possible technique to assess skeletal maturation: methodology and data in normal youths.

Ninety five normal Caucasian subjects (51F, 44M) aged from 2 to 25 y were measured at the hand and wrist level with a small DXA system (pDEXA) in order to obtain the normal values of the bone mineral content (BMC), density (BMD) and projected area (A) of carpal (c) and metacarpal (m) bones. BMDc ranged from 0.065 +/- 0.007 g/cm2 to 0.365 +/- 0.035 g/cm2 in females and 0.425 +/- 0.040 g/cm2 in males. It presented a sharp change of increase rate at 15.5 and 17 y of age in girls and boys, respectively. Ac presented the same kind of evolution as BMDc, but had a larger value dispersion. The second metacarpal bone had the highest BMCm value in 85% of females and 90% of males. The sum of BMCmi or Ami values (i = 1-5) and the projected mean density of the 5 metacarpal bones was well correlated with BMCc, Ac and BMDc, respectively (r > 0.90). A volumetric mineral density, dmi, calculated for each of these bones, approximated to a cylinder, was correlated with age (r > 0.85).

MR cholangiography in neonates and infants: feasibility and preliminary applications.

OBJECTIVE: The objective of the study was to evaluate the accuracy of MR cholangiography in showing the biliary tree in neonates and infants and to show preliminary applications in a pediatric population. SUBJECTS AND METHODS: MR cholangiography was performed with T2-weighted turbo spin-echo sequences (8000/300 [TR/TE], six or eight excitations). The study included seven patients with suspected bile duct disorders and 10 control individuals. RESULTS: In the control group, the extrahepatic bile ducts (EHBDs) were revealed by MR cholangiography in all patients. In one of the five patients with neonatal cholestasis, biliary atresia was excluded by identifying the entire EHBD on MR cholangiograms. In the four other patients with neonatal cholestasis, biliary atresia was suspected because the EHBD could not be seen on MR cholangiography. The diagnosis was confirmed in three of these four patients, in whom the MR finding was associated with significant periportal thickening. In the remaining patient, in whom periportal thickening was not seen, sclerosing cholangitis was diagnosed on biopsy. In the sixth patient with neonatal cholestasis, who had received a liver transplant, MR cholangiography showed biliary dilatation above the biliary-digestive anastomosis. In the seventh patient, a neonate with a prenatal diagnosis of hepatic cyst, MR cholangiography showed a choledochal cyst. CONCLUSION: MR cholangiography may become an important diagnostic tool in the detection of biliary atresia, congenital choledochal dilatation, and biliary complications in hepatic transplantation for pediatric patients.

MRI in Sturge-Weber syndrome.

Five children (3 girls, 2 boys, aged from 1 to 18 years) presenting with Sturge-Weber syndrome were explored by MRI with contrast injection in 2 cases. The respective positions of CT and MRI are discussed: CT is the method of choice to display leptomeningeal calcifications. MRI seems to be more accurate than CT to determine the location of the lesions and to demonstrate the enhancement of the angioma after contrast injection.