The role of 18F-FDG PET/CT in the metabolic characterization of lung nodules in pediatric patients with bone sarcoma.

BACKGROUND: The principal aim of this study was to identify the lowest nodule diameter and the SUV(max) capable of characterizing lung nodules in pediatric patients with bone sarcoma. PROCEDURE: Eighteen consecutive bone sarcoma patients (M/F = 11:7; mean age 14 years) with suspicious lung lesions at CT were enrolled. Overall, 63 lung nodules with a mean diameter of 3.35 mm (range 1.2-39.8 mm) were investigated. (18) F-FDG PET was performed according to standard procedure using a hybrid PET/CT system and results were compared with histology and/or clinical/radiological follow-up. For each lesion, we evaluated SUV(max) , SUV(ratio) to the mediastinal blood pool and maximum nodule diameter. RESULTS: Of the 63 nodules, 32 proved to be benign and 31 malignant. On a visual basis, (18) F-FDG PET had an accuracy of 88.9%, a sensitivity of 90.3%, a specificity of 87.5%, a PPV of 87.5%, and a NPV of 90.3%. ROC curve analysis of SUV(max) for all nodules showed a value around 1 (>1.09) to be capable of differentiating metastases from benign lesions: sensitivity and specificity were 90.3% and 93.8%, respectively (accuracy 92.1%). Similar analysis revealed a cut-off value around 1 (>0.83) for SUV(ratio) (sensitivity and specificity were 90.3% and 90.6%, respectively) and a cut-off value of ca. 6 mm (>5.8 mm) for nodule diameter (sensitivity and specificity of 90.3% and 81.3%, respectively). CONCLUSIONS: (18) F-FDG PET/CT is an accurate modality for the metabolic characterization of lung nodules in the pediatric population with bone sarcoma, and a SUV(max) (or SUV(ratio) ) >1 is capable of discriminating malignant from benign lesions.

Is thrombocytopenia suggestive of organism-specific response in neonatal sepsis?

BACKGROUND: It is controversial whether thrombocytopenia is suggestive of one (or more) causative agents of neonatal sepsis: a low platelet count has been related in turn to Gram-positive, Gram-negative or fungal sepsis. METHODS: A retrospective, cohort study on 514 very low-birthweight (VLBW) neonates admitted over a 9 year period to a large tertiary neonatal intensive care unit (NICU) in Italy was carried out. Through database search, data on platelet counts, sepsis, clinical course, and microbiological culture were collected and analyzed. Statistical analysis was performed to look for significant association between thrombocytopenia and sepsis caused by different (Gram-positive, Gram-negative or fungal) organisms. RESULTS: Sepsis diagnosed on microbiological criteria occurred in 197 of 514 VLBW neonates (38.3%), and thrombocytopenia (at least one finding of platelet count <80,000/mm(3)) was detected in 34 (17.2%) of the 197 septic infants. Thrombocytopenia occurred in 10 of 51 neonates with fungal sepsis (19.6%), and in 24 of 146 with bacterial sepsis (16.4%; P = 0.37). The difference was not significant when clustering for sepsis caused by Gram-positive (nine thrombocytopenic of 51 with Gram-positive sepsis, 17.6%; P = 0.40) and Gram-negative organisms (15/95, 15.7%; P = 0.22), or when considering only coagulase-negative Staphylococcus sepsis (6/37, 16.2%; P = 0.25). CONCLUSIONS: In contrast with previous reports, thrombocytopenia might not be an organism-specific marker of sepsis. Caution should be maintained in relating a low platelet count to any infectious agent (or group of agents) in preterm VLBW neonates.

Routine use of fluconazole prophylaxis in a neonatal intensive care unit does not select natively fluconazole-resistant Candida subspecies.

BACKGROUND: We have previously demonstrated efficacy against fungal colonization and infection of fluconazole prophylaxis that was routinely administered since 2001 in our ICU for preterm infants <1500 g at birth (VLBW). With prolonged use, concerns exist for the emergence of acquired fungal resistance and of Candida subspecies that are natively fluconazole-resistant (NFR), mostly Candida glabrata and Candida krusei. METHODS: We evaluated retrospectively all clinical and surveillance fungal isolates obtained from VLBW infants in our NICU during a 10-year period (1997-2006). Each fungal isolate was speciated, infants colonized or infected with NFR-Candida spp were identified and the incidence rates of colonization and infection by these fungal species were calculated. A comparison was made of the 6-year (2001-2006) prophylaxis period with the 4-year (1997-2000) preprophylaxis period. RESULTS: Overall, colonization by NFR-Candida spp ranged between 2.8% and 6.6% of VLBW infants yearly admitted, without any increasing trend during the study period. There were 18 of 434 (4.1%) neonates colonized by these species. Five episodes of systemic fungal infections caused by NFR-Candida spp occurred (incidence rate, 1.1%). No significant differences were detected when compared with the preprophylaxis period, when 11 of 295 infants (3.7%) were colonized by NFR-Candida spp and 4 episodes of infection occurred (1.4%) (P = 0.84 and 0.76, respectively). CONCLUSIONS: Fluconazole prophylaxis administered to VLBW neonates in 4- to 6-week courses after birth does not lead to the emergence of natively fluconazole-resistant Candida spp.

Stem cell transplantation as consolidation therapy for children in first-remission AML: a single-center report.

A large number of patients affected by acute myeloid leukemia (AML) achieve complete remission following induction chemotherapy based on high-dose aracytin and anthracyclines. However, a postremission consolidation treatment appears to be essential to maintain the remission status. Sixteen patients with newly diagnosed AML received induction chemotherapy according to the AIEOP LAM 92P/Mod protocol. All patients were HLA-typed, and if no donor was identified within the family, patients underwent autologous stem cell transplantation (autoSCT) with mafosfamide-purged bone marrow. Patients with very high-risk AML (cytogenetics with t(9;22), hyperleukocytosis (540x10(9)/L), and AML-M7 with trilineage myelodysplasia) underwent unrelated donor transplantation. One patient relapsed before autoSCT. Eleven patients underwent autoSCT with purged bone marrow, 3 patients underwent unrelated donor transplantation (UD), and 1 patient underwent HLA-identical, matched familiar donor transplantation (MFD). All patients achieved complete remission following one course. No treatment-related deaths occurred during first-line treatment. The median interval between diagnosis and transplant was 175 days (129-277). Three patients relapsed following autoSCT; none relapsed after alloSCT. Taking stem cell transplantation as the starting point, overall survival was 93%, disease-free survival (according to the chosen treatment) was 80%, the relapse rate was 20%, and transplant-related mortality was 0%.