High dose craniospinal irradiation as independent risk factor of permanent alopecia in childhood medulloblastoma survivors: cohort study and literature review.

PURPOSE: Our aim was to determine the main risk factors related to the occurrence of permanent alopecia in childhood medulloblastoma (MB) survivors. METHODS: We retrospectively analyzed the clinical features of all consecutive MB survivors treated at our institute. We divided the patients into 3 groups depending on the craniospinal irradiation (CSI) dose received and defined permanent alopecia first in terms of the skin region affected (whole scalp and nape region), then on the basis of the toxicity degree (G). Any relationship between permanent alopecia and other characteristics was investigated by a univariate and multivariate analysis and Odds ratio (OR) with confidence interval (CI) was reported. RESULTS: We included 41 patients with a mean10-year follow-up. High dose CSI resulted as an independent factor leading to permanent hair loss in both groups: alopecia of the whole scalp (G1 p-value 0.030, G2 p-value 0.003) and of the nape region (G1 p-value 0.038, G2 p-value 0.006). The posterior cranial fossa (PCF) boost volume and dose were not significant factors at multivariate analysis neither in permanent hair loss of the whole scalp nor only in the nuchal region. CONCLUSION: In pediatric patients with MB, the development of permanent alopecia seems to depend only on the CSI dose ≥ 36 Gy. Acute damage to the hair follicle is dose dependent, but in terms of late side effects, constant and homogeneous daily irradiation of a large volume may have a stronger effect than a higher but focal dose of radiotherapy.

Community composition and functional prediction of prokaryotes associated with sympatric sponge species of southwestern Atlantic coast.

Prokaryotes contribute to the health of marine sponges. However, there is lack of data on the assembly rules of sponge-associated prokaryotic communities, especially for those inhabiting biodiversity hotspots, such as ecoregions between tropical and warm temperate southwestern Atlantic waters. The sympatric species Aplysina caissara, Axinella corrugata, and Dragmacidon reticulatum were collected along with environmental samples from the north coast of São Paulo (Brazil). Overall, 64 prokaryotic phyla were detected; 51 were associated with sponge species, and the dominant were Proteobacteria, Bacteria (unclassified), Cyanobacteria, Crenarchaeota, and Chloroflexi. Around 64% and 89% of the unclassified operational taxonomical units (OTUs) associated with Brazilian sponge species showed a sequence similarity below 97%, with sequences in the Silva and NCBI Type Strain databases, respectively, indicating the presence of a large number of unidentified taxa. The prokaryotic communities were species-specific, ranging 56%-80% of the OTUs and distinct from the environmental samples. Fifty-four lineages were responsible for the differences detected among the categories. Functional prediction demonstrated that Ap. caissara was enriched for energy metabolism and biosynthesis of secondary metabolites, whereas D. reticulatum was enhanced for metabolism of terpenoids and polyketides, as well as xenobiotics' biodegradation and metabolism. This survey revealed a high level of novelty associated with Brazilian sponge species and that distinct members responsible from the differences among Brazilian sponge species could be correlated to the predicted functions.

Brain DSC MR Perfusion in Children: A Clinical Feasibility Study Using Different Technical Standards of Contrast Administration.

BACKGROUND AND PURPOSE: Dynamic susceptibility contrast MR perfusion imaging has limited results in children due to difficulties in reproducing technical standards derived from adults. This prospective, multicenter study aimed to determine DSC feasibility and quality in children using custom administration of a standard dose of gadolinium. MATERIALS AND METHODS: Eighty-three consecutive children with brain tumors underwent DSC perfusion with a standard dose of gadobutrol administered by an automated power injector. The location and size of intravenous catheters and gadobutrol volume and flow rates were reported, and local and/or systemic adverse effects were recorded. DSC was qualitatively evaluated by CBV maps and signal intensity-time curves and quantitatively by the percentage of signal drop and full width at half-maximum, and the data were compared with the standards reported for adults. Quantitative data were grouped by flow rate, and differences among groups were assessed by analysis of covariance and tested for statistical significance with a t test. RESULTS: No local or systemic adverse events were recorded independent of catheter location (63 arm, 14 hand, 6 foot), size (24-18 ga), and flow rates (1-5 mL/s). High-quality CBV maps and signal intensity-time curves were achieved in all patients, and quantitative evaluations were equal or superior to those reported for adults. No significant differences (P ≥ .05) were identified among the higher-flow-rate groups in the quantitative data. CONCLUSIONS: A custom administration of a standard dose of gadobutrol allows safe and high-quality DSC MR perfusion imaging in children.