Tumor control and QoL outcomes of very young children with atypical teratoid/rhabdoid Tumor treated with focal only chemo-radiation therapy using pencil beam scanning proton therapy

The aim of this analysis was to assess the early clinical results of pencil beam scanning proton therapy (PT) in the treatment of young children with non-metastatic atypical teratoid/rhabdoid tumor (ATRT) of the CNS. Fifteen children (male, n = 8, 53 %) were treated with PT between May 2008 and January 2013. Mean age at diagnosis was 17.4 ± 7.0 months. The localization was infratentorial in 9 (60 %) patients. Gross total resection of the primary tumors was achieved in 7 (47 %) patients. The dose administered focally under sedation was 54 Gy (RBE). After a median follow-up of 33.4 months (range 9.7-69.2), 3 (20 %), 4 (27 %) and 2 (13 %) patients presented with local failure (LF), distant brain failure (DBF) and spinal failure (SF), respectively. Six patients died, all of tumor progression. The 2-year overall- and progression-free survival was 64.6 and 66.0 %. Tumor location (supratentorial) and the extent of surgical resection (non-gross total resection) were negative prognostic factors for both OS and PFS. PT was well tolerated. No grade >2 acute toxicity was observed. The estimated 2-year toxicity-free survival was 90 %. As assessed by the PedsQoL proxy, no decrease in QoL was observed after PT. We conclude that PBS PT is an effective treatment for young children with ATRT. After PT, with or without concomitant chemotherapy, two third of the patients survived >2 years. Acute toxicity was manageable. Longer follow-up and larger numbers of patients are needed to assess long-term outcomes and treatment-induced toxicity

Reconstruction of the recent history of a large deep prealpine lake (Lake Bourget, France) using subfossil chironomids, diatoms, and organic matter analysis: towards the definition of a lake-specific reference state

This paper presents the recent history of a large prealpine lake (Lake Bourget) using chironomids, diatoms and organic matter analysis, and deals with the ability of paleolimnological approach to define an ecological reference state for the lake in the sense of the European Framework Directive. The study at low resolution of subfossil chironomids in a 4-m-long core shows the remarkable stability over the last 2.5 kyrs of the profundal community dominated by a Micropsectra-association until the beginning of the twentieth century, when oxyphilous taxa disappeared. Focusing on this key recent period, a high resolution and multiproxy study of two short cores reveals a progressive evolution of the lake's ecological state. Until AD 1880, Lake Bourget showed low organic matter content in the deep sediments (TOC less than 1%) and a well-oxygenated hypolimnion that allowed the development of a profundal oxyphilous chironomid fauna (Micropsectra-association). Diatom communities were characteristic of oligotrophic conditions. Around AD 1880, a slight increase in the TOC was the first sign of changes in lake conditions. This was followed by a first limited decline in oligotrophic diatom taxa and the disappearance of two oxyphilous chironomid taxa at the beginning of the twentieth century. The 1940s were a major turning point in recent lake history. Diatom assemblages and accumulation of well preserved planktonic organic matter in the sediment provide evidence of strong eutrophication. The absence of profundal chironomid communities reveals permanent hypolimnetic anoxia. From AD 1995 to 2006, the diatom assemblages suggest a reduction in nutrients, and a return to mesotrophic conditions, a result of improved wastewater management. However, no change in hypolimnion benthic conditions has been shown by either the organic matter or the subfossil chironomid profundal community. Our results emphasize the relevance of the paleolimnological approach for the assessment of reference conditions for modern lakes. Before AD 1900, the profundal Micropsectra-association and the Cyclotella dominated diatom community can be considered as the Lake Bourget reference community, which reflects the reference ecological state of the lake

Development of a Chironomid-based Air Temperature Inference Model for the Central Canadian Arctic

Subfossil midge remains were identified in surface sediment recovered from 88 lakes in the central Canadian Arctic. These lakes spanned five vegetation zones, with the southern-most lakes located in boreal forest and the northern-most lakes located in mid-Arctic tundra. The lakes in the calibration are characterized by ranges in depth, summer surface-water temperature (SSWT), average July air temperature (AJAT) and pH of 15.5 m, 10.60°C, 8.40°C and 3.69, respectively. Redundancy analysis (RDA) indicated that maximum depth, pH, AJAT, total nitrogen-unfiltered (TN-UF), Cl and Al capture a large and statistically significant fraction of the overall variance in the midge data. Inference models relating midge abundances and AJAT were developed using different approaches including: weighted averaging (WA), weighted averaging-partial least squares (WA-PLS) and partial least squares (PLS). A chironomid-based inference model, based on a two-component WA-PLS approach, provided robust performance statistics with a high coefficient of determination (r 2 = 0.77) and low root mean square error of prediction (RMSEP = 1.03°C) and low maximum bias. The use of a high-resolution gridded climate data set facilitated the development of the midge-based inference model for AJAT in a region with a paucity of meteorological stations and where previously only the development of a SSWT inference model was possible

The influence of environmental changes on local and regional vegetation patterns at Rieme (NW Belgium): implications for Final Palaeolithic habitation

Late-glacial vegetation changes were studied at Rieme, NW Belgium. Human occupation of this cover sand area occurred from the Final Palaeolithic onwards. The research area is situated on the northern side of a large cover sand ridge in an undulating landscape with small ridges and depressions. The past landscape was reconstructed using a multi-disciplinary approach, including geomorphological, sedimentological, loss-on-ignition, botanical (micro- and macrofossil) and zoological analyses. AMS 14C dating provided an accurate chronology for the sediments. Analyses were performed on three sequences located ~200–300 m apart. Our study shows that during the Bølling (GI-1e) wet meadows developed on the sandy soils and groundwater levels increased probably as result of permafrost melting. Shallow pools formed in depressions. During the Older Dryas (GI-1d) shrubs with juniper, seabuckthorn and willow developed. Many shallow depressions were overblown with sand and deposition of organic material almost ceased. In the early Allerød (GI-1c) open birch woodlands developed. Due to the final melting of permafrost, groundwater levels rose further and ponds with floating-leaved open water vegetation developed. Large water level fluctuations occurred in one of the ponds. Accumulation of organic deposits ceased during the mid- Allerød. Indirect evidence for human occupation during the Allerød (GI-1c) was found in indications of burning of the reed-swamps in combination with the presence of large herbivores. Final Palaeolithic people probably used the northern side of the cover sand ridge as hunting area, while they settled their temporary (base) camps on the steep southern side along the extensive and deeper Moervaart lake