Regional deep hyperthermia: quantitative evaluation of predicted and direct measured temperature distributions in patients with high-risk extremity soft-tissue sarcoma

Background: Temperature distributions resulting from hyperthermia treatment of patients with high-risk soft-tissue sarcoma (STS) were quantitatively evaluated and globally compared with thermal simulations performed by a treatment planning system. The aim was to test whether the treatment planning system was able to predict correct temperature distributions. Methods: Five patients underwent computed tomography (CT) fluoroscopy-guided placement of tumor catheters used for the interstitial temperature measurements. For the simulations, five 3 D patient models were reconstructed by segmenting the patient CT datasets into different tissues. The measured and simulated data were evaluated by calculating the temperature change (ΔT), T90, T50, T20, Tmean, Tmin and Tmax, as well as the 90th percentile thermal dose (CEM43T90). In order to measure the agreement between both methods quantitatively, the Bland–Altman analysis was applied. Results: The absolute difference between measured and simulated temperatures were found to be 2°, 6°, 1°, 4°, 5° and 4 °C on average for Tmin, Tmax, T90, T50, T20 and Tmean, respectively. Furthermore, the thermal simulations exhibited relatively higher thermal dose compared to those that were measured. Finally, the results of the Bland–Altman analysis showed that the mean difference between both methods was above 2 °C which is considered to be clinically unacceptable. Conclusion: Given the current practical limitations on resolution of calculation grid, tissue properties, and perfusion information, the software SigmaHyperPlan™ is incapable to produce thermal simulations with sufficient correlation to typically heterogeneous tissue temperatures to be useful for clinical treatment planning

Intracellular nitrate storage by diatoms can be an important nitrogen pool in freshwater and marine ecosystems

Identifying and quantifying nitrogen pools is essential for understanding the nitrogen cycle in aquatic ecosystems. The ubiquitous diatoms represent an overlooked nitrate pool as they can accumulate nitrate intracellularly and utilize it for nitrogen assimilation, dissipation of excess photosynthetic energy, and Dissimilatory Nitrate Reduction to Ammonium (DNRA). Here, we document the global co-occurrence of diatoms and intracellular nitrate in phototrophic microbial communities in freshwater (n = 69), coastal (n = 44), and open marine (n = 4) habitats. Diatom abundance and total intracellular nitrate contents in water columns, sediments, microbial mats, and epilithic biofilms were highly significantly correlated. In contrast, diatom community composition had only a marginal influence on total intracellular nitrate contents. Nitrate concentrations inside diatom cells exceeded ambient nitrate concentrations ∼100–4000-fold. The collective intracellular nitrate pool of the diatom community accounted for <1% of total nitrate in pelagic habitats and 65–95% in benthic habitats. Accordingly, nitrate-storing diatoms are emerging as significant contributors to benthic nitrogen cycling, in particular through Dissimilatory Nitrate Reduction to Ammonium activity under anoxic conditions

Emissions of Primary Biological Aerosol Particles in GISS-E2.1 Earth system model.

International audienc

Primary BIOlogical Aerosol in the ATmosphere: origins, microphysical processes, and climatic feedbacks (BIOAAT) project.

International audienc

Treatment of primary, recurrent or inadequately resected high-risk soft-tissue sarcomas (STS) of adults : Results of a phase II pilot study (RHT-95) of neoadjuvant chemotherapy combined with regional hyperthermia.

The efficacy of thermochemotherapy in adult patients with primary, recurrent or inadequately resected non-metastatic high-risk soft-tissue sarcomas (STS) was assessed. 54 patients were prospectively treated with four cycles of etoposide, ifosfamide and doxorubicin (EIA) combined with regional hyperthermia (RHT) followed by surgery, another four cycles of EIA without RHT and external beam radiation. The objective response rate was 16% and at a median follow-up time of 57 months, the 4-year estimated rates of local failure-free survival (LFFS), distant metastasis-free survival (DMFS), event-free survival (EFS) and overall survival (OS) were 59% (95% confidence interval (CI) 45&ndash;73%), 59% (95% CI 44&ndash;73%), 26% (95% CI 14&ndash;38%) and 40% (95% CI 27&ndash;53%), respectively. OS was in favour of patients responding to neoadjuvant treatment (P=0.073). In comparison to a preceding phase II study including pre- and postsurgical thermochemotherapy (RHT-91), at a 4-year follow-up the RHT-95 study cohort showed an inferior LFFS rate (P=0.027), but this did not affect DMFS (P=0.558) or OS (P=0.126). Hence, postsurgical thermochemotherapy seems critical for local tumour control without affecting survival

Comparison of radiological and pathohistological response to neoadjuvant chemotherapy combined with regional hyperthermia (RHT) and study of response dependence on the applied thermal parameters in patients with soft tissue sarcomas (STS).

Purpose: To compare the radiological criteria RECIST, WHO, and tumor volume for evaluation of tumor response in patients with soft tissue sarcomas (STS) showing either good or poor pathohistological response to neoadjuvant chemotherapy combined with regional hyperthermia, and to examine the dependence of the findings on the applied thermal dose. Materials and methods: 19 patients with pathohistological complete response (no vital tumor cells, group 1) and 27 with pathohistological no response (&lt; 25% necrosis, group 2) were selected from our previous clinical trials. The change in tumor size before and after therapy was determined. Intratumoral temperature (T-90) and thermal dose (CEM 43 degrees C T-90) were calculated for 13 patients. Results: In the first group, 6 partial response (PR) and 13 stable disease (SD) according to RECIST, 7 PR and 12 SD according to WHO, 7 PR and 12 SD according to volumetric criteria were evaluated. In the second group, the results were 10 PR and 17 SD (RECIST), 9 PR and 18 SD (WHO), 8 PR and 19 SD (volume). The concordance of these criteria was 73.7% in group 1 and 74% in group 2. PR and SD were equally distributed in both groups (p&gt;0.421). Thermal parameters were not different between the groups (p&gt;0.327). Conclusions: SD or PR in radiological response assessment does not correlate with the pathohistological response after neoadjuvant thermochemotherapy. RECIST, WHO and volumetric criteria for response evaluation in STS are in substantial agreement. For irregularly shaped lesions, volumetric criteria seem to be more appropriate