Frameless Stereotactic Radiosurgery With Linear Accelerator (LINAC)-Based Technology for Brain Metastases: Outcomes Analysis in 141 Patients

Objectives Brain metastases (BM) are the most common intracranial tumors in adults. Surgery and frame-based stereotactic radiosurgery (SRS) are well-described treatment options. Frameless SRS is an emerging BM treatment option offering fewer side effects. The aim of this study was to describe the therapeutic outcomes and toxicity of frameless SRS with linear accelerator (LINAC)-based technology for BM treatment in our institution. Materials and methods We performed a retrospective study including all adult patients treated with frameless SRS with LINAC-based technology for BM between October 2010 and July 2016. Patients were followed routinely with MRI scans at three-month intervals. Primary endpoints were progression-free survival, local control, overall survival, and toxicity related to the treatment. All survival times were computed with the Kaplan-Meier method. All cumulative incidences were computed using competing risk analyses. Results A total of 194 metastatic lesions in 141 patients were treated in a 69-month interval. At the time of analysis, 33 patients were still alive, with a median follow-up time of 25.1 months. The overall median survival was 8.7 months. The median progression-free survival was 5.3 months. Local recurrence as a first event was 25% and 38% at one and two years, respectively, while distant brain recurrence as a first event was 18% and 21%. Death before any brain event occurred in 31% of patients. The cumulative incidence of radiation necrosis as a first brain event was 2% at one and two years. Conclusions The treatment of BM with LINAC-based frameless SRS in our institution had an overall and progression-free survival comparable with the literature for frameless SRS and for conventional frame-based SRS while being less invasive and more comfortable for the patient. In our study, frameless SRS with LINAC technology seems to be safe for BM treatment with minimal rates of radiation necrosis.

Adverse events during nursing care procedure in intensive care unit: The PREVENIR study

OBJECTIVES

Intensive care unit patients undergo several nursing care procedures (NCP) every day. These procedures involve a risk for adverse events (AE). Yet, their prevalence, intensity, and predisposing risk factors remain poorly established. The main objective of the study was to measure the incidence and severity of NCP related AE.

DESIGN

This prospective observational multicentre study was conducted in 9 ICUs. All NCP were recorded for four consecutive weeks. For each NCP, the following were collected: patients' baseline characteristics, type of NCP, characteristics of the NCP, AE and therapeutic responses.

RESULTS

5849 NCP occurred in 340 patients. Among the 340 patients included, 292 (85.9%) were affected by at least one AE, and 141 (41.5%) by an SAE during a NCP. Thirty % of NCP were associated with at least one AE: hemodynamic AE in 17.1%, respiratory AE in 13.6%, agitation and pain (3.7% and 3.3%). Eight invasive devices were accidentally removed. Severe Adverse Events (SAE) occurred in 5.5% of NCP. The main risk factor associated with SAE was pain/agitation at the beginning of the NCP.

CONCLUSION

AE are frequent during NCP in ICU. We identified several risk factors, some of them preventable, that could be considered for the development of recommendations for the nursing care of critically ill patients.

TRIAL REGISTRATION

ClinicalTrials.gov NCT02881645.

Secondary organic aerosol origin in an urban environment: influence of biogenic and fuel combustion precursors

Source contributions of organic aerosol (OA) are still not fully understood, especially in terms of quantitative distinction between secondary OA formed from anthropogenic precursors vs. that formed from natural precursors. In order to investigate the OA origin, a field campaign was carried out in Barcelona in summer 2013, including two periods characterized by low and high traffic conditions. Volatile organic compound (VOC) concentrations were higher during the second period, especially aromatic hydrocarbons related to traffic emissions, which showed a marked daily cycle peaking during traffic rush hours, similarly to black carbon (BC) concentrations. Biogenic VOC (BVOC) concentrations showed only minor changes from the low to the high traffic period, and their intra-day variability was related to temperature and solar radiation cycles, although a decrease was observed for monoterpenes during the day. The organic carbon (OC) concentrations increased from the first to the second period, and the fraction of non-fossil OC as determined by ¹⁴C analysis increased from 43% to 54% of the total OC. The combination of ¹⁴C analysis and Aerosol Chemical Speciation Monitor (ACSM) OA source apportionment showed that the fossil OC was mainly secondary (>70%) except for the last sample, when the fossil secondary OC only represented 51% of the total fossil OC. The fraction of non-fossil secondary OC increased from 37% of total secondary OC for the first sample to 60% for the last sample. This enhanced formation of non-fossil secondary OA (SOA) could be attributed to the reaction of BVOC precursors with NO_x emitted from road traffic (or from its nocturnal derivative nitrate that enhances night-time semi-volatile oxygenated OA (SV-OOA)), since NO₂ concentrations increased from 19 to 42 μg m⁻³ from the first to the last sample.

Evaluation of activation parameters of molecular mobility of parylene C using differential scanning calorimetry, dielectric spectroscopy, and thermally stimulated depolarization currents

The molecular kinetics of α-relaxation were studied by dielectric spectroscopy (DS) and thermally stimulated depolarization currents (TSDC) for the thermoplastic semicrystalline parylene C (-H2C-C6H3Cl-CH2-)n thin film. Activation energy of the α-relaxation process brings very close values with both methods (155 ± 2 kJ mol(-1)). Dielectric spectroscopy carried out in a wide temperature range allowed one to determine the α-relaxation time against the temperature and then to estimate the Kauzmann and Angell temperatures for parylene C. From these temperatures and the determination of kinetics and thermodynamics parameters from DSC analysis, it was possible to investigate the cooperative rearranging region (CRR) in parylene C. CRR is quantified in terms of characteristic length (ζCRR), volume (VCRR), number z of rearranging units, and height barrier Δμ of the rearranging unit. Moreover, the fragility index m, calculated from these three methods, is discussed. A value of m = 94 is obtained by DSC confirming a "strong" character of parylene C. A lowest value of 35 ± 4 obtained from electric analyses (DS and TSDC) must be considered with caution because these methods of characterizations bring into play only dipolar relaxations. Last, the kinetic and thermodynamic parameters for parylene C highlighted in this work are positioned in comparison with other organic and inorganic materials.

[Helical tomotherapy in the treatment of malignant pleural mesothelioma: The impact of low doses on pulmonary and oesophageal toxicity]

PURPOSE

To evaluate the adjuvant treatment of malignant pleural mesothelioma by helical tomotherapy and the impact of low doses on esophageal and pulmonary toxicity.

PATIENTS AND METHODS

Between June 2007 and May 2011, 29 patients diagnosed with malignant pleural mesothelioma received adjuvant radiotherapy by helical tomotherapy. The median age was 63 years (34-72). Histologically, 83 % of patients had epithelioid malignant pleural mesothelioma. Clinically, 45 % of patients were T3 and 55 % N0. Eighty six percent of the patients were treated by extrapleural pneumonectomy and 35 % received neoadjuvant chemotherapy with platinum and pemetrexed. The median dose in the pneumonectomy cavity was 50Gy at 2Gy/fraction.

RESULTS

The mean follow-up was 2.3 years after diagnosis. Overall survival at 1 and 2 years was 65 and 36 % respectively. The median survival from diagnosis was 18 months. Median lung volumes receiving 2, 5, 10, 13, 15 and 20Gy (V2, V5, V10, V13, V15 and V20) were 100, 98, 52, 36, 19 and 5 %. The median of the mean remaining lung dose was 11Gy. Two patients died of pulmonary complications, three patients had grade 3 lung toxicity, while esophageal grade 3-4 toxicity was observed in three other patients. No significant impact of clinical characteristics and dosimetric parameters were found on pulmonary toxicity, however a V10≥50 %, a V15≥15 % and mean lung dose of 10Gy or more had a tendency to be predictive of pulmonary toxicity (P<0.1). Moreover, in our analysis, the mean lung dose seems to have a significant impact on esophageal toxicity (P=0.03) as well as low doses to the controlateral lung: V5, V10 and V13 (P<0.05).

CONCLUSION

Helical tomotherapy is a promising technique in the multimodality treatment of malignant pleural mesothelioma. Low doses received by the contralateral lung appear to be the limiting factor. A dosimetric comparison with volumetric modulated arctherapy techniques would be interesting in this setting.

Mesothelioma at era of helical tomotherapy: results of two institutions in combining chemotherapy, surgery and radiotherapy

PURPOSE

There is a scarce clinical experience about adjuvant helical tomotherapy (HT) in patients affected by malignant pleural mesothelioma (MPM) even though it appears as a useful technique to treat complex volume as the pleural cavity, and seems to have better dose distribution than the "classic" intensity modulated radiotherapy (IMRT).

METHODS AND MATERIALS

Twenty-four patients received adjuvant radiotherapy (RT) by HT from August 1st, 2007 to December 1st, 2009 at Curie Institute (Paris) and René Gauducheau Cancer Center (Nantes). Thirteen patients had neoadjuvant chemotherapy. Extrapleural pleuropneumonectomy (EPP) was done in 23 patients. Median dose to PTV was 50Gy [48.7-55.9Gy] (2Gy/fraction). Acute and long term toxicities, disease free survival (DFS), overall survival (OS) and relapses are presented.

RESULTS

Average follow up after RT was 7 months. The disease was staged mostly as T2-T3, N1-N2. Nineteen patients had epithelial type histology. Most patients tolerated radiotherapy with grade 1-2 side effects: redness of the skin, light cough or dyspnea, fatigue, nausea and odynophagia, mild increase of the post-operative thoracic pain. Grade 3 pneumonitis was suspected in 2 patients. Two grade 5 pneumonitis were also suspected. Eleven patients had a follow up of more than 6 months and no long term side effects related with HT were noted. At 24 months, 51.8% of patients were free of disease. Thirty percent of patients relapsed, with 2 patients presenting local relapses. Two patients died from recurrence.

CONCLUSION

With limited follow up, HT has comparable toxicity to those observed with traditional IMRT. Higher radiation dose and good coverage results in excellent local control.

Carbohydrate production in relation to microphytobenthic biofilm development: an integrated approach in a tidal mesocosm

Experiments were performed to evaluate short-term changes in sediment extracellular carbohydrates for a multispecific assemblage of benthic diatoms in relation to physiological status, endogenous migratory rhythms, and environmental conditions. For this purpose, a mesocosm was used, which simulated both tidal and dark: light alternating cycles under controlled conditions. Scanning electronic microscopy in combination with picture analyses indicated that natural diatom migration patterns were reproduced in the mesocosm. Two EPS fractions were operationally separated in colloidal carbohydrate measurements: alcohol-soluble EPS (termed "soluble EPS") and alcohol-insoluble EPS (termed "bound EPS"). Microphytobenthic biomass followed a logistic-type curve and converged toward a maximal value termed the "biotic capacity of the local environment." Both EPS fractions showed oscillations with production during photosynthetic periods and sharp decreases during night immersion periods. Productions of both EPS fractions increased with Chl a production during light periods suggesting a light dependence in relation to migratory patterns. The decreases in both EPS fractions, which occurred during night immersion periods suggest that carbohydrate hydrolysis and/or washaway affected both EPS fractions similarly in benthic environments. Our results confirm the theory according to which the two distinct fractions are under different metabolic controls. No change in soluble EPS release was obtained during the transition from logarithmic to stationary phase. On the other hand, a metabolism modification of microalgae, probably related to ammonium depletion, occurred when cells entered the stationary phase, since there was a high enhancement in bound EPS production. Mesocosm results can serve as a system of reference useful to characterize biofilm development in field investigations and to revisit the effective implication of each EPS fraction in sediment stability.

[Non-Hodgkin lymphoma mimicking renal carcinoma: apropos of 1 case of follicular lymphoma]

Primary renal non-Hodgkin's lymphoma (NHL) is unusual, in contrast to the frequent renal involvement in disseminated NHL. We report a case of follicular lymphoma presenting initially as a renal mass. In the literature, twenty-seven similar cases have been described since 1980. The median age at diagnosis is 64 years with a male predominance. Clinical and radiological findings generally evoke renal carcinoma. Histologically, tumors are usually large B-cell lymphomas. The existence of renal non-Hodgkin lymphoma mimicking renal carcinoma must be recognized. Such lymphomas can either be primitive or be nodal with a renal presentation. Nephrectomy followed by chemotherapy permits long disease free survival.

Blood vessel density in canine osteosarcoma

Canine osteosarcoma is a prevalent bone neoplasm which has similarities to the human disease. We used a retrospective study to investigate the possibility that tumor vascularity may provide useful prognostic information, indicative of the role of this parameter in progression of this cancer. We quantified microvessel density in 52 histological specimens of primary tumor, immunostained for von Willebrand's Factor to identify vascular endothelium. For the 20 cases not euthanized at presentation or lost to follow-up, we found significantly higher tumor microvascular densities in animals presenting with detectable pulmonary metastases (5 of 20), and significantly lower densities in animals without metastatic disease at presentation, but later surviving to develop pulmonary metastases (7 of 20; P < 0.05). Animals with no evidence of pulmonary metastases at time of death (8 of 20) had intermediate vascular densities in their tumors. The results of this preliminary study suggest that vascularity of the primary tumor may be an indication of tumor progression. Future studies with a larger number of cases should establish whether vascular density can be a useful prognostic parameter for canine osteosarcoma.