Experimental investigation of the repeatability of direct damage induced by lightning strikes on metallic panels

Metallic parts of aircrafts used for fuel tanks areas or even for the fuselage can suffer from severe direct damage due to lightning strikes. Metallic aircrafts are naturally protected against current flows because of their high electrical conductivity. But at the arc attachment location, there is a major risk of perforation which can result in a dramatic explosion due to fuel tank ignition. A lightning strike is a current discharge between opposite charge locations inside clouds and on the ground. Currents under considerations here are D+B+C* current waveforms prescribed by the standard regulations and reproduced in by specific current delivery devices at DGA-Ta lightning lab. It is well known that the risk to perforate a metallic panel directly increases with the duration of the C* component, mainly because of heat transfer at the arc root. But it is nevertheless not well understood how the variability of the test parameters of the electrical charge and the electro-thermo-mechanical behaviour of the structure influence the variability of the critical perforation point. This paper presents the analysis synthesis of experimental investigations on the risk of perforation of a metallic panel to a laboratory prescribed D+B+C* lightning strike. A sensitivity analysis compares different tests campaigns and gives insight into the damage patterns related to perforation risk grades. The effect of the variability of some lab test parameters is reported. It is shown that a linear but not monotonously increasing relationship exists between the damaged zone in the panel and the delivered current charge. The perforation risk is shown to be not proportional to the current charge but rather to damage instability

20-Year Risks of Breast-Cancer Recurrence after Stopping Endocrine Therapy at 5 Years

The administration of endocrine therapy for 5 years substantially reduces recurrence rates during and after treatment in women with early-stage, estrogen-receptor (ER)-positive breast cancer. Extending such therapy beyond 5 years offers further protection but has additional side effects. Obtaining data on the absolute risk of subsequent distant recurrence if therapy stops at 5 years could help determine whether to extend treatment

Long-term outcomes for neoadjuvant versus adjuvant chemotherapy in early breast cancer: meta-analysis of individual patient data from ten randomised trials

Background Neoadjuvant chemotherapy (NACT) for early breast cancer can make breast-conserving surgery more feasible and might be more likely to eradicate micrometastatic disease than might the same chemotherapy given after surgery. We investigated the long-term benefits and risks of NACT and the influence of tumour characteristics on outcome with a collaborative meta-analysis of individual patient data from relevant randomised trials. Methods We obtained information about prerandomisation tumour characteristics, clinical tumour response, surgery, recurrence, and mortality for 4756 women in ten randomised trials in early breast cancer that began before 2005 and compared NACT with the same chemotherapy given postoperatively. Primary outcomes were tumour response, extent of local therapy, local and distant recurrence, breast cancer death, and overall mortality. Analyses by intention-to-treat used standard regression (for response and frequency of breast-conserving therapy) and log-rank methods (for recurrence and mortality). Findings Patients entered the trials from 1983 to 2002 and median follow-up was 9 years (IQR 5–14), with the last follow-up in 2013. Most chemotherapy was anthracycline based (3838 [81%] of 4756 women). More than two thirds (1349 [69%] of 1947) of women allocated NACT had a complete or partial clinical response. Patients allocated NACT had an increased frequency of breast-conserving therapy (1504 [65%] of 2320 treated with NACT vs 1135 [49%] of 2318 treated with adjuvant chemotherapy). NACT was associated with more frequent local recurrence than was adjuvant chemotherapy: the 15 year local recurrence was 21·4% for NACT versus 15·9% for adjuvant chemotherapy (5·5% increase [95% CI 2·4–8·6]; rate ratio 1·37 [95% CI 1·17–1·61]; p=0·0001). No significant difference between NACT and adjuvant chemotherapy was noted for distant recurrence (15 year risk 38·2% for NACT vs 38·0% for adjuvant chemotherapy; rate ratio 1·02 [95% CI 0·92–1·14]; p=0·66), breast cancer mortality (34·4% vs 33·7%; 1·06 [0·95–1·18]; p=0·31), or death from any cause (40·9% vs 41·2%; 1·04 [0·94–1·15]; p=0·45). Interpretation Tumours downsized by NACT might have higher local recurrence after breast-conserving therapy than might tumours of the same dimensions in women who have not received NACT. Strategies to mitigate the increased local recurrence after breast-conserving therapy in tumours downsized by NACT should be considered—eg, careful tumour localisation, detailed pathological assessment, and appropriate radiotherapy

IR-192 VERSUS CO-60 BOOST IN 3-7-CM BREAST-CANCER TREATED BY IRRADIATION ALONE - FINAL RESULTS OF A RANDOMIZED TRIAL

This prospective randomized trial compared an iridium-192 implant boost with a cobalt-60 external irradiation boost to the primary tumor site, in 255 patients with breast cancers 3-7 cm in diameter. All patients had a partial (>50%) or complete response following primary external beam irradiation of 58 Gy to the whole breast, as well as irradiation to the axillary, supraclavicular and internal mammary nodes. Patients with clinically positive axillary nodes also received a cobalt-60 10-15 Gy boost to the inferior axilla. All patients had core biopsy only. Both groups were comparable in age, tumor size, node involvement, grade, and progesterone receptor levels. The boost dose was 20 Gy in both groups. At the median 8-year follow-up, the breast recurrence risk was 24% in the iridium group and 39% in the cobalt group (p = 0.02). When adjusted to other prognostic and treatment factors, the brachytherapy boost decreased the breast recurrence risk by 60%. The 8-year breast preservation rates were 81% and 67%, respectively (p = 0.024). Cosmetic outcome in both groups was evaluated in 120 patients with a minimum 3-year follow-up and was comparable in both groups. This study demonstrates that in selected patients with large tumors treated with irradiation alone, local control and breast preservation rates are improved by the use of brachytherapy to boost the primary tumor

Experimental investigation of the repeatability of direct damage induced by lightning strikes on metallic panels

International audienceMetallic parts of aircrafts used for fuel tanks areas or even for the fuselage can suffer from severe direct damage due to lightning strikes. Metallic aircrafts are naturally protected against current flows because of their high electrical conductivity. But at the arc attachment location, there is a major risk of perforation which can result in a dramatic explosion due to fuel tank ignition. A lightning strike is a current discharge between opposite charge locations inside clouds and on the ground. Currents under considerations here are D+B+C* current waveforms prescribed by the standard regulations and reproduced in by specific current delivery devices at DGA-Ta lightning lab. It is well known that the risk to perforate a metallic panel directly increases with the duration of the C* component, mainly because of heat transfer at the arc root. But it is nevertheless not well understood how the variability of the test parameters of the electrical charge and the electro-thermo-mechanical behaviour of the structure influence the variability of the critical perforation point. This paper presents the analysis synthesis of experimental investigations on the risk of perforation of a metallic panel to a laboratory prescribed D+B+C* lightning strike. A sensitivity analysis compares different tests campaigns and gives insight into the damage patterns related to perforation risk grades. The effect of the variability of some lab test parameters is reported. It is shown that a linear but not monotonously increasing relationship exists between the damaged zone in the panel and the delivered current charge. The perforation risk is shown to be not proportional to the current charge but rather to damage instability