Investigation of vibro-acoustic properties of modern lathe collet chuck

Manufacturing industry has been attempting to attain the required cutting performance in order to achieve high precision, fast productivity and lower maintenance costs. Vibrations generated during machining can be a serious problem degrading component quality, precision, tool service life, lathe performance and cutting rates. This paper is concerned with analysis of cutting process by using modal testing. Static and dynamic deformations of lathe collet chuck have a significant impact on cutting process stability, which affects workpiece quality and production output. Modal analysis was applied to develop a mathematical model of chucks dynamics, which consist of a number of mode shapes each with natural frequency and modal damping. Modal analysis and experimental measurements were performed on a collet chuck of CNC lathe installed in metal working company UAB “Stevila”

148. Changes in lateral dimensions of irradiated volume and their impact on the accuracy of dose delivery during radiotherapy for head and neck cancer

AimTo assess changes in lateral dimensions of irradiated volume during head and neck cancer radiotherapy and their impact on dose delivery accuracy.Material and methodsLateral dimensions of irradiated volumes were measured in 5 predefined points using computed tomography, simulator and manually with calipers, prior to treatment and then bi-weekly. For each measurement reference point dose was calculated and verified using in vivo dosimetry. Early radiation reactions, patient's weight changes and the need to modify radiotherapy accessories were also assessed. All these parameters were analyzed in relation to tumor site and stage, treatment field size, radiation dose and the degree of radiation reactions.ResultsThe study included 33 head and neck cancer patients (24 men and 9 women) aged 24–77 (median 56). All patients were irradiated using the parallel opposed megavoltage fields ranging from 49 to 180 cm2 (median 121 cm2) to the dose of 44 to 80 Gy (median 66 Gy). Radiation reactions included mucositis (grade 3 – 1 patient, grade 2 – 17 patients, grade 1 – 13 patients) and dysphagia (grade 2 – 12 patients, grade 1 – 16 patients). The body mass changes during radiotherapy ranged from −18 to +4 kg (median −5 kg). In 1 patient radiotherapy accessories had to be modified three times during the treatment, in 6 – twice and in 10 – once. Lateral dimensions changes >5 mm occurred in all but one patient (range −37 to +16 mm). Theoretical doses calculated for changed dimensions varied from prescribed by −2.5% to +6% (median +2%). Differences larger than 5% were present in 4.8% of calculations. In vivo dose measurements (after introduction of necessary corrections) demonstrated difference from prescribed dose larger than 5% in 7.6% of measurements.ConclusionChanges in the lateral dimensions of irradiated volume during head and neck cancer radiotherapy may lead to some inaccuracies in delivered doses. Such situations may necessitate adequate corrections of dose calculations and modification of radiotherapy accessories during the course of treatment

Clinical use of biomarkers in breast cancer: Updated guidelines from the European Group on Tumor Markers (EGTM)

Abstract Biomarkers play an essential role in the management of patients with invasive breast cancer. For selecting patients likely to respond to endocrine therapy, both oestrogen receptors (ERs) and progesterone receptors (PRs) should be measured on all newly diagnosed invasive breast cancers. On the other hand, for selecting likely response to all forms of anti-HER2 therapy (trastuzumab, pertuzumab, lapatinib or ado-trastuzumab emtansine), determination of HER2 expression or gene copy number is mandatory. Where feasible, measurement of ER, PR and HER2 should be performed on recurrent lesions and the primary invasive tumour. Although methodological problems exist in the determination of Ki67, because of its clearly established clinical value, wide availability and low costs relative to the available multianalyte signatures, Ki67 may be used for determining prognosis, especially if values are low or high. In oestrogen receptor (ER)-positive, HER2-negative, lymph node–negative patients, multianalyte tests such as urokinase plasminogen activator (uPA)-PAI-1, Oncotype DX, MammaPrint, EndoPredict, Breast Cancer Index (BCI) and Prosigna (PAM50) may be used to predict outcome and aid adjunct therapy decision-making. Oncotype DX, MammaPrint, EndoPredict and Prosigna may be similarly used in patients with 1–3 metastatic lymph nodes. All laboratories measuring biomarkers for patient management should use analytically and clinically validated assays, participate in external quality assurance programs, have established assay acceptance and rejection criteria, perform regular audits and be accredited by an appropriate organisation

Recommendations for triage, prioritization and treatment of breast cancer patients during the COVID-19 pandemic

The Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) associated disease (COVID-19) outbreak seriously challenges globally all health care systems and professionals. Expert projections estimate that despite social distancing and lockdown being practiced, we have yet to feel the full impact of COVID-19. In this manuscript we provide guidance to prepare for the impact of COVID-19 pandemic on breast cancer patients and advise on how to triage, prioritize and organize diagnostic procedures, surgical, radiation and medical treatments