40 research outputs found
Universal testing for COVID-19 in patients undergoing cancer treatment during the second outbreak in Brescia
Background: The impact of coronavirus disease 2019 (COVID-19) has been overwhelming on patients with cancer, who may be at higher risk of developing severe disease. During the second COVID-19 outbreak in Italy, we planned universal microbiologic screening for patients scheduled for antineoplastic treatment. Methods: All patients with planned active treatment at Brescia University Radiation Oncology Department were screened for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA with repeated nasopharyngeal swabs (NPS) from October 31, 2020. Treatment continuation, suspension, or delay was modulated for patients testing positive according to clinical presentation. Results: From October 31, 2020, to February 6, 2021, 636 patients were enrolled and 1243 NPS were performed, of which 28 (2.25%) were positive. The infection rate was 2.52%; 81.3% of the patients with a positive NPS were asymptomatic, 2 had mild disease, and 1 severe disease that led to death. All patients already on treatment with mild or asymptomatic COVID-19 carried on the therapy with no or minimal delay. Median delay for patients with infection detected before treatment start was 16.5 days. Conclusions: Detected incidence of COVID-19 was lower during the second outbreak in our patients (2.52% vs 3.23%), despite the extensive testing schedule, and substantiates the high rate of asymptomatic infections and the low mortality among patients with COVID-19 (6.3% vs 38.5% during the first outbreak). Universal SARS-CoV-2 screening for all patients with planned treatment might allow early identification of patients with COVID-19, resulting in timely management that could improve clinical outcomes and prevent spread of the infection
Stereotactic Radiotherapy and Androgen Deprivation Therapy for Localized Prostate Cancer: A Retrospective Mono-institutional Experience
Background/Aim: Stereotactic radiotherapy (SRT) is an effective treatment for localized prostate cancer. However, is it not clear whether the addition of androgen deprivation therapy (ADT) to SRT is beneficial. The aim of this study was to analyze the outcomes of a series of patients treated with SRT plus ADT for localized prostate cancer. Patients and Methods: Patients were treated with SRT with 42 Gy in 7 fractions with volumetric-modulated arc therapy plus Image Guided Radiotherapy (V-MAT IGRT) technique. ADT was administered to patients with intermediate unfavorable-and high-risk disease. Study endpoints were biochemical disease-free survival (bDFS), overall survival (OS), acute and late toxicity and patient-reported outcomes (PROs) using international prostate cancer symptoms scale (IPSS) and international index of erectile function (IIEF). Results: A total of 170 consecutive patients were identified, of which 49 (28.8%) with low-risk, 15 (8.8%) with favorable intermediate-risk 76 (44.7%) with unfavorable intermediate risk and 30 (17.6%) with high-risk class. All patients of unfavorable intermediate-and high-risk groups were for administered LHRH analogue concurrently to SRT and for at least 6 months. Patients with unfavorable intermediate and high-risk presented a 5-year bDFS of 81.7% and 76.9%, respectively. Conclusion: SRT consisting of 42 Gy in seven fractions with short-term ADT represents a safe and effective treatment for unfavorable intermediate and high risk prostate cancer. Our results support the need of high quality studies to test the efficacy of ADT combined with SRT for unfavorable intermediate-and high-risk localized prostate cancer
Early results of PRO-EPI: PROspective multicenter observational study on elective pelvic nodes irradiation in patients with intermediate/high/very high-risk non-metastatic prostate cancer submitted to radical, adjuvant, or salvage radiotherapy with or without concomitant androgen deprivation therapy
Simple Summary: Although radiotherapy plays a fundamental role in the management of intermediate/high/very high-risk non-metastatic prostatic cancer (IHR-nmPca), there is still no consensus on the optimal treatment strategy in this setting. Remarkably, the role of elective nodal irradiation (ENI) is still highly controversial. The PROspective multicenter observational study on Elective Pelvic nodes Irradiation (PRO-EPI) was designed to provide "real life" data regarding the patterns of care for IHR-nmPca.Forty-three Italian Radiation Oncology centers participated in the PROspective multicenter observational study on Elective Pelvic nodes Irradiation (PRO-EPI) project, with 1029 patients enrolled. In this preliminary analysis, we longitudinally evaluated the impact of Elective Nodal Irradiation (ENI) and radiotherapy features on toxicity and quality of life (QoL). Six months follow-up data were available for 913 patients and 12 months data for 762 patients. Elective Nodal Irradiation was given to 506 patients (48.9%). Volumetric Intensity-Modulated Radiation Therapy (IMRT) was adopted in more than 77% of patients and Image-Guided Radiation Therapy (IGRT) in 84.4%. Androgen deprivation therapy (ADT) was administered to the majority of patients (68.3%), and it was associated to ENI in 408 cases (81.1%). Toxicity was mostly mild and reversible and IGRT resulted in a significant reduction of rectal toxicity, although a non-significant trend toward increased urinary toxicity was observed. No statistically significant differences in QoL and toxicity were seen in patients treated with or without ENI. The adoption of IGRT is widespread and increasing and could reduce treatment toxicity. ENI is not yet the standard treatment, but it is performed in a growing fraction of cases and not resulting into an increase in toxicity or in a deterioration of QoL. Further analyses are needed to clarify the long-term toxicity profile and the impact of ENI on survival
Whole brain radiotherapy with adjuvant or concomitant boost in brain metastasis: dosimetric comparison between helical and volumetric IMRT technique
To compare and evaluate the possible advantages related to the use of VMAT and helical IMRT and two different modalities of boost delivering, adjuvant stereotactic boost (SRS) or simultaneous integrated boost (SIB), in the treatment of brain metastasis (BM) in RPA classes I-II patients
Stereotactic Radiation Therapy of Lung Cancers and Subsequent Parenchymal Alterations: from Their Spatial Distribution to the Use in Clinical Practice
An AC Power Supply with Sliding-Mode Control
A sliding-mode control in electronic AC power supplies is presented. This control technique makes it possible to satisfy the increasing demand for the high-level performance of these systems, which include uninterruptible power supplies, test supplies, and fuel cell, and solar cell supplies. The existence and hitting conditions are discussed, and criteria for the selection of the control parameters which define the sliding surface and determine the quality of response are described. Improvements of the method are introduced to accommodate for the time-varying voltage reference and in the presence of an insulation transformer. A three-level, constant-frequency, variable-band dead-beat modulation technique is associated with the sliding control, producing ultrasonic, low-ripple modulation. Tests performed on an experimental prototype confirm the outstanding performance of the adopted contro
Performance optimization of Cuk converters by sliding-mode control
A novel approach to the design of sliding-mode controllers for Cuk converters is presented, which is valid for both complete state feedback (fourth-order controller) and reduced state feedback (second-order controller). According to the proposed design criteria, both control techniques ensure excellent static and dynamic performances, also resulting in simple control implementation and minimum size of energy transfer capacitor. Experimental results are reported, and compared with those obtained with other popular control technique
An AC Power Supply with Sliding Mode Control
Electronic AC power supplies are classic products in power electronics. They include uninterruptible power supplies (UPS), test supplies, and conversion apparatus connecting DC power sources and DC storage systems to the utility grid or to AC loads. There is continuing pressure for increased performance in these supplies. In this article we propose an AC power supply with sliding-mode control. It is characterized by both outstanding performance and simple structure. The control method is similar to that already introduced for DC/DC converters with improvements necessitated by AC operation and by the presence of the insulating transformer. A simple, robust, fast and accurate operation is obtained, demonstrating the features of the sliding-mode approach in the control of electronic power system
High efficiency electronic lamp ballast with unity power factor
A soft-switched single-phase AC/AC power converter for a high-frequency electronic ballast is presented which includes one controlled switch only. In spite of its simplicity, the power converter provides high-frequency lamp current with small amplitude fluctuations, lamp power control, low-distorted and in-phase input current, and high efficiency due to soft switching both at turn-on and turn-off. Two different circuit topologies, suitable for discontinuous and continuous current operation, are presented. Their behaviour is analyzed and design criteria are given. Simulated and experimental results are reported, showing the actual circuit performance in terms of lamp behavior, AC power factor, and efficiency