J R Coll Physicians Edinb
December 2024
We present the theory, concept and design of an efficient, megawatt coherent Cherenkov radiation source based on a two-dimensional periodic surface lattice (2D-PSL) cavity combined with a novel energy recovery system for the generation of highly efficient (> 50%) single-frequency radiation. We demonstrate the scalability of the transverse dimension of the 2D-PSL cavity of the Cherenkov source and thus the potential for efficient, continuous-wave, high-power (> 1 MW) operation; fundamental to the eventual realization of clean, fusion energy. These new sources, with the capacity to operate in the 0.
View Article and Find Full Text PDFThe application of radio frequency (RF) vacuum electronics for the betterment of the human condition began soon after the invention of the first vacuum tubes in the 1920s and has not stopped since. Today, microwave vacuum devices are powering important applications in health treatment, material and biological science, wireless communication-terrestrial and space, Earth environment remote sensing, and the promise of safe, reliable, and inexhaustible energy. This article highlights some of the exciting application frontiers of vacuum electronics.
View Article and Find Full Text PDFChronic kidney disease (CKD) increases the risk of adverse outcomes in acute coronary syndrome (ACS). The optimal regimen of dual antiplatelet therapy (DAPT) post-percutaneous coronary intervention (PCI) in CKD poses a challenge due to the increased bleeding and clotting tendencies, particularly since patients with CKD were underrepresented in randomized controlled trials. We examined the practice patterns of DAPT prescription stratified by the presence of CKD.
View Article and Find Full Text PDFBackground: Traditionally, elective nodal irradiation (ENI) has been used in clinical trials that have established thoracic radiotherapy as instrumental in improving survival for patients with limited-stage small-cell lung cancer (LS-SCLC). However, several reports have suggested that the omission of ENI might be appropriate. Current US practice patterns are unknown regarding ENI for patients with LS-SCLC.
View Article and Find Full Text PDFBackground: Thoracic radiotherapy (TRT) with concurrent chemotherapy is standard for limited-stage small-cell lung cancer (LS-SCLC). However, the optimal dosing and fractionation remain unclear. The National Comprehensive Cancer Network guidelines have recommended either 45 Gy delivered twice daily (BID) or 60 to 70 Gy delivered once daily (QD).
View Article and Find Full Text PDFIntroduction: For limited-stage small-cell lung cancer (LS-SCLC), National Comprehensive Cancer Network guidelines recommend that thoracic radiotherapy (TRT) be delivered concurrently with chemotherapy and early in the regimen, with cycle 1 or 2. Evidence is conflicting regarding the benefit of early timing of TRT. A Korean randomized trial did not see a survival difference between early (cycle 1) and late (cycle 3) TRT.
View Article and Find Full Text PDFPurpose: Prophylactic cranial irradiation (PCI) in patients with limited-stage small-cell lung cancer (LS-SCLC) is considered the standard of care. Meta-analysis of 7 clinical trials indicates a survival benefit to PCI, but all of these trials were conducted in the pre-magnetic resonance imaging (MRI) era. Therefore, routine brain imaging with MRI before PCI-as recommended by National Comprehensive Cancer Network guidelines-is not directly supported by the evidence.
View Article and Find Full Text PDFBackground: Contemporary use of dual antiplatelet therapy and consistency with guideline recommendations in acute coronary syndrome patients undergoing percutaneous coronary intervention (PCI) have not been well characterized.
Methods: The COAPT was a prospective, observational, multicenter, longitudinal study of patients with myocardial infarction (MI) undergoing PCI. Baseline characteristics, treatment patterns, processes of care, factors associated with switching to and from novel adenosine diphosphate receptor inhibitors (ADPris), and in-hospital outcomes are described.
Background: Since the introduction of newer, more potent P2Y12 receptor inhibitors (P2Y12ris), practice patterns and associated clinical outcomes in patients with myocardial infarction (MI) undergoing percutaneous coronary intervention (PCI) and also requiring oral anticoagulation (OAC) have not been fully characterized.
Methods: The Canadian Observational Antiplatelet Study was a prospective, multicenter, longitudinal, observational study (26 hospitals, December 2011 to May 2013) describing P2Y12ri treatment patterns and outcomes in patients with ST-elevation and non-ST-elevation MI undergoing PCI. We describe the clinical characteristics, treatment patterns, bleeding, and ischemic outcomes over the 15-month follow-up within and between the subgroups of patients discharged on either dual-antiplatelet therapy (DAPT) (acetyl salicylic acid [ASA]+P2Y12ri) or triple therapy (ASA+P2Y12ri+OAC).
Introduction: Conflicting data from randomized clinical trials incite the debate over the appropriate use of prophylactic cranial irradiation (PCI) for patients with extensive-stage SCLC (ES-SCLC) who achieve clinical response to systemic chemotherapy. The current pattern of practice among U.S.
View Article and Find Full Text PDFAim: To compare the clinical utility of the Recursive Partitioning Analysis (RPA) and Graded Prognostic Assessment (GPA) in predicting outcomes for moderate prognosis patients with brain metastases.
Methods & Materials: We reviewed 101 whole brain radiotherapy cases. RPA and GPA were calculated.
We report clinical outcomes of proton therapy in patients with World Health Organization grade 2 (atypical) meningiomas. Between 2005 and 2013, 22 patients with atypical meningiomas were treated to a median dose of 63 Gy (RBE) using proton therapy, as an adjuvant therapy after surgery (n = 12) or for recurrence or progression of residual tumor (n = 10). Six patients had presumed radiation-induced meningiomas, but none had received prior radiotherapy for their meningioma.
View Article and Find Full Text PDFJ Palliat Med
August 2014
Pretreatment evaluation is performed to determine the number, location, and size of the brain metastases and magnetic resonance imaging (MRI) is the recommended imaging technique, particularly in patients being considered for surgery or stereotactic radiosurgery. A contiguous thin-cut volumetric MRI with gadolinium with newer gadolinium-based agents can improve detection of small brain metastases. A systemic workup and medical evaluation are important, given that subsequent treatment for the brain metastases will also depend on the extent of the extracranial disease and on the age and performance status of the patient.
View Article and Find Full Text PDFBackground: Patients with brain metastases from solid tumors can be subdivided by characteristics into separate prognostic groups, such as the Radiation Therapy Oncology Group's Recursive Partitioning Analysis (RPA) or the Graded Prognostic Assessment (GPA). At our institution, patients falling into the poorest prognostic groups are often treated with whole brain radiotherapy (WBRT).
Objective: To determine if observed survival of poor prognosis patients treated with WBRT for brain metastases at our institution matches the survival predicted by RPA and GPA prognostic indices.
Brain metastases are common in patients with advanced, Human Epidermal Growth Factor Receptor 2 (HER2)-positive breast cancer. We evaluated the maximum tolerated dose (MTD) and feasibility of lapatinib given concurrently with whole brain radiotherapy (WBRT). Eligible patients had (HER2)-positive breast cancer and ≥1 brain metastasis.
View Article and Find Full Text PDFMultiple options for retreatment are available, which include whole-brain radiation therapy, stereotactic radiosurgery, surgery, chemotherapy, and supportive care. Size, number, timing, location, histology, performance status, and extracranial disease status all need to be carefully considered when choosing a treatment modality. There are no randomized trials examining the retreatment of brain metastases.
View Article and Find Full Text PDFTraditional palliative treatment of metastatic cancer to the vertebral bodies often results in doses to the spinal cord that are higher than the dose prescribed to the target, or gross tumor volume (GTV). This study compares traditional techniques of spine palliation with intensity-modulated radiation therapy (IMRT). The purpose of the study is 2-fold: first, the study demonstrates the benefits of using IMRT to lower the dose to the organs at risk (OAR), particularly for the spinal cord and other nonspecified normal tissues; second, the article provides information regarding the advantages and disadvantages of commonly used conventional techniques for treating the vertebral bodies based on patient anatomy.
View Article and Find Full Text PDFBackground: Hepatocellular carcinoma (HCC) is increasing in incidence due to hepatitis C. Stereotactic body radiotherapy (SBRT) is a noninvasive, effective therapy in the management of liver malignancies. The authors evaluated radiological response in 26 patients with HCC treated with SBRT at Indiana University.
View Article and Find Full Text PDFPurpose: To quantify the frequency of rib fracture and chest wall (CW) pain and identify the dose-volume parameters that predict CW toxicity after stereotactic body radiotherapy (SBRT).
Methods And Materials: The records of patients treated with SBRT between 2000 and 2008 were reviewed, and toxicity was scored according to Common Terminology Criteria for Adverse Events v3.0 for pain and rib fracture.
Purpose: To examine the rates and risk factors of radiation pneumonitis (RP) in non-small cell lung cancer (NSCLC) patients treated with stereotactic body radiotherapy (SBRT).
Methods And Materials: Dosimetry records for 251 patients with lymph node-negative Stage I-IIB NSCLC and no prior chest radiation therapy (RT) treated with SBRT were reviewed. Patients were coded on the basis of the presence of at least Grade (G) 2 RP using the Common Toxicity Criteria version 2 criteria.
Background: Hepatocellular carcinoma (HCC) is increasing in incidence and the majority of patients are not candidates for radical therapies. Therefore, interest in minimally invasive therapies in growing.
Methods: A Phase I dose escalation trial was conducted at Indiana University to determine the feasibility and toxicity of stereotactic body radiation therapy (SBRT) for primary HCC.
Planning for long-duration manned lunar and interplanetary missions requires an understanding of radiation-induced cataractogenesis. Previously, it was demonstrated that low-linear energy transfer (LET) irradiation with 10 Gy of (60)Co gamma rays resulted in an increased incidence of cataracts in male rats compared to female rats. This gender difference was not due to differences in estrogen, since male rats treated with the major secreted estrogen 17-beta-estradiol (E2) showed an identical increase compared to untreated males.
View Article and Find Full Text PDFThe standard of care for stage I non-small-cell lung carcinoma is generally accepted to be lobectomy. In patients who are deemed not to be candidates for lobectomy, various treatment strategies are available, including observation, sublobar resection, conventional fractionated radiotherapy, stereotactic body radiotherapy and radiofrequency ablation. However, there is no standardized, clearly established therapy to offer patients in this situation.
View Article and Find Full Text PDFRadiation cataractogenesis is an important consideration for radiotherapy patients and for astronauts. Data in the literature suggest that gender and/or estrogen may play a role in the incidence of age-related cataracts. However, few data exist on the effect of gender on radiation-induced cataractogenesis.
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