SU-FF-T-330: Optimal Dose Fractionation Schedules Computed with Different Tumor Reoxygenation Rates

2007 ◽  
Vol 34 (6Part12) ◽  
pp. 2477-2477
Author(s):  
A Chvetsov ◽  
D Siemann ◽  
W Mendenhall ◽  
J Palta
Keyword(s):  
Optimal Dose ◽  
Dose Fractionation ◽  
Fractionation Schedules

scholarly journals Prostate SBRT: Comparison the Efficacy and Toxicity of Two Different Dose Fractionation Schedules

2020 ◽  
Vol 10 ◽  
Author(s):  
Donald Blake Fuller ◽  
John Naitoh ◽  
Reza Shirazi ◽  
Tami Crabtree ◽  
George Mardirossian
Keyword(s):  
Dose Fractionation ◽  
Fractionation Schedules

Palliative whole brain radiotherapy: Predictors of prescribing 5 versus 10 fractions.

2016 ◽  
Vol 34 (26_suppl) ◽  
pp. 219-219
Author(s):  
Adele Duimering ◽  
Sarah Baker ◽  
Kim Paulson ◽  
Brock J Debenham ◽  
Sunita Ghosh ◽  
...  
Keyword(s):  
Karnofsky Performance Status ◽  
Performance Status ◽  
Whole Brain Radiotherapy ◽  
Binary Logistic Regression ◽  
Optimal Dose ◽  
Dose Fractionation ◽  
Disease Extent ◽  
Whole Brain ◽  
Brain Radiotherapy ◽  
Practice Methods

219 Background: The optimal dose for palliative whole brain radiotherapy (WBRT) continues to be debated. Common regimens include 20 Gy in five and 30 Gy in 10 fractions. We aimed to identify factors associated with WBRT dose schedules, hypothesizing that clinical prediction of survival (CPS) would influence prescribing practice. Methods: Demographic and clinicopathologic data were collected for consecutive patients with brain metastases receiving WBRT through a dedicated palliative radiation oncology clinic. At initial consultation, CPS were prospectively collected from treating radiation oncologists. Karnofsky performance status (KPS) and Mini-Mental Status Examination were available for 88.6% and 75.1%, respectively. Dose fractionation was collected and summary statistics calculated. Parameters were assessed for association with five fraction schedules using binary logistic regression, with odds ratios and 95% CI reported. Results: 193 patients underwent WBRT (N = 102 from 2010-2012; N = 91 from 2013-2014); 38/193 had 48 extracranial sites irradiated concurrently. 46.1% were male, mean age was 64.7 years (SD 11.6), and 63.7% had lung cancer. Median KPS was 70 (range 20-100) and median MMSE score was 27/30 (range 13-30). Median CPS and actual survival were 150 days (range 21-730d) and 96 days (range 11-1029d), respectively. 18.7% received WBRT within 30 days of death. 78.2% (151/193) and 17.6% (34/193) received five and 10 fractions, respectively; 8/193 were prescribed other schedules. On multivariate analysis, patients with KPS ≤ 70 were 5.93 times more likely to have received 5-fractions (95% CI 2.51-14.1; p < 0.0001). Those treated 2010-2012 were less likely to have received 5 fractions (OR 0.28; 95% CI 0.11-0.68; p = 0.005). CPS, age, gender, MMSE, histology, disease extent, and extracranial irradiation were not predictive of WBRT schedule. Conclusions: Patients treated with WBRT with KPS ≤70 and those treated more recently were more likely to receive five fractions. Oncologist CPS was not a statistically significant predictor of schedule in this cohort.

scholarly journals Optimal dose-fractionation schedule of palliative radiotherapy for patients with bone metastases: a protocol for systematic review and network meta-analysis

BMJ Open ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. e033120 ◽  
Author(s):  
Xiaofang Tang ◽  
Qiancheng Hu ◽  
Ye Chen ◽  
Xin Wang ◽  
Xiaofen Li ◽  
...  
Keyword(s):  
Systematic Review ◽  
Bone Metastases ◽  
Meta Analysis ◽  
Palliative Radiotherapy ◽  
Optimal Dose ◽  
Dose Fractionation ◽  
Cochrane Library ◽  
Assessment Development ◽  
Fractionation Schedule ◽  
American Society

IntroductionThe optimal dose-fractionation schedule of palliative radiotherapy has been debated in patients with bone metastases. Our objective is to comprehensively compare multiple fraction schedules with single fraction radiotherapy in terms of efficacy and toxicities by performing a systematic review and network meta-analysis.Methods and analysisElectronic searches of titles/abstracts of palliative radiotherapy for bone metastases will be performed, using PubMed, Cochrane Library, Embase,clinical trials, American Society for Therapeutic Radiology and Oncology and European Society of Radiotherapy and Oncology. The primary outcome of interest is the incidence of skeletal-related event following palliative radiotherapy for bone metastases in prospective studies. The risk of bias and quality of evidence will be evaluated based on Cochrane Collaboration’s tool and Grades of Recommendation, Assessment, Development and Evaluation in the network meta-analysis. We will conduct subgroup analysis and sensitivity analysis regardless of heterogeneity estimates.Ethics and disseminationThis study will synthesise the evidence regarding dose-fractionation schedule of palliative radiotherapy in patients with bone metastases. We hope the findings from this study will help clinicians and patients select optimum palliative radiotherapy by identifying the optimal dose-fractionation schedule of palliative radiotherapy with the most value in terms of patient-important outcomes. The evidence obtained from network meta-analysis will help to guide head-to-head research in the future. The results will be disseminated through international conference reports and peer-reviewed manuscripts. Ethics review board is not required for this network meta-analysis.PROSPERO registration numberCRD42019135195.

scholarly journals Pharmacodynamics of Fluconazole in a Murine Model of Systemic Candidiasis

1998 ◽  
Vol 42 (5) ◽  
pp. 1105-1109 ◽  
Author(s):  
Arnold Louie ◽  
George L. Drusano ◽  
Partha Banerjee ◽  
Qing-Feng Liu ◽  
Weiguo Liu ◽  
...  
Keyword(s):  
Total Dose ◽  
Murine Model ◽  
Dose Fractionation ◽  
Maximal Effect ◽  
Systemic Candidiasis ◽  
Pharmacodynamic Parameter ◽  
Dose Response Relationship ◽  
Time Curve ◽  
Dose Ranging ◽  
Fractionation Schedules

ABSTRACT In this study we defined the pharmacodynamic parameter that optimizes outcome in deep-seated Candida albicansinfections treated with fluconazole. Using a murine model of systemic candidiasis, we conducted single-dose dose-ranging studies with fluconazole to determine the dosage of this drug that resulted in a 50% reduction in fungal densities (50% effective dose [ED50]) in kidneys versus the fungal densities in the kidneys of untreated controls. We found that the ED50 of fluconazole given intraperitoneally was 4.56 mg/kg of body weight/day (95% confidence interval, 3.60 to 5.53 mg/kg/day), and the dose-response relationship was best described by an inhibitory sigmoid maximal effect (E max) curve. To define the pharmacodynamics of fluconazole, we gave dosages lower than, approximating, and higher than the ED50 of fluconazole (range, 3.5 to 5.5 mg/kg/day, equivalent to the ED16 to the ED75) to various groups of infected animals using three dose-fractionation schedules. For each total dose of fluconazole examined, the dose-fractionation schedules optimized the ratio of the area under the concentration-time curve (AUC) to the MIC (the AUC/MIC ratio), the ratio of the maximum concentration of drug in serum (C max) to the MIC, and the time that the drug remained above the MIC for the infecting C. albicansisolate. Similar reductions in fungal densities in kidneys were seen between groups that received the same total dose of fluconazole in one, two, or four equally divided doses. Thus, dose-fractionation studies demonstrated that the pharmacodynamic parameter of fluconazole that best predicted outcome was the AUC/MIC ratio.

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