Optimization of radiotherapy dose-time fractionation with consideration of tumor specific biology

2005 ◽  
Vol 32 (12) ◽  
pp. 3666-3677 ◽  
Author(s):  
Yong Yang ◽  
Lei Xing
Keyword(s):  
Dose Time ◽  
Radiotherapy Dose

Dose/time-dependent modulation of the endothelial function through immunosuppressive agents

2014 ◽  
Vol 62 (S 01) ◽  
Author(s):  
I. Kanzler ◽  
N. Bogert ◽  
F. Guo ◽  
A. Moritz ◽  
A. Beiras-Fernandez
Keyword(s):  
Endothelial Function ◽  
Immunosuppressive Agents ◽  
Time Dependent ◽  
Dose Time

In Vitro Effects of Urokinase — Prevention by Different Inhibitors

1990 ◽  
Vol 64 (03) ◽  
pp. 402-406 ◽  
Author(s):  
M D Oethinger ◽  
E Seifried
Keyword(s):  
In Vitro Study ◽  
Thrombin Time ◽  
Plasma Samples ◽  
Temperature Dependent ◽  
Chloromethyl Ketone ◽  
Control Value ◽  
Dose Time ◽  
In Vitro Effects ◽  
Full Protection

SummaryThe present in vitro study investigated dose-, time- and temperature-dependent effects of two-chain urokinase plasminogen activato(u-PA, urokinase) on normal citrated plasma. When 10 μg/ml u-PA wereadded to pooled normal plasma and incubated for 30 min at an ambient temperature (25° C), α2-antiplas-min decreased to 8% of the control value. Incubation on ice yielded a decrease to 45% of control,whereas α2-antiplasmin was fully consumed at 37° C. Fibrinogen and plasminogen fell to 46% and 39%, respectively, after a 30 min incubation at 25° C. Thrombin time prolonged to 190% of control.Various inhibitors were studied with respect to their suitability and efficacy to prevent these in vitro effects. Aprotinin exhibited a good protective effect on fibrinogen at concentrations exceeding 500 KlU/ml plasma. Its use, however, was limited due to interferences with some haemostatic assays. We could demonstrate that L-Glutamyl-L-Glycyl-L-Arginyl chloromethyl ketone (GGACK) and a specific polyclonal anti-u-PA-antibody (anti-u-PA-IgG) effectively inhibited urokinase-induced plasmin generation without interfering with haemostatic assays. The anti-u-PA-antibody afforded full protection ofα2-antiplasmin at therapeutic levels of u-PA.It is concluded that u-PA in plasma samples from patients during thrombolytic therapy may induce in vitro effects which should be prevented by the use of a suitable inhibitor such as GGACK or specific anti-u-PA-antibody.

Echocardiography for the 10-year prediction of cardiomyopathy in long-term survivors of childhood cancer

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
J.M Leerink ◽  
H.J.H Van Der Pal ◽  
E.A.M Feijen ◽  
P.G Meregalli ◽  
M.S Pourier ◽  
...  
Keyword(s):  
Childhood Cancer ◽  
Median Time ◽  
Cancer Diagnosis ◽  
Predictive Value ◽  
Validation Cohort ◽  
Funding Source ◽  
Derivation Cohort ◽  
After Cancer ◽  
Radiotherapy Dose

Abstract Background Childhood cancer survivors (CCS) treated with anthracyclines and/or chest-directed radiotherapy receive life-long echocardiographic surveillance to detect cardiomyopathy early. Current risk stratification and surveillance frequency recommendations are based on anthracycline- and chest-directed radiotherapy dose. We assessed the added prognostic value of an initial left ventricular ejection fraction (EF) measurement at >5 years after cancer diagnosis. Patients and methods Echocardiographic follow-up was performed in asymptomatic CCS from the Emma Children's Hospital (derivation; n=299; median time after diagnosis, 16.7 years [inter quartile range (IQR) 11.8–23.15]) and from the Radboud University Medical Center (validation; n=218, median time after diagnosis, 17.0 years [IQR 13.0–21.7]) in the Netherlands. CCS with cardiomyopathy at baseline were excluded (n=16). The endpoint was cardiomyopathy, defined as a clinically significant decreased EF (EF<40%). The predictive value of the initial EF at >5 years after cancer diagnosis was analyzed with multivariable Cox regression models in the derivation cohort and the model was validated in the validation cohort. Results The median follow-up after the initial EF was 10.9 years and 8.9 years in the derivation and validation cohort, respectively, with cardiomyopathy developing in 11/299 (3.7%) and 7/218 (3.2%), respectively. Addition of the initial EF on top of anthracycline and chest radiotherapy dose increased the C-index from 0.75 to 0.85 in the derivation cohort and from 0.71 to 0.92 in the validation cohort (p<0.01). The model was well calibrated at 10-year predicted probabilities up to 5%. An initial EF between 40–49% was associated with a hazard ratio of 6.8 (95% CI 1.8–25) for development of cardiomyopathy during follow-up. For those with a predicted 10-year cardiomyopathy probability <3% (76.9% of the derivation cohort and 74.3% of validation cohort) the negative predictive value was >99% in both cohorts. Conclusion The addition of the initial EF >5 years after cancer diagnosis to anthracycline- and chest-directed radiotherapy dose improves the 10-year cardiomyopathy prediction in CCS. Our validated prediction model identifies low-risk survivors in whom the surveillance frequency may be reduced to every 10 years. Calibration in both cohorts Funding Acknowledgement Type of funding source: Foundation. Main funding source(s): Dutch Heart Foundation

scholarly journals Risk factors for radiation-induced lung injury in patients with advanced non-small cell lung cancer: implication for treatment strategies

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Sha Sha ◽  
Jigang Dong ◽  
Maoyu Wang ◽  
Ziyu Chen ◽  
Peng Gao
Keyword(s):  
Risk Factors ◽  
Lung Cancer ◽  
Logistic Regression ◽  
Concurrent Chemotherapy ◽  
Small Cell ◽  
Regression Analyses ◽  
Small Cell Lung ◽  
Radiation Induced ◽  
Radiotherapy Dose ◽  
Nsclc Patients

Abstract Background The radiation-induced lung injury (RILI) in patients with advanced non-small cell lung cancer (NSCLS) is very common in clinical settings; we aimed to evaluate the risk factors of RILI in NSCLS patients, to provide insights into the treatment of NSCLS. Methods NSCLC patients undergoing three-dimensional conformal radiotherapy (3D-CRT) in our hospital from June 1, 2018, to June 30, 2020, were included. The characteristics and treatments of RILI and non-RILI patients were analyzed. Logistic regression analyses were conducted to assess the risk factors of RILI in patients with NSCLC. Results A total of 126 NSCLC patients were included; the incidence of RILI in NSCLC patients was 35.71%. There were significant differences in diabetes, smoke, chronic obstructive pulmonary disease (COPD), concurrent chemotherapy, radiotherapy dose, and planning target volume (PTV) between the RILI group and the non-RILI group (all P < 0.05). Logistic regression analyses indicated that diabetes (OR 3.076, 95%CI 1.442~5.304), smoke (OR 2.745, 95%CI 1.288~4.613), COPD (OR 3.949, 95%CI 1.067~5.733), concurrent chemotherapy (OR 2.072, 95%CI 1.121~3.498), radiotherapy dose ≥ 60 Gy (OR 3.841, 95%CI 1.932~5.362), and PTV ≥ 396 (OR 1.247, 95%CI 1.107~1.746) were the independent risk factors of RILI in patients with NSCLC (all P < 0.05). Conclusions RILI is commonly seen in NSCLS patients; early targeted measures are warranted for patients with those risk factors; future studies with larger sample sizes and different areas are needed to further elucidate the influencing factors of RILI in the treatment of NSCLS.

scholarly journals Is There a Selection Bias in Radiotherapy Dose-Escalation Protocols?

2007 ◽  
Vol 68 (5) ◽  
pp. 1359-1365 ◽  
Author(s):  
Elisabeth Weiss ◽  
Viswanathan Ramakrishnan ◽  
Paul J. Keall
Keyword(s):  
Selection Bias ◽  
Dose Escalation ◽  
Radiotherapy Dose

T3 glottic cancer: An analysis of dose time-volume factors

1980 ◽  
Vol 6 (6) ◽  
pp. 675-680 ◽  
Author(s):  
Andrew R Harwood ◽  
Frank A Beale ◽  
Bernard J Cummings ◽  
Nigel V Hawkins ◽  
Thomas J Keane ◽  
...  
Keyword(s):  
Glottic Cancer ◽  
Dose Time
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