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Published byGyles Blair Modified over 8 years ago
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Klinisk strålebiologi - normalvev
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Tidlig reaksjon
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teleangiectasi Sen reaksjon
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Basis for dose-respons-kurver
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Stigetallet for dose-responskurven
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Gaussian distribution of radiation sensitivity Dose response curve Uniquely described by two parameters: - gradient at 50% response level D 50% - dose to achieve 50% response Gaussian distribution of technical and dosimetrical factors biolo > clin Pettersen M et al Radiotherapy and Oncology 2008 Clinical dose response curve
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Uniquely described by two parameters: - gradient at 50% response level D 50% - dose to achieve 50% response is linked to the standard deviation, , of the Gaussian distribution by: Pettersen M et al Radiotherapy and Oncology 2008 and
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Steepness of clinical dose-response curve is depending of the dose variation Pettersen M et al Radiotherapy and Oncology 2008 Roué et al 2004 ESTRO-Equal external audit 102 centres, 235 beams in France 3% beams had deviations > 5% 24 centres had deviations > 5%
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Design of a randomised clinical study The null hypothesis is that the two treatment options produce no different outcome To prove a difference, the null hypothesis has to be rejected The number of patients needed is linked to , the difference in response ( R), the level of significance ( ) and the power ( ) = 0.2 = 0.05 Pettersen M et al Radiotherapy and Oncology 2008
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The number of patients required Conclusions: To keep the number of patients required for RCT as low as possible, the standard deviation of the dosimetry should be kept below 5%.
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Volumeffet for rektumblødning
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Strandqvist plot
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-kill -kill LQ-formelverket
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