Linear-quadratic analysis of tumour response to fractionated radiotherapy
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Linear-quadratic analysis of tumour response to fractionated radiotherapy : a study on human squamous cell carcinoma xenografts. / Petersen, C; Baumann, M; Dubben, H H; Arps, H; Melenkeit, A; Helfrich, J.
in: INT J RADIAT BIOL, Jahrgang 73, Nr. 2, 01.02.1998, S. 197-205.Publikationen: SCORING: Beitrag in Fachzeitschrift/Zeitung › SCORING: Zeitschriftenaufsatz › Forschung › Begutachtung
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TY - JOUR
T1 - Linear-quadratic analysis of tumour response to fractionated radiotherapy
T2 - a study on human squamous cell carcinoma xenografts
AU - Petersen, C
AU - Baumann, M
AU - Dubben, H H
AU - Arps, H
AU - Melenkeit, A
AU - Helfrich, J
PY - 1998/2/1
Y1 - 1998/2/1
N2 - PURPOSE: To compare values for the alpha/beta ratio in experimental tumours irradiated either under conditions of clamping and short overall time or under more 'clinically realistic' conditions.MATERIALS AND METHODS: Human squamous cell carcinomas, FaDu and GL, were grown in nude mice. Alpha/beta values were determined from local tumour control data after treatment with single doses and 2, 4, and 8 fractions under clamp hypoxia in 3.5 days, using maximum likelihood analysis. Effective alpha/beta values (alpha/beta(eff)) were determined from treatment with 12, 30, and 60 fractions under ambient conditions in a constant overall treatment time of 6 weeks.RESULTS: After correction for an oxygen enhancement ratio of 2.7 the alpha/beta values were 15 Gy (95% CI 9; 24) for FaDu and 49 Gy (26; 122) for GL. In FaDu the TCD50 values after 12 to 60 fractions were not significantly different, the alpha/beta(eff) value was infinite (52; inf.). Unexpected from the high alpha/beta value, the TCD50 values of GL tumours increased from 37 Gy (28; 47) after 12 fractions to 59 Gy (52; 67) after 60 fractions: the alpha/beta(eff) value was 3 Gy (0.6; 12 Gy).CONCLUSIONS: The results support the view that mechanisms other than recovery from sublethal radiation damage and repopulation of clonogenic tumour cells may importantly impact on treatment outcome when the number of fractions is changed in clinical radiotherapy.
AB - PURPOSE: To compare values for the alpha/beta ratio in experimental tumours irradiated either under conditions of clamping and short overall time or under more 'clinically realistic' conditions.MATERIALS AND METHODS: Human squamous cell carcinomas, FaDu and GL, were grown in nude mice. Alpha/beta values were determined from local tumour control data after treatment with single doses and 2, 4, and 8 fractions under clamp hypoxia in 3.5 days, using maximum likelihood analysis. Effective alpha/beta values (alpha/beta(eff)) were determined from treatment with 12, 30, and 60 fractions under ambient conditions in a constant overall treatment time of 6 weeks.RESULTS: After correction for an oxygen enhancement ratio of 2.7 the alpha/beta values were 15 Gy (95% CI 9; 24) for FaDu and 49 Gy (26; 122) for GL. In FaDu the TCD50 values after 12 to 60 fractions were not significantly different, the alpha/beta(eff) value was infinite (52; inf.). Unexpected from the high alpha/beta value, the TCD50 values of GL tumours increased from 37 Gy (28; 47) after 12 fractions to 59 Gy (52; 67) after 60 fractions: the alpha/beta(eff) value was 3 Gy (0.6; 12 Gy).CONCLUSIONS: The results support the view that mechanisms other than recovery from sublethal radiation damage and repopulation of clonogenic tumour cells may importantly impact on treatment outcome when the number of fractions is changed in clinical radiotherapy.
KW - Animals
KW - Carcinoma, Squamous Cell
KW - Dose-Response Relationship, Radiation
KW - Female
KW - Head and Neck Neoplasms
KW - Humans
KW - Male
KW - Mice
KW - Mice, Nude
KW - Radiotherapy Dosage
KW - Transplantation, Heterologous
KW - Tumor Cells, Cultured
M3 - SCORING: Journal article
C2 - 9489567
VL - 73
SP - 197
EP - 205
JO - INT J RADIAT BIOL
JF - INT J RADIAT BIOL
SN - 0955-3002
IS - 2
ER -