Relative biological effectiveness of carbon ions for tumor control, acute skin damage and late radiation-induced fibrosis in a mouse model

TY - JOUR

T1 - Relative biological effectiveness of carbon ions for tumor control, acute skin damage and late radiation-induced fibrosis in a mouse model

AU - Sørensen, Brita Singers

AU - Horsman, Michael Robert

AU - Alsner, Jan

AU - Overgaard, Jens

AU - Durante, Marco

AU - Scholz, Michael

AU - Friedrich, Thomas

AU - Bassler, Niels

PY - 2015

Y1 - 2015

N2 - Background. The aim of the present study was to compare the biological effectiveness of carbon ions relative to x-rays between tumor control, acute skin reaction and late RIF of CDF1 mice.Material and methods. CDF1 mice with a C3H mouse mammary carcinoma implanted subcutaneously on the foot of the right hind limb were irradiated with single fractions of either photons, or 12 C ions using a 30-mm spread-out Bragg peak. The endpoint of the study was local control (no tumor recurrence within 90 days). For the acute skin reaction, non-tumor bearing CDF1 mice were irradiated with a comparable radiation scheme, and monitored for acute skin damage between Day 7 and 40. Late RIF was assessed in the irradiated mice.Results. The TCD 50 (dose producing tumor control in 50% of mice) values with 95% confi dence interval were 29.7 (25.4 – 34.8) Gy for C ions and 43.9 (39.2 – 49.2) Gy for photons, with a corresponding Relative biological effectiveness (RBE) value of 1.48 (1.28 – 1.72). For acute skin damage the MDD 50 (dose to produce moist desquamation in 50% of mice) values with 95% confi dence interval were 26.3 (23.0 – 30.1) Gy for C ions and 35.8 (32.9 – 39.0) Gy for photons, resulting in a RBE of 1.36 (1.20 – 1.54). For late radiation-induced fi brosis the FD 50 (dose to produce severe fibrosis in 50% of mice) values with 95% confi dence interval were 26.5 (23.1 – 30.3) Gy for carbon ions and 39.8 (37.8 – 41.8) Gy for photons, with a RBE of 1.50 (1.33 – 1.69).Conclusion. The observed RBE values were very similar for tumor response, acute skin damage and late RIF when irradiated with large doses of high- linear energy transfer (LET) carbon ions. This study adds information to the variation in biological effectiveness in different tumor and normal tissue models.

AB - Background. The aim of the present study was to compare the biological effectiveness of carbon ions relative to x-rays between tumor control, acute skin reaction and late RIF of CDF1 mice.Material and methods. CDF1 mice with a C3H mouse mammary carcinoma implanted subcutaneously on the foot of the right hind limb were irradiated with single fractions of either photons, or 12 C ions using a 30-mm spread-out Bragg peak. The endpoint of the study was local control (no tumor recurrence within 90 days). For the acute skin reaction, non-tumor bearing CDF1 mice were irradiated with a comparable radiation scheme, and monitored for acute skin damage between Day 7 and 40. Late RIF was assessed in the irradiated mice.Results. The TCD 50 (dose producing tumor control in 50% of mice) values with 95% confi dence interval were 29.7 (25.4 – 34.8) Gy for C ions and 43.9 (39.2 – 49.2) Gy for photons, with a corresponding Relative biological effectiveness (RBE) value of 1.48 (1.28 – 1.72). For acute skin damage the MDD 50 (dose to produce moist desquamation in 50% of mice) values with 95% confi dence interval were 26.3 (23.0 – 30.1) Gy for C ions and 35.8 (32.9 – 39.0) Gy for photons, resulting in a RBE of 1.36 (1.20 – 1.54). For late radiation-induced fi brosis the FD 50 (dose to produce severe fibrosis in 50% of mice) values with 95% confi dence interval were 26.5 (23.1 – 30.3) Gy for carbon ions and 39.8 (37.8 – 41.8) Gy for photons, with a RBE of 1.50 (1.33 – 1.69).Conclusion. The observed RBE values were very similar for tumor response, acute skin damage and late RIF when irradiated with large doses of high- linear energy transfer (LET) carbon ions. This study adds information to the variation in biological effectiveness in different tumor and normal tissue models.

UR - http://www.ncbi.nlm.nih.gov/pubmed/26271798

U2 - 10.3109/0284186X.2015.1069890

DO - 10.3109/0284186X.2015.1069890

M3 - Journal article

C2 - 26271798

SN - 0284-186X

VL - 54

SP - 1623

EP - 1630

JO - Acta Oncologica

JF - Acta Oncologica

IS - 9

T2 - Acta Oncologica symposium on biology-guided adaptive radiotherapy (BiGART 2015)

Y2 - 10 June 2015 through 12 June 2015

ER -