TY - JOUR
T1 - Which alpha/beta ratio and half-time of repair are useful for predicting outcomes in prostate cancer?
AU - Nickers, Philippe
AU - Hermesse, Johanne
AU - Deneufbourg, Jean-Marie
AU - Vanbelle, Sophie
AU - Lartigau, Eric
PY - 2010/12
Y1 - 2010/12
N2 - To calculate the ?/? of prostate adenocarcinoma.From January 1997 to December 2005, 328 patients were treated consecutively with external beam radiotherapy and brachytherapy boost. The patients with at least one of the following adverse prognostic factors were included: PSA>10 ng/ml, Gleason score ?7, T?2B. A total EQD2 of 80 Gy was delivered uniformly within the same timeframe. Prior to August 2002, the patients were treated to low-dose-rate brachytherapy using (192)Ir (n=201), and those treated thereafter received a high-dose-rate brachytherapy boost (n=127). The equivalency of dose was established using the incomplete repair model, with generally accepted ?/? ratio of 3 Gy, and half-time for repair of sublethal damage (HTR) of 1.5h.In a Cox proportional hazards model, the two groups displayed no difference (HR: 0.99, 95% CI: 0.87-1.1, p=0.98) in biochemical control. Analyzing using the linear quadratic model, the data fit well an ?/? ratio of 3.41 Gy (95% CI: 2.56-4.26) and the recently published HTR of 1.9 h (95% CI: 1.4-2.4), but also an ?/? of 5.87 Gy (95% CI: 4.67-7.07) and the more widely established HTR of 1.5 h.Unlike the previously published data, calculation of the ?/? ratio from consecutive patients and using a uniform treatment duration points to higher values than 2.5 Gy.
AB - To calculate the ?/? of prostate adenocarcinoma.From January 1997 to December 2005, 328 patients were treated consecutively with external beam radiotherapy and brachytherapy boost. The patients with at least one of the following adverse prognostic factors were included: PSA>10 ng/ml, Gleason score ?7, T?2B. A total EQD2 of 80 Gy was delivered uniformly within the same timeframe. Prior to August 2002, the patients were treated to low-dose-rate brachytherapy using (192)Ir (n=201), and those treated thereafter received a high-dose-rate brachytherapy boost (n=127). The equivalency of dose was established using the incomplete repair model, with generally accepted ?/? ratio of 3 Gy, and half-time for repair of sublethal damage (HTR) of 1.5h.In a Cox proportional hazards model, the two groups displayed no difference (HR: 0.99, 95% CI: 0.87-1.1, p=0.98) in biochemical control. Analyzing using the linear quadratic model, the data fit well an ?/? ratio of 3.41 Gy (95% CI: 2.56-4.26) and the recently published HTR of 1.9 h (95% CI: 1.4-2.4), but also an ?/? of 5.87 Gy (95% CI: 4.67-7.07) and the more widely established HTR of 1.5 h.Unlike the previously published data, calculation of the ?/? ratio from consecutive patients and using a uniform treatment duration points to higher values than 2.5 Gy.
KW - Prostate cancer
KW - Radiotherapy
KW - Radiobiology
KW - alpha/beta ratio
KW - Androgen deprivation therapy
U2 - 10.1016/j.radonc.2010.06.006
DO - 10.1016/j.radonc.2010.06.006
M3 - Article
C2 - 20724012
SN - 0167-8140
VL - 97
SP - 462
EP - 466
JO - Radiotherapy and Oncology
JF - Radiotherapy and Oncology
IS - 3
ER -