TY - JOUR
T1 - Complications from radiotherapy dose escalation in prostate cancer
T2 - Preliminary results of a randomized trial
AU - Storey, Mark R.
AU - Pollack, Alan
AU - Zagars, Gunar
AU - Smith, Lewis
AU - Antolak, John
AU - Rosen, Isaac
PY - 2000/10/1
Y1 - 2000/10/1
N2 - Objective: To compare early and late side effects in prostate cancer patients with Stage T1b-T3 disease randomized to receive 70 Gy or 78 Gy. Methods: There were 189 patients randomized with a minimum follow-up of 2 years, that were available for this analysis. All patients were initially treated with a 4-field box to an isocenter dose of 46 Gy at 2 Gy per fraction. In the 70-Gy arm, treatment was continued to a reduced volume using a 4-field box technique. In the 78-Gy arm, treatment was continued to a reduced volume using a conformal 6-field arrangement. Side effects were graded on a 1-4 scale, adapted from Radiation Therapy Oncology Group and Late Effects Normal Tissue Task Force criteria. Results: No significant differences in acute rectal or bladder toxicity were seen between the two treatment techniques (p > 0.6 for all comparisons). The 5-year Kaplan-Meier risks of Grade 2 or higher late bladder toxicity were 20% and 9% for 70-Gy and 78-Gy groups, respectively (log rank, p = 0.8). The 5-year risks of Grade 2 or higher late rectal toxicity were 14% and 21% for 70 Gy and 78 Gy, respectively (p = 0.4). Dose-volume histogram analysis of the 78-Gy patients showed a significant correlation between the percentage of rectum irradiated to 70 Gy or greater and the likelihood of developing late rectal complications. Patients with more than 25% of the rectum receiving 70 Gy or greater had a 5-year risk of Grade 2 or higher complications of 37% compared to 13% for patients with 25% or less (p = 0.05). All three Grade 3 complications occurred when greater than 30% of the rectum received 70 Gy or more. Conclusion: The overall rate of complications was similar in both treatment arms. However, there is evidence for a significant increase in late rectal complications when more than 25% of the rectum received 70 Gy or greater. This parameter may serve as a benchmark for the design of future three-dimensional conformal trials. (C) 2000 Elsevier Science Inc.
AB - Objective: To compare early and late side effects in prostate cancer patients with Stage T1b-T3 disease randomized to receive 70 Gy or 78 Gy. Methods: There were 189 patients randomized with a minimum follow-up of 2 years, that were available for this analysis. All patients were initially treated with a 4-field box to an isocenter dose of 46 Gy at 2 Gy per fraction. In the 70-Gy arm, treatment was continued to a reduced volume using a 4-field box technique. In the 78-Gy arm, treatment was continued to a reduced volume using a conformal 6-field arrangement. Side effects were graded on a 1-4 scale, adapted from Radiation Therapy Oncology Group and Late Effects Normal Tissue Task Force criteria. Results: No significant differences in acute rectal or bladder toxicity were seen between the two treatment techniques (p > 0.6 for all comparisons). The 5-year Kaplan-Meier risks of Grade 2 or higher late bladder toxicity were 20% and 9% for 70-Gy and 78-Gy groups, respectively (log rank, p = 0.8). The 5-year risks of Grade 2 or higher late rectal toxicity were 14% and 21% for 70 Gy and 78 Gy, respectively (p = 0.4). Dose-volume histogram analysis of the 78-Gy patients showed a significant correlation between the percentage of rectum irradiated to 70 Gy or greater and the likelihood of developing late rectal complications. Patients with more than 25% of the rectum receiving 70 Gy or greater had a 5-year risk of Grade 2 or higher complications of 37% compared to 13% for patients with 25% or less (p = 0.05). All three Grade 3 complications occurred when greater than 30% of the rectum received 70 Gy or more. Conclusion: The overall rate of complications was similar in both treatment arms. However, there is evidence for a significant increase in late rectal complications when more than 25% of the rectum received 70 Gy or greater. This parameter may serve as a benchmark for the design of future three-dimensional conformal trials. (C) 2000 Elsevier Science Inc.
KW - Dose escalation
KW - Prostate cancer
KW - Radiotherapy
KW - Rectal complications
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U2 - 10.1016/S0360-3016(00)00700-8
DO - 10.1016/S0360-3016(00)00700-8
M3 - Article
C2 - 11020558
AN - SCOPUS:0034307033
VL - 48
SP - 635
EP - 642
JO - International Journal of Radiation Oncology Biology Physics
JF - International Journal of Radiation Oncology Biology Physics
SN - 0360-3016
IS - 3
ER -