Radiotherapy in addition to radical surgery in rectal cancer: Evidence for a dose-response effect favoring preoperative treatment

摘要: Abstract Purpose : This study explored the relationship between radiation dose and reduction in local recurrence rate after preoperative postoperative radiotherapy rectal cancer. Methods Materials All randomized trials initiated prior to 1988 comparing with surgery alone or each other were included. Local failure rates available 5626 patients. The linear quadratic formula was used compensate for different schedules. Results: For radiotherapy, a clear dose-response could be established. range of doses narrow, not demonstrated. At similar doses, preoperativ appeared moe efficient reducing than post-operative. only trial confirms this notion. A 15–20 Gy higher may required postoperatively reach efficacy. Neither approach significantly influences survival, although it is likely that small survival benefit seen pre-operative radiotherapy. Conclusions information from entire experience suggests more