Department of Radiation Oncology, Erasmus MC-Daniel den Hoed Cancer Center, Rotterdam, The Netherlands.
Radiother Oncol. 2011 May;99(2):235-9. doi: 10.1016/j.radonc.2011.03.010. Epub 2011 Apr 15.
To explore the outcome, cumulative dose and toxicity in 23 patients after a third radiation treatment, with a partial or complete overlap of the previous two irradiated regions.
The dose summation of the three radiation plans was made by the planning system. For patients treated with cyberknife or brachytherapy dose summation was done by dose point calculations. Efficacy and toxicity was scored by looking at the reduction of tumor, pain and bleeding.
Symptomatic response was observed in 81% and 73% of the patients after, respectively, the third and second radiation. The median cumulative maximum dose to the tumor and its regions was 133Gy(3) (range: 82-496Gy(3)). The median corrected cumulative dose for the rectum, bowel and bladder resulted in 91Gy(3), 73Gy(3) and 79Gy(3), respectively. Grade 3 acute skin toxicity was only seen in the third radiation course.
The constraints of 100Gy(3) for rectum, 90Gy(3) for bowel and 110Gy(3) for bladder are safe and can be used as guidelines in the decision for re-irradiation. Symptomatic relieve was seen in 81% of the patients with low grade 3 and no grade 4 acute and late toxicity.
探讨 23 例患者在接受第三部分放疗时，前两次照射区域有部分或完全重叠的情况下，其治疗结果、累积剂量和毒性。
通过计划系统对三个放射治疗计划进行剂量叠加。对于接受 Cyberknife 或近距离放射治疗的患者，通过剂量点计算进行剂量叠加。通过观察肿瘤、疼痛和出血的减少来评估疗效和毒性。
分别在第三次和第二次放疗后，81%和 73%的患者出现了症状缓解。肿瘤及其区域的中位累积最大剂量为 133Gy（3）（范围：82-496Gy（3））。直肠、肠和膀胱的中位校正累积剂量分别为 91Gy（3）、73Gy（3）和 79Gy（3）。仅在第三次放射治疗中观察到 3 级急性皮肤毒性。
对于直肠、肠和膀胱，100Gy（3）、90Gy（3）和 110Gy（3）的限制是安全的，可以作为再次放射治疗决策的指导原则。81%的患者出现症状缓解，急性毒性为 3 级，无 4 级急性和迟发性毒性。
