Renard-Oldrini S, Brunaud C, Huger S, Marchesi V, Tournier-Rangeard L, Bouzid D, Harter V, Peiffert D
Département de radiothérapie, centre Alexis-Vautrin, avenue de Bourgogne, Vandoeuvre-lès-Nancy, France.
Cancer Radiother. 2012 May;16(3):209-14. doi: 10.1016/j.canrad.2012.02.002. Epub 2012 Apr 10.
Concurrent radiochemotherapy is the standard treatment for locally advanced cervical cancer. This treatment is responsible for bowel and hematologic toxicities. The use of intensity-modulated radiotherapy (IMRT), in static beams, allows a decrease of this toxicity. The technique of RapidArc(®) IMRT could lower the dose delivered to the organs at risk and improve the homogeneity of the planning target volume coverage, while decreasing the processing time.
For 20 patients, treatment plans performed with IMRT and RapidArc(®) were compared. The target volumes were: the clinical target volume (gross tumour volume, uterus, upper third of the vagina, the hypogastric, iliac and presacral nodal regions), and the planning target volume (clinical target volume+1cm). The delineated organs at risk were: rectum, bladder, bowel and bone marrow. The dose was 45 Gy in 25 fractions. IMRT were delivered with five beams and RapidArc(®) with two arcs. The comparisons were made by the non-parametric test of Wilcoxon.
Medium coverage of the planning target volume was better with RapidArc(®) (P=0.01). It was also better regarding the sparing of bowel (P=0.01) and IMRT was better regarding the sparing of bladder (P=0.01) and rectum (P=0.05). The total volume receiving 20 Gy was less important with RapidArc(®) (P<0.001). RapidArc(®) allowed to decrease the treatment time (3 versus 12 minutes with IMRT) and the number of monitor units (MU) (376.5 versus 962.2, on average, P=0.0001).
The technique of RapidArc(®) seems to obtain better dosimetric results compared to RCMI, with fewer MU, and a significant decrease in treatment time.
同步放化疗是局部晚期宫颈癌的标准治疗方法。这种治疗会导致肠道和血液学毒性。采用静态射野的调强放疗（IMRT）可降低这种毒性。容积旋转调强放疗（RapidArc®）技术能降低危及器官的受照剂量，提高计划靶区覆盖的均匀性，同时缩短治疗时间。
对20例患者进行了IMRT和RapidArc®治疗计划的比较。靶区包括：临床靶区（大体肿瘤体积、子宫、阴道上三分之一、下腹、髂骨和骶前淋巴结区域）以及计划靶区（临床靶区+1cm）。勾画的危及器官有：直肠、膀胱、肠道和骨髓。剂量为45Gy，分25次给予。IMRT采用五野照射，RapidArc®采用两弧照射。通过Wilcoxon非参数检验进行比较。
RapidArc®在计划靶区的平均覆盖方面更好（P=0.01）。在保护肠道方面也更好（P=0.01），而IMRT在保护膀胱（P=0.01）和直肠（P=0.05）方面更好。接受20Gy照射的总体积RapidArc®更小（P<0.001）。RapidArc®可缩短治疗时间（与IMRT的12分钟相比为3分钟）和监测单位（MU）数量（平均为376.5对962.2，P=0.0001）。
与IMRT相比，RapidArc®技术似乎能获得更好的剂量学结果，MU更少，治疗时间显著缩短。
