宫颈癌三维适形近距离治疗腔内联合插植施源器对比研究

目的：比较局部晚期宫颈癌三维适形近距离治疗Utrecht与Ring施源器剂量学差异。方法 MRI引导的三维适形近距离治疗局部晚期宫颈癌患者25例，间隔采用Utrecht与Ring施源器，共96次。按照施源器不同分成2个组，每组48次，其中26次先采用Ring施源器，22次先采用Utrecht施源器。考察高危CTV体积和在A点水平处宽、厚、D90；OAR的D2 cm3；V7 Gy 、W7 Gy，A、T7 Gy，A、W／T7 Gy，A；配对t检验差异。结果 Utrecht与Ring组高危CTV体积、在A点水平处宽、厚、D90均相近（P＝0．487、0．340、0．857、0．921）；膀胱、直肠、乙状结肠、小肠D2 cm3均相近（P＝0．136、0．802、0．985、0．458）；V7 Gy 、T7 Gy，A相近（P＝0．076、0．435），W／T7 Gy，A为Utrecht组大于Ring组（P＝0．002）。结论高危CTV在A点水平处较宽，且在A点水平处宽厚比大的患者，适合采用Utrecht施源器。

A comparative study of Utrecht interstitial applicator and ring interstitial applicator in three-dimensional conformal brachytherapy for cervical cancer

Objective To investigate the dosimetric differences between Utrecht applicator and ring applicator in three-dimensional (3D) conformal brachytherapy for locally advanced cervical cancer.Methods Twenty-five patients with locally advanced cervical cancer were treated with magnetic resonance imaging-guided 3D conformal brachytherapy.Utrecht applicator and ring applicator were used interchangeably for 96 cycles.Patients were divided into two groups according to the type of applicator.Each group received 48 cycles of treatment, in which ring applicator was first applied for 26 cycles and Utrecht applicator was first applied for 22 cycles.High-risk clinical target volume ( HR-CTV) , width, thickness, and D90 at the point A level, D2 cm3 of organs at risk (OARs), V7 Gy , W7 Gy,A, V7 Gy ,A, and W/T7 Gy were evaluated and analyzed using paired t-test.Results There were no significant differences in HR-CTV and the width, thickness, and D90 at the point A level between the Utrecht group and the ring group ( P=0.487;P=0.340;P=0.857;P=0.921);there were no significant differences in D2 cm3 values of bladder, rectum, sigmoid, and bowel between the two groups ( P=0.136;P=0.802;P=0.985;P=0.458);there were no significant differences in V7 Gy and T7 Gy,A between the two groups ( P=0.076;P=0.435) .The Utrecht group had a significantly larger W/T7 Gy,A than the ring group ( P=0.002 ) .Conclusions Utrecht applicator is appropriate for patients with relatively large width and width/thickness ratio of HR-CTV at the point A level.