Abstract:Objective To compare the dose distribution, radiation in organs at risk and treatment time
of five-fields static intensity-modulated radiotherapy (IMRT) with different segment quantities in the
target area of the middle and late stage cervical cancers, and to provide references for clinical treatment.
Methods Altogether 25 patients with Ⅱb-Ⅲb stage cervical cancers were enrolled in this study. The
target area and organs at risk were contoured on the contrast-enhanced CT images. The radiotherapy plan
was designed by Eclipse 10.0 Treatment Planning System (TPS), and the number of segments were set up
as 50 (G1 Group), 35 (G2 Group) and 25 (G3 Group) respectively. Through analysis of DVH (Dose-volume
Histogram), the homogeneity index (HI), conformity index (CI) in the target area, radiation in organs
at risk and treatment time of three different methods were compared. Results G1 Group had the lower
maximum dose (Dmax) average dose (Dmean), and its homogeneity and conformity were the best, better than
the other two methods significantly (P<0.05). For bladder, intestine and rectum, V20 differed little among
three methods. As for V30, V40, V50 and Dmax, G1 was lower than the other two methods and G2 was lower
than G3, among which statistical significance existed between Dmax and V50 for rectum (P<0.05). G1 had
the fewest machine units (MUs) than G2 and G3 (P>0.05), and the treatment time of G1, G2 and G3 was
about 8.5, 7.2 and 6.5 minutes respectively. Conclusion Static intensity-modulated radiotherapy with
more segments had better homogeneity and conformity, and could protect the organs at risk effectively,
but had a prolonged treatment time. The quantity of segments should be selected according to practical
demand reasonably.
朱均强. 不同子野数对中晚期宫颈癌静态调强影响的研究[J]. 中国医疗设备, 2016, 31(8): 101-103.
ZHU Jun-qiang. Study on Effects of Different Segment Quantities on Static Intensity-Modulated
Radiotherapy for Middle and Late Stage Cervical Carcinoma. China Medical Devices, 2016, 31(8): 101-103.