Yang Xinglong, Li Zhouyu, Cai Zhantuo, Tang Xi, Liu Jinquan, Cui Shuzhong, Li Mingyi
Department of Radiation Oncology, Affiliated Cancer Hospital and Institute of Guangzhou Medical University, Guangzhou 510095, China.
Affiliated Dongguan People's Hospital, Southern Medical University, (Dongguan People's Hospital) Radiotherapy Ward 3, Dongguan 523059, China.
J Oncol. 2022 Mar 12;2022:6499744. doi: 10.1155/2022/6499744. eCollection 2022.
Recent prevalent use of three-dimensional image-guided brachytherapy (3D brachytherapy) has dramatically improved the treatment outcomes of cervical cancer. Inverse planning simulated annealing (IPSA) is one of the commonly used algorithms in 3D brachytherapy, but different conditions may affect the treatment plan quality. In this study, we compared HRCTV (high-risk clinical target volume) D90 (dose prescription) and HRCTV D95 D2cc (dose received by 2.0cc) of the rectum, bladder, and sigmoid in 30 patients with cervical cancer under four IPSA conditions. The HRCTV D90 (mean ± SD cGy) was 607.32 ± 37.86, 599.01 ± 23.62, 598.67 ± 13.07, and 596.45 ± 10.94 in four groups, respectively. The HRCTV D95 was 558.19 ± 38.51, 558.17 ± 25.72, 557.03 ± 16.12, and 555.26 ± 12.78, respectively. The sigmoid D2cc was 282.96 ± 44.84, 273.14 ± 60.69, 268.94 ± 62.32, and 292.69 ± 52.44. HRCTV D90, HRCTV D95, and sigmoid D2cc were not statistically different among the four groups ( > 0.05). However, the target fitness in group one, especially at the cervix, was poor. The rectum D2cc was 351.49 ± 32.90, 361.49 ± 28.09, 370.82 ± 24.44, and 375.33 ± 30.90. The rectum D2cc in group one was the lower than that in group three and group four ( < 0.05). The bladder D2cc was 423.59 ± 31.39, 380.75 ± 37.25, 383.27 ± 32.55, and 385.22 ± 25.79. The bladder D2cc in group one was higher than the other groups ( < 0.05). The maximum rectum limit dose (400cGy) is lower than the bladder (500cGy), and HRCTV is a whole in the IPSA algorithm; these result in the insufficiency or even absence of cervix dose that first need to meet in clinics. In conclusion, IPSA condition optimization can improve the quality of treatment plan in 3D brachytherapy and make it closer to clinical practice.
近期三维图像引导近距离放射治疗（3D近距离放射治疗）的广泛应用显著改善了宫颈癌的治疗效果。逆向计划模拟退火算法（IPSA）是3D近距离放射治疗中常用的算法之一，但不同条件可能会影响治疗计划质量。在本研究中，我们比较了30例宫颈癌患者在四种IPSA条件下直肠、膀胱和乙状结肠的高危临床靶区（HRCTV）D90（剂量处方）以及HRCTV D95 D2cc（2.0cc所接受的剂量）。四组中HRCTV D90（均值±标准差cGy）分别为607.32±37.86、599.01±23.62、598.67±13.07和596.45±10.94。HRCTV D95分别为558.19±38.51、558.17±25.72、557.03±16.12和555.26±12.78。乙状结肠D2cc分别为282.96±44.84、273.14±60.69、268.94±62.32和292.69±52.44。四组间HRCTV D90、HRCTV D95和乙状结肠D2cc无统计学差异（P>0.05）。然而，第一组的靶区适形度较差，尤其是在宫颈处。直肠D2cc分别为351.49±32.90、361.49±28.09、370.82±24.44和375.33±30.90。第一组的直肠D2cc低于第三组和第四组（P<0.05）。膀胱D2cc分别为423.59±31.39、380.75±37.25、383.27±32.55和385.22±25.79。第一组的膀胱D2cc高于其他组（P<0.05）。直肠的最大限量剂量（400cGy）低于膀胱（500cGy），且在IPSA算法中HRCTV是一个整体；这些导致临床上首先需要满足的宫颈剂量不足甚至缺失。总之，优化IPSA条件可提高3D近距离放射治疗的治疗计划质量，并使其更接近临床实际。
