基于iCBCT在线自适应放疗在盆腔肿瘤中的临床应用

Clinical implementation of iterative cone-beam computed tomography guided online adaptive radiotherapy for the pelvic malignancies

目的初步探讨基于迭代锥形线束CT(iCBCT)引导的在线自适应放疗在盆腔恶性肿瘤中的临床应用。方法北京协和医院放疗科开展了基于iCBCT引导的在线自适应放疗在盆腔恶性肿瘤中应用的前瞻性临床试验, 本研究初步分析了2022年8—11月接受在线自适应放疗的13例盆腔恶性肿瘤(2例宫颈癌、4例宫颈癌术后、3例子宫内膜癌术后、3例膀胱癌、1例前列腺癌)患者的临床数据, 探讨在线自适应放疗的可行性、自适应放疗相关流程时间、危及器官及靶区的修改程度、靶区剂量覆盖度、相关危及器官受量等。采SPSS软件进行分析, 符合正态分布的数据以xˉ±s表示, 否则用M(Q1, Q3)表示。方差齐性数据采用t检验分析, 非正态分布或方差不齐的数据则采用非参数检验进行分析。结果在自适应治疗过程中, 在线自适应平均时间为15 min 38 s(从接受CBCT扫描到最后计划选择完成的时间)。85.4%(830/972分次)的人工智能自动生成的influencer结构(与临床靶区、计划靶区相邻并可能对靶区轮廓生成有高度影响的器官, 在盆腔肿瘤中通常为膀胱、直肠、小肠)不需要任何修改或只需进行小修, 89.8%(491/547分次)人工智能自动生成的临床靶区无需修改或只需要小修。98.5%(319/324分次)的放疗分次选择了adapted计划, 与scheduled计划相比, adapted计划展示出较好的靶区剂量覆盖度, 同时可以降低危及器官的受量。结论在临床可接受的时间内可实现基于iCBCT的盆腔恶性肿瘤在线自适应放疗, 且更好的靶区剂量覆盖展现了在线自适应放疗的优势。

Objective To evaluate the clinical application of online adaptive radiotherapy based on iterative cone-beam computed tomography(iCBCT)for the pelvic malignancies.Methods This was a prospective clinical trial of iCBCT guided online adaptive radiotherapy for pelvic malignancies in Department of Radiation Oncology,Peking Union Medical College Hospital.Clinical data of 13 patients with pelvic malignancies who received online adaptive radiotherapy from August to November,2022 were preliminarily analyzed(2 cases of cervical cancer,4 postoperative cervical cancer,3 postoperative endometrial cancer,3 bladder cancer and 1 prostate cancer).The feasibility of online adaptive radiotherapy,adaptive radiotherapy time,the frequency and magnitude of edits for organs at risk and target volume,target volume coverage and organs at risk doses were analyzed.Statistical analysis was performed by SPSS software.Data conforming to normal distribution were described by Mean±SD,and data with non-normal distribution were expressed by M(Q1,Q3).Data with homogeneous variances were analyzed by t-test,and data with non-normal distribution or heterogeneous variances were analyzed by nonparametric test.Results The average adaptive time was 15 min and 38 s(from acceptance of acquired CBCT scan to completion of the final plan selection).85.4%(830/972 fractions)of influencer structures(system-defined organs adjacent to and with high impact on the generation of clinical target volume and planning target volume,primarily bladder,rectum and small intestine in pelvic neoplasms)automatically generated by artificial intelligence required no edits or minor editors,and 89.8%(491/547 fractions)of clinical target volume automatically generated by artificial intelligence required no edits or minor editors.The adapted plan was adopted in 98.5%(319/324 fractions)of radiotherapy fractions.Compared with the scheduled plan,the adapted plan showed better target volume coverage and reduced the dose of organs at risk.Conclusions iCBCT guided online adaptive radiotherapy for the pelvic malignancies can be achieved within clinically acceptable timeslots.In addtion,better dose coverage of target volume shows the advantages of online adaptive radiotherapy.