Yang Changzhao, Lv Zhengtong, Chen Lingxiao, Wang Jie, Hu Xiheng, Chand Harripersaud, Sun Xi, Tang Guyu, Tang Congyi, Jiang Huichuan, Li Yuan
Department of Urology, Xiangya Hospital, Central South University, Changsha, City, Hunan Province, P. R. China.
Department of Radiotherapy, Hunan Cancer Hospital, Changsha City, Hunan Province, P. R. China.
J Contemp Brachytherapy. 2020 Aug;12(4):327-334. doi: 10.5114/jcb.2020.98111. Epub 2020 Aug 21.
To explore the possibility of intraoperative transrectal ultrasound (TRUS)-based dose verification in transperineal brachytherapy (BT) with iodine-125 (I) seeds for prostate cancer.
Fifteen patients with prostate cancer were treated using BT with I seeds. Post-implant TRUS and computed tomography (CT) images were imported into treatment planning system (TPS) for dosimetry. Dosimetry parameters, including minimum dose received by 90% of the volume (D), percentage of the volume receiving 100% of prescribed dose (V), and percentage of the volume receiving 200% of prescribed dose (V) were calculated based on TRUS and CT images, separately. The D value of TRUS-based dosimetry was transformed to its expected value. Comparisons of the dosimetric parameters between post-operative verification and preoperative plans were made by paired -test. One-way ANOVA model was used to assess the differences in preoperative plans. Agreements were evaluated between the preoperative planning and post-operative actual dose parameters using Bland-Altman analysis.
In total, 825 of I seeds were implanted successfully in 15 patients. In TRUS-based dosimetry, 674 seeds (81%) were identified clearly in TRUS-based images, and the expected value of D parameter showed no significant differences compared with the preoperative planning and CT post-operation results ( > 0.05). In CT-based dosimetry, 810 seeds (98%) were identified clearly in CT-based images, and there was good consistency of D, V, and V values ( > 0.05). Post-implant CT-based dosimetry indicated that I seed implantation had fulfilled the expected plan.
Intraoperative TRUS can be used for dosimetric verification of BT for prostate cancer.
探讨在经会阴近距离放射治疗（BT）中使用碘-125（I）粒子治疗前列腺癌时基于术中经直肠超声（TRUS）进行剂量验证的可能性。
15例前列腺癌患者接受了I粒子BT治疗。将植入后的TRUS和计算机断层扫描（CT）图像导入治疗计划系统（TPS）进行剂量测定。分别基于TRUS和CT图像计算剂量测定参数，包括90%体积所接受的最小剂量（D）、接受100%处方剂量的体积百分比（V）以及接受200%处方剂量的体积百分比（V）。将基于TRUS的剂量测定的D值转换为其预期值。通过配对t检验对术后验证与术前计划之间的剂量测定参数进行比较。使用单向方差分析模型评估术前计划的差异。使用Bland-Altman分析评估术前计划与术后实际剂量参数之间的一致性。
15例患者共成功植入825枚I粒子。在基于TRUS的剂量测定中，基于TRUS的图像中清晰识别出674枚粒子（81%），D参数的预期值与术前计划和术后CT结果相比无显著差异（P>0.05）。在基于CT的剂量测定中，基于CT的图像中清晰识别出810枚粒子（98%），D、V和V值具有良好的一致性（P>0.05）。植入后基于CT的剂量测定表明I粒子植入符合预期计划。
术中TRUS可用于前列腺癌BT的剂量测定验证。
