Taussky Daniel, Igidbashian Levon, Donath David, Béliveau-Nadeauv Dominic, Larouche Renée X, Hervieux Yanick, Delouya Guila
Department of Radiation Oncology, Centre hospitalier de l'Université de Montréal, Hôpital Notre-Dame, Montréal, QC.
Centre de recherche du Centre Hospitalier de l'Université de Montréal, Montréal, QC.
J Contemp Brachytherapy. 2017 Aug;9(4):304-308. doi: 10.5114/jcb.2017.68467. Epub 2017 Jun 22.
To analyze intraoperative (IO) dosimetry using transrectal ultrasound (TRUS), performed before and after prostate low-dose-rate brachytherapy (LDR-BT), and compare it to dosimetry performed 30 days following the LDR-BT implant (Day 30).
A total of 236 patients underwent prostate LDR-BT using I that was performed with a three-dimensional TRUS-guided interactive inverse preplanning system (preimplant dosimetry). After the implant procedure, the TRUS was repeated in the operating room, and the dosimetry was recalculated (postimplant dosimetry) and compared to dosimetry on Day 30 computed tomography (CT) scans. Area under curve (AUC) statistics was used for models predictive of dosimetric parameters at Day 30.
The median follow-up for patients without BF was 96 months, the 5-year and 8-year biochemical recurrence (BR)-free rate was 96% and 90%, respectively. The postimplant median D was 3.8 Gy lower (interquartile range [IQR], 12.4-0.9), and the V only 1% less (IQR, 2.9-0.2%) than the preimplant dosimetry. When comparing the postimplant and the Day 30 dosimetries, the postimplant median D was 9.6 Gy higher (IQR [-] 9.5-30.3 Gy), and the V was 3.2% greater (0.2-8.9%) than Day 30 postimplant dosimetry. The variables that best predicted the D of Day 30 was the postimplant D (AUC = 0.62, = 0.038). None of the analyzed values for IO or Day 30 dosimetry showed any predictive value for BR.
Although improving the IO preimplant and postimplant dosimetry improved dosimetry on Day 30, the BR-free rate was not dependent on any dosimetric parameter. Unpredictable factors such as intraprostatic seed migration and IO factors, prevented the accurate prediction of Day 30 dosimetry.
分析在前列腺低剂量率近距离放射治疗（LDR - BT）前后使用经直肠超声（TRUS）进行的术中（IO）剂量测定，并将其与LDR - BT植入后30天（第30天）进行的剂量测定相比较。
共有236例患者接受了使用三维TRUS引导的交互式逆向预计划系统进行的前列腺LDR - BT（植入前剂量测定）。植入手术后，在手术室重复进行TRUS检查，并重新计算剂量测定（植入后剂量测定），并与第30天计算机断层扫描（CT）扫描的剂量测定进行比较。曲线下面积（AUC）统计用于预测第30天剂量学参数的模型。
无生化失败（BF）患者的中位随访时间为96个月，5年和8年无生化复发（BR）率分别为96%和90%。植入后D的中位数比植入前剂量测定低3.8 Gy（四分位间距[IQR]，12.4 - 0.9），V仅低1%（IQR，2.9 - 0.2%）。当比较植入后和第30天的剂量测定时，植入后D的中位数比第30天植入后剂量测定高9.6 Gy（IQR [-] 9.5 - 30.3 Gy），V大3.2%（0.2 - 8.9%）。最能预测第30天D的变量是植入后D（AUC = 0.62，P = 0.038）。IO或第30天剂量测定的任何分析值均未显示出对BR的预测价值。
虽然改善IO植入前和植入后剂量测定可改善第30天的剂量测定，但无BR率并不依赖于任何剂量学参数。前列腺内籽源迁移和IO因素等不可预测因素妨碍了对第30天剂量测定的准确预测。
