Department of Radiation Oncology, Istituto Nazionale Tumori - IRCCS - Fondazione G. Pascale, Naples, Italy;
Department of Radiation Oncology, Istituto Nazionale Tumori - IRCCS - Fondazione G. Pascale, Naples, Italy.
In Vivo. 2021 May-Jun;35(3):1849-1856. doi: 10.21873/invivo.12447.
The use of intra-fractional monitoring and correction of prostate position with the Image Guided Radio Therapy (IGRT) system can increase the spatial accuracy of dose delivery. Clarity is a system used for intrafraction prostate-motion management, it provides a real-time visualization of prostate with a transperineal ultrasound. The aim of this study was to evaluate the use of Clarity-IGRT on proper intrafraction alignment and monitoring, its impact on Planning Tumor Volume margin and on urinary and rectal toxicity in elderly patients not eligible for surgery.
Twenty-five elderly prostate cancer patients, median age=75 years (range=75-90 years) were treated with Volumetric Radiotherapy and Clarity-IGRT using 3 different schemes: A) 64.5/72 Gray (Gy) in 30 fractions on prostate and seminal vesicles (6 patients); B) 35 Gy in 5 fractions on prostate and seminal vesicles (12 patients); C): 35 Gy in 5 fractions on prostate (7 patients). Ultrasound identification of the overlapped structures to the detected ones during simulation has been used in each session. A specific software calculates direction and entity of necessary shift to obtain the perfect match. The average misalignment in the three-dimensional space has been determined and shown in a box-plot.
All patients completed treatment with mild-moderate toxicity. During treatment, genitourinary toxicity was 32% Grade 1; 4% Grade 2, rectal was 4% Grade 1. At follow-up of 3 months, genitourinary toxicity was 20% Grade 1; 4% Grade 2, rectal toxicity was 4% Grade 2. At follow-up of 6 months, genitourinary toxicity was 4% Grade 1; 4% Grade 2. Rectal toxicity was 4% Grade 2.
Radiotherapy with the Clarity System allows a reduction of PTV margins, the amount of fractions can be reduced increasing the total dose, not exacerbating urinary and rectal toxicity with greater patient's compliance.
使用图像引导放射治疗（IGRT）系统进行分次内监测和校正前列腺位置，可以提高剂量递送的空间准确性。Clarity 系统用于分次内前列腺运动管理，它通过经会阴超声实时可视化前列腺。本研究的目的是评估 Clarity-IGRT 在适当的分次内对准和监测中的使用，以及它对计划肿瘤体积（PTV）边界的影响，以及对不适合手术的老年患者的尿和直肠毒性的影响。
25 名老年前列腺癌患者，中位年龄=75 岁（范围=75-90 岁），接受容积放射治疗和 Clarity-IGRT 治疗，使用 3 种不同方案：A）前列腺和精囊 64.5/72Gy（6 例）；B）前列腺和精囊 35Gy（12 例）；C）前列腺 35Gy（7 例）。在每次治疗中，都使用超声识别与模拟时检测到的重叠结构。特定软件计算获得完美匹配所需的方向和位移量。确定三维空间中的平均错位，并以箱线图显示。
所有患者均完成了轻度至中度毒性的治疗。治疗期间，泌尿生殖毒性为 32%1 级；4%2 级，直肠为 4%1 级。随访 3 个月时，泌尿生殖毒性为 20%1 级；4%2 级，直肠毒性为 4%2 级。随访 6 个月时，泌尿生殖毒性为 4%1 级；4%2 级。直肠毒性为 4%2 级。
使用 Clarity 系统进行放射治疗可以减少 PTV 边界，减少分次次数，增加总剂量，不会增加尿和直肠毒性，同时提高患者的依从性。
