Promaxo Inc, Oakland, CA, 94607, USA.
Int J Comput Assist Radiol Surg. 2021 May;16(5):741-748. doi: 10.1007/s11548-021-02364-7. Epub 2021 Apr 23.
Prostate cancer is the second most prevalent cancer in US men, with about 192,000 new cases and 33,000 deaths predicted for 2020. With only a 31% 5-year survival rate for patients with an initial diagnosis of stage-four prostate cancer, the necessity for early screening and diagnosis is clear. In this paper, we present navigation accuracy results for Promaxo's MR system intended to be used in a physician's office for image-guided transperineal prostate biopsy.
The office-based low-field MR system was used to acquire images of prostate phantoms with needles inserted through a transperineal template. Coordinates of the estimated sample core locations in the office-based MR system were compared to ground truth needle coordinates identified in a 1.5T external reference scan. The error was measured as the distance between the planned target and the ground truth core center and as the shortest perpendicular distance between the planned target and the ground truth trajectory of the whole core.
The average error between the planned target and the ground truth core center was 2.57 ± 1.02 mm, [1.93-3.21] 95% CI. The average error between the planned target to the actual core segment was 2.05 ± 1.24 mm, [1.53-2.56] 95% CI.
The average navigation errors were below the clinically significant threshold of 5 mm. The initial phantom results demonstrate the feasibility of the office-based system for prostate biopsy.
前列腺癌是美国男性中第二大常见的癌症，预计 2020 年将有 192000 例新发病例和 33000 例死亡病例。对于初始诊断为四期前列腺癌的患者，其 5 年生存率仅为 31%，因此早期筛查和诊断的必要性是显而易见的。在本文中，我们介绍了 Promaxo 的 MR 系统在医生办公室进行图像引导经会阴前列腺活检时的导航精度结果。
该基于办公室的低场 MR 系统用于采集经会阴模板插入针的前列腺模型的图像。将基于办公室的 MR 系统中估计的样本芯位置坐标与在 1.5T 外部参考扫描中确定的地面实况针坐标进行比较。误差的测量方法是计划目标与地面实况芯中心之间的距离以及计划目标与地面实况芯全长的最短垂直距离。
计划目标与地面实况芯中心之间的平均误差为 2.57±1.02mm，[1.93-3.21]95%置信区间。计划目标与实际芯段之间的平均误差为 2.05±1.24mm，[1.53-2.56]95%置信区间。
平均导航误差低于 5mm 的临床显著阈值。初步的体模结果表明，基于办公室的系统用于前列腺活检是可行的。
