Polytechnique Montreal, Montreal, Canada.
Centre Hospitalier de l'Universite de Montreal Research Center, Montreal, Canada.
Int J Comput Assist Radiol Surg. 2020 May;15(5):867-876. doi: 10.1007/s11548-020-02136-9. Epub 2020 Mar 29.
Transrectal ultrasound (TRUS) image guidance is the standard of care for diagnostic and therapeutic interventions in prostate cancer (PCa) patients, but can lead to high false-negative rates, compromising downstream effectiveness of therapeutic choices. A promising approach to improve in-situ detection of PCa lies in using the optical properties of the tissue to discern cancer from healthy tissue. In this work, we present the first in-situ image-guided navigation system for a spatially tracked Raman spectroscopy probe integrated in a PCa workflow, capturing the optical tissue fingerprint. The probe is guided with fused TRUS/MR imaging and tested with both tissue-simulating phantoms and ex-vivo prostates. The workflow was designed to be integrated the clinical workflow for trans-perineal prostate biopsies, as well as for high-dose rate (HDR) brachytherapy.
The proposed system developed in 3D Slicer includes an electromagnetically tracked Raman spectroscopy probe, along with tracked TRUS imaging automatically registered to diagnostic MRI. The proposed system is tested on both custom gelatin tissue-simulating optical phantoms and biological tissue phantoms. A random-forest classifier was then trained on optical spectrums from ex-vivo prostates following prostatectomy using our optical probe. Preliminary in-human results are presented with the Raman spectroscopy instrument to detect malignant tissue in-situ with histopathology confirmation.
In 5 synthetic gelatin and biological tissue phantoms, we demonstrate the ability of the image-guided Raman system by detecting over 95% of lesions, based on biopsy samples. The included lesion volumes ranged from 0.1 to 0.61 cc. We showed the compatibility of our workflow with the current HDR brachytherapy setup. In ex-vivo prostates of PCa patients, the system showed a 81% detection accuracy in high grade lesions.
Pre-clinical experiments demonstrated promising results for in-situ confirmation of lesion locations in prostates using Raman spectroscopy, both in phantoms and human ex-vivo prostate tissue, which is required for integration in HDR brachytherapy procedures.
经直肠超声（TRUS）图像引导是前列腺癌（PCa）患者诊断和治疗干预的标准，但可能导致高假阴性率，从而影响治疗选择的下游效果。提高 PCa 原位检测能力的一种很有前景的方法是利用组织的光学特性将癌症与健康组织区分开来。在这项工作中，我们首次展示了一种集成在 PCa 工作流程中的空间跟踪拉曼光谱探头的原位图像引导导航系统，该系统可以捕获光学组织指纹。该探头采用融合的 TRUS/MR 成像进行引导，并分别在组织模拟体模和离体前列腺上进行了测试。该工作流程旨在集成经会阴前列腺活检的临床工作流程，以及高剂量率（HDR）近距离放射治疗。
该系统在 3D Slicer 中开发，包括一个电磁跟踪拉曼光谱探头，以及自动与诊断 MRI 配准的跟踪 TRUS 成像。该系统在定制的明胶组织模拟光学体模和生物组织体模上进行了测试。然后，我们使用光学探头对前列腺切除术后的离体前列腺进行了随机森林分类器训练，以从光学光谱中提取信息。初步的人体试验结果表明，使用拉曼光谱仪可以原位检测恶性组织，并通过组织病理学进行确认。
在 5 个合成明胶和生物组织体模中，我们通过活检样本检测到超过 95%的病变，证明了图像引导拉曼系统的能力。包含的病变体积范围为 0.1 至 0.61 cc。我们展示了我们的工作流程与当前 HDR 近距离放射治疗设置的兼容性。在 PCa 患者的离体前列腺中，该系统在高级别病变中的检测准确率为 81%。
临床前实验表明，使用拉曼光谱在前列腺中进行原位确认病变位置具有很大的潜力，无论是在体模还是人类离体前列腺组织中，这对于集成到 HDR 近距离放射治疗过程中都是必需的。
