Abstract：
BACKGROUND: Intraoperative ultrasound (IOUS) is a profitable tool for neurosurgical procedures\' assistance, especially in neuro-oncology. It is a rapid, ergonomic and reproducible technique. However, its known handicap is a steep learning curve for neurosurgeons. Here, we describe an interesting postoperative analysis that provides extra feedback after surgery, accelerating the learning process.
METHODS: We conducted a descriptive retrospective unicenter study including patients operated from intra-axial brain tumors using neuronavigation (Curve, Brainlab) and IOUS (BK-5000, BK medical) guidance. All patients had preoperative Magnetic Resonance Imaging (MRI) prior to tumor resection. During surgery, 3D neuronavigated IOUS studies (n3DUS) were obtained through craniotomy N13C5 transducer\'s integration to the neuronavigation system. At least two n3DUS studies were obtained: prior to tumor resection and at the resection conclusion. A postoperative MRI was performed within 48 h. MRI and n3DUS studies were posteriorly fused and analyzed with Elements (Brainlab) planning software, permitting two comparative analyses: preoperative MRI compared to pre-resection n3DUS and postoperative MRI to post-resection n3DUS. Cases with incomplete MRI or n3DUS studies were withdrawn from the study.
RESULTS: From April 2022 to March 2024, 73 patients were operated assisted by IOUS. From them, 39 were included in the study. Analyses comparing preoperative MRI and pre-resection n3DUS showed great concordance of tumor volume (p < 0,001) between both modalities. Analysis comparing postoperative MRI and post-resection n3DUS also showed good concordance in residual tumor volume (RTV) in cases where gross total resection (GTR) was not achieved (p < 0,001). In two cases, RTV detected on MRI that was not detected intra-operatively with IOUS could be reviewed in detail to recheck its appearance.
CONCLUSIONS: Post-operative comparative analyses between IOUS and MRI is a valuable tool for novel ultrasound users, as it enhances the amount of feedback provided by cases and could accelerate the learning process, flattening this technique\'s learning curve.
METHODS: We conducted a descriptive retrospective unicenter study including patients operated from intra-axial brain tumors using neuronavigation (Curve, Brainlab) and IOUS (BK-5000, BK medical) guidance. All patients had preoperative Magnetic Resonance Imaging (MRI) prior to tumor resection. During surgery, 3D neuronavigated IOUS studies (n3DUS) were obtained through craniotomy N13C5 transducer\'s integration to the neuronavigation system. At least two n3DUS studies were obtained: prior to tumor resection and at the resection conclusion. A postoperative MRI was performed within 48 h. MRI and n3DUS studies were posteriorly fused and analyzed with Elements (Brainlab) planning software, permitting two comparative analyses: preoperative MRI compared to pre-resection n3DUS and postoperative MRI to post-resection n3DUS. Cases with incomplete MRI or n3DUS studies were withdrawn from the study.
RESULTS: From April 2022 to March 2024, 73 patients were operated assisted by IOUS. From them, 39 were included in the study. Analyses comparing preoperative MRI and pre-resection n3DUS showed great concordance of tumor volume (p < 0,001) between both modalities. Analysis comparing postoperative MRI and post-resection n3DUS also showed good concordance in residual tumor volume (RTV) in cases where gross total resection (GTR) was not achieved (p < 0,001). In two cases, RTV detected on MRI that was not detected intra-operatively with IOUS could be reviewed in detail to recheck its appearance.
CONCLUSIONS: Post-operative comparative analyses between IOUS and MRI is a valuable tool for novel ultrasound users, as it enhances the amount of feedback provided by cases and could accelerate the learning process, flattening this technique\'s learning curve.
摘要：
背景：术中超声（IOUS）是神经外科手术辅助的有利工具，尤其是神经肿瘤学.这是一个快速的，符合人体工程学和可重复的技术。然而,它已知的障碍是神经外科医生学习的陡峭曲线。这里,我们描述了一个有趣的术后分析，在手术后提供额外的反馈，加快学习过程。
方法：我们进行了一项描述性回顾性单中心研究，包括使用神经导航从轴内脑肿瘤手术的患者（Curve，Brainlab）和IOUS（BK-5000，BK医疗）指导。所有患者在肿瘤切除前均进行了术前磁共振成像（MRI）。手术期间,3D神经导航IOUS研究（n3DUS）是通过开颅术N13C5换能器整合到神经导航系统获得的。获得了至少两个n3DUS研究:在肿瘤切除之前和在切除结束时。术后在48小时内进行MRI检查。MRI和n3DUS研究向后融合，并使用Elements（Brainlab）计划软件进行分析。允许进行两种比较分析：术前MRI与切除前n3DUS比较，术后MRI与切除后n3DUS比较。MRI或n3DUS研究不完整的病例从研究中撤出。
结果：从2022年4月至2024年3月，73例患者接受了IOUS辅助手术。从他们那里,39人被纳入研究。比较术前MRI和切除前n3DUS的分析显示，两种方式之间的肿瘤体积非常一致（p<0,001）。比较术后MRI和切除后n3DUS的分析也显示，在未实现总切除（GTR）的情况下，残余肿瘤体积（RTV）具有良好的一致性（p<0,001）。在两种情况下，在MRI上检测到的RTV在术中未检测到IOUS，可以详细检查以重新检查其外观。
结论：IOUS和MRI之间的术后比较分析对于新型超声使用者来说是一个有价值的工具，因为它增加了案例提供的反馈量，并可以加速学习过程，扁平化这种技术的学习曲线。
方法：我们进行了一项描述性回顾性单中心研究，包括使用神经导航从轴内脑肿瘤手术的患者（Curve，Brainlab）和IOUS（BK-5000，BK医疗）指导。所有患者在肿瘤切除前均进行了术前磁共振成像（MRI）。手术期间,3D神经导航IOUS研究（n3DUS）是通过开颅术N13C5换能器整合到神经导航系统获得的。获得了至少两个n3DUS研究:在肿瘤切除之前和在切除结束时。术后在48小时内进行MRI检查。MRI和n3DUS研究向后融合，并使用Elements（Brainlab）计划软件进行分析。允许进行两种比较分析：术前MRI与切除前n3DUS比较，术后MRI与切除后n3DUS比较。MRI或n3DUS研究不完整的病例从研究中撤出。
结果：从2022年4月至2024年3月，73例患者接受了IOUS辅助手术。从他们那里,39人被纳入研究。比较术前MRI和切除前n3DUS的分析显示，两种方式之间的肿瘤体积非常一致（p<0,001）。比较术后MRI和切除后n3DUS的分析也显示，在未实现总切除（GTR）的情况下，残余肿瘤体积（RTV）具有良好的一致性（p<0,001）。在两种情况下，在MRI上检测到的RTV在术中未检测到IOUS，可以详细检查以重新检查其外观。
结论：IOUS和MRI之间的术后比较分析对于新型超声使用者来说是一个有价值的工具，因为它增加了案例提供的反馈量，并可以加速学习过程，扁平化这种技术的学习曲线。
