Robot-Assisted MRI-Guided Prostate Biopsy

描述（由申请人提供）：该申请涉及广泛的挑战领域（06）使能技术，具体主题06- eb -101*微创图像引导系统的开发和目标领域(1)提高活检取样/疾病分期的准确性，例如在前列腺癌的评估中，使用一种新的mri引导前列腺活检仪器。

DESCRIPTION (provided by applicant): This application addresses broad challenge area (06) Enabling Technologies, specific topic 06-EB-101* Development of minimally-invasive image-guided systems, and target area (1) Improving the accuracy of biopsy sampling/staging of disease such as in the evaluation for prostate cancer, with a new instrument for MRI-guided prostate biopsy. Needle biopsy is a regularly performed procedure that is required for diagnosing prostate cancer (PC). An estimated 1.3 million biopsies are performed yearly in the US at a healthcare cost of $2.6 billion. Biopsies are typically triggered by elevated prostate specific antigen (PSA) tests, which are highly sensitive but insufficiently specific for PC. Screening with PSA in the last two decades has led to the early detection of PC which coincided with a steady decline of mortality from the disease [1]. Yet the early detection has also led to disease overtreatment, because the aggressiveness of the disease is especially difficult to predict at an early stage. A large number of PCs represent indolent lesions unlikely to limit the Lifespan of the patient due to competing comorbidities. On the other hand some PCs are aggressive, killing 28,000 US men annually. Yet treatment is not a general solution because of adverse effects such as urinary incontinence and erectile dysfunction, and of potentially having a staggering impact on our healthcare system. While active surveillance represents a viable treatment option, the decision to pursue this approach is not straightforward. The ambiguity recently deepened with two recent publications in the New England Journal of Medicine that evaluated the utility of PSA screening and resulted in somewhat conflicting conclusions [2, 3]. With the healthcare community so divided and providers giving mixed recommendations based on their own biases, the patients are increasingly puzzled when making decisions. The fact is that PC is a very complex disease. A question of paramount importance is can we distinguish indolent and harmless tumors from aggressive and lethal PC? Patients with persistently elevated PSA levels who have had a negative biopsy are left worried about their cancer status. Unfortunately, with current technology the negative-predictive value of the biopsy is low such that as many as half of cancers may be initially missed [4]. On the other hand, if biopsy is positive but the Gleason score is low (3+3, 3+4), the patient is not elderly and does not have other high-risk features, will he be comfortable with active surveillance? Or could the biopsy have actually missed lesions of higher Gleason scores? With current transrectal ultrasound-guided (TRUS) biopsy technology, the needle is aimed within the gland but does not aim suspicious lesions because these are typically invisible on ultrasound. As a result of the recent PSA controversy the media and increasingly the medical community labeled TRUS biopsies "blind". This is partially true because the needle is guided to regions of the gland known to develop cancer in man, but is not patient specific. A way to lessen the ambiguity associated with PC diagnosis and staging may be to introduce a more precise and sensitive method to detect PC and better map its presence, grade, and extent. Employing a biopsy system guided by a superior imaging modality, identifying suspicious regions within the prostate, and capable of reproducibly sampling specific regions could be a possible solution to this public health problem. MRI with special contrast, spectroscopy, and diffusion weighted methods is perhaps the most promising candidate for imaging PC [5]. Even though no current imaging method can absolutely differentiate benign from malignant lesions, imaging could point to abnormities that should be biopsied. We propose to develop and perform a first pilot clinical test of a robot to assist the physician in collecting biopsy under MRI guidance. Our Urology Robotics laboratory has developed a unique MRI stealth robot. In the proposed research the hardware and software will be adapted for biopsy, device regulatory protocols will be completed for the biopsy protocol, and a pilot feasibility study will be conducted. The device goes alongside the patient in the scanner and automatically orients a needle-guide based on the images so that the physician can precisely and reproducibly collect the samples. TRUS guided biopsy costs on the order of $2,000. MRI guidance is expected to increase the cost to approximately $3,000, yet overall, if successful, healthcare costs could be substantially reduced. First, improved primary biopsy could reduce the number of 2nd, 3rd, and 4th repeat biopsies which now account for roughly 36% of biopsies costing nearly $1 billion annually. Second, improved biopsy could provide more reliable means of managing the disease by boosting confidence in negative biopsy results, resulting Gleason grades, and mapping of cancer. This could allow more patients to be enrolled in watchful waiting or expectant management thus reducing overtreatment rates, possibly shifting part of the nearly $2 billion spent annually on aggressive therapy. Most importantly, this could improve PC management for fewer related complications, less patient anxiety and physician stress, and hopefully lessen the 15% current rate of PC death. Every year Johns Hopkins Institutions directly generate about $10 billion in economic activity in the State of Maryland, a 43% increase from the $7 billion generated in 2002 and the equivalent of one of every twenty-four dollars in the state's economy today. In 2008 JHI provided 45,000 jobs and created 700 new jobs each year since 2002. Directly and indirectly JHI support more than 100,000 jobs in Maryland, one of every 29 in the state. In Baltimore City JHI support 60,000 jobs, or 16.7 % of all City employment. This application will create or retain the equivalent of 3.7 jobs. PUBLIC HEALTH RELEVANCE: Prostate biopsies are commonly performed freehanded under transrectal ultrasound guidance. Due to the manual approach and the limitations of the ultrasound imager, the procedure has disappointingly high false-negative rates. Moreover, no mechanism is yet available to determine the aggressiveness of prostate cancer at an early stage. These represent a daily problem for urologists managing the disease, create uncertainty and emotional stress for patients, and initiate a cascade of repeat testing and biopsies or overtreatment. We believe that prostate biopsy can be improved by using a new technology and biopsy paradigm. A needle-guide robot that is uniquely capable of operating inside magnetic resonance imaging (MRI) scanners will be developed for prostate biopsy and tested for clinical feasibility. Unlike current biopsy technology that targets regions of the gland, the MRI-guided instrument will assist the physician target lesions of image abnormality.