A New Image Navigation System for MR-Guided Cryosurgery

Abstract

Purpose: To evaluate the feasibility of Interactive Scan Control (ISC), a new MR image navigation system, during percutaneous puncture in cryosurgery.Materials and Methods: With the ISC system in place, percutaneous MR-guided cryosurgery was performed in 26 cases, with the ISC system being used in 11 cases (ˆve renal tumors, three uterineˆbroids and three metastatic liver tumors). The ISC system comprised infrared cameras and an MR-compatible optical tracking tool that was directly connected to a cryoprobe. Tumor sizes ranged from 1.2 cm (metastatic liver tumor) to 9.0 cm (uterineˆbroid), for a mean size of 3.9 cm. With ISC, one to three cryoprobes with a diameter of 2 mm or 3 mm were advanced into the tumors with the guidance of an MR ‰uoroscopic image. Two freeze-thaw cycles were used for cryosurgery. During the cryosurgery, the formation of iceballs was monitored on MR images. Follow-up dynamic CT or MRI as well as physical examinations were conducted after two weeks and six weeks.Results: Placement of probes was successfully performed under the control of the ISC system. During cryosurgery, engulfment of the tumors by iceballs was carefully monitored by MRI. Necrosis of the cryoablated area was conˆrmed in all renal tumors by follow-up dynamic CT. The size regression of the uterineˆbroids was observed through follow-up MRI. Two of the three cases of metastatic liver tumor were ablated completely. Additional therapy for a residual tumor was performed on one patient with a metastatic liver tumor. A small amount of pneumothorax was the only complication found in a patient with a metastatic liver tumor.Conclusion: MR-guided cryosurgery with this new navigation system was feasible with low morbidity and allowed for safe and accurate puncture with a cryoprobe.

Comparison of Percutaneous and Surgical Approaches to Renal Tumor Ablation: Metaanalysis of Effectiveness and Complication Rates

“…To address this question, we conducted a metaanalysis to see if Zagoria 26 Weizer 20 Veltri 41 Varkarakis 25 Ukimura 40 Silverman 22 Shingleton 39 Shingleton 38 Sabharwal 37 Roy-Choudhury 36 Pavlovich 35 Ogan 34 Mogami 28 Miki 33 Merkle 23 Memarsadeghi 32…”

Interventional navigation systems for treatment of unresectable liver tumor

“…The drawback of the optical tracking system is that the line of sight has to be maintained between the position sensor and the tracking marker attached to the surgical instrument. Furthermore, the measurement is not accurate when there is a bending of probe [1,3,4,10,11,18,20,25]. The basic setup of the optical tracking system is illustrated in Fig.…”

“…The following section reviews the current research development of different INS for treatment of unresectable liver tumor according to their image modalities they are based on. [18]. Real-time MRI images were collected and overlaid with tracking coordinates from optical or MR gradient-based tracking system.…”

A MRI-Guided Robot for Neurosurgery: Optimization, Registration and Tracking

“…As a result, conventional robots with mechanical parts, containing ferromagnetic components are not allowed to work in MRI scanner room [14][15]. Possible techniques for building MR compatible robots can be found in [2][3][4][5][6][7][8][9]. In this study, the solutions for MR-compatibility are as following: All the motion stages are actuated by non-magnetic (piezoelectric) ultrasonic motors (USM, with rotary encoder units, Xi'an Ultrasonic Technology Co., Ltd., Xian, China).…”

“…Moser et al [8] designed and developed a one DOF MR-compatible master-slave robotics system and a haptic interface using hydraulic transmission. One of the most well known MR-compatible robot devices is called NeuroArm [9]. NeuroArm is designed especially for neurosurgical operations, i.e., for performing perform image-guided biopsies or haptically controlled microsurgery.…”