|- candidate number||25292|
|- NTR Number||NTR6023|
|- ISRCTN||ISRCTN no longer applicable|
|- Date ISRCTN created|
|- date ISRCTN requested|
|- Date Registered NTR||14-sep-2016|
|- Secondary IDs||NL569830.42.16 |
|- Public Title||FREE-hand versus NAVIgation guided percutaneous liver tumor ablation|
|- Scientific Title||FREE-hand versus NAVIgation guided percutaneous liver tumor ablation|
|- hypothesis||Percutaneous CT-guided thermoablation of liver tumours is a minimally invasive alternative for patients who cannot undergo a partial liver resection. The major drawback of TA is ablation site recurrence (ASR) which is reported in 4% to 46%. The most critical first step is precise positioning of the ablation needle in the tumour to ensure complete tumour ablation. Currently, this is done using an iterative free-hand technique supported by computed tomography (CT) images generated during the ablation procedure. In this study, a CT-table-mounted Needle Positioning System (NPS) –which is not in contact with the patient- guides the operator to insert the ablation needle exactly in the desired position in the tumour. This navigation guided approach is compared to the free-hand approach. It is expected that the NPS improves needle positioning resulting in fewer puncture attempts to target the tumor. This will probably result in a more complete tumor ablation.|
|- Healt Condition(s) or Problem(s) studied||Hepatocellular carcinoma, Colorectal metastised cancer|
|- Inclusion criteria|| Indication to be treated by CT-guided percutaneous liver ablation|
• Age >18 years
• Able to read Dutch language
• Signed written informed consent
• Physical and mental state allow general anesthesia as judged by the anesthesiologist
|- Exclusion criteria||Every patient who qualifies for a percutaneous ablation of a liver tumour, can participate in the study except for patients in whom intravenous contrast cannot be administered. This can happen in patients in whom no contrast can be given despite preventive measures like untreatable contrast allergy or severe kidney dysfunction in whom even pre-hydration and other measures according to the UMCG contrast-nephropathy protocol do not allow i.v. contrast injection. Since precision is an important issue in this study, liver tumors need to be precisely located and measured. Therefore precise demarcation of the tumor in relation to the surrounding liver parenchyma is essential and this requires the use of i.v. contrast. Rarely, tumors are visible on non-contrast-enhanced CT scans. Patients with absolute contraindications for contrast administration will nevertheless be treated by percutaneous ablation, but we do not want to include these patients in this study.|
|- mec approval received||no|
|- multicenter trial||no|
|- Type||2 or more arms, randomized|
|- planned startdate ||1-okt-2016|
|- planned closingdate||1-okt-2017|
|- Target number of participants||42|
|- Interventions||CT-guided percutaneous liver tumor ablation|
|- Primary outcome||The number of needle insertions to reach an adequate target position. |
|- Secondary outcome||-1- deviation from predefined optimal tip-of-needle position based on lateral displacement (3D), angle deviation and longitudinal displacement, -2- time span needed to obtain adequate position, -3- number of control CT scans during the procedure to check the needle position, including calculation of radiation dose, -4- completeness of ablation zone as evaluated during the standard one-week post-procedural CT scan.|
|- Timepoints||Moment of tumor ablation
1-week follow-up scan after ablation|
|- Trial web site|
|- CONTACT FOR PUBLIC QUERIES|| W.J. Heerink|
|- CONTACT for SCIENTIFIC QUERIES|| W.J. Heerink|
|- Sponsor/Initiator ||University Medical Center Groningen (UMCG)|
(Source(s) of Monetary or Material Support)
|Samenwerkingsverband Noord Nederland|
|- Brief summary||Liver tumors|
Malignant liver tumors can originate in the liver itself (called hepatocellular carcinoma or cholangiocarcinoma) or can be derived from other primary cancers. Especially colorectal carcinoma is a frequent site of cancer which spreads (metastasizes) to the liver.
Depending on tumor stage surgical resection or liver transplantation offer the best outcome, but because of associated diseases or advanced stage this is not always a possibility. For both diseases local tumor ablation is advised as therapy in case surgery is not possible. Furthermore, ablation is used as a bridge to liver transplantation for patients with cirrhosis and HCC.
Radiofrequency and microwave ablation
Radiofrequency ablation (RFA) and microwave ablation (MWA) are therapeutic procedures that can be used when surgical resection (partial hepatectomy) is not an option. RFA and MWA rely on high frequency currents (RFA: 450-500 kHz, MWA: 300 MHz – 300 GHz) that are passed through a needle electrode inside the tumor. This creates heat which destroys the tumor cells. For both correct positioning of the ablation needle in the tumor is critical. This can be achieved by various imaging modalities: ultrasound (US); computed tomography (CT); magnetic resonance imaging (MRI) or fluoroscopy. US is the most frequently used modality, because it can be used intra-operatively. US is often not applicable when ablation is performed percutaneously. Reasons for this are incomplete visualization of tumors (obesity, interposition of gas-containing organs, cirrhotic liver etc. In those cases, (contrast enhanced) CT offers a higher resolution and thus better delineation of tumor contours, better identification of adjacent structures, more precise placement of the needle and a better baseline for post procedural follow-up. Several observational series of liver tumors treated with ablation have been reported and Dutch guidelines advocate ablation as an indispensable treatment modality for patients with liver tumors.
Percutaneous ablation is a minimal invasive treatment which can be performed as an outpatient procedure or a one-day admission procedure. Several series –including our own results on more than 500 procedures- show a low complication rate and -in patients with colorectal liver metastases- a similar 5 year survival rate of 40% as compared to partial liver resection. Especially in patients with recurrent liver metastases after previous partial liver resection, thermoablation is an attractive –intentionally curative- treatment option in otherwise not resectable liver tumors. (J Hof, MWJLAE Wertenbroek, PMJG Peeters, J Widder, E Sieders, KP de Jong. Outcomes with resection and/or radiofrequency ablation for recurrent colorectal liver metastases. BJS 2016 In press.)
THE great unsolved problem of ablation of liver tumors is incomplete ablation resulting in ablation site recurrences. The first step to prevent this is accurate placement of the needle in the tumor, thereby creating a total destruction of the tumor including a "safety zone" of adjacent liver tissue. Nowadays the free-hand approach is performed which consists of iterative insertion of the needle followed by position check by performing a CT scan. In a benchmark study we found that for each adequate position in the tumor to start ablation, a median number of 2.1 (range 1 – 6) needle insertions were necessary to obtain that adequate position.
If the operator is aided by a system that helps him to guide the needle towards the target, it is expected that it will improve needle positioning. An improved and more accurate positioning of the ablation needle has several advantages:
• More precise positioning of the needle in the tumor
• More reliable position planning in case of multiple overlapping ablation zones in the case of larger tumors
• Higher rate of single needle insertion to obtain adequate position in tumor
- Less tissue damage
- lower chance of needle track seeding.
- lower radiation dose
- shorter duration of procedure
- lower costs because of shorter CT scan and personnel occupation
• A shorter learning curve to master needle placement especially for tumors for which off-slice angulation is necessary.
All these issues will reduce costs associated with the procedure and will probably contribute to better tumor coverage by the ablation zone and reduction of ablation site recurrences and thus repeat procedures.
Needle Positioning System
The needle positioning system was developed by DEMCON specifically but not exclusively for application in the UMCG CT-guided percutaneous liver ablation program. The device is mounted on the CT-table, and does not have direct contact with the patient. After an initial scan, the NPS can be manually positioned on top of the insertion point on the skin. This step is not motorized to make the NPS a relatively small and easy to handle device and to cut down on costs. Next, an additional scan is acquired and using interactive volumetric software, the target –liver tumor- can be selected. Subsequently, the needle guidance platform is automatically, spatially oriented in such a way that the needle, inserted by the operator through the platform, will reach the tumor in the predefined optimal position. After insertion to the correct depth (as indicated on the needle) the NPS will immediately be disconnected from the needle and moved out of the way, leaving the needle in place. A control scan will be made to verify if the needle is in the correct position before the ablation process starts.
The advantage of the NPS is its simplicity and the possibility to integrate it easily in a standard interventional CT room.
|- Main changes (audit trail)|
|- RECORD||14-sep-2016 - 19-okt-2016|