This study aims to evaluate electromagnetic (EM) tracked navigation in robot-assisted partial nephrectomy (RAPN), addressing kidney movement issues by attaching a tracked EM sensor close to the lesion. This assessment will be based on the navigation's ability to achieve preoperatively planned resection volumes aiming to assist in radical resection margins of the lesion. The current challenge for surgeons performing RAPN is to minimize the removal of healthy kidney tissue, as the rates of positive resections are very low. Additionally, the study aims to explore the practical application of image guidance in RAPN, evaluating aspects such as duration, surgical and technical success, and the surgeons' perceptions. Ultimately, this research seeks to determine if the addition of navigation can enhance RAPN outcomes, particularly in terms of kidney tissue preservation and radical lesion removal. The success of this technique could result in broader adoption of kidney-sparing surgeries, even in complex scenarios where radical resection is at risk.

Robot-assisted partial nephrectomy (RAPN) is now the preferred option for treatable renal lesions due to its ability to preserve kidney function while effectively treating cancer. Despite RAPN's effectiveness, its surgical complexity and varied approach requirements pose challenges. Image-guided surgery applies pre-operative imaging for patient-specific intra-operative visualization of the kidney and lesion margins to support the surgeon during resection. However, adapting to surgery-induced deformations remains a challenge. An approach that is able to correct for organ movements during surgery might result in an optimal preservation rate of healthy kidney parenchyma and improved decisiveness for the surgeon during resection. On the long term, this might result in a larger shift from radical to partial nephrectomies, leading to patients with improved renal functions after lesion resection.

The primary objective is to assess the ability to achieve preoperatively planned resection volumes by adding EM tracked navigation in RAPN, as minimizing the removal of healthy kidney tissue is challenging nowadays. A deviation within 35% between the planned and actual resection volumes is considered comparable and therefore deemed successful. Secondary objectives are the time for localizing and removing the renal lesion, the impact on surgical decisiveness, and the clinical and technical success of implementing the navigation setup.

Inclusion Criteria:

• Age ≥ 18 years
• Patient provides written informed consent form
• Patient is scheduled for robot-assisted partial nephrectomy

Exclusion Criteria:

• Ferro-magnetic implants or other factors in the abdominal or thoracic area that could influence image quality
• Pacemaker or defibrillator