MRI-Based 3-Dimensional Visualization Workflow for the Preoperative Planning of Nephron-Sparing Surgery in Wilms’ Tumor Surgery: A Pilot Study

Jene W. Meulstee,Annemieke S. Littooij,Matthijs Fitski,Alida F. W. van der Steeg,Cornelis P. van de Ven,Marc H. W. A. Wijnen

doi:10.1155/2020/8899049

Abstract

Purpose. Due to the size and localization of Wilms’ tumor (WT), nephron-sparing surgery (NSS) is only possible in a limited number of cases. When NSS is considered, the surgeon preoperatively requires a thorough understanding of the patient-specific anatomy to prevent positive surgical margins and other complications. Through a collaboration between the radiology and pediatric surgery departments and 3D imaging specialists, a 3D visualization workflow was developed to improve preoperative planning of NSS for WT patients. Methods. The 3D visualization workflow combines a MRA sequence, a segmentation protocol, and augmented reality (AR) visualization, additional to in-house 3D printing. A noncontrast-enhanced MRA scan was added to the MRI protocol. MRI sequences were segmented with a segmentation protocol in an open-source software package. The resulting 3D models were visualized in AR with a HoloLens and 3D print. Results. In a pilot study, five WT patients eligible for NSS were preoperatively planned through the 3D visualization workflow. AR visualization software was fast and free to use and allowed adequate handling of the 3D holograms. The 3D printed models were considered convenient and practical for intraoperative orientation. The patient-friendly, fast, and low-cost 3D visualization workflow was easily implemented and appeared to be valuable for the preparation of NSS. Conclusion. This pilot study demonstrates how a strong collaboration between the pediatric surgery and radiology departments and 3D imaging specialists will help to shape the future of pediatric oncological surgery. This 3D visualization workflow aims to prepare pediatric oncological surgeons for nephron-sparing surgery in patients with Wilms’ tumors.

Highlights

Wilms’ tumor (WT) is the second most common abdominal pediatric tumor in Europe, with children being diagnosed at a median age of approximately 3.5 years [1]
An overview of the proposed workflow is given in Figure 1. e following sections describe the employment of the noncontrast-enhanced MRA (NC-MRA) sequence, segmentation protocol, and visualization with Augmented Reality (AR) and with 3D printing
Five patients were considered for nephron-sparing surgery (NSS), and their surgeries were preoperatively planned with the 3D visualization workflow in addition to the standard protocol. e patients’ ages ranged from 2 to 8 years

Summary

Introduction

Wilms’ tumor (WT) is the second most common abdominal pediatric tumor in Europe, with children being diagnosed at a median age of approximately 3.5 years [1]. In accordance with the International Society for Pediatric Oncology—Renal Tumor Study Group (SIOP-RTSG) Umbrella treatment protocol, therapy generally consists of neoadjuvant chemotherapy, followed by radical nephrectomy and adjuvant chemotherapy [2]. In contrast to a radical nephrectomy for local treatment, nephron-sparing surgery (NSS) can be used for nephrogenic preservation. NSS is a technically demanding procedure and it requires a thorough preoperative understanding of the patient-specific renal anatomy and intraparenchymal vasculature [4]. With or without a predisposing syndrome, might be eligible for NSS depending on the tumor location, size, and infiltration. Due to the risk of a positive surgical margin with

Objectives

Methods

Results

Conclusion