WCE 2019: Developing a Free Three-dimensional Tool for Kidney Stones’ Surgical Planning: “Calculator”

Abu Dhabi, United Arab Emirates (UroToday.com) Flexible ureteroscopy has gained a fair degree of popularity for kidney stone treatment over the years. However, operative times vary quite dramatically depending on the volume of the stone burden that is being treated. In his study, Dr. Frederic Panthier of the Hospital Tenon Department of Urology aimed to develop a 3D tool for calculating the volume of stone burden for purposes of surgical preoperative planning.

For his study, Dr. Panthier utilized a program known as 3DSlicer, a free open-source software for medical image computing (DICOM) and 3D visualization. Specifically, within the 3DSlicer program, Dr. Panthier worked with a tool known as the “Extension Developing Tool,” which helps to create new modules in the 3DSlicer program using Python scripting. He and his team sought to develop an application within 3DSlicer that could interpret a CT scan DICOM series, be able to define a region of interest within a CT scan, detect single or multiple stones and calculate their respective stone densities based on Hounsfield Units (HU), and, finally, allow for 3D visualization of a patient’s stone burden.

WCE 2019 3DSlicer calculator

Fortunately, Dr. Panthier was able to develop an application in 3DSlicer that was able to achieve this set of criteria, which he named “calculator.” The application allows for the user to define an adjustable region of interest based on axial, sagittal, and coronal views using the pre-existing “Crop Volume” feature in 3DSlicer. From the regions of interest identified, “calculator” is able to define an adjustable segmentation based on thresholds to detect stones. In addition, the “split islands into segments” feature of the “calculator” module was developed by Dr. Panthier to be used in cases when multiple stones are present. The most impressive capability of this “calculator” module, however, is its ability to calculate stone volumes and the estimated amount of time needed to break up stones during lithotripsy (if the application is provided with some information regarding laser parameters being used).

Presented by: Frederic Panthier, MD, Service d’Urologie, Hospital Tenon, Paris, France

Written by: Andrew Shea Afyouni, BS, Junior Research Specialist and Medical Student, University of California, Irvine Department of Urology at the 37th World Congress of Endourology (WCE) – October 29th-November 2nd, Abu Dhabi, United Arab Emirates