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Updated: Jun 26, 2026

Electromagnetic Navigation Transthoracic Nodule Localization for Minimally Invasive Thoracic Surgery
Published on: May 4, 2022
Intraoperative mobile CT and virtual-assisted lung mapping for pulmonary nodule localization: workflow
Keita Nakao1,2, Takahiro Karasaki3, Yue Cong1
1Department of Thoracic Surgery, The University of Tokyo Graduate School of Medicine, 7-3-1 Hongo, Bunkyo-ku, 113-8655, Tokyo, Japan.
Objectives:
Intraoperative mobile CT (iCT) and virtual-assisted lung mapping (VAL-MAP) are used to localize pulmonary nodules that are difficult to palpate during minimally invasive surgery. Because these techniques differ in workflow structure and timing of image acquisition, their operative time and radiation exposure may differ. We aimed to describe workflow characteristics and radiation exposure associated with newly implemented iCT and to contextualize these findings against our established VAL-MAP practice.
Methods:
We retrospectively reviewed 50 consecutive patients who underwent thoracoscopic wedge resection with localization between January 2024 and December 2025. Twenty-four underwent iCT-guided localization using an O-arm system, and 26 underwent VAL-MAP with bronchoscopic dye marking followed by post-mapping CT. Technique selection was based on device availability and surgeon discretion. CT dose metrics and time components related to localization were analyzed.
Results:
Median CT-related dose-length product (DLP) was higher in the iCT group, primarily due to high-definition scans. When performed in standard mode with a limited scan frequency, iCT radiation exposure approximated that of post-VAL-MAP CT. Preparation CT after lateral positioning reduced repeat scans and iCT-related interruption time. Anesthesia and operative times were shorter in the VAL-MAP cohort, reflecting localization outside the operating room. Overall procedural burden appeared modestly different.
Conclusion:
Our single-center retrospective study quantified the total procedural time for VAL-MAP and iCT, finding modest differences in time and radiation exposure. These real-world data aid institutions considering these localization strategies, but do not establish superiority. Definitive comparative conclusions require future prospective evaluations controlling for nodule characteristics and cost.

