# CT-Guided Lung Biopsy Using Dual-Energy Iodine Mapping to Target Lung Masses with Necrotic Tissue—A Proof-of-Concept Study

## TL;DR

This study shows that using dual-energy CT iodine maps can help guide lung biopsies to target viable tumor tissue, improving diagnostic accuracy and safety.

## Contribution

The study demonstrates the clinical feasibility of using DECT iodine mapping to improve biopsy targeting in necrotic lung lesions.

## Key findings

- DECT-guided biopsy achieved a 90% diagnostic yield in 20 patients.
- Biopsy samples were sufficient for molecular testing in 65% of cases.
- Complications were minor, with no major adverse events reported.

## Abstract

Background: Computed tomography (CT)-guided lung biopsy plays a pivotal role in diagnosing thoracic lesions. However, its diagnostic yield may be compromised in large, necrotic, or heterogeneous tumours due to inadvertent sampling of non-viable tissue. Dual-energy CT (DECT) iodine mapping provides functional imaging by identifying iodine-avid, perfused areas, thereby offering the potential to improve biopsy targeting. Methods: This single-centre retrospective study evaluated the clinical feasibility and diagnostic performance of DECT-guided biopsy. Adult patients with suspected necrotic lung or mediastinal lesions who underwent DECT iodine mapping prior to CT-guided biopsy between April 2021 and December 2022 were evaluated. DECT iodine maps were generated using dual-source CT and used to identify viable tumour regions for targeted biopsy. The primary outcome was diagnostic yield, defined as obtaining a definitive histopathological diagnosis. Secondary outcomes included safety and adequacy of samples for molecular testing. Results: Twenty patients were included. A definitive diagnosis was obtained in 18/20 biopsies (90%). Diagnostic yield was 9/11 (81.8%) for pulmonary lesions and 9/9 (100%) for mediastinal/pleural lesions. Diagnoses included non-small-cell lung cancer (n = 8), Hodgkin lymphoma (n = 4), thymoma (n = 3), and other malignancies (n = 3). Biopsy material was sufficient for additional molecular testing in 13/20 cases (65%). Complications were minor (one pneumothorax not requiring drainage and two self-limited bleeding events). Conclusions: DECT iodine map-guided targeting was feasible in this retrospective cohort and was associated with high diagnostic yield, low complication rates, and frequent acquisition of tissue suitable for molecular analyses. Prospective controlled studies are needed to quantify benefit over conventional CT guidance.