Assessment of pulmonary nodules using [18F]-FDG PET/CT in deep inspiration breath-hold

Abstract

The characterization of pulmonary nodules (PN) is a primary indication for [¹⁸F]-FDG PET/CT. However, respiratory movements hinder this characterization, especially for PN located in the lower lobes. Various methods have been developed to improve image resolution.

Objective: Our objective was to compare the diagnostic efficacy of [¹⁸F]-FDG PET/CT in deep inspiration breath-hold (DIBH) versus free-breathing corrected by software, in the evaluation of PN.

Methods: We prospectively analyzed 51 patients to assess PN using [¹⁸F]-FDG PET/CT in DIBH and free-breathing corrected by software. A total of 84 nodules with an average size of 10 mm were analyzed, with pathological anatomy or medical treatment decide by a multidisciplinary tumor board used as reference.

Results: A total of 84 PN were evaluated, comparing those in DIBH versus free-breathing, finding statistically significant differences in SUVmax values P(< 0.05) (mean SUVmax 3.7 in free-breathing vs. 5.33 in DIBH). When analyzed by location in lobes, we did not find statistically significant differences, though there was a trend towards higher SUVmax values in the lower lobes. [¹⁸F]-FDG PET/CT in DIBH showed high sensitivity (95%) and negative predictive value (NPV) (92%), indicating it may be a promising tool for PN characterization.

Conclusions: The acquisition of [¹⁸F]-FDG PET/CT in DIBH significantly improves the sensitivity and diagnostic efficacy in the assessment of PN. Although no statistically significant differences were found based on location, there is a potential benefit for the lower lobes. These findings could support its use in clinical practice.

Keywords: Gating respiratorio; Nódulo pulmonar; PET en inspiración libre; PET en inspiración profunda mantenida; PET in deep held inspiration; PET in free-breathing; Pulmonary nodule; Respiratory gating.