Mesothelioma Contrast Pharmacokinetics: A Feasibility Trial of the Use of Pharmacokinetic Analysis in Small-Volume Pleural Malignancy

Purpose To assess the feasibility of dynamic contrast-enhanced (DCE) MRI-derived pharmacokinetic factor acquisition and performance in patients with suspected small-volume pleural malignancy. Materials and Methods This retrospective analysis involved the use of pharmacokinetic parameter computation software for prospectively performed DCE MRI in patients with suspected pleural malignancy performed between January 2013 and October 2016. Pharmacokinetic calculation was performed using pre- and postgadobutrol three-dimensional T1-weighted sequences within a volume of interest. Systematic placement of multiple pleural regions of interest allowed computation of mean pleural volume transfer constant (<i>K</i>^trans), fractional volume (<i>V</i>_e), and rate constant (<i>k</i>_ep) per patient. Identification of malignancy involved using cut points calculated from mean <i>K</i>^trans, <i>V</i>_e, and <i>k</i>_ep values obtained from macronodular pleural disease. Pharmacokinetic diagnostic performance was assessed individually (<i>K</i>^trans, <i>V</i>_e, and <i>k</i>_ep) and in combination with morphology and early contrast enhancement (ECE). Results The study included 58 patients (median age, 76 years [IQR, 70-81 years]; 51 of 58 [88%] male). The primary end point was achieved in 47 of 58 (81%) patients, with successful calculation of pharmacokinetic metrics. A total of 29 of 47 patients (62%) were diagnosed with malignancy with minimal pleural thickening; 24 of 29 (83%) had pleural mesothelioma and 20 of 24 (83%) had stage I disease. Sensitivity (<i>K</i>^trans, 73%; <i>V</i>_e, 83%; and <i>k</i>_ep, 87%) and negative predictive value (NPV; <i>K</i>^trans, 50%; <i>V</i>_e, 60%; and <i>k</i>_ep, 25%) were calculated using single pharmacokinetic values (<i>P</i> > .05 for each). Combining pharmacokinetic thresholds with morphology and ECE improved sensitivity and NPV to 100% (<i>P</i> = .03 for each factor) but reduced specificity (16.7% for <i>K</i>^trans/<i>V</i>_e [<i>P</i> = .04]; 5.6% for <i>k</i>_ep [<i>P</i> = .002]). Conclusion Pharmacokinetic analysis was feasible in small-volume pleural malignancy. <b>Keywords:</b> MR-Dynamic Contrast-enhanced, MR Imaging, Thorax, Pleura, Oncology <i>Supplemental material is available for this article.</i> © RSNA, 2026.