Contrast-enhanced Harmonic Compound US of the Spleen to Increase Staging Accuracy in Patients with Hodgkin Lymphoma: A Prospective Study

Purpose: To prospectively compare contrast material-enhanced harmonic compound ultrasonography (US), computed tomography (CT), and fluorine 18 fluorodeoxyglucose (FDG) positron emission tomography (PET) in detecting nodular infiltration in the spleen of patients with newly diagnosed Hodgkin lymphoma. Materials and Methods: After institutional review board approval and informed consent, 100 consecutive patients with Hodgkin lymphoma during pretreatment staging were prospectively investigated for possible spleen involvement by comparing harmonic compound US (integrated with intravenous infusion of microbubbles in 33 patients) with CT and FDG PET. Findings indicative of malignant nodules with the imaging procedures were regarded as lymphoma infiltration; in case of discrepancy, response to treatment was regarded as evidence of lymphoma. Results: Malignant nodules were detected with CT in 13 patients, with FDG PET in 13 patients, and with contrast-enhanced harmonic compound US in 30 patients. Coincidental findings of malignancy with all three imaging techniques occurred in 13 patients; 17 patients had only US-detectable malignant nodules, which showed disappearance or relevant decrease after chemotherapy. Overall, the spleen had nodular infiltration in 30 patients (13 for imaging finding concordance; 17 for typical contrast-enhanced harmonic compound US findings and chemotherapy-related nodule size modifications). Thus, both CT and FDG PET provided false-negative results in 17 of 30 patients compared with contrast-enhanced harmonic compound US, the results of which translated into disease upstaging in 13 patients. Conclusion: Harmonic compound US with contrast enhancement for the characterization of possible nodules provides a higher sensitivity than does CT or FDG PET in the detection of splenic involvement by Hodgkin lymphoma.