Laparoscopic ultrasound vs triphasic computed tomography for detecting liver tumors

Background: Accurate staging of malignant tumors in the liver has major implications in defining prognosis and guiding both surgical and nonsurgical therapy. Intraoperative ultrasound in open surgery compares favorably with computed tomography (CT) in the detection of liver tumors; however, there is little experience with laparoscopic ultrasound (LUS). Hypothesis: Laparoscopic ultrasound is more sensitive than triphasic CT for detecting primary and metastatic liver tumors. Design: Prospective study. Setting: University hospital. Patients: Fifty-five patients with a total of 222 lesions, including primary and metastatic liver tumors, who underwent both CT examinations and LUS as a part of a tumor ablation procedure. Interventions: Triphasic spiral CT scans of the liver were obtained within 1 week before surgery. Liver LUS was performed with a linear 7.5-MHz side-viewing laparoscopic transducer. Results: The LUS detected all 201 tumors seen on preoperative CT and detected 21 additional tumors (9.5%) in 11 patients (20.0%). These tumors missed by CT ranged in size from 0.3 to 2.7 cm. Smaller tumors tended to be missed by CT scan (28.6% of the lesions <1 cm, 15.8% of those 1-2 cm, 4% of those 2-3 cm, and 0% of chose >3 cm), as did those in segments III and IV. There was good correlation between the size of lesions imaged by the 2 modalities (Pearson r=0.86; P<.001). Conclusion: Laparoscopic ultrasound offers increased sensitivity over CT for the detection of liver tumors, especially for smaller lesions. This study documents the ability of LUS in detecting liver tumors and argues for more widespread use in laparoscopic staging procedures.