Is intraoperative ultrasound (IOUS) still useful for the detection of liver metastases?

Abstract

KEYWORDSLiver; Metastases; Ultrasound; Computed tomography; Magnetic resonance; Intraoperative ultrasound.Abstract Purpose: To evaluate the clinical impact of intraoperative ultrasound (IOUS) in the detection of liver metastases during the years, as compared with those of other imaging modalities. Materials and methods: All IOUS scans performed for detection of liver metastases from 2000 to 2006 were retrospectively reviewed and compared with the results of preoperative imaging modalities: Ultrasound (US), Computed Tomography (CT), and/or Magnetic Resonance (MR). The number of cases in which IOUS and preoperative imaging studies produced discordant results, in terms of presence/absence of focal liver lesions, was calculated per year. Statistical analysis was performed using the McNemar test. A p value < 0.05 was considered statistically significant. Results: Eighty-three IOUS scans performed in 2000e2003 were reviewed, and discordance with preoperative imaging findings was found in 19/83 (23%) cases. Of the 42 IOUS scans done during the 2004e2006 period, 10/42 (24%) showed discordance with preoperative studies. All metastases diagnosed with imaging studies were pathologically confirmed. The number of discordant cases in the two periods were not significantly different (p Z 0.2). Conclusion: IOUS is still useful in the detection of liver metastases. Its decreased use is probably due to the improved accuracy of preoperative imaging modalities.Sommario Scopo: Valutare l'impatto clinico negli anni dell'ecografia intraoperatoria (IOUS) nella identificazione delle metastasi epatiche rispetto alle altre metodiche di imaging. Materiali e metodi: risultati delle ecografie intraoperatorie effettuate per l'identificazione delle metastasi epatiche in un periodo compreso tra gli anni 2000 e 2006 sono stati retrospettivamente revisionati e comparati con le metodiche di imaging preoperatorio: Ecografia (US), Tomografia Computerizzata (TC) e/o Risonanza Magnetica (RM). Tutti i casi sono stati patologicamente provati. Sono stati calcolati per anno i casi discordanti in termini di presenza/assenza di lesione focale epatica. Il confronto statistico è stato effettuato con il test di McNemar. Un valore del p < 0,05 è stato considerato statisticamente significativo. Risultati: Nel triennio 2000e2003, i dati di 83 pazienti sono stati revisionati e i casi discordanti sono stati 19/83 (23%). Nel triennio 2004e2006, i dati di 42 pazienti sono stati revisionati e i casi discordanti sono stati 10/42 (24%). Non vi è stata differenza statisticamente significativa (p Z 0,2) circa il numero di casi discordanti nei due periodi. L'esame patologico ha confermato la presenza di metastasi in tutti i casi. Conclusioni: L'ecografia intraoperatoria (IOUS) risulta una metodica di imaging tuttora utile nella identificazione delle metastasi epatiche. La riduzione del suo impiego negli anni è probabilmente dovuta alla maggiore accuratezza diagnostica dell'imaging preoperatorio. ª

The role of intraoperative ultrasound for the assessment of the focal liver lesions in patients with colorectal cancer

“…The increase in the number of benign lesions in the study group is correlated with the reduction of the specificity of preoperative imaging [15]. In the literature, discordances between IOUS and preoperative imaging range between 23-32% [16,17]. Our study found discordances between IOUS and abdominal US in 26 of the 73 patients (35.6%), while the values of the Kw concordance index were 0.64 (the values of the Kw concordance index are considered to be good within the [0.6-0.8] interval and very good within the [0.8-1.0] interval).…”

The role of intraoperative ultrasonography in the diagnosis and management of focal hepatic lesions

“…Due to its high spatial resolution, IOUS is commonly regarded as the gold standard for the staging of liver tumors [ 13 , 14 ]. Previous studies have also suggested that IOUS is superior to preoperative imaging modalities in identifying hepatic lesions in patients with primary or metastatic hepatic tumors [ 9 , 31 ]. Furthermore, the detection of additional hepatic lesions has been observed to lead to changes in the surgical strategy in a widely varying range of cases (2.7%-49%) [ 1 , 32 , 33 ].…”

“…Conlon et al [ 33 ] reported that in patients with hepatic metastases from colorectal cancer, IOUS identified additional hepatic lesions in 47% of patients compared to preoperative magnetic resonance imaging (MRI). In another study, D’Onofrio et al [ 9 ] compared the diagnostic performance of IOUS in patients from two different time periods (2000-2003 vs. 2004-2006), and demonstrated that IOUS was still useful in detecting unexpected hepatic metastases, despite improvements in preoperative imaging. In addition, several recent studies have demonstrated that IOUS is still superior to preoperative imaging in detecting CRLM, and that IOUS findings can have a substantial impact on the choice of surgical strategy [ 3 , 34 , 35 ].…”

“…IOUS-guided therapeutic procedures for liver tumors include ethanol ablation, radiofrequency ablation (RFA), and microwave ablation (MWA). Previous studies have shown that a combination of IOUS-guided tumor ablation with hepatic resection can, in fact, extend the limits of hepatic surgery [ 9 - 11 ]. In this article, we examine the current role of IOUS in the field of hepatic surgery and review the clinical applications of IOUS in the diagnosis and management of focal hepatic lesions.…”

Value of Intraoperative Sonography in Pancreatic Surgery

“…The ability of laparoscopic sonography to improve detection of small hepatic metastases and thus affect resectability also remains controversial 9 , 21 – 23 . D'Onofrio et al 22 , 24 found small liver lesions on intraoperative sonography that were not previously identified on preoperative imaging. With improved MRI techniques, specifically the use of liver‐specific contrast agents and diffusion sequences, the sensitivity of MRI is currently as high as that of intraoperative sonography for detection of focal lesions and metastases 21 .…”