Value of preoperative ultrasound in evaluating the peritoneal cancer index of pseudomyxoma peritonei.

Purpose: This study aimed to explore the value of preoperative ultrasonography (US) in evaluating the peritoneal cancer index (PCI) of pseudomyxoma peritonei (PMP).

Methods: An ultrasound examination was performed on 59 patients with PMP before surgery, and the ultrasound PCI was evaluated. The accuracy of ultrasound PCI score was evaluated with the surgical PCI score as the gold standard.

Results: The preoperative ultrasound PCI was compared with the surgical PCI. The Spearman correlation coefficient of the total PCI score was 0.608 (P < 0.05). The difference in the Spearman correlation coefficient between the preoperative ultrasound PCI and the surgical PCI in areas 0-7 was statistically significant. (1) Among them, the total score and the correlation between 0-3 and 6 were higher. (2) Compared with the surgical PCI, overestimation (> 20%) was concentrated mainly in areas 2 and 4-8 for 2 points, and underestimation (< 20%) was concentrated mainly in areas 1, 3, 4, and 8 for 3 points. (3) The sensitivity and specificity of preoperative ultrasound for predicting the presence or absence of lesions were 85.7% and 50.0%, respectively. The sensitivity of LS 1, LS 2, and LS 3 was 31.7%, 48.2%, and 71.0%, respectively, and the specificity was 44.8%, 55.3%, and 58.8%, respectively.

Conclusion: The ultrasound examination can be used to score the preoperative PCI, judge the severity, and predict the prognosis in patients with PMP.