Long-term results of liver thermal ablation in patients with hepatocellular carcinoma and colorectal cancer liver metastasis regarding spatial features and tumor-specific variables

Abstract

Purpose: Colorectal cancer liver metastasis (CRLM) and hepatocellular carcinoma (HCC) are widely treated using microwave and radiofrequency ablation. Local tumor progression (LTP) may develop depending on the shortest vascular distance and large lesion diameter. This study aims to explore the effect of these spatial features and to investigate the correlation between tumor-specific variables and LTP.

Methods: This is a retrospective study covering the period between January 2007 and January 2019. One hundred twenty-five patients (CRLM: HCC: 64:61) with 262 lesions (CRLM: HCC: 142:120) were enrolled. The correlation between LTP and the variables was analyzed using the chi-square test, Fischer's exact test, or the Fisher-Freeman-Halton test where applicable. The local progression-free survival (Loc-PFS) was analyzed using the Kaplan-Meier method. Univariable and multivariable Cox regression analyses were performed to identify prognostic factors.

Results: Significant correlations were observed for LTP in both CRLM and HCC at a lesion diameter of 30-50 mm (P = 0.019 and P < 0.001, respectively) and SVD of ≤3 mm (P < 0.001 for both). No correlation was found between the ablation type and LTP (CRLM: P = 0.141; HCC: P = 0.771). There was no relationship between residue and the ablation type, but a strong correlation with tumor size was observed (P = 0.127 and P < 0.001, respectively). In CRLM, LTP was associated with mutant K-ras and concomitant lung metastasis (P < 0.001 and P = 0.003, respectively). In HCC, a similar correlation was found for Child-Pugh B, serum alpha-fetoprotein (AFP) level of >10 ng/mL, predisposing factors, and moderate histopathological differentiation (P < 0.001, P = 0.008, P = 0.027, and P < 0.001, respectively). In CRLM, SVD of ≤3 mm proved to be the variable with the greatest negative effect on Loc-PFS (P = 0.007), followed by concomitant lung metastasis (P = 0.027). In HCC, a serum AFP level of >10 ng/mL proved to be the variable with the greatest negative effect on Loc-PFS (P = 0.045).

Conclusion: In addition to the lesions' spatial features, tumor-specific variables may also have an impact on LTP.

Keywords: Ablation techniques (D055011); colorectal neoplasm (D015179); hepatocellular carcinoma (D006528); local tumor progression (D009364); survival analysis (D016019).

Figure 1

The flowchart of patient selection. CRC, colorectal carcinoma; HCC, hepatocellular carcinoma; MWA, microwave ablation; RFA, radiofrequency ablation.

Figure 2

The measurement of the shortest vascular distance. Dynamic T1W volume sections in a patient with CRC metastasis in segment 6 are shown (a). Two vessels with the smallest distance to the lesion, 1.12 mm and 1.46 mm and a width of approximately 4 mm, (3.65 mm and 4.22 mm, respectively) are seen in the axial sections. To determine the exact distance, the dimensional indicators were centered on the lesion (b). Rotating through 360 degrees in the coronal and sagittal planes (c), the closest vessel distance was sought. On this plane represented with the yellow line (c), the exact distance was determined to be 5.78 mm in the axial-oblique section (d). CRC, colorectal carcinoma.

Figure 3

Biliary obstruction after RFA of CRC metastasis. A segment 4b metastasis is seen on the fat-suppressed T2-weighted slice (a). Ultrasound-guided percutaneous radiofrequency ablation is performed (b). Approximately nine months after the procedure, the patient developed biliary dilatation (c) due to the central ablation scar, and percutaneous biliary drainage (d) was performed. RFA, radiofrequency ablation; CRC, colorectal carcinoma.

Figure 4

Abscess formation after MWA of CRC metastasis. A segment-5 metastasis is visible on the portal venous phase enhanced MRI (a). Ultrasound-guided intraoperative MWA and the ablation zone with echogenic borders are seen (b, c). On the fourth day after surgery, an abscess associated with the ablation zone and subcapsular suppuration were observed on contrast-enhanced abdominal CT examination (d), which was performed after the addition of fever to persistent right upper quadrant pain. CRC, colorectal carcinoma; MWA, microwave ablation; CT, computed tomography; MRI, magnetic resonance imaging.

Figure 5

Costochondritis after RFA of HCC. A patient with segment 8 HCC who underwent RFA one month ago has right upper quadrant pain that does not resolve. Follow-up MRI in the first month shows a costochondral inflammatory signal increase adjacent to the ablation zone in the postcontrast T1 (a) and fat-suppressed T2 slices (b). At the sixth month follow-up, the postcontrast fat-suppressed T1 (c) and fat-suppressed T2 (d) slices show a regression of costochondral inflammation and a shrunken ablation cavity. RFA, radiofrequency ablation; HCC, hepatocellular carcinoma; MRI, magnetic resonance imaging.