Stereotactically navigated percutaneous microwave ablation (MWA) compared to conventional MWA: a matched pair analysis.

PURPOSE: To compare CT-navigated stereotactic microwave ablation (SMWA) to non-navigated conventional MWA (CMWA) for percutaneous ablation of liver malignancies.

METHODS: A matched pair analysis of 36 patients who underwent MWA of primary or secondary liver malignancies (10 hepatocellular carcinoma and 8 metastases) was conducted. A total of 18 patients undergoing SMWA were included in this prospective study. Patients were matched in terms of tumor size, liver segment and entity to retrospective CMWA procedures. The endpoints were procedure time, accuracy of needle placement, technical success rate, complication rate and dose-length product (DLP).

RESULTS: The procedure durations were 23.9 min (SD 3.7) for CMWA and 21.8 min (SD 16.3) for SMWA (p = 0.22). The procedural accuracy for SMWA and CMWA was identical for both groups (3.7 mm). The total DLP was significantly lower for SMWA than for CMWA (2115 mGy cm (SD 276) vs. 3109 mGy cm (SD 1137), respectively; p < 0.01). Complete ablation without residual tumor was observed in 94% (17 of 18) of SMWA and in 83% (15 of 18) of CMWA patients (p = 0.31). No complications occurred.

CONCLUSIONS: SMWA is highly accurate and reduces the radiation dose without increasing the procedure time.