MRI-guided microwave ablation and albumin-bound paclitaxel for lung tumors: Initial experience

Abstract

Magnetic resonance-guided microwave ablation (MRI-guided MWA) is a new, minimally invasive ablation method for cancer. This study sought to analyze the clinical value of MRI-guided MWA in non-small cell lung cancer (NSCLC). We compared the precision, efficiency, and clinical efficacy of treatment in patients who underwent MRI-guided MWA or computed tomography (CT)-guided microwave ablation (CT-guided MWA). Propensity score matching was used on the prospective cohort (MRI-MWA group, n = 45) and the retrospective observational cohort (CT-MWA group, n = 305). To evaluate the advantages and efficacy of MRI-guided MWA, data including the accuracy of needle placement, scan duration, ablation time, total operation time, length of hospital stay, progression-free survival (PFS), and overall survival (OS) were collected and compared between the two groups. The mean number of machine scans required to adjust the needle position was 7.62 ± 1.69 (range 4-12) for the MRI-MWA group and 9.64 ± 2.14 (range 5-16) for the CT-MWA group (p < 0.001). The mean time for antenna placement was comparable between the MRI and CT groups (54.41 ± 12.32 min and 53.03 ± 11.29 min, p = 0.607). The microwave ablation time of the two groups was significantly different (7.62 ± 2.65 min and 9.41 ± 2.86 min, p = 0.017), while the overall procedure time was comparable (91.28 ± 16.69 min vs. 93.41 ± 16.03 min, p = 0.568). The overall complication rate in the MRI-MWA group was significantly lower than in the CT-MWA group (12% vs. 51%, p = 0.185). The median time to progression was longer in the MRI-MWA group than in the CT-MWA group (11 months [95% CI 10.24-11.75] vs. 9 months [95% CI 8.00-9.99], p = 0.0003; hazard ratio 0.3690 [95% CI 0.2159-0.6306]). OS was comparable in both groups (MRI group 26.0 months [95% CI 25.022-26.978] vs. CT group 23.0 months [95% CI 18.646-27.354], p = 0.18). This study provides hitherto-undocumented evidence of the clinical effects of MRI-guided MWA on patients with NSCLC and determines the relative safety and efficiency of MRI- and CT-guided MWA.

Keywords: albumin-bound paclitaxel; magnetic resonance imaging; microwave ablation; non-small cell lung cancer; safety and efficiency.

FIGURE 1

Screening process for eligible patients.

FIGURE 2

Images of the MRI-guided MWA procedure and follow-up in 59-year-old woman with pulmonary adenocarcinoma in superior lobe of right lung. (A) Skin markers were applied to locate the needle insertion site under magnetic resonance imaging (MRI) guidance. (B) Guided by magnetic-resonance T1WI image, 16G-ablation antenna was punctured to the center of the tumor lesion. (C–E) After two 8-min ablation cycles, we achieved a satisfactory ablation area, which is clearly seen in axial- (C) and sagittal- (D) phase images, and a large area of ground glass covers the entire tumor on the lung window of CT I. (F–I) Computed tomography (CT) images of follow-up. Follow-up CT scans at 3 (F), 6 (G), and 12 (H) months show significantly shrinking, and follow-up CT scan at 21 months (I) showed the tumor had increased in size.

FIGURE 3

Images of the MRI-guided MWA procedure and follow-up in 69-year-old man with pulmonary adenocarcinoma in inferior lobe of left lung. (A) Tumor lesion seen on MRI immediately prior to MWA. (B) Combined with axial (1) and sagittal (2) MRI scans, the ablation needle reached the tumor site (C,D). By comparing T2WI MRI scan images (C) and lung window CT images (D), we found MRI to be more accurate in the assessment of microwave-ablation boundaries. (E-I) Follow-up CT scans at 3 (E), 6 (F), 12 (G), and 20 (H) months showed no change in the GGO size. At the 26-month follow-up (I), the tumor size was increased.

FIGURE 4

Images from 72-year-old man with 50 × 36 mm primary pulmonary adenocarcinoma in lower lobe of left lung. (A) Preoperative MRI scan and external puncture site location. (B) Ablation needle puncture reached the center of the lesion. (C,D) Due to the large lesion, a second ablation was performed by adjusting the ablation needle in real time under the sagittal image. (E) T2WI MRI scan immediately after the operation showing the surrounding ring-shaped high-signal thermal-injury response zone completely covered the ablation area with low signal and was well demarcated from the adjacent abdominal aorta. (F–I) Follow-up CT images showing the ablative zone was gradually shrinking at postoperative months 3 (F) 6 (G) 12 (H) and 16 (I).

FIGURE 5

Graphs show Kaplan–Meier survival estimates for progression-free survival between MRI-MWA group and CT-MWA group.

FIGURE 6

Graphs show Kaplan–Meier survival estimates for overall survival between MRI-MWA group and CT-MWA group.