Irreversible Electroporation of Metastatic Malignancy in the Liver
A 75-year-old male presented who was diagnosed in 2010 with sigmoid colon adenocarcinoma. His history included a low anterior resection of the mass in the distal sigmoid colon in January 2011 followed by 12 cycles of FOLFOX chemotherapy. In January 2012, an elevated level of carcinoembryonic antigen (CEA) and positron emission tomography/computed tomography (PET/CT) demonstrated a 3.5-cm segment VIII liver lesion. In March 2012 the patient received FOLFIRI chemotherapy with cetuximab (Erbitux).
A delayed phase contrast CT demonstrated a 3.5-cm hypodense lesion (arrow, Figure 1A) immediately adjacent to the inferior vena cava.
Additionally there was a mass effect by the lesion (arrow, Figure 1B) on the adjacent hepatic veins. The PET/CT demonstrated a fluorodeoxyglucose-avid segment VIII lesion with a maximum standardized uptake value of 7.4 (arrows, Figure 2).
The patient underwent irreversible electroporation (IRE) treatment with NanoKnife (AngioDynamics). NanoKnife ablation monopolar probes were advanced to their respective target zones. Figure 3A demonstrates 2 inferior probes placed in parallel fashion in close proximity to the inferior vena cava (IVC), and Figure 3B demonstrates 2 superior probes placed in parallel fashion adjacent to IVC and right hepatic vein prior to the initiation of the therapy. Figure 4 shows 3-dimensional acquisition with postprocessing showcasing relative needle tip position and distance prior to initiation of IRE procedure. Contrast CT 24 hours post treatment demonstrated a lack of contrast enhancement, a slightly increased size of the lesion and small hypodensities, which represent air (arrow, Figure 5) consistent with therapeutic changes in the liver lesion. The mass effect on the hepatic veins was no longer identified. There were no complications in the immediate post-treatment period and the patient was discharged.
A PET/CT scan performed 2 months after the NanoKnife procedure demonstrates no FDG avid activity in the treatment area, which is consistent with complete response to the therapy, as well as no new fluorodeoxyglucose-avid areas in the liver (Figures 6A and B).
A triple phase liver study completed 2 months after the IRE demonstrated interval decrease in the size of the previously ablated lesion from 3.5cm to 2.9cm (arrows, Figures 7A and B). Hepatic veins and IVC were patent. At 8 months of follow-up a further decrease in size to 1.5 cm of the previously ablated lesion (arrows, Figure 8) was appreciated on CT contrast. The hepatic veins and IVC were patent and no new lesions were identified. The findings are consistent with complete response to the therapy.
來源：Irreversible Electroporation of Metastatic Malignancy in the Liver