Eradication of Missing Liver Metastases After Fiducial Placement

Background: The risk of colorectal liver metastases (CLM) disappearing on cross-sectional imaging has increased with advances in preoperative chemotherapy, but <50 % of disappearing CLM demonstrate complete pathological response. Objective: The aim of this study was to evaluate the role of fiducial marker placement before potentially curative treatment of CLM at risk of disappearing with chemotherapy. Methods: All consecutive patients who underwent fiducial placement for tracking of CLM at a tertiary center were reviewed. Results: Among 1377 patients undergoing CLM resection between 2005 and 2015, 35 patients underwent fiducial placement. Three patients were excluded due to disease progression. The study population comprised 32 patients who underwent fiducial placement in 41 CLM. Among the 41 marked CLM, 34 (83 %) were located >10 mm deep in the liver parenchyma, 25 (61 %) were in the right liver, and median size was 12 mm (range, 6–20 mm). No complication occurred after fiducial placement. After chemotherapy, 19 (46 %) of the 41 marked metastases disappeared on cross-sectional imaging. All fiducial-tracked CLM were treated with resection (n = 31) or ablation (n = 10). After median follow-up of 14 months (range, 0–64 months), no local recurrences were observed. Conclusion: Fiducial placement represents a safe procedure that facilitates accurate localization for resection or ablation of small CLM at risk of disappearing with chemotherapy.