Preoperative Ultrasound-Guided Metastasectomy: Enhancing Surgical Planning and Complete Resection of Metastatic Disease

Abstract

Background: Curative resection of asynchronous metastatic colon cancer can be technically challenging when metastatic implants are difficult to identify intraoperatively. Accurate preoperative localization may facilitate complete resection while allowing preservation of surrounding structures and achievement of negative margins. Computed tomography (CT)-guided localization has previously been described; however, ultrasound-guided localization may provide a practical alternative. Case Presentation: A 72-year-old woman with a history of a 15.5-cm moderately differentiated mucinous adenocarcinoma of the colon with visceral peritoneal and small bowel involvement underwent en bloc resection with negative margins and 15 negative lymph nodes, followed by six cycles of adjuvant FOLFOX chemotherapy. Two years and four months after her initial operation, surveillance PET imaging demonstrated a right lower quadrant peritoneal/retroperitoneal lesion concerning for asynchronous metastatic disease. Multidisciplinary review at GI Oncology Tumor Board led to the decision to perform ultrasound-guided biopsy and preoperative localization. Ultrasound identified the lesion, which was confirmed to represent metastatic mucinous adenocarcinoma and was subsequently marked with 7 cc of tattoo dye. The patient subsequently underwent laparoscopic metastasectomy, with successful identification and complete resection of the marked lesion and negative margins. She was discharged 48 hours after surgery and resumed adjuvant chemotherapy 14 days later. Conclusion: Ultrasound-guided preoperative localization and tattoo marking represents a novel and potentially useful alternative to CT-guided localization for selected patients with asynchronous metastatic colon cancer. In this case, ultrasound localization facilitated minimally invasive identification and complete resection of a difficult-to-localize metastatic implant with negative margins. Although additional experience is needed to establish the broader applicability of this technique, ultrasound-guided localization may provide a practical, real-time approach to facilitating curative-intent metastasectomy in appropriately selected patients.