Computed tomography-guided microwave ablation of perivascular liver metastases from colorectal cancer: a study of the ablation zone, feasibility, and safety

Jean Izaaryene (1) , Maxime Drai (1) , Cécile Deniel (1) , Pauline Bridge (2, 3) , Geoffrey Rico (1) , Nassima Daidj (1) , Marine Gilabert (1, 4) , Jacques Ewald (1, 4) , Olivier Turrini (1, 4) , Gilles Piana (1)

1 IPC - Institut Paoli-Calmettes
2 LIIE - Laboratoire d'Imagerie Interventionnelle Expérimentale
3 CERIMED - Centre Européen de Recherche en Imagerie médicale
4 CRCM - Centre de Recherche en Cancérologie de Marseille

Objectives: To compare the ablation margins and safety of microwave ablation (MWA) of perivascular versus non-perivascular liver metastases from colorectal cancer (CRC) and to determine the risk factors for local tumor progression (LTP) after perivascular MWA. Methods: Between June 2017 and June 2019, 84 metastases were treated: 39 perivascular (<5 mm from a vessel >3 mm), and 46 non-perivascular. Perivascular metastases were treated with either conventional or optimized protocols (maximum power and/or several heating cycles after repositioning the needle regardless of the initial tumor dimensions). The mean diameter of metastases was 15.4 mm (SD: 7.56). Results: Vascular proximity did not result in a significant difference in ablation margins. The technical success rate, primary efficacy, and secondary efficacy were 90%, 66%, and 83%, respectively. Perivascular location was not a risk factor for time to LTP (p ¼ 0.49), RFS (p ¼ 0.52), or OS (p ¼ 0.54). LTP was statistically related to the presence of a colonic obstruction (p < 0.05), number of metastases at the time of diagnosis (p < 0.05), type of protocol (p < 0.05), ablation margins (p < 0.001) and LTP was proportional to the number of liver resections before MWA (p < 0.05). There was no LTP in tumors ablated with margins over 10 mm. Two grade 4 complications occurred. Conclusion: MWA is an effective and safe treatment for perivascular liver metastases from CRC, provided that satisfactory margins are achieved. A maximalist attitude could be related to better local control.

Mots clés: liver metastasis; microwave ablation; large vessels; ablation margin

Domaines: Imagerie; Hépatologie et Gastroentérologie; Cancer

Jean Izaaryene, Maxime Drai, Cécile Deniel, Pauline Bridge, Geoffrey Rico, et al.. Computed tomography-guided microwave ablation of perivascular liver metastases from colorectal cancer: a study of the ablation zone, feasibility, and safety. International Journal of Hyperthermia, 2021, 38 (1), pp.887 - 899. ⟨10.1080/02656736.2021.1912413⟩. ⟨hal-03611059⟩