Frequency and risk factors for major complications after stereotactic radiofrequency ablation of liver tumors in 1235 ablation sessions: a 15-year experience

Abstract

Objectives: To assess the frequency of major complications after multi-probe stereotactic radiofrequency ablation (SRFA) in a large cohort of patients over 15 years and to elucidate risk factors for adverse events.

Materials and methods: A retrospective study was carried out between July 2003 and December 2018. Seven hundred ninety-three consecutive patients (median 65.0 years (0.3-88), 241 women and 552 men, were treated in 1235 SRFA sessions for 2475 primary and metastatic liver tumors with a median tumor size of 3.0 cm (0.5-18 cm). The frequency of major complications was evaluated according to SIR guidelines and putative predictors of adverse events analyzed using simple and multivariable logistic regression.

Results: Thirty-day mortality after SRFA was 0.5% (6/1235) with an overall major complication rate of 7.4% (91/1235). The major complication rate decreased from 11.5% (36/314) (before January 2011) to 6.0% (55/921) (p = 0.001). 50.5% (46/91) of major complications were successfully treated in the same anesthetic session by angiographic coiling for hemorrhage and chest tube insertion for pneumothorax. History of bile duct surgery/intervention, number of coaxial needles, and location of tumors in segment IVa or VIII were independent prognostic factors for major complications following multivariable logistic regression analysis. Simple logistic regression revealed the number of tumors, tumor size, location close to the diaphragm, tumor conglomerate, and segment VII as other significant predictors.

Conclusion: SRFA of liver tumors is safe and can extend the treatment spectrum of conventional RFA. Adaptations over time combined with increasing experience resulted in a significant decrease in complications.

Key points: • In 1235 ablation sessions in 793 patients over 15 years, we found a mortality rate of 0.5% (6/1235) and an overall major complication rate of 7.4%, which fell from 11.5 (36/314) to 6.0% (55/921, p = 0.001) after January 2011, likely due to procedural adaptations. • History of bile duct surgery/intervention (p = 0.013, OR = 3.290), number of coaxial needles (p = 0.026, OR = 1.052), and location of tumors in segment IVa (p = 0.016, OR = 1.989) or VIII (p = 0.038, OR = 1.635) were found to be independent prognostic factors. • Simple logistic regression revealed that number of tumors, tumor size, location close to the diaphragm, tumor conglomerates, and segment VII were other significant predictors of major complications.

Keywords: Liver; Neoplasm; Radiofrequency ablation; Therapy.

Fig. 1

Flowchart of SRFA selection

Fig. 2

Illustration of multi-probe RF ablation with multiple overlapping ablation zones (grey ellipsoids with central RF probe) covering the entire tumor volume (yellow sphere); a top view, b oblique view

Fig. 3

Case of an 81-year-old male with a single 6.0-cm HCC in segment VII/VIII. a, b Portal venous phase initial CT scan with a hyper-enhancing nodule in segment VII/VIII (red dashed circle). c, d Volume rendering and maximum intensity projection (MIP) of the native control CT with 11 needles in place (red arrowhead). e Portal venous phase final control CT scan showing complete ablation zone (red dashed circle). No complications were noted. f The red dashed circle illustrates the ablation zone at 6 months with no evidence of a late complication or local recurrence

Fig. 4

Forest plot of multivariable logistic regression analysis of major complications

Fig. 5

Overview of the most frequent major complications between 2004 and 2018