Purpose: To retrospectively assess safety and efficacy of laser ablation (LA) of multiple liver metastases (LM) from neuroendocrine neoplasms (NEN).
Methods: Twenty-one patients with NEN and at least 3 LM ≤ 4 cm in diameter underwent ultrasonography-guided LA. Up to seven LM were ablated in a single session; if the number of LM exceeded seven, the remaining LM were ablated in further LA sessions with a time interval of 3-4 weeks. LA was performed according to the multifiber technique. The patients underwent contrast-enhanced CT 1 month after LA, and were subsequently monitored every 3 months for the first 2 years and then every 6 months.
Results: In total, 189 LM were treated in 21 patients (mean 9 ± 8.2, median 6) in 41 LA sessions (range 1-5). The diameter of LM ranged from 5 to 35 mm (median 19 mm, mean 17.9 ± 6.4 mm). One grade 4 complication occurred (0.53%): a bowel perforation managed by surgery. Technical efficacy was 100%, primary efficacy rate 94.7%, and secondary efficacy rate 100%. Complete relief of hormone-related symptoms was obtained in all the 13 symptomatic patients. Median follow-up was 39 months (range 12-99). 1-, 2-, 3-, and 5-year survival rates were 95%, 86%, 66%, and 40%, respectively. Overall survival resulted higher for patients with Ki-67 expression ≤ 7% than for those with Ki-67 > 7% (p = 0.0347).
Conclusions: LA is a promising and safe technique to treat LM from NEN. A longer follow-up should provide definitive information on the long-term efficacy of this liver-directed therapy.
Level of evidence: Retrospective study, local non-random sample, level 3.
Keywords: Ablation techniques; Laser therapy; Liver neoplasms; Neuroendocrine tumors.