Intra-arterial peptide-receptor radionuclide therapy for neuro-endocrine tumour liver metastases: an in-patient randomised controlled trial (LUTIA).

Abstract

Peptide receptor radionuclide therapy (PRRT) using [¹⁷⁷Lu]Lu-DOTATATE has been shown to effectively prolong progression free survival in grade 1-2 gastroenteropancreatic neuroendocrine tumours (GEP-NET), but is less efficacious in patients with extensive liver metastases. The aim was to investigate whether tumour uptake in liver metastases can be enhanced by intra-arterial administration of [¹⁷⁷Lu]Lu-DOTATATE into the hepatic artery, in order to improve tumour response without increasing toxicity. Twenty-seven patients with grade 1-2 GEP-NET, and bi-lobar liver metastases were randomized to receive intra-arterial PRRT in the left or right liver lobe for four consecutive cycles. The contralateral liver lobe and extrahepatic disease were treated via a "second-pass" effect and the contralateral lobe was used as the control lobe. Up to three metastases (> 3 cm) per liver lobe were identified as target lesions at baseline on contrast-enhanced CT. The primary endpoint was the tumour-to-non-tumour (T/N) uptake ratio on the 24 h post-treatment [¹⁷⁷Lu]Lu-SPECT/CT after the first cycle. This was calculated for each target lesion in both lobes using the mean uptake. T/N ratios in both lobes were compared using paired-samples t-test. After the first cycle, a non-significant difference in T/N uptake ratio was observed: T/N_IA = 17·4 vs. T/N_control = 16·2 (p = 0·299). The mean increase in T/N was 17% (1·17; 95% CI [1·00; 1·37]). Of all patients, 67% (18/27) showed any increase in T/N ratio after the first cycle. Intra-arterial [¹⁷⁷Lu]Lu-DOTATATE is safe, but does not lead to a clinically significant increase in tumour uptake.