Purpose: The aim of this study is to evaluate the effectiveness of (111)In-DTPA-Phe(1)-octreotide infusions after selective catheterization of the hepatic artery in inoperable metastasised liver, sst(2) receptor-positive neuroendocrine tumours due to the effect of (111)In Auger electron emission, minimising in parallel the toxicity of non-target tissue.
Methods: The average dose per session administered monthly to each patient (17 cases in total) was 6.3+/-2.3 GBq. Repetitions did not exceed 12-fold, except in one case (15 sessions). Response assessment was classified according to the Response Evaluating Criteria in Solid Tumours. CT/MRI scans were performed as baseline before, during and after the end of treatment, and monthly ultrasound images for follow-up measurements. Toxicity (World Health Organization criteria) was measured using blood and urine tests of renal, hepatic and bone marrow function.
Results: Complete response was achieved in one (5.9%) patient and partial in eight (47.0%), and disease stabilization in 3 (17.7%) patients; five (29.4%) did not respond. A 32-month median survival time was estimated in 12 (70.5%). Nine of these 12 surviving had a mean target diameter shrinkage from 144+/-81 to 60+/-59 mm. Grade 1 erythro-, leuko- and thrombo-cytopenia occurred in three (17.6%) cases.
Conclusion: In unresectable metastatic liver lesions positive for somatostatin receptors repeated, transhepatic high doses of (111)In-DTPA-Phe(1)-octreotide show an effective therapeutic outcome. Given the locoregional modality character of the administration technique plus the extremely short range of (111)In Auger and internal conversion electrons emission, no nephro-, liver- or myelo-toxicity has so far been observed.