RESUMEN
OBJECTIVE: To determine the effectiveness of therapy with the radiolabelled somatostatin analogues, 90Y-DOTATOC and 177Lu-DOTATATE, in the treatment of metastatic neuroendocrine tumours with progression to first-line treatment. MATERIAL AND METHODS: A study was conducted on 30 patients diagnosed with neuroendocrine tumours (gastroenteropancreatic, bronchopulmonary, MEN2A, MEN2B, phaeochromocytoma, and paraganglioma) with metastatic disease diagnosed by the pathology department, with progression to first-line treatment, and recruited from December 2014 to February 2016. Efficacy was analysed using computed tomography (CT) according RECIST 1.1 criteria, and the molecular changes using the SUVmax of PET/CT with 68Ga-DOTATOC. Safety was carried out with a renal scan with 99mTc-MAG3. RESULTS: The 30 patients received a total of 49 cycles 90Y-DOTATOC (21 doses) and 177 Lu-DOTATATE (28 doses), with a mean of 1.5 cycles per patient. Of these, 17 (56.7%) showed a partial morphological response, 22 (73.3%) molecular and biochemical response, and 23 (76.6%) clinical response. One patient died during the median follow-up of 13 months. The median overall survival from diagnosis was 54 months (95% CI; 31.18-76.81), and median progression-free survival was 32 months (95% CI; 15.00-48.99). CONCLUSION: Therapy with 90Y-DOTATOC and 177Lu-DOTATATE is a promising therapy for patients with well and moderately differentiated neuroendocrine tumours. The efficacy is better the larger the number of cycles administered, inversely proportional to the number of metastases (<10), and is associated with the level of uptake according to the SUVmax by the metastases, regardless of metabolically active tumour volume.