Long-term tolerability of PRRT in 807 patients with neuroendocrine tumours: the value and limitations of clinical factors.

Abstract

PurposePeptide receptor radionuclide therapy (PRRT) with (90)Y and (177)Lu provides objective responses in neuroendocrine tumours, and is well tolerated with moderate toxicity. We aimed to identify clinical parameters predictive of long-term renal and haematological toxicity (myelodysplastic syndrome and acute leukaemia).MethodsOf 807 patients studied at IEO-Milan (1997-2013), 793 (98 %) received (177)Lu (278, 34.4 %), (90)Y (358, 44.4 %) or (177)Lu and (90)Y combined (157. 19.5 %), and 14 (2 %) received combinations of PRRT and other agents. Follow-up was 30 months (1-180 months). The parameters evaluated included renal risk factors, bone marrow toxicity and PRRT features. Data analysis included multiple regression, random forest feature selection, and recursive partitioning and regression trees.ResultsTreatment with (90)Y and (90)Y + (177)Lu was more likely to result in nephrotoxicity than treatment with (177)Lu alone (33.6 %, 25.5 % and 13.4 % of patients, respectively; p ConclusionIdentified risk factors provide a limited (<30 %) risk estimate even with target tissue dosimetry. These data strongly suggest the existence of unidentified individual susceptibilities to radiation-associated disease.