New forms of radionuclide therapy with (90)Y in oncology.

Background: Currently, there is growing interest in the use of the beta emitter (90)Y in systemic therapy in oncology. For successful therapy, an appropriate ligand is chosen to carry the isotope to the place of its action. As well as performing this function, the type of the ligand influences both the course and the side effects of the treatment. For RIT of lymphomas, bone marrow becomes the critical organ; in NET patients treated with labelled somatostatin analogues, increased kidney irradiation can occur. The aim of this study was to evaluate the side effects of therapy using 90Y associated with different ligands, depending on the charge to critical organs after treatment in two groups of patients: those with neuroendocrine tumours and those with non-Hodgkin's lymphomas.
Material and Methods: 32 patients with histopathologically confirmed NET treated with (90)Y-DOTATATE (7.4 GBq/m(2) cumulative dose) and 30 NHL patients treated with (90)Y-ibritumomab tiuxetan (1200 MBq max dose) were enrolled in the study. The kidney function and changes of blood indices were assessed during the course of the therapy.
Results: 59% of NET patients treated with (90)Y-DOTATATE displayed transient reduction of blood indices, the largest after cycles III and IV of therapy. After 5 months an increase in creatinine level was noticed, but no statistically important changes in creatinine level and GFR were observed. In the group of patients with NHL, the change of haematological indices after RIT concerned mainly PLT, ANC and WBC. The reduction of the average PLT and WBC values started in the first weeks after the treatment application, reaching nadir in the 6(th) week and 8(th) week, respectively. No life threatening infections were observed in either group of patients.
Conclusions: After treatment with the use of the (90)Y radionuclide, no significant treatment toxicity, including disorders involving the critical organs for both types of therapies, was found in the groups of neuroendocrine tumour and non-Hodgkin's lymphoma patients.