Abstract
1180
Objectives Peptide receptor radionuclide therapy (PRRT), using radiolabelled somatostatin analogues, is established for the treatment of metastatic neuroendocrine tumours (NETs). Our aim was to assess the role of PRRT in patients with unresectable or metastatic pulmonary NETs.
Methods Sixteen patients (pts) with metastatic or non-operable pulmonary NETs were enrolled in this study. To prove suitability for treatment, each pt underwent scanning with 68Ga-DOTATOC PET/CT. Out of 16 pts, three were excluded because only 1 cycle of therapy were administered while 13 pts received three-six cycles of PRRT (interval: 8 weeks). Cumulative activities ranged from 10 GBq to 29 GBq. Pts were evaluated before and after each cycle with blood tests. After the second cycle and at the end of the treatment, pts underwent 68Ga-DOTATOC PET/CT for assessment of response to therapy. Six pts received a combination of radionuclide therapy using 177Lu- and 90Y-labeled somatostatin analogues, five pts were treated with 90Y-DOTATOC and 2 pts received treatment with 177Lu- DOTATOC alone.
Results Partial response occurred in 7 of 13 (54%) pts; moreover 3 of 13 (23%) pts had stable disease and 3 of 13 (23%) pts had progression disease. Out of 6 pts treated with combination radionuclide therapy, 4 (67%) had partial response and 2 (33%) stable disease. Two (40%) patients treated with 90Y-DOTATOC had partial response and 3 (60%) had progression disease. Finally, among pts treated with 177Lu-DOTATOC, 1 had partial response and 1 stabilized. Therapy was well tolerated and no serious adverse events occurred.
Conclusions PRRT can be effective in pts with pulmonary NETs. In our experience the combination of 177Lu- and 90Y-somatostatin analogues has superior effects compared with either 90Y- or 177Lu-analogues used alone. However, because of the limited number of pts, further studies are needed to confirm the treatment outcome