Peptide receptor radionuclide therapy of neuroendocrine tumors: Case series

Abstract

Background: Peptide Receptor Radionuclide Therapy (PRRT) is novel and efficacious treatment of neuroendocrine tumors (NETs). Methods: Twenty-seven patients (14 females, 13 males, mean age 54.37±11.14 years; range 30-74 years) with progressive, metastatic neuroendocrine tumors, were treated at least once during the period of 31 months (from July the 6th 2009 to February the 6th 2012) with PRRT in Nuclear Medicine Center, Clinical Center Kragujevac. There were carcinoids in 8 cases (6pts had intestinal and 2pts had lung carcinoid), medullary thyroid carcinoma in 5 cases, pancreatic carcinoma in 3 cases, paraganlioma in 2 cases, pheochromocytoma in 2 cases and in 7 cases primary tumors were not detected. We used 56 doses of different kinds of radiopharmaceuticals: 32 doses of 90Y-DOTATOC, 12 doses of 177Lu-DOTATATE, and 12 doses combining the 90Y-DODTATOC and 177Lu-DOTATATE. The PRRT was given in cycles: 12 pts received one cycle, 9 pts two cycles, 4 pts three cycles, 1 patient 4cycles and 2 pts five cycles of PRRT. The radioactivity was 3.2-7.40 GBq per cycle, and intervals between cycles ranged from 6 to 8 weeks. Results: The response to PRRT was assessed by morphological imaging (MSCT and MRI) as well as by tumor marker follow up (CgA, 5-HIAA, catecholamines, CT and CEA). Seven pts (25.9%) had partial response (PR), 17 pts (63.0%) had stable disease (SD), and 3 pts (11.1%) had progressive disease (PD). None of our patients had complete response (CR). All patients received PRRT under renal protection with amino acid infusions. In spite of this precaution, two patients with previously diagnosed diabetes mellitus suffered from serious deterioration of renal function after PRRT. Conclusion: The efficacy and safety of PRRT observed in our case series was in accordance with previously published data.

Keywords

• Neuroendocrine Tumors
• Receptors
• Peptide
• Radioisotopes
• Radiopharmaceuticals
• Treatment Outcome