Abstract
Peptide receptor radionuclide therapy (PRRT) is a relatively new mode of internally targeted radiotherapy currently in clinical trials. In PRRT, ionizing radioisotopes conjugated to somatostatin analogues are targeted to neuroendocrine tumors (NETs) via somatostatin receptors. Despite promising clinical results, very little is known about the mechanism of tumor control. By using NCI-H727 cells in an in vivo murine xenograft model of human NETs, we showed that 177Lu-DOTATATE PRRT led to increased infiltration of CD86+ antigen presenting cells into tumor tissue. We also found that following treatment with PRRT, there was significantly increased tumor infiltration by CD49b+/FasL+ NK cells potentially capable of tumor killing. Further investigation into the immunomodulatory effects of PRRT will be essential in improving treatment efficacy.
Highlights
Neuroendocrine tumors (NETs) are a heterogeneous group of epithelial neoplasms of both neurological and endocrine differentiation and are characterized by their common expression of chromogranin A and synaptophysin [1]
Total delivered doses of Peptide receptor radionuclide therapy (PRRT) were calculated as the decay corrected difference between the residual and initial doses drawn up in each injection syringe (Figure 1(A))
Mice in the high dose treatment group received a mean of 41.2 MBq (±7.2 MBq) while mice in the low dose group received a mean of 3.84 MBq (±0.36 Mbq) of 177Lu-DOTATATE (Figure 1(A))
Summary
Neuroendocrine tumors (NETs) are a heterogeneous group of epithelial neoplasms of both neurological and endocrine differentiation and are characterized by their common expression of chromogranin A and synaptophysin [1]. Most NETs are well differentiated displaying a low mitotic and proliferative status associated with slow growth patterns compared to other malignant carcinomas [4]. Despite their slow growth, the variable anatomical sites from which NETs arise and their difficult diagnosis contributes to a late clinical presentation, often following metastatic spread [5]. Current treatment of metastatic NETs remains centered on disease control. The lack of a curative treatment in advanced disease and an increasing incidence make these tumors clinically relevant and highlight the need for research into novel therapies
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
