Peptide receptor radionuclide therapy: focus on bronchial neuroendocrine tumors

Well-differentiated bronchial neuroendocrine tumors (B-NETs) are rare. They represent 1-5 % of all lung cancers. The incidence of these neoplasms has risen over the past 30 years and, especially for advanced or metastatic disease, management is complex and requires a multidisciplinary approach. Treatment with somatostatin analogs (SSAs) is the most important first-line therapy, in particular in well-differentiated NETs with high somatostatin type receptor (SSTR) expression. In these tumors, the role of mammalian target of rapamycin (m-TOR) inhibitors and the potential utility of other target therapies remain unclear while chemotherapy represents the gold standard treatment only for aggressive forms with low SSTR expression. Peptide receptor radionuclide therapy (PRRT) is an emerging treatment modality for advanced NETs. There are many cumulative evidences about the effectiveness and tolerability of this therapeutic approach, especially in gastro-entero-pancreatic (GEP)-NETs. For B-NETs, scientific research is moving more slowly. Here, we performed a review in order to evaluate the efficacy and toxicity of PRRT with a focus on patients with inoperable or metastatic well-differentiated B-NETs.