Supplementary Material for: Successful Combination of Olaparib and 225Ac-Dotatate in a Patient with NET G3 and BRCA mutation

Based on the results of the NETTER-1 trial, peptide receptor radionuclide therapy (PRRT) with Lutetium-177 (177Lu) –DOTATATE is authorized for the treatment of neuroendocrine tumors (NET) grade 1 (G1) and G2 of the intestine. After the failure of 177Lu‑DOTATATE, targeted alpha‑particle therapy (TAT) may be a possible treatment option. Here, we present a patient with cancer of unknown primary (CUP) NET G2 later G3. The patient was referred to our hospital with urosepsis due to a second-degree urinary retention. After stent insertion, a contrast-enhanced computed tomography (CT) revealed a huge pelvic tumor without metastasis. Initially the patient had undergone surgical treatment. Later the patient developed liver metastasis and was treated by 177Lu‑DOTATATE therapy and four lines of systemic therapy. A disease progression was observed and with the knowledge of a germline BRCA1 mutation, the patient was treated with TAT (Actinium-225 (225Ac)-DOTATATE) combined with olaparib. The patient achieved a significant treatment response for 12 month indicating that a combination therapy with an alpha emitter plus olaparib might deserve further investigations in clinical trials.