Lutathera Therapy for Olfactory Neuroblastoma

Background: Olfactory neuroblastoma (ONB) is a rare neuroectodermal tumor of the nasal cavity and paranasal sinuses. Most of these tumors express somatostatin receptors (SSTR), providing a potential target for peptide-radionuclide receptor therapy (PRRT). Lutathera is a form of PRRT that targets the SSTR receptor. As options for treatment of recurrent or metastatic ONB are limited, Lutathera has been used in case reports and a small trial in Europe. Numerous publications have shown the utility of Lutathera in gastrointestinal neuroendocrine tumors, but its benefit in treating ONB remains unclear.

Methods: We retrospectively reviewed 6 cases of ONB treated with Lutathera at our institution who started treatment between January 2020 and January 2022. Demographics, tumor location/grade, metastasis/recurrence, previous therapy, imaging modalities, complications, and pathology (e.g., SSTR expression) were extracted from patient charts. A full course of Lutathera was defined as 4 treatments at intervals of 2 months. Patients completed bi-monthly complete blood count (CBC) and complete metabolic panel during therapy. They were monitored for response with DOTATATE imaging at 6 months following completion of therapy.

Results: Six patients received Lutathera therapy for recurrent metastatic ONB following surgery and radiation therapy. Ages ranged from 37 to 65 with 3 males/3 females. Three patients had Hyam's grade II tumors, 1 grade III and 2 unknown. All had positive SSTR2 expression. Sites of recurrence included the dura, cervical lymph nodes and parotid gland with regional lymph nodes. All patients completed a full course of Lutathera treatment. One patient completed 2/4 treatments of a second course. This patient had partial response with decrease in DOTATATE avidity of their lymph node disease but had persistent disease of the pterygoid plate requiring a second course of Lutathera. The second course was discontinued due to grade-1 thrombocytopenia and grade-2 anemia ([Table 1]). Two other patients responded to Lutathera, with decrease in DOTATATE avidity of disease and/or decrease in tumor size. Three patients have not yet received their post-treatment DOTATATE imaging. Five of six patients tolerated Lutathera therapy with minimal complications ([Table 1]). CBC values are reported in [Fig. 1].

Conclusion: Lutathera was generally well-tolerated in this cohort, with only one-sixth patients developing complications requiring cessation of therapy. While our sample size is small, it represents one of the largest cohorts of ONB treated with Lutathera. Two patients showed response to therapy, with results from 3 others still pending. This underlines the need for further investigation of clinical outcomes after Lutathera therapy in ONB.

Table 1 Complications

Patient	Sex	Lutathera doses received	Toxicity	Therapy discontinued
1	F	6/8	Grade-1 thrombocytopenia/grade-2 anemia	Yes
2	M	4/4	None	No
3	M	4/4	Grade-1 anemia/thrombocytopenia	No
4	M	4/4	Grade-1 leukopenia	No
5	F	4/4	Grade-1 leukopenia/thrombocytopenia	No
6	F	4/4	Grade-1 leukopenia/thrombocytopenia	No

Publication History

Article published online:
01 February 2023