Long-term Efficacy, Survival, and Toxicity of Peptide Receptor Radionuclide Therapy in Patients With Refractory Meningioma

Background: Peptide receptor radionuclide therapy (PRRT) offers a promising treatment option by targeting the high density of somatostatin receptors overexpressed in meningiomas. The objective of this study aimed to evaluate the long-term outcome of PRRT in patients with refractory meningioma. Patients and Methods: Eighteen patients with refractory meningioma, presenting with progression or recurrence despite surgery or radiotherapy or having inoperable tumors and lack of other therapeutic options, received PRRT with 177 Lu-labeled or 90 Y-labeled somatostatin analogs (DOTATATE, DOTATOC, or HA-DOTATATE) between January 2004 and December 2019. Treatment response was evaluated according to the Response Assessment in Neuro-Oncology, Response Evaluation Criteria in Solid Tumors, and molecular imaging criteria. Results: Most patients received 2 cycles of PRRT, and up to 4 cycles were applied. The mean total administered activity was 12.7 GBq (range: 8.5–28.5 GBq). Of 14 patients monitored after 2 cycles of PRRT, disease control was reached in 12 (85.7%) patients. The median progression-free survival was 32.3 months, and the median OS has yet to be reached with a median follow-up of 67.1 months. All patients tolerated the therapy without any serious acute adverse effects. No Common Terminology Criteria for Adverse Event grades 2–4 anemia, leukopenia, or thrombocytopenia toxicities were observed during or after PRRT. No renal toxicity, hepatotoxicity, or late radiation adverse effects were reported during long-term follow-up. Conclusions: PRRT showed promising outcomes in patients with refractory meningiomas, with high disease control and encouraging progression-free survival and OS, and therefore appears to be a favorable therapeutic option. With long-term follow-up, PRRT demonstrated a favorable safety profile, resulting in very few side effects in this cohort of patients with meningioma.