Peptide receptor radionuclide therapy with 177Lu- or 90Y-SSTR peptides in malignant pheochromocytomas (PCCs) and paragangliomas (PGLs): results from a single institutional retrospective analysis

Malignant pheochromocytomas (PCCs) and paragangliomas (PGLs) are rare tumors and available systemic therapies are limited.

To explore the role of peptide receptor radionuclide therapy (PRRT) with Yttrium-90 (⁹⁰Y) and Lutetium-177 (¹⁷⁷Lu) peptides in pheochromocytomas (PCCs) and paragangliomas (PGLs).

We retrospectively analyzed more than 1500 patients with histologically proven neuroendocrine tumors treated with ¹⁷⁷Lu- or ⁹⁰Y-DOTA-TATE or –TOC between 1999 to 2017 at our Institute. Overall, 30 patients with confirmed malignant PCCs and PGLs matched inclusion/exclusion criteria and were considered eligible for this analysis.

Thirty (n = 30) patients were treated: 22 with PGLs and 8 with PCCs (12 M and 18 F, median age 47 [IQR: 35–60 years]). Eighteen patients (n = 18) had head and neck PGLs, 3 patients thoracic PGLs and 1 patient abdominal PGL. Sixteen patients (53%) had locally advanced and fourteen (47%) had metastatic disease. Twenty-seven (90%) patients had disease progression at baseline. Four (13%) patients were treated with ⁹⁰Y, sixteen (53%) with ¹⁷⁷Lu and ten (33%) with ⁹⁰Y + ¹⁷⁷Lu respectively. The median total cumulative activity from treatment with ⁹⁰Y- alone was 9.45 GBq (range 5.11–14.02 GBq), from ¹⁷⁷Lu- alone was 21.9 GBq (7.55–32.12 GBq) and from the combination treatment was 4.94 GBq from ⁹⁰Y- and 6.83 GBq from ¹⁷⁷Lu- (ranges 1.04–10.1 and 2.66–20.13 GBq, respectively). Seven out of 30 (23%) patients had partial response and 19 (63%) stable disease. Median follow up was 8.9 years (IQR: 2.9–12). The 5-y and 10-y PFS was 68% (95% CI: 48–82) and 53% (95% CI: 33–69), respectively, whereas 5-y and 10-y OS was 75% (95% CI: 54–87) and 59% (95% CI: 38–75), respectively. Grade 3 or 4 acute hematological toxicity occurred in three patients, two with leucopenia and one with thrombocytopenia, respectively.

PRRT with ¹⁷⁷Lu- or ⁹⁰Y-DOTA-TATE or –TOC is feasible and well tolerated in advanced PGLs and PCCs.