ObjectiveTo evaluate the efficacy and adverse effects of ¹⁷⁷Lu-1, 4, 7, 10-tetraazacyclododecane-1, 4, 7, 10-tetraacetic acid- D-Phel-Tyr3-Thr8-octreotide (DOTA-TATE) in patients with advanced pheochromocytoma and paraganglioma (PPGL).

MethodsSixteen patients with metastatic PPGL, treated with ¹⁷⁷Lu-DOTA-TATE in the Affiliated Hospital of Southwest Medical University between April 2020 and December 2023, were retrospectively included. Among these patients, nine were male and seven were female, with an a median age of 44.5(26.5, 51.0) years. Treatment response was assessed based on changes in blood catecholamine level and ⁶⁸Ga-DOTA-TATE PET/CT imaging. Evaluation criteria included the response evaluation criteria in solid tumors (RECIST) 1.1 and the modified PET response criteria in solid tumors (PERCIST) 1.0. Treatment-related adverse events were graded according to the common terminology criteria for adverse events (CTCAE) 5.0. All patients received long-term follow-up after treatment, with endpoints including disease progression and death. Paired t-test was used to compare laboratory parameters before and after treatment.

ResultsThe median number of treatment cycles of ¹⁷⁷Lu-DOTA-TATE was 3(3, 4) per patient, with an average dose of (7.51±0.67) GBq per cycle. Grade 1 hematologic toxicity was observed in 4 patients (4/16), while grade 2 hematologic toxicity occurred in 2 patients (2/16), primarily manifesting as leukopenia and anemia. A slight decrease was noted post-treatment in PLT ( t=4.06, P=0.001) and Hb levels ( t=2.85, P=0.012), while WBC counts showed no statistically significant change ( t=1.57, P=0.137). No grade 3 or 4 hematologic, renal, or hepatic toxicities were observed. The glomerular filtration rate ( t=-0.29, P=0.778), creatinine ( t=0.04, P=0.697), alanine transaminase ( t=0.08, P=0.938), aspartate transaminase ( t=0.08, P=0.463), and total bilirubin ( t=-0.37, P=0.719) after treatment were not significantly different from those before treatment. According to RECIST 1.1, 13 patients achieved stable disease, 2 patients showed partial response and 1 had progression disease. Based on the modified PERCIST 1.0, stable disease was observed in 11 patients, partial response in 3 patients, and progression disease in 2 patients. Among 9 patients with catecholamine-secreting PPGL, 8 showed reduction in blood norepinephrine level. The median follow-up duration was 21.5(21.1, 42.6) months, with a median progression-free survival of 8.6(6.0, 14.6) months, and no mortality reported during the follow-up period.

Conclusion ¹⁷⁷Lu-DOTA-TATE appears to be a safe and promising therapeutic option for patients with advanced PPGL demonstrating elevated somatostatin receptor expression.