Purpose: As patients with progressive medullary thyroid cancer (MTC) and radioiodine-refractory metastatic differentiated nonmedullary thyroid cancer (DTC) have poor prognoses and present therapeutic challenges, peptide receptor radionuclide therapy (PRRT) targeting the somatostatin receptor provides a promising option. This meta-analysis evaluated the therapeutic effects and outcomes of PRRT in differentiated thyroid cancer.
Patients and methods: PUBMED, EMBASE, CINAHL, SCOPUS, and COCHRANE were systematically searched using appropriate key words. The primary therapeutic effect was the radiological response after PRRT, and the objective response rate (ORR) and disease control rate (DCR) were identified in MTC and DTC, respectively. The outcome of serious adverse events (grade 3 or 4), additional therapeutic effects of F-FDG PET/CT and biochemical (calcitonin and thyroglobulin) responses, and radionuclides for PRRT were assessed as subgroup analyses. The parameters were generated as pooled proportions.
Results: Eleven articles with 165 patients were included (98 patients with MTC and 67 patients with DTC). PRRT achieved pooled proportions of ORR in 8.53% to 15.61%, DCR in 53.95% to 59.99%, and serious adverse events in 2.79% to 2.82% in MTC and DTC patients. F-FDG PET/CT and biochemical responses revealed similar results as the radiological response. Lu-based PRRT (ORR, 11.48%-24.52%; DCR, 61.47%-67.26%) showed better therapeutic effects than Y-based PRRT (ORR, 6.98%-13.82%; DCR, 50.86%-57.29%).
Conclusions: This meta-analysis suggests that PRRT could be a potential and safe strategy for MTC and DTC. In particular, PRRT with Lu exhibited improved therapeutic effects relative to PRRT with Y.