Management of children/young adolescents and adult patients with metastatic/progressive phaeochromocytomas and paragangliomas

Background Malignant phaeochromocytomas-(PCCs) and paragangliomas-(PGLs) are rare neuroendocrine tumours and evidence guiding the selection of systemic molecular radiotherapy-(MRT) remains limited. 131I-MIBG and 177Lu-DOTATATE are commonly used following surgery. This study compared treatment outcomes between children/young-adolescents-(<21years; CYA) and adults-(>21years). Method A retrospective analysis was conducted to record patient characteristics, tumour features, treatment details, and MRT administered. Outcomes were assessed using Kaplan-Meier analysis of overall survival-(OS) and progression-free survival-(PFS). Results Fifty-one patients were included (CYA n=15; adults n=36), Mean age at presentation was 13.4 years in CYAs and 47.7 years in adults. Surgical resection was performed in 81% of CYA PGLs and 75% of PCCs (R0/R1:44% and 100%), and in 95% of adult PGLs and 92% of PCCs (R0/R1:59% and 75%). Bone and lung metastases were the most frequent metastatic sites. No statistically significant differences were observed in OS or PFS between ¹³¹I-MIBG and 177Lu-DOTATATE. However, analysis consistently favoured 177Lu-DOTATATE, particularly in PGLs. In CYA-PGL patients, 177Lu-DOTATATE demonstrated longer median OS (4.5 vs 3.5yrs) and PFS (4.5 vs 1.8yrs) compared with MIBG. In Adult PGLs, median OS was similar (3.0yrs each), while 177Lu-DOTATATE showed longer PFS (3.0 vs 2.5yrs). Conclusion Surgical resection was frequently incomplete in both groups with metastatic PGLs. Although 177Lu-DOTATATE is not currently approved by NICE for metastatic PCCs/PGLs, it demonstrated consistently longer OS and PFS than 131I-MIBG, particularly in PGLs. These findings support a potential therapeutic advantage of 177Lu-DOTATATE over 131I-mIBG, though benefits in PCCs remain less clear due to smaller treated numbers and the absence of statistically significant differences.