A 54-year-old man was referred with metastatic organ-of-Zuckerkandl paraganglioma with lytic T3 vertebral lesion, cardiomyopathy and previously unrecognised family history of paraganglioma. Biochemical investigation revealed markedly elevated plasma normetanephrine levels 45200 pmol/L (N<900), 3-methoxytyramine 1950 pmol/L (N<110) and chromogranin A 2420 ug/L (N<94). ¹⁸F-FDG and ⁶⁸Ga-DOTATATE PET/CT scans demonstrated concordant intense tracer uptake in the organ-of-Zuckerkandl primary, small volume nodal and multifocal osseous sites of disease confirming suitability for treatment with peptide receptor radionuclide therapy (PRRT).

The first cycle of treatment with ¹⁷⁷Lu-DOTATATE was commenced whilst an inpatient to stabilise catecholamine secretion and confirm lesional dosimetry to direct a subsequent multimodality management approach. He received a total cumulative dose of 26 GBq ¹⁷⁷Lu-DOTATATE over 4 cycles with concomitant radiosensitising temozolomide chemotherapy. Surgical stabilisation of the T3 vertebral body was subsequently performed and planned external beam radiotherapy (EBRT) was administered to T3 vertebral body after the second cycle to augment the internally administered radiation dose.

Restaging ⁶⁸Ga-DOTATATE PET/CT performed 7 months after commencing treatment demonstrated a favourable partial scintigraphic and radiologic response at all measurable sites of disease, including a near-complete functional imaging response of the T3 vertebral lesion. His pain has significantly improved and he continues to work full-time. There has been a commensurate biochemical response with 70-80% reduction in chromogranin A, plasma normetanephrine and plasma 3-Methoxytyramine levels. Genetic testing confirmed a germline SDHB mutation.

This case illustrates a novel and highly successful individualised multimodality treatment approach using ¹⁷⁷Lu-DOTATATE peptide receptor chemo-radionuclide therapy (PRCRT) upfront for the management of SDHB-mutated metastatic paraganglioma. It highlights the theranostic role of ⁶⁸Ga-DOTATATE PET/CT to assess suitability for and response to PRRT. It also demonstrates the role of post-therapy dosimetric verification to direct consolidative EBRT to augment radiation dose to critical lesions and adds to the evidence base supporting ¹⁷⁷Lu-DOTATATE PRRT for metastatic paragangliomas.