225Ac-DOTATATE therapy in a case of metastatic pheochromocytoma

Excerpt

A 26-year-old man had a history of pheochromocytoma diagnosed 7 years ago, and he underwent surgery at that time. Recently, the patient was diagnosed with pheochromocytoma recurrence with multiple metastases. For losing the opportunity for surgery, the patient was recruited into the study of ²²⁵Ac therapy for neuroendocrine tumors in our hospital and signed an informed consent. The study was approved by the ethics committee of our hospital (AHSWMU_2020_035). The patient received three cycles of ²²⁵Ac-DOTATATE, and each treatment cycle lasting 2 months at a dose of approximately 0.2 mCi per treatment injection. The patient received ⁶⁸ Ga-DOTATATE PET/CT before the first treatment and after the last treatment. The maximum intensity projection (MIP) before treatment showed multiple elevated tracer uptake in the whole body (a). Axial fusion images (b–f) showed multiple metastatic lesions with obviously increased tracer uptake, which mainly involved the bone (lung metastases 1 SUVmax 13.4, lung metastases 2 SUVmax 3.0, thoracic vertebra SUVmax 34.5, transverse process SUVmax 30.7, lumbar spine SUVmax 69.8; red arrow). After treatment, the MIP image (g) still showed multiple tracer uptake in the whole body. However, axial fusion imaging (h–l) showed that the tracer uptake of almost all lesions was significantly reduced (lung metastases 1 SUVmax 5.0, lung metastases 2 SUVmax 0.6, thoracic vertebra SUVmax 3.1, transverse process SUVmax 17.8, lumbar spine SUVmax 35.4; red arrow). Although the number of lesions did not change significantly (g), the SUVmax of almost all lesions decreased by 20–50%, and the tumor-to-background ratio of the lesions was consistent with the change of SUVmax. Compared with before treatment, the patient’s blood pressure decreased and stably controlled in the normal range, and catecholamine was also in the normal range. …