Lutetium 177 Radionuclide Therapy–Induced Proliferative Arrest in a Metastatic High-Grade Rectal Neuroendocrine Tumor
An adult man with low-volume liver metastases from grade 3 rectal neuroendocrine tumor (Ki67 index of 25%) sequentially underwent multiple systemic therapies. Gallium (88Ga)-DOTATATE scan showed avid metastases, including a scalp deposit (Figure A, B). He received lutetium (177Lu)-DOTATATE, 200 mCi times 3 cycles. The scalp metastasis was excised 8 days after cycle 3 of 177Lu therapy. Histopathologic evaluation was consistent with a metastasis of his neuroendocrine tumor (Figure C). The tumor showed proliferative arrest, with no tumor cell showing reactivity for Ki67 (Figure D), whereas the nontumorous controls showed variable reactivity.
