A 41-year-old man with gastric adenocarcinoma presented with hepatic metastases. The metastases were refractory to systemic chemotherapy, so radioembolization with Y microspheres was performed. Because of stasis or saturation of the tumor with embolic particles, 79% of the microspheres were injected. At follow-up, the patient complained of "red bumps" that had developed on his right foot/ankle the day after the radioembolization. Because a portion of the dose was still in the catheter when withdrawn from the right femoral artery, the interventional radiologist used a Geiger counter to confirm radioactivity in the cutaneous lesions and thus the distal embolization of the microspheres.