The following are 3 cases of abnormal hepatic Tc99m MAA studies. Please see topic discussion on Role of Nuclear Medicine in Y90 radioembolization.
60 year old woman with refractory multifocal HCC, being evaluated for left hepatic radioembolization.
SPECT/CT images after MAA injection demonstrate a large left hepatic lobe tumor with intense activity AND activity in the fundus and body of the the stomach. This indicates nontarget embolization of MAA to the stomach.
Angiogram demonstrates left hepatic artery branch originating from the left gastric artery, a “replaced left hepatic artery”. Catheter positioning could not eliminate the perfusion of the stomach, and this patient was not treated with Y90 radioembolization.
56 year old man with metastatic neuroendocrine tumor being evaluated for right radioembolization.
SPECT/CT images demonstrate intense perfusion to the gallbladder, which may represent a risk for radiation-induced cholecystitis.
This can be corrected by distal positioning of the catheter (as in this case, pictured below with arrowhead at the catheter tip), or cystic artery embolization.
82 year old man who is a poor surgical candidate with hepatocellular carcinoma, planned for right hepatic radioembolization.
Planar Tc99m MAA images demonstrate intense activity in the lungs after hepatic artery injection, compatible with a high degree of intrahepatic shunting.
Right hepatic angiogram from the procedure demonstrated a tangle of abnormal vessels with in the right hepatic tumor, with early venous drainage to IVC and right heart. Lung shunting >20% is generally associated with unacceptable risk of radiation pneumonitis (seen with >30 Gy absorbed dose to the lungs in a single treatment). This patient’s shunt fraction was greater than 50%.