Multimodality Imaging Following⁹⁰Y Radioembolization: A Comprehensive Review and Pictorial Essay

Abstract

Radioembolization with yttrium 90 (90Y) microspheres represents an emerging transarterial therapy for the treatment of liver malignancies that continues to generate interest in the medical community. The classic indication of treatment response is a reduction in tumor size; however, parenchymal changes (eg, necrosis, lack of enhancement, specific findings at positron emission tomography and functional magnetic resonance imaging) and other benign findings (pleural effusions, perivascular edema, contralateral hypertrophy, ring enhancement, perihepatic fluid, fibrosis) may occur following treatment, requiring proper image interpretation. With classic imaging findings and surrogates (time to progression, duration of response, disease-free interval), response rates range from 20% to 80% in patients treated for hepatocellular carcinoma or metastatic disease to the liver. Complications of 90Y radioembolization include cholecystitis, abscess, and bilomas and should be recognized early in the imaging follow-up of these patients. Radiologists who are involved in the posttreatment assessment of patients undergoing 90Y radioembolization should be familiar with the imaging findings and potential imaging pitfalls associated with this therapy.

Yttrium-90 microsphere radioembolization for the treatment of liver malignancies: a structured meta-analysis

“…However, lesion size reduction does not always occur even if treatment is effective. This is associated with different peri-and endotumoral processes that can occur post 90 Y-RE, e.g., peritumoral edema and hemorrhage, and ring enhancement [56]. Therefore, actual tumor response may often be better than is reported, based on CT measurements alone.…”

“…In a significant number of cases 'stable disease' could actually be minor, partial, or even complete response. In order to improve sensitivity in assessing tumor response, it is therefore strongly recommended that 18 F-FDG-PET or functional MRI (diffusion-weighted MRI) is added to posttreatment response assessment protocols [56][57][58][59].…”

Transarterial Therapies for Hepatocellular Carcinoma: a Comprehensive Review with Current Updates and Future Directions

“…Other than the usual imaging findings seen with TACE and TAE, including necrosis, ascites, pleural effusion, and perihepatic fluid, important additional findings with 90Y therapy include hepatic fibrosis and ring enhancement (Atassi et al, 2008). Ring enhancement can sometimes be seen which represents granulation tissue and fibrosis.…”

Update on the Role of Imaging in Management of Metastatic Colorectal Cancer

“…Perivascular edema in the distribution of the embolized vessels is a transient phenomenon and should not be confused with infiltrative disease. Radio-or chemoembolization results in ischemia and hepatitis of the normal liver parenchyma, which in turn can result in abnormal patchy parenchymal enhancement of the treated liver segment, causing difficulty in interpreting treatment response (34). Capsular retraction and hepatic fibrosis resulting in portal hypertension have been reported following radio-and chemoembolization.…”

“…Radioembolization and stereotactic body radiation therapy can result in radiation hepatitis, cholecystitis, gastritis, gastric and duodenal ulcers, biliary necrosis, and lobar atrophy of the liver. Late complications associated with radiation include hepatic fibrosis, bile duct necrosis, and eventual portal hypertension (34). Major complications associated with percutaneous ablation include hepatic abscess, intraperitoneal hemorrhage, biliary injury, vascular thrombosis (Fig 17), tumor seeding, liver failure, gastrointestinal perforation, and pulmonary complications such as pneumothorax and pleural effusions (65).…”