Hepatic parenchymal changes after intraarterial Y-90 therapy: CT findings.

Abstract

The serial contrast material-enhanced computed tomographic scans of 23 patients treated with intraarterial yttrium-90 microspheres as therapy for hepatic metastatic disease were reviewed for evidence of parenchymal changes in the liver in areas not involved with tumor. Irregular low-attenuation geographic areas that developed in the hepatic parenchyma after therapy were graded as mild, moderate, or severe and were evident in 12 of 23 patients. In nine cases of mild to moderate changes in the hepatic parenchyma, the abnormality was either focal or asymmetric. In all three patients receiving the highest dose (15,000 cGy), severe diffuse parenchymal changes were seen in all hepatic segments. In the remaining 11 patients, no parenchymal changes were seen. The most pronounced changes were seen at 8 weeks after therapy and were partially or completely reversible at 16-24 weeks. All patients had minimal or no change in liver function and no clinical sequelae attributable to liver injury.

Assessment of response to treatment of unresectable liver tumours with 90Y microspheres: Value of FDG PET versus computed tomography

“…In most patients followed up with CT imaging, the area of the liver treated with 90 Y microspheres becomes lower in attenuation and this may be diffuse where the dose is greater than 125 Gy. These transient changes (most pronounced at 8 weeks and diminish by 16 weeks) are thought to represent liver oedema, congestion and micro-infarction and should not be mistaken for recurrence [9,10]. Later changes include a reduction in size and number of metastases, but simple measurement of orthogonal diameters is insensitive because of the presence of necrosis, haemorrhage and cystic changes [7].…”

Y90 Selective Internal Radiation Therapy

“…34,35 The most common postprocedure initial imaging finding at 1 month is decreased attenuation or intensity in the treated regions, which represents hepatic edema, congestion, and microinfarction of tissue. 34,35 Of note, early CT findings may not represent the efficacy of the radioembolization procedure because many of these changes are reversible or partially reversible and self-limiting. Therefore, additional follow-up imaging at 3 or 6 months postprocedure is recommended to evaluate tumor response.…”

“…Therefore, additional follow-up imaging at 3 or 6 months postprocedure is recommended to evaluate tumor response. 34,35 In addition, PET imaging may be beneficial in select patients with hypovascular tumors to track postprocedural changes and can show decreased metabolic activity of treated areas. 36 …”

The triple-phase CT image appearance of post-irradiated livers

“…External‐beam radiotherapy continues to integrate in the treatment of unresectable hepatocellular carcinoma (HCC) (15, 16, 21–23). Dynamic CT has been one of the most important modalities for evaluation of treatment effect and diagnosis of treatment‐related toxicities (1, 2, 11, 14, 18, 24, 25). Different CT features after hepatic irradiation have been reported from several institutions, including findings of edematous hypodense appearance in the pre‐contrast phase (1, 11, 14, 24, 25), and compensatory hyperdense changes in the post‐contrast phase (1, 2, 4, 5, 10, 18, 24).…”