Assessment of HCC response to Yttrium-90 radioembolization with gadoxetate disodium MRI: correlation with histopathology

Abstract

Background and aims Transarterial 90 Y radioembolization (TARE) is increasingly being used for hepatocellular carcinoma (HCC) treatment. However, tumor response assessment after TARE may be challenging. We aimed to assess the diagnostic performance of gadoxetate disodium MRI for predicting complete pathologic necrosis (CPN) of HCC treated with TARE, using histopathology as the reference standard. Methods This retrospective study included 48 patients (M/F: 36/12, mean age: 62 years) with HCC treated by TARE followed by surgery with gadoxetate disodium MRI within 90 days of surgery. Two radiologists evaluated tumor response using RECIST1.1, mRECIST, EASL, and LI-RADS-TR criteria and evaluated the percentage of necrosis on subtraction during late arterial, portal venous, and hepatobiliary phases (AP/PVP/HBP). Statistical analysis included inter-reader agreement, correlation between radiologic and pathologic percentage of necrosis, and prediction of CPN using logistic regression and ROC analyses. Results Histopathology demonstrated 71 HCCs (2.8 ± 1.7 cm, range: 0.5-7.5 cm) including 42 with CPN, 22 with partial necrosis, and 7 without necrosis. EASL and percentage of tumor necrosis on subtraction at the AP/PVP were independent predictors of CPN (p = 0.02-0.03). Percentage of necrosis, mRECIST, EASL, and LI-RADS-TR had fair to good performance for diagnosing CPN (AUCs: 0.78 -0.83), with a significant difference between subtraction and LI-RADS-TR for reader 2, and in specificity between subtraction and other criteria for both readers (p-range: 0.01-0.04). Radiologic percentage of necrosis was significantly correlated to histopathologic degree of tumor necrosis (r = 0.66 -0.8, p < 0.001). Conclusions Percentage of tumor necrosis on subtraction and EASL criteria were significant independent predictors of CPN in HCC treated with TARE. Image subtraction should be considered for assessing HCC response to TARE when using MRI. Key Points• Percentage of tumor necrosis on image subtraction and EASL criteria are significant independent predictors of complete pathologic necrosis in hepatocellular carcinoma treated with 90 Y radioembolization. • Subtraction, mRECIST, EASL, and LI-RADS-TR have fair to good performance for diagnosing complete pathologic necrosis in hepatocellular carcinoma treated with 90 Y radioembolization.

Early post-treatment MRI predicts long-term hepatocellular carcinoma response to radiation segmentectomy

“…In our study, inter-reader agreement was higher compared with the current literature for mRECIST (our results: κ , 0.71; vs. κ , 0.34–0.56 [ 21 , 36 ]) and LI-RADS TRA (our results: κ , 0.62, vs. κ , 0.48 [ 21 ]) in patients with HCC who underwent TARE and post-treatment MRI. However, data on treatment response assessment after TARE using MRI in patients with HCC is scarce and to the best of our knowledge, only one previous study (from our group) evaluated subtraction in this setting [ 37 ]. Our results suggest that either of these response assessment methods can be used for HCC response assessment after radiation segmentectomy, with similar substantial agreement between methods, and between readers.…”

Updates on LI‐RADS Treatment Response Criteria for Hepatocellular Carcinoma: Focusing on MRI

“…47 Riaz et al show that 61% of HCCs treated with TARE exhibited complete pathologic necrosis despite residual nodular APHE on posttreatment imaging. 22 King et al evaluated the performance of LI-RADS TRA vs. mRECIST in predicting treatment response after TARE in 57 patients with 77 HCCs and found that LI-RADS TRA was a better predictor of pathologic necrosis and treatment response, 48 a finding that was confirmed by Violi et al 49 Few studies have assessed the ability of LI-RADS TRA to predict overall survival following radiation-based therapies, and further longitudinal studies are needed.…”

Value of Dynamic Subtraction MRI in Assessing HCC Response to Image-guided loco-regional Therapy

“…Some complications may occur following TACE, such as arterio-portal fistula, portal vein occlusion, bile duct injury, or parenchymal infarction [8]. Recently, Transarterial Yttrium-90 radioembolization (TARE) has progressively increased in HCC treatment with subsequent tumor necrosis [9]. Therefore, accurate imaging is vital in tumor assessment after management to detect active lesions and any post-treatment complications.…”