Abstract
PURPOSE: To evaluate the histopathologic effects of resin Yttrium-90 Transarterial Radioembolization (90Y-TARE) on intrahepatic cholangiocarcinoma (iCCA), and correlate dose with outcomes.
MATERIALS AND METHODS: This retrospective, single-center study included adult patients with iCCA treated with 90Y-TARE using resin microspheres. Histopathologic and dosimetry results were evaluated. Imaging response was assessed. Complete pathologic necrosis (CPN) was defined as 100% tumor necrosis, and extensive necrosis as > 90% necrosis. Treatment factors affecting the pathologic necrosis rate were evaluated.
RESULTS: For 18 patients, the median age was 69 years [IQR, 67-71 years], with 56% male, and median tumor size of 6.4 cm [IQR,5.1-8.2 cm]. Surgical resection was performed 127 [IQR, 100-182] days after 90Y-TARE. CPN was achieved in 4/18 (22%) patients, with extensive necrosis in 13/18 (72%) patients. Extensive necrosis rate was higher in patients with a prescribed dose ≥ 180 Gy (10/11 [91%]), compared to patients with a prescribed dose < 180 Gy (3/7 [43%], p = 0.03). Patients treated with 90Y-TARE as a first line treatment had higher odds of achieving extensive necrosis compared to patients who received 90Y-TARE after chemotherapy (OR = 11, p = 0.047). All lesions classified as complete response by mRECIST at the 3-month evaluation exhibited extensive necrosis, corresponding to a sensitivity of 58% and a positive predictive value (PPV) of 100%.
CONCLUSION: 90Y-TARE with resin microspheres is associated with a CPN rate of 22% and extensive necrosis rate of 72% in iCCA, with a prescribed dose of ≥ 180 Gy predicting extensive necrosis.