Selective Internal Radiation Therapy with Yttrium-90 for Intrahepatic Cholangiocarcinoma: A Systematic Review on Post-Treatment Dosimetry and Concomitant Chemotherapy

Abstract

Selective internal radiation therapy (SIRT) with yttrium-90 (90Y)-loaded microspheres is increasingly used for the treatment of Intrahepatic Cholangiocarcinoma (ICC). Dosimetry verifications post-treatment are required for a valid assessment of any dose-response relationship. We performed a systematic review of the literature to determine how often clinics conducted post-treatment dosimetry verification to measure the actual radiation doses delivered to the tumor and to the normal liver in patients who underwent SIRT for ICC, and also to explore the corresponding dose-response relationship. We also investigated other factors that potentially affect treatment outcomes, including the type of microspheres used and concomitant chemotherapy. Out of the final 47 studies that entered our study, only four papers included post-treatment dosimetry studies after SIRT to quantitatively assess the radiation doses delivered. No study showed that one microsphere type provided a benefit over another, one study demonstrated better imaging-based response rates associated with the use of glass-based TheraSpheres, and two studies found similar toxicity profiles for different types of microspheres. Gemcitabine and cisplatin were the most common chemotherapeutic drugs for concomitant administration with SIRT. Future studies of SIRT for ICC should include dosimetry to optimize treatment planning and post-treatment radiation dosage measurements in order to reliably predict patient responses and liver toxicity.

Emerging Indications for Interventional Oncology: Expert Discussion on New Locoregional Treatments

“…The majority of research on the use of SIRT in CCA makes use of treatment planning that delivers a mean absorbed dose of 120 Gy to the tumor and a threshold dose of no more than 50-70 Gy to the surrounding healthy liver parenchyma [66]. Various studies have shown sizable disparities between dosimetry verification studies performed after yttrium-90 TARE and the pretreatment predictive planning marked albumin macroaggregates: These differences may result from variations in the flow dynamics, catheter position, and particle size, weight, and density [67][68][69].…”

Promising Highly Targeted Therapies for Cholangiocarcinoma: A Review and Future Perspectives

“…Chemotherapy has been developed with an understanding of the biology and molecular mechanisms of CCA [6]. Radiotherapy has also improved with internal small, sealed sources [7,8] and proton beams [9], mainly with palliative and supportive intent. Immunotherapy has evolved and improved with the advent of immune checkpoint inhibitors, such as durvalumab (a PD-L1 antibody) [10] and CAR-T therapy [11].…”