User:Blarson3/sandbox

Deleted the bullet point that just said "intervention radiology" and added it's link to the above section.

• • Transcatheter arterial chemoembolization (TACE) is usually performed for unresectable tumors or as a temporary treatment while waiting for liver transplant. TACE is done by injecting an antineoplastic drug (e.g. cisplatin) mixed with a radio-opaque contrast (e.g. Lipiodol) and an embolic agent (e.g. Gelfoam) into the right or left hepatic artery via the groin artery. The goal of the procedure it to restrict the tumor’s vascular supply while supplying a targeted chemotherapeutic agent. TACE has been shown to increase survival and to downstage HCC in patients who exceed the Milan criteria for liver transplant. Patients who undergo the procedure may are followed with CT scans and may need additional TACE procedures if the tumor persists. As of 2005, multiple trials show objective tumor responses and slowed tumor progression but questionable survival benefit compared to supportive care; greatest benefit seen in patients with preserved liver function, absence of vascular invasion, and smallest tumors. TACE is not suitable for big tumors (>8 cm), the presence of portal vein thrombus, tumors with a portal-systemic shunt, and patients with poor liver function. The field was then introduced to a new delivery system that utilized beads to deliver the chemotherapy into the tumor vasculature that is called drug-eluting bead transarterial chemoembolization (DEB-TACE). These embolic microspheres consist of a polyvinyl alcohol hydrogel that utilizes covalently bound sulfonate groups to deliver doxorubicin in its salt form to the tumor. This method has been gaining popularity for its efficacy and ease of use. 

• Selective internal radiation therapy (SIRT) can be used to destroy the tumor from within (thus minimizing exposure to healthy tissue). Specifically, transarterial radioembolization (TARE) aims to administer toxic doses of radiation to the target lesion, while minimizing damage to healthy liver parenchyma. Similar to TACE, this is a procedure in which an interventional radiologist selectively injects the artery or arteries supplying the tumor with a chemotherapeutic agent. The agent is typically Yttrium-90 (Y-90) incorporated into embolic microspheres that lodge in the tumor vasculature causing ischemia and delivering their radiation dose directly to the lesion. This technique allows for a higher, local dose of radiation to be delivered directly to the tumor while sparing normal healthy tissue. While not curative, patients have increased survival. No studies have been done to compare whether SIRT is superior to TACE in terms of survival outcomes, although retrospective studies suggest similar efficacy. There are currently two products available, SIR-Spheres and TheraSphere. The latter is an FDA approved treatment for primary liver cancer (HCC) which has been shown in clinical trials to increase the survival rate of low-risk patients. SIR-Spheres are FDA approved for the treatment of metastatic colorectal cancer but outside the US SIR-Spheres are approved for the treatment of any non-resectable liver cancer including primary liver cancer.