Published online Jul 21, 2015. doi: 10.3748/wjg.v21.i27.8271
Peer-review started: January 5, 2015
First decision: April 13, 2015
Revised: April 29, 2015
Accepted: June 16, 2015
Article in press: June 16, 2015
Published online: July 21, 2015
Processing time: 198 Days and 6.3 Hours
The liver is a common site of metastasis, with essentially all metastatic malignancies having been known to spread to the liver. Nearly half of all patients with extrahepatic primary cancer have hepatic metastases. The severe prognostic implications of hepatic metastases have made surgical resection an important first line treatment in management. However, limitations such as the presence of extrahepatic spread or poor functional hepatic reserve exclude the majority of patients as surgical candidates, leaving chemotherapy and locoregional therapies as next best options. Selective internal radiation therapy (SIRT) is a form of catheter-based locoregional cancer treatment modality for unresectable tumors, involving trans-arterial injection of microspheres embedded with a radio-isotope Yttrium-90. The therapeutic radiation dose is selectively delivered as the microspheres permanently embed themselves within the tumor vascular bed. Use of SIRT has been conventionally aimed at treating primary hepatic tumors (hepatocellular carcinoma) or colorectal and neuroendocrine metastases. Numerous reviews are available for these tumor types. However, little is known or reviewed on non-colorectal or non-neuroendocrine primaries. Therefore, the aim of this paper is to systematically review the current literature to evaluate the effects of Yttrium-90 radioembolization on non-conventional liver tumors including those secondary to breast cancer, cholangiocarcinoma, ocular and percutaneous melanoma, pancreatic cancer, renal cell carcinoma, and lung cancer.
Core tip: Selective internal radiotherapy or transarterial radioembolization with Yttrium-90 microspheres is a targeted catheter-based therapy indicated for unresectable metastatic liver tumors. A number of reviews and meta-analyses have been written on the use of Yttrium-90 in the treatment of liver metastases, however few broadly investigate results from non-colorectal or non-neuroendocrine primaries. Our objective is to consolidate the current literature to better delineate the response and survival outcomes of Yttrium-90 radioembolization on non-conventional liver tumors including breast cancer, cholangiocarcinoma, ocular and percutaneous melanoma, pancreatic cancer, renal cell carcinoma and lung cancer.