In every kind of malignant tumor, blood is
delivered by means of arteries. Anticancer drugs mixed with some 'embolic' particles such as polyvinyl alcohol and gelatin
powder can be injected selectively in the arteries that feed tumors. This causes clotting in those arteries, and infarcts
tumors [kills tumor cells by removing their blood supply]. Additionally the anticancer drugs work on the tumor. Their work
is enhanced by their not being quickly washed away by the blood circulation [which has been clotted or slowed]. Radio-opaque
contrast media can also be present in the mixture, and the progress of the mixture monitored radiologically. Chemoembolization
is usually done by an Interventional Radiologist.
The feeding artery is reached by advancing a catheter from the femoral
or other artery. The catheter can be advanced into the artery that feeds the majority of the tumor blood supply, and the embolization
material is injected, followed by the chemotherapy regimen previously decided upon, until the feeder artery no longer transports
liquid. Chemoembolization causes massive shrinkage due to ischemia [loss of blood supply], and increases the local drug intensity
and drug exposure to the tumor tissue.
Side Effects and Complications
are obvious ones: local trauma, artery rupture,
infection, abscess, reaction to the injected materials, the side effects due to the injected materials, fever, pain, misdirected
drainage of the injected material resulting in damage to other structures. It is usually painful, because some normal tissue
is also infarcted, and the pain would probably be coming from some normal tissue around the periphery of the tumor.
can be used to deal with almost any metastases, whether in bone, lung, liver, or other organs. It is often used for shrinking
liver metastases. Chemoembolization is not curative nor ablative, but it does shrink tumors quite often, and quite well. However,
some of the tumor will have an adjacent blood supply, or survive long enough to create new blood vessels, so the tumors do
regrow. This is an excellent method for downsizing tumors, whether as part of neoadjuvant treatment to become operable, or
as palliation for pain and symptoms, or simply for increased survival time.
Embolization or chemoembolization could
be of use for unresectable lung metastases. Also, this regional therapy may offer new hope for those sarcoma patients who
have lung metastases resistant to combination systemic chemotherapy, either for downgrading of tumors prior to surgical resection,
or for palliation or decreasing total tumor load. Embolization or chemoembolization is not curative by itself, and additional
therapy is required to eradicate residual disease.