Blood Flow and Arterial Infusion by Implanted Port in In-111 Octreotide Therapy: Critical Overview

In-111-Octreotide infusion, via intrahepatic catheterization is well established technique in our
Institution in hepatocellular carcinoma and neuroendocrine tumors treatment. In order to facilitate
repetitive infusions of our patients, a method of implanted ports use, gave a simpler therapeutic way
but also improved therapy results. Our aim is to show that radiopharmaceutical fluid flow through
implanted port is rich; the absorbed dose in the tumor increased for best therapy results.
Surgically implanted ports have been used in repetitive intra-arterial In-111 radiolabeled Octreotide
infusions for 22 patients with hepatocellular carcinoma and similarly 18 patients with neuroendocrine
tumors in a continuous base. A percutaneous implantation procedure facilitates safe and less invasive
radiopharmaceutical infusions for the treatment. We have focused on the interventional techniques for
percutaneous implantation of a vascular access device, consisting of an implantable port, to perform
In-111 Octreotide infusions. Hepatic arterial infusion radiotherapy employs a hepatic artery catheter
as a conduit to achieve a high concentration of radiolabeled agent to liver tumors. It is performed
using less-invasive percutaneous image guided procedures. Various techniques were used to ensure
high concentration of radiopharmaceutical in liver tumors, as there are many anatomical hepatic
arterial variations and complicated blood flow patterns. These techniques are composed of arterial
redistribution by embolization, percutaneous catheter placement, evaluation and management of flow
patterns that reflect In-111 Octreotide distribution.
Using fluid flow theory, we describe blood flow alterations that could be performed to obtain selective
radiopharmaceutical distribution to the target area and avoid side effects caused by the accumulation
of the radiolabeled agent into non tumor areas. By steady, laminar and disturbed flow equations, the
rich distribution of our agent in the scintigraphy imaging of the tumor, by the implanted ports
technique, can be explained.
The factors affecting hepatic arterial flow in tumor feeding artery were analyzed. The patency rate of
the hepatic artery was significantly higher in patients with catheter placement using fixed port method
than those undergo fully interventional catheterization. A ratio of 5: 1 to 3: 1 flow increase was
calculated through poiseuille flow and Reynolds number for circular pipe.
We consider that in continuous therapy, it is important to use the simplest fixed port method for
percutaneous catheter placement instead of interventional catheterization, in order to increase
absorbed dose into tumor for best response of radionuclide therapy.