Intra-arterial chemotherapy is a specialized cancer treatment that delivers chemotherapy drugs directly into an artery supplying blood to a tumor. This localized method concentrates medication at the disease site, offering a precise approach to managing certain cancers.
Understanding Intra-arterial Chemotherapy
Intra-arterial chemotherapy administers anti-cancer drugs directly into an artery feeding a tumor. This contrasts with systemic chemotherapy, where drugs circulate throughout the bloodstream via intravenous (IV) delivery. The localized approach maximizes drug concentration at the tumor for a potent effect on cancer cells. This method also minimizes exposure of healthy tissues to chemotherapy agents, potentially reducing widespread side effects.
The Mechanism of Intra-arterial Drug Delivery
The procedure for intra-arterial drug delivery begins with the patient under general anesthesia. An interventional radiologist or neurosurgeon makes a small incision, often in the groin to access the femoral artery, or in the upper arm to access the brachial artery. A thin, flexible tube called a catheter is then inserted into the artery.
Using imaging guidance, the specialist navigates the catheter through the arterial network until its tip is positioned within the artery supplying blood to the tumor. Once in place, chemotherapy drugs are slowly infused directly into the tumor’s blood supply, over 30 minutes to two hours. After the infusion is complete, the catheter is removed, and pressure is applied to the access site to prevent bleeding. Patients remain in bed for up to 6 hours following the procedure to ensure proper healing of the access site.
For prolonged or repeated treatments, a permanent arterial port may be implanted under the skin in the groin or arm. This port allows for direct and repeated administration of chemotherapy into the target artery without the need for multiple catheterizations. This approach enables sustained drug delivery to the tumor over time.
Advantages of Targeted Chemotherapy
Intra-arterial chemotherapy offers several advantages over traditional systemic chemotherapy. Delivering drugs directly to the tumor’s blood supply allows a much higher concentration of the agent to reach cancerous cells. This increased localized drug concentration can lead to improved tumor response rates and better disease control within the targeted area.
This direct delivery method also reduces systemic exposure to chemotherapy drugs. Less medication circulates throughout the body, lowering the risk of widespread side effects common with intravenous chemotherapy, such as nausea, hair loss, and myelosuppression (a decrease in bone marrow activity). This can contribute to a better quality of life for patients undergoing treatment.
Specific Cancers Treated
Intra-arterial chemotherapy is used for localized cancers where a direct blood supply to the tumor can be identified. One notable application is in the treatment of retinoblastoma, a childhood eye cancer. In these cases, chemotherapy is infused into the ophthalmic artery, the primary blood supply to the eye. This approach has significantly increased the chances of saving the affected eye.
The treatment is also applied to liver cancers, including hepatocellular carcinoma and colorectal metastases to the liver, because the liver receives a significant portion of its blood supply from the hepatic artery, making it an accessible target. Additionally, intra-arterial chemotherapy has been used for certain head and neck cancers, and for lung, breast, and limb tumors. This method is considered for tumors located in a single site or organ where feeding arteries can be reached effectively.
Patient Journey and Potential Side Effects
Before an intra-arterial chemotherapy procedure, patients undergo a thorough evaluation, which may include imaging studies to map the tumor’s blood supply. During the procedure, patients are under general anesthesia, ensuring they are asleep and comfortable. A small incision is made, usually in the groin, to insert a catheter into an artery.
Following the procedure, patients are monitored in a recovery room. They are usually required to lie flat for several hours, often between 4 to 6 hours, to minimize the risk of bleeding or complications at the catheter insertion site. Most patients can return home the same day, though some cases may require a 1-2 day hospital stay. Treatment cycles are often repeated, every 2 to 4 weeks, with 3 to 6 cycles.
While intra-arterial chemotherapy aims to reduce systemic side effects, localized side effects can occur due to concentrated drug delivery. Common local effects include pain or bruising at the access site in the groin, and transient redness or inflammation in the area where the drug was administered. Eye-specific side effects, particularly in retinoblastoma treatment, can include eye redness, eyelid swelling, pain, and limited eye movement. Rare complications such as optic nerve swelling, retinal detachment, bleeding, or issues with blood supply to the eye have been reported. Although systemic side effects like nausea or decreased blood counts are milder than with intravenous chemotherapy, they can still occur.