The method of chemotherapy administration depends on the type of drugs used and the type of cancer they should treat. Chemo is usually given with breaks between treatments, helping patients to regain strength and giving the body time to rebuild new healthy cells. Doctors determine the length of treatment depending on the type of cancer, treatment goals and how a patient responds to it.
Methods to Perform Chemotherapy
During clinical trials---rigorous testing done before the specific drug is commercially available---scientists and doctors determine how the body absorbs specific chemo drugs and how the drugs work. If stomach juices destroy the drugs, these drugs are impossible to give by mouth. Some medications function better if given intravenously---with a needle in the vein, according to the chemocare.com website.
Intravenous, or IV, chemo treatments
In this method, a needle or tiny plastic tube called a catheter is inserted into the vein, allowing for rapid entry into the body's circulation. Since most chemotherapy drugs are easily absorbed through the blood stream this is the most common method of administration. IV allows more flexibility with drug dosing and continuous infusions over a few days or weeks at a time.
Intra-arterial chemo treatments
Intra-arterial drugs are given into the artery that is supplying the blood to the tumor. It can be performed with insertion of temporary catheter, or with implanted pump, which is surgically implanted into the layer between the skin and the muscle.
Oral chemotherapy medications
Oral chemo drugs are administered by mouth, and then absorbed by the stomach, or under the tongue. They come as pills, tablets, capsules, or liquid. Those that are swallowed are encased in a protective coating that is broken down by the digestive juices in the stomach, releasing the medication.
Injections
If injections are given with a short needle under the skin into the space between the skin and the muscle they are subcutaneous. With intramuscular chemo injections, a large needle goes through the skin into the muscle layer, where the medication is deposited. Intramuscular injection bypasses an already irritated stomach, protecting from nausea. But most chemo drugs are too harsh to be given intramuscularly, says chemocare.com.
Applying Chemo Directly
When drugs need to reach the cerebrospinal fluid---the fluid that is in the brain and spinal cord---the treatment used is intraventricular---into the brain chambers. Some chemotherapy medications can be given directly into the abdominal cavity with a catheter---intraperitoneally, or into the bladder--- intravesicularly, or intrapleurally---into the pleural cavity---the space between the lung and the lining of the lung, or even topically---creams applied directly to the skin. One type of chemo drug called Gliadel wafer can be implanted and left inside the head after a brain tumor surgery in order to kill tumor cells left behind after the surgery.
Concerns About Pain
Patients might experience a little pain when a needle is used to perform chemo, the same as during blood drawing for lab work. According to the American Cancer Society, the drugs themselves should not cause any pain. In case of pain, burning, coolness, or anything new during treatment, they advise patients to inform the doctor or nurse right away.
