What is Chemoembolization?
Chemoembolization treatment is a treatment method applied by interventional radiologists. It is among the locoregional treatment methods among cancer treatments. It is a treatment method in which chemotherapy treatment and embolization treatment are applied together. In classical chemotherapy methods, the chemotherapy drug that the patient will receive is given to the patient through the arm veins, the chemotherapy drug given in this way is distributed throughout the body and causes some side effects in the body.
In chemoembolization treatment, unlike conventional treatment, a much higher dose of chemotherapy is administered only to the cancerous tissue. A much higher dose of medication is injected into the veins that feed the cancer cells, ensuring that all of the medication penetrates the cancerous tissue, and preventing the chemotherapy medication from reaching unwanted areas significantly reduces the side effects of chemotherapy. In the second part of the treatment, embolization, the blood flow in the arteries leading to the cancerous tissue is cut off (embolized), thus preventing the cancerous tissue from being fed and killing the cancer cells.
Which Patients Can Have Chemoembolization?
Chemoembolization is usually and frequently applied to liver tumors. There are also other rare areas of application. It is an alternative method that can be applied to cancerous tissues that are inoperable, whose location is not suitable for surgery, and whose removal is technically not possible one by one because they are observed in many areas in the liver. Sometimes it can be applied in addition to traditional treatment methods and surgery with the idea that it provides patients with a longer chance of survival.
Tumors that are frequently applied to the liver
can be stated as; 1) Primary liver cancers (e.g. hepatocellular cancer (HCC)) 2) Secondary liver cancers (liver metastases of stomach, breast, colon etc. cancers).
How is the Treatment Decision Made?
The department that performs the treatment is the interventional radiology department, while other main branches that play an active role in making the treatment decision are oncology, gastroenterology, internal medicine sub-branches, general surgery, radiation oncology, or other branches of medicine that are closely related to the subject. The treatment decision is made by the joint council decision of the specialist physicians of these branches of medicine. The interventional radiologist is the first responsible person to evaluate the technical aspect of the treatment. Because he/she is the decision maker on technical issues such as whether the treatment can be applied technically, whether the patient’s liver arteries and veins are suitable for the treatment, what kind of medical materials will be used, whether additional interventions will be required during the treatment (for example, whether the stomach and pancreas vessels will be closed as well), and the selection of the area to be intervened, etc.
Advantages of Chemoembolization
Chemoembolization has some advantages over other classical treatment regimens. However, it should not be forgotten that in some patients, surgery alone, in some patients, classical chemotherapy alone, and in some patients, both may be more appropriate for the patient. In fact, it should not be forgotten that chemoembolization is a part of the treatment rather than a method that completely destroys (cures) cancer.
Advantages of the treatment;
Less chemotherapy side effects, Higher doses of the drug can be administered more intensively to the cancerous tissue, Less distribution of the administered drug to the unwanted organs, thus reducing side effects, Double effect on the cancerous tissue by applying embolization together with chemotherapy, The procedure is performed in the angiography room with local anesthesia, does not require general anesthesia, It is far from the possible risks of surgery, The patient (depending on their general condition) has a short time to stand up, mobilize and return to daily activities, It is cosmetic.
Patient Preparation Before Chemoembolization
Before the procedure, the patient’s general condition, blood count, and medical readiness for the procedure are evaluated by the relevant departments mentioned above. It is particularly important that the physician who closely monitors the patient is included in the decision-making team.
After the patient is examined by the physician team mentioned above and a treatment decision is made, the cancerous tissue is evaluated with some imaging methods such as Computerized Tomography (CT), PET/CT (PET/CT), MR imaging, CT Angiography, Ultrasonography in terms of some technical issues such as the size, activity, and spread to surrounding tissues. This initial evaluation will later guide the evaluation of the effectiveness of the treatment after the treatment. Since the procedure is performed with Angiography, the patient is evaluated with some blood tests in terms of suitability for angiography. Allergy to the contrast agents (drugs to be used to paint the vessels and tumor) to be used in angiography is questioned. The vascular structure is evaluated with some tests. Technical suitability for the procedure is thus evaluated. All these preparation procedures can usually be completed within one day. The patient should be fasting before the procedure. It is important to follow the doctor’s recommendations before the procedure, if any.
How is Chemoembolization Performed?
Chemoembolization is not much different from angiography procedures in the classical sense. Patients are taken into the angiography room under local anesthesia, just like in heart-brain angiography. As in heart-brain angiography, catheters (plastic tubes) and guidewires are used to advance to the cancerous tissue. The procedure up to this point is no different from classical angiography procedures. However, afterward, the arteries that feed the cancerous tissue are searched for (or directly found if they have been previously detected) and these vessels are entered with microcatheters and microguidewires. After the vessel feeding the cancer is found, a large amount of chemotherapy drug and embolization material (occlusive particle) are injected into this vessel. The occlusive particles used are usually microspheres that can start from 15-20 microns and reach sizes as high as 1000 microns, and have the ability to block blood vessels.
Sometimes, chemotherapy substances can be impregnated into these spheres and injected. There are special medical technologies developed for this. Alternatively, in addition to microspheres, special alcohol particles (PVA) designed for embolization or occlusive metals (coils) that mechanically provide embolization can be used. The procedure is completed in a very short time after the injection process is completed. The procedure takes approximately 1 hour (including patient preparation).
What Does the Patient Feel After Chemoembolization?
After the procedure, patients may experience short-term pain. Nausea may be added to this pain. This condition is usually controlled with simple pain and nausea medications.
Some patients may experience flu-like symptoms called post-embolization syndrome after the chemoembolization procedure. In post-embolization syndrome, these symptoms are temporary symptoms such as mild pain, fever, and fatigue that last 1-2 days.
After the chemoembolization procedure, patients are usually hospitalized for 1 day. Patients who have no other excuse to stay in the hospital can be discharged the day after the procedure. During this one-day process, patients are given pain control. In addition, since the procedure is an angiographic procedure, the veins of these patients are checked at short intervals through the groin veins.
How Are Patients Who Underwent Chemoembolization Followed Up?
After the chemoembolization procedure, the patient’s general condition and response to treatment are monitored with a number of clinical scoring methods and close examination and laboratory follow-up by the oncologist who follows the patient.
The mass lesion in the liver should also be monitored with imaging. Ultrasonography, Computerized Tomography, MR or PET/CT devices are usually and frequently used in this imaging follow-up. After the chemoembolization procedure, radiological follow-up (USG, MRI, CT) provides very important information in terms of size, and it is monitored whether the cancer focus has shrunk and whether its spread has decreased. In addition, PET/CT, a Nuclear Medicine method, helps understand whether the metabolism of the cancer focus has decreased and whether there are still live-active cells in the cancer tissue.
After chemoembolization treatment, patients should have imaging follow-up at 3 months, 6 months, and thereafter, with a frequency that varies depending on the patient. In some patients, this frequency may vary depending on the patient’s specific condition.