Interventional oncology is a modern field in cancer care, offering precise, minimally invasive, and targeted treatments. It focuses on delivering therapies directly to tumors, minimizing impact on healthy surrounding tissues.
What Interventional Oncology Is
Interventional oncology (IO) is a subspecialty of interventional radiology that diagnoses and treats cancer using minimally invasive, image-guided procedures. These procedures employ imaging techniques like computed tomography (CT), ultrasound, magnetic resonance imaging (MRI), and fluoroscopy to precisely guide instruments to the tumor site. This allows for direct, localized treatment of solid tumors in organs such as the liver, kidneys, lungs, and bones.
IO targets tumors directly, differentiating it from systemic treatments that affect the entire body. By focusing on local tumor control, IO aims to reduce impact on healthy tissues, often leading to less pain, fewer side effects, and shorter recovery times compared to traditional open surgeries. Many IO procedures can be performed on an outpatient basis, allowing patients to return home sooner.
Key Interventional Oncology Procedures
Interventional oncology encompasses various procedures, primarily categorized into ablation and embolization techniques. Both are designed to target and destroy cancer cells.
Ablation Techniques
Ablation techniques destroy tumors by applying extreme temperatures, either heat or cold, directly to the cancerous tissue. These procedures involve inserting thin, needle-like probes into the tumor under image guidance.
Radiofrequency Ablation (RFA) uses high-energy radio waves to generate heat. An electrical current passes through a needle electrode inserted into the tumor, causing the tissue to heat and destroy cancer cells through coagulation necrosis. This heat also helps seal small blood vessels. RFA is commonly used for small tumors.
Microwave Ablation (MWA) employs electromagnetic waves to create heat. A needle-like antenna emits microwaves that agitate water molecules in the tissue, producing frictional heating and inducing coagulation necrosis. MWA can create larger ablation zones and achieve higher temperatures more rapidly than RFA.
Cryoablation destroys tumors by freezing them using extreme cold. Thin metal probes, called cryoprobes, are inserted into the tumor, circulating very cold gases like argon or liquid nitrogen. This rapidly cools the tissue, forming ice crystals that dehydrate cells and cause cold-induced injury. The procedure often involves multiple freeze-thaw cycles to maximize tumor destruction.
Embolization Techniques
Embolization techniques block the blood supply to tumors, effectively starving them of oxygen and nutrients. These procedures involve navigating catheters through blood vessels to reach the tumor’s feeding arteries.
Transarterial Chemoembolization (TACE) involves injecting chemotherapy drugs and embolic agents directly into the arteries supplying the tumor. The embolic agents trap the chemotherapy within the tumor, allowing a high concentration of the drug to act on cancer cells while limiting systemic exposure. TACE is particularly effective for liver cancer tumors, which often receive most of their blood supply from the hepatic artery.
Radioembolization, also known as Transarterial Radioembolization (TARE) or Selective Internal Radiation Therapy (SIRT), delivers microscopic radioactive beads directly to the tumor via its arterial blood supply. These microspheres lodge in the small vessels of the tumor. The radiation then causes DNA damage and cell death within the tumor, while minimizing exposure to healthy surrounding tissues.
Cancers Targeted by Interventional Oncology
Interventional oncology treatments apply to various cancers, particularly those in specific organs. They are also used when traditional treatments are unsuitable.
Primary and metastatic liver cancers are often targeted due to the liver’s dual blood supply, allowing selective targeting via the hepatic artery. This includes hepatocellular carcinoma and metastases from other cancers.
Kidney and lung cancers are also treated with interventional oncology techniques. For early-stage lung tumors, ablation techniques like microwave ablation provide an alternative to surgery. Bone tumors, including painful bone metastases, can be managed. IO can achieve local control, reduce tumor burden, or manage symptoms in patients with unresectable tumors.
Patient Suitability and Recovery
Patient suitability for interventional oncology treatments is determined through a comprehensive assessment, often involving a multidisciplinary team. Factors considered include the tumor’s size, location, and number, as well as the patient’s overall health and ability to tolerate the procedure. These treatments are often considered for patients who may not be candidates for open surgery due to other health conditions or when tumors are difficult to access surgically.
The patient journey typically involves pre-procedure preparation, which includes various assessments to ensure fitness for the intervention and any necessary pain relief. Since interventional oncology procedures are minimally invasive, they generally involve small incisions, sometimes as tiny as a pinhole. This less invasive approach often translates to shorter hospital stays, with many procedures allowing for discharge within 24 hours or even on an outpatient basis. Recovery is generally faster and associated with less pain compared to traditional open surgery. Patients might experience mild discomfort, bruising, or swelling at the insertion site, and some may have temporary flu-like symptoms, which typically resolve within a few days.