Oncology

Types of Radiation Therapy for Cancer Treatment: An Overview

admin Aug 01, 2024

People with a knack for oncology research would have read about - Stanford Medicine launching a new method of delivering radiation that utilizes signals from cancer-targeting molecules known as tracers to target tumors in real time. It is the first time the novel approach is called biology-guided radiation therapy or SCINTIXTM.

Before directly discussing advancements, let us first understand what exactly radiation therapy is and what are the distinct types of radiation therapy:

What is radiation therapy (radiotherapy)?

Radiation therapy — or radiotherapy — is a predominant cancer treatment that utilizes radiation (usually high-powered X-rays) to destroy cancer cells. Radiation therapy may be utilized independently or alongside other treatments, like surgery or chemotherapy.

Radiation oncologists - healthcare professionals who specialize in radiation therapy. They determine whether radiation therapy would benefit the patient and, if so, the best type of radiation therapy for the kind of cancer the patient has. They also craft the radiation treatment plan with the radiation dosage that will kill cancer cells without harming nearby healthy tissue.

What are the types of radiation therapy?

There are two key forms of radiation therapy: external beam radiation therapy (EBRT) along with internal radiation therapy. Both types work by decimating a cancer cell’s - genetic material - DNA. Cancer cells die without DNA instructions directing them to grow and proliferate, and tumors shrink.

External beam radiation therapy (EBRT)

This therapy is the most prevalent type of radiotherapy. With EBRT, a machine guides beams of high-energy radiation toward the tumor. The energy may be X-rays (the most common type), electrons, or protons. Precision is vital with EBRT. The patient's radiation oncologists will craft a treatment plan to attack the tumor with radiation while avoiding the patient’s healthy tissue.

There are several forms of EBRT:

3D conformal radiation therapy utilizes CT scans as well as computer software to generate a 3D model of the tumor. Utilizing the model as a guide, the machine sends out radiation beams that target the cancer site while sparing healthy tissue.

Intensity-modulated radiation therapy (IMRT) is an extremely innovative form of radiation therapy. It uses many radiation beams that vary the dose intensity. IMRT delivers a higher radiation dose to the tumor and lower doses to healthy tissue.

Arc-based radiotherapy is a form of IMRT. It directs energy beams of changing intensity in a rotational arc-like pattern, delivering radiation rapidly than traditional IMRT. Volumetric modulated arc therapy (VMAT) as well as tomotherapy are two forms of arc-based radiotherapy.

Image-guided radiotherapy (IGRT) refers to a form of EBRT in which the radiation machine fetches a low-dose X-ray/mini-CT scan prior to each treatment. This image aids in aligning the treatment site, delivering more precise radiation.

Particle therapy utilizes radiation therapy that consists of protons instead of photons (X-rays). For certain individuals, protons can deliver the same radiation dose to the tumor and lessen the radiation dose to healthy tissues.

Stereotactic radiosurgery, such as Gamma Knife surgery, utilizes high doses of focused radiation to destroy miniature brain tumors with surgical accuracy. Unlike surgery, it doesn’t require cutting. Typically, this treatment takes one-five days.

Stereotactic body radiation therapy (SBRT) utilizes high doses of focused radiation to kill tumors exterior of person's brain. Like stereotactic radiosurgery, it eliminates tumors with surgical accuracy but without actual surgery.

Intraoperative radiation (IORT) delivers radiation during surgery. Post a tumor has been taken out surgically, IORT kills any remaining cancer cells that aren’t safe to remove surgically.

Internal radiation therapy

Internal radiation therapy places radiation inside of an individual’s body, close to cancer cells. It treats smaller tumors in an individual’s head, neck, breast, cervix, uterus, or prostate.

Patient can receive internal radiation through a solid source/in liquid form:

Brachytherapy implants a solid radioactive source/ “seed,” inside or beside a tumor. The source sends out radiation to a small portion to kill cancer cells. Some implants release low doses for more extended periods (weeks). Others may release high doses for shorter duration (minutes). Few implants utilized in brachytherapy are temporary. Others stay in the patient’s body forever. Eventually, they stop releasing radiation.

Systemic therapy sends liquid radioactive material through a patient’s blood to find and destroy cancer cells. Some forms are swallowed. Patients will receive an injection through a vein (IV) for others. Treatments include radionuclide therapy (radioimmunotherapy). With radioimmunotherapy, a radioactive protein identifies specific cancer cells, adheres to them, and then releases radiation to kill them.

In a nutshell, radiation therapy treatment, along with chemotherapy and surgery, is one of the most superior tools healthcare providers use to treat cancer. The most common types are external beam radiation therapy (EBRT) as well as internal radiation therapy. A patient’s radiation oncologist can recommend radiotherapy tailored to the patient’s condition and the kind of cancer they have.