Radiation Oncology

What is radiation?

Radiation is energy moving from one place to another. The energy may move through waves or particles. High-energy radiation, like x-rays, can change or destroy cells. Radiation therapy uses high-energy x-rays or proton beams to destroy cancer.

Goals of radiation therapy

Doctors called radiation oncologists oversee radiation therapy. They use this treatment to destroy cancer cells and slow tumor growth, without harming nearby healthy tissue.

Sometimes, doctors recommend radiation therapy as the primary cancer treatment. Other times, patients receive radiation therapy after surgery or chemotherapy. This is called adjuvant therapy. It targets cancer cells remaining after the primary treatment.

When it is not possible to destroy all of the cancer, doctors may use palliative radiation therapy to shrink tumors and relieve symptoms. This may reduce pressure, pain, and other symptoms. The goal is to improve a person’s quality of life.

More than half of people with cancer receive some type of radiation therapy. For some cancers, radiation therapy alone is an effective treatment. Other types of cancer respond best to combination treatments. This may include radiation therapy plus surgery, chemotherapy, or immunotherapy.

External-beam radiation therapy

This is the most common type of radiation therapy. It delivers radiation from a machine outside the body. And it can treat large areas of the body, if needed.

A machine called a linear accelerator, or linac, creates the radiation beam for x-ray or photon radiation therapy. Special computer software adjusts the beam’s size and shape. This helps target the tumor while avoiding healthy tissue near the cancer cells.

Most treatments are given every weekday for several weeks. Form-fitting supports or plastic mesh masks (for radiation therapy to the head, neck, or brain) help patients stay still during treatment.

The types of external-beam radiation therapy are:

Three-dimensional conformal radiation therapy (3D-CRT). 

This allows the treatment team to aim the radiation more precisely. It often means they can safely use higher doses of radiation while reducing damage to healthy tissue.

Intensity modulated radiation therapy (IMRT).

This a more complex form of 3D-CRT. The radiation intensity is varied within each beam in IMRT unlike conventional 3D-CRT, which uses the same intensity in each beam. IMRT targets the tumor and avoids healthy tissue better than conventional 3D-CRT.

Proton beam therapy. This treatment uses protons rather than x-rays. A proton is a positively charged particle. At high energy, protons can destroy cancer cells. The protons go to the targeted tumor and deposit the specific dose of radiation therapy. Unlike with x-ray beams, the radiation does not go beyond the tumor. This limits damage to nearby healthy tissue. Currently, doctors use proton therapy to treat certain cancer types. This therapy is relatively new and requires special equipment. Therefore, it is not available at every medical center. Learn more about proton therapy.

Image-guided radiation therapy (IGRT). This type of therapy allows the doctor to take images of a patient throughout treatment. These images can then be compared to the images used to plan treatment. It allows better targeting of the tumor and helps reduce damage to healthy tissue.

Stereotactic radiation therapy. This treatment delivers a large, precise radiation dose to a small tumor area. The patient must remain very still. Head frames or individual body molds help limit movement. This therapy is often given as a single or a few treatments. However, some patients may need several treatments.

Internal radiation therapy

Work Flow In a Radiation Oncology department:

• OPD consultation by a qualified radiation Oncologist
• Investigations and Tissue diagnosis leading to complete Oncological
• Inter and intrafraction monitoring to obtain highest form of precision
• Weekly or bi-weekly blood works and clinical monitoring