Radiation Oncology Treatment Guide: How Radiation Therapy Works, Types, and Uses

February 4, 2026

Dr. Sharaschandra Shankar
MBBS, MD (Radiation Oncology) Consultant Radiation Oncologist

Radiation oncology plays a vital role in modern cancer care. With advances in medical technology, radiation therapy has become safer, more precise, and more effective than ever before. Today, millions of patients worldwide receive radiation treatment either as a primary therapy or in combination with surgery and chemotherapy.

This blog explains about what radiation therapy is, how it works, why and when it is given, the different types, what patients can expect during treatments and why using radiation in cancer care remains so popular.

What Is Radiation Therapy?

Radiation therapy is a treatment that uses high-energy rays or particles to kill cancer cells or stop them from growing. It is meticulously planned and tightly controlled by experts called radiation oncology doctors, who specialize in using radiation to treat cancer, while sparing healthy tissue as much as possible.

Radiation therapy can be given alone or with other treatments, such as surgery, chemotherapy or immunotherapy, based on the type and stage of cancer.

Purpose of Radiation Therapy

The primary objectives of radiation therapy are:

• Destroying cancer cells completely
• Shrinking tumors before surgery
• Destroying any cancer cells that are left after surgery
• Preventing cancer from returning
• Pain or bleeding in advanced cases Symptomatic relief

Radiotherapy is not only curative, but also a modality to improve quality of life in case cure is not possible.

Radiation Treatment for Cancer: How It Works

The living tissue of the cervix grows and divides in a certain order, as it normally would. Radiation destroys the DNA within those cells, which prevents them from replicating. The damaged cancer cells die and are naturally expelled by the body over time.

Healthy cells can also be harmed, but healthy cells are generally better at repairing themselves than cancer cells. With modern radiation techniques, doctors can pinpoint tumors very precisely and cause minimal damage to surrounding tissues.

The treatment is normally administered in small daily doses over a few days to weeks. This approach allows healthy cells time to recover while cancer cells continue to weaken.

Types of Radiation Therapy

There are a number of different types of radiation therapy that are used to treat cancer:

External Beam Radiation Therapy (EBRT)

This is the most common type. Radiation is beamed at the tumor from a machine outside the body. It is a painless process and may only take a few minutes to complete each session.

Internal Radiation Therapy (Brachytherapy)

In this approach, the radioactive material is put into or near the cancer. And it can provide large doses directly to cancer cells and limit exposure to surrounding tissue.

Systemic Radiation Therapy

Patients swallow or are injected with radioactive substances. These substances circulate throughout the body and find and attach to cancer cells, including thyroid cancer cells.

Advanced Techniques

Modern radiation oncology also uses:

• IMRT (Intensity-Modulated Radiation Therapy)
• IGRT (Image-Guided Radiation Therapy)
• Stereotactic Radiosurgery (SRS)
• Proton Therapy

These methods increase accuracy and decrease side effects.

What to Expect During Radiation Therapy?

Before Treatment

• Medical imaging (CT, MRI, or PET scans)
• Treatment planning session (simulation)
• Skin markings or positioning devices may be used

During Treatment

• Sessions usually last 10–30 minutes
• Painless procedure
• No hospital stay required in most cases
• Treatments may continue for several weeks

After Treatment

Common short-term side effects may include:

• Fatigue
• Skin irritation
• Mild swelling
• Appetite changes

Side effects depend on the area treated and usually improve after therapy ends.

Radiation oncology doctors monitor patients closely and adjust treatment when necessary.

Why Is Radiation Therapy Used?

Radiation is selected since it:

• Targets cancer precisely
• Preserves organs and body functions
• Works well with other treatments
• Reduces tumor size
• Helps control pain and symptoms
• Improves survival rates

It is particularly beneficial in cases where surgery is not an option, or where tumours are close to delicate organs.

Role of Radiation Oncology Doctors

Radiation Oncologists Radiation oncology physicians are cancer specialists and are trained to:

• Design treatment plans
• Determine safe radiation doses
• Monitor side effects
• Collaborate with medical oncologists and surgeons
• Adjust therapy as needed

Their knowledge guarantees treatments are effective as well as safe.

Radiation treatments make possible the control of cancer and have revolutionized the approach to this disease by delivering a safe, accurate and effective means of “killing” cancer while minimizing harm to normal tissue. The use of radiation oncology has advanced significantly over the years, both in terms of treatment and to lessen side effects, such that patients can feel more confident about their care. Experienced radiation oncologists provide precise and safe treatment planning, and Nanjappa Life Care Super-Specialty Hospital facilities offer patients the latest technology alongside specialized cancer care on every step of their way.

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