What is Radiotherapy?
Radiotherapy is a common, effective cancer treatment that doctors have used for decades. This page explains simply what it is, how it works, and why it is safe for the people around you.
A precisely aimed energy treatment
Radiotherapy uses highly focused energy beams — similar to imaging X-rays but stronger — to destroy cancer cells in a specific part of the body.
You cannot see, hear, or feel the beams during a session, just like having an ordinary X-ray.
The treatment is aimed at the tumor with high precision, while the surrounding healthy tissues are protected as much as possible.
How does it work?
Radiation damages the genetic material inside cancer cells so they lose the ability to divide and grow; they then die and the body gradually clears them away.
Healthy cells are affected too, but they are much better at repairing themselves than cancer cells.
That is why treatment is usually divided into small daily sessions (called "fractions"): the tumor takes repeated hits while healthy tissue gets time to recover between sessions.
Am I radioactive? Am I a risk to my family?
In external beam radiotherapy (the most common type), radiation passes through the body only during the session — none of it stays behind.
With external beam radiotherapy, no radiation remains in your body after the session, and you can usually be around family and children safely. If your treatment is internal or uses radioactive medicine, your team will give you special instructions.
Some internal treatments (such as brachytherapy with implanted sources) have special instructions — if your treatment is of that type, your team will explain the details clearly.
Who takes care of you?
A full team stands behind your treatment: the radiation oncologist who designs your plan and follows you up, medical physicists who verify the accuracy of every dose, radiation therapists who deliver your daily sessions, and nurses who help you manage side effects.
At every step of your journey there is someone you can ask — never hesitate.
Common fears… and the facts
Common fear
“Radiation will burn my whole body”
The fact
Treatment is aimed with millimetric precision at one specific area only; it may cause local skin redness similar to mild sunburn, which is easily managed.
Common fear
“I will become radioactive and harm people around me”
The fact
With external beam radiotherapy, no radiation remains in your body after the session, and you can usually be around family and children safely. If your treatment is internal or uses radioactive medicine, your team will give you special instructions.
Common fear
“The session will be painful”
The fact
The session itself is completely painless — exactly like having an X-ray. All you do is lie still for a few minutes.
Common fear
“All my hair will fall out”
The fact
Radiation affects hair only in the treated area; chest treatment, for example, does not cause head-hair loss. Ask your doctor what applies to your area.
Important notice
This platform is for explanation and education only and does not replace medical advice. Your treating physician is the final source of truth for your condition and treatment plan. Do not make any treatment decision based on this content alone.