Breast Radiotherapy: What Will Happen, Will It Hurt, and What Should I Expect?

Dr Vidhi Vaghasiya | MD Radiation Oncologist | Bhavnagar

If your doctor has advised radiotherapy after breast cancer treatment, you may have many questions before the first session:

“Will radiation hurt?”
“What exactly will they do to me?”
“When will treatment start?”
“How many days will I have to come?”
“Will my skin burn?”
“Will I feel weak?”

These are very common concerns.

The first thing I want you to know is this: breast radiotherapy is usually an outpatient treatment. You come to the radiation department, receive treatment, and go home the same day. There is usually no admission, no anaesthesia and no injection during each radiation session.

Let me explain the entire process in simple terms.

Why Do I Need Radiotherapy?

If you have undergone breast-conserving surgery, radiotherapy is commonly given to the remaining breast tissue to reduce the chance of cancer coming back in that breast.

If you have undergone mastectomy, radiotherapy may still be advised depending on factors such as the size of the tumour, lymph-node involvement, surgical margins and other pathology findings.

Sometimes the nearby lymph-node areas also need treatment.

So radiotherapy is not being given because surgery “failed.” Surgery and radiotherapy often work together as different parts of the same cancer treatment plan.

When Will My Radiotherapy Start?

Radiotherapy does not necessarily start immediately after surgery.

Your wound usually needs time to heal first.

If chemotherapy is also required, radiotherapy is commonly started after chemotherapy has been completed.

Your oncologist will decide the timing based on your surgery, wound healing, chemotherapy schedule, pathology report and general health.

Before the actual radiation begins, there is also a planning process.

This planning is extremely important because radiotherapy is not simply aimed at the breast from outside. Your treatment is carefully designed specifically for your body.

What Happens During Radiation Planning?

Your first visit may be for a CT simulation or planning CT scan.

You will lie on a special flat treatment couch, usually on your back, with one or both arms raised above your head.

A support device may be used to help you stay comfortable and reproduce the same position every day.

The radiation team will carefully position your body.

Small marks may be placed on your skin to help reproduce your position during every treatment session. Depending on the department, these may be temporary markings or tiny permanent tattoo dots.

The CT scan itself is painless.

After the scan, you can go home.

Your radiation oncologist and medical physics team then work on your treatment plan.

They identify the area that needs radiation and carefully limit the dose reaching nearby normal structures such as the heart and lungs.

This planning work happens before your first treatment and may take several days.

What If My Cancer Was in the Left Breast?

If your left breast is being treated, your doctor may ask you to use a technique called deep inspiration breath hold, or DIBH.

You take a deep breath and hold it for a short period while the radiation is delivered.

When your lungs expand, the heart naturally moves slightly farther away from the chest wall. This can help reduce the amount of radiation reaching the heart.

The team will teach you how to do this.

You do not need unusually strong lungs or special fitness. Most patients learn it with a little practice.

What Happens on My First Radiation Day?

When you enter the treatment room, you will see a large radiotherapy machine called a linear accelerator.

It may look intimidating because it is large, but the machine does not touch you during treatment.

The radiation therapists will help you lie in exactly the same position that was used during your planning scan.

They may take imaging before treatment to confirm that your position is correct.

The machine may then rotate around you.

You may hear sounds from the machine.

You will be alone in the treatment room for a few minutes while the radiation is being delivered, but the therapists can see you on cameras and communicate with you through an intercom throughout the session.

If you feel uncomfortable, they can stop the treatment and come inside.

Will Radiotherapy Hurt?

No. You do not normally feel the radiation entering your body.

It is somewhat similar to having an X-ray or CT scan.

You cannot see the radiation.

You cannot smell it.

You cannot feel it passing through the breast.

There is no burning sensation while the beam is on.

The actual radiation delivery usually takes only a few minutes, although your total time in the department may be longer because correct positioning and safety checks take time.

How Many Radiation Sessions Will I Need?

The exact number varies.

Many patients now receive breast radiotherapy over a shorter course than was traditionally used.

Some patients may receive treatment over approximately one week, while others may receive around three weeks or occasionally longer depending on the clinical situation.

Some patients also receive an additional focused radiation dose called a boost to the area where the tumour was removed.

Your doctor will choose the schedule according to your surgery, pathology, breast anatomy, lymph-node treatment and individual risk factors.

A shorter course does not automatically mean weaker treatment. Modern radiotherapy schedules are carefully calculated to deliver an effective biological dose safely.

What Side Effects Should I Expect?

Most breast radiotherapy side effects are limited to the area being treated.

Skin changes

Your skin may gradually become:

This usually develops gradually rather than after the first treatment.

The skin reaction may become more noticeable toward the end of radiotherapy or during the first week or two after treatment finishes.

Areas such as the breast fold and armpit can sometimes become more irritated.

Your radiation team will guide you about moisturisers, clothing and skin care.

Breast swelling or tenderness

The breast may temporarily feel:

Some patients also notice occasional short shooting pains or twinges.

These usually improve gradually.

Tiredness

You may feel more tired than usual during treatment.

This does not mean radiation is weakening your entire body.

Cancer treatment itself, previous surgery, chemotherapy, travelling daily for radiotherapy, sleep disturbance and emotional stress can all contribute to fatigue.

Most patients can still walk, eat normally and perform routine daily activities.

Shoulder stiffness

If you have undergone breast or lymph-node surgery, your shoulder may already feel stiff.

Keeping the shoulder moving is important.

Your doctor or physiotherapist may advise simple arm and shoulder exercises.

Will My Hair Fall Out?

Breast radiotherapy does not normally cause hair loss from your scalp.

Radiotherapy causes hair loss only in the area receiving radiation.

If the armpit is within the treatment area, some underarm hair may temporarily or permanently reduce.

Will My Breast Become Permanently Burnt?

No.

Some temporary darkening of the skin is common, especially in people with naturally darker skin tones.

Most skin reactions improve after radiotherapy is completed.

Over time, the treated breast can sometimes become slightly firmer, smaller or different in shape because of tissue healing and fibrosis, but severe long-term skin injury is uncommon with modern treatment.

Can Radiation Affect My Heart or Lungs?

The heart and lungs are close to the breast, so protecting them is an important part of treatment planning.

Modern CT-based planning allows your radiation team to see these organs and minimise unnecessary radiation exposure.

Techniques such as DIBH can further reduce heart exposure in suitable patients.

Serious heart or lung complications are uncommon with carefully planned modern breast radiotherapy.

What Should I Remember Before Starting?

Do not judge your treatment by whether you can feel radiation.

You are not supposed to feel the radiation beam.

Wear loose, non-irritating clothes.

Do not worry if your breast does not immediately look or feel different after the first few sessions.

Radiotherapy works by damaging the cancer cells' ability to survive and reproduce. Its biological effect continues even after each treatment session has finished.

Your job during treatment is mainly to come regularly, maintain your nutrition, keep the treated skin comfortable, continue gentle activity and tell your treatment team about any symptoms.

Radiotherapy is much less dramatic than many patients imagine before starting.

You will usually walk into the department, lie comfortably in your planned position, receive a few minutes of completely painless treatment and walk out again.

The dramatic part is The Planning Process, which happens behind the door in your absence!

Once you understand what is going to happen, the machine often becomes much less frightening.

And throughout the process, you are not expected to manage everything yourself.

Your radiation team will be checking your position, your treatment plan, your skin and your symptoms along the way.