Patient Guide · Head + Neck Radiotherapy
Your radiation-oncology team has scheduled you amask fitting.Here's what to expect.
Radiotherapy for cancer in the head, neck, brain or upper spine uses a custom-shaped mesh mask that clips to the treatment table — so your head is in exactly the same position for every session. The mask lets your team aim the radiation carefully at the tumour while sparing the important parts nearby (like the glands that make saliva, the spinal cord, and the nerves for the eyes). This page walks you through the fitting appointment, what each daily session feels like, how to manage side effects over the 6 to 7 week course, and questions to ask your team.
Important: this page is educational. It does not replace the specific advice of your radiation-oncology team — oncologist, medical physicist, radiation therapist, dietician, nurse. Always follow their instructions in preference to anything on this page.
What is the mask?
A custom-fitted mesh, worn only during treatment
A custom-shaped mask that keeps your head still during treatment
For cancer in the head, neck, brain or upper spine, the treatment beams need to hit the tumour extremely precisely — within about 1 to 2 millimetres of the plan. If your head moves during treatment, the beam can miss part of the tumour and hit healthy tissue instead. A custom-shaped mask, made specifically for your head and shoulders, clips to the treatment table so your position is exactly the same for every session.
It doesn't stop breathing or swallowing
The mask is a fine mesh, not a solid shell. You can breathe, blink, swallow and talk normally underneath. It stops you turning your head, tilting your chin, or shrugging your shoulders — but nothing that keeps you comfortable or safe is blocked.
You wear it only during treatment — about 15 to 20 minutes
The mask is clipped on when you lie down on the table and unclipped as soon as treatment ends. Most sessions take 15 to 20 minutes on the table, with the actual radiation on for only 2 to 5 minutes. You're alone in the room but the team is watching by camera and speaking to you by intercom — you can wave or call out at any time.
Why the mask matters
Reproducible position = clean plan = kinder side-effects
Radiation goes to the tumour, not the healthy parts nearby
Modern treatment plans concentrate the radiation on your tumour while sparing important healthy areas — the glands that make saliva (avoiding dry mouth), the spinal cord, the nerves for your eyes, and the moist lining of your mouth. All of that only works if your head is in exactly the position the plan was designed for. A well-fitted mask makes the careful plan possible.
The same position every session, for over a month
A typical course is 30 to 35 daily sessions over 6 to 7 weeks. The mask makes sure your position on day 1 is the same as your position on day 30. Without it, small differences build up.
You're unlikely to need re-planning mid-course
When your set-up is the same every day, the team doesn't need to redo the scans and the plan halfway through — which would mean extra imaging and a pause in treatment. Steady set-up means smooth treatment.
How to prepare
Before your mask fitting
Complete any dental work first
For head-and-neck radiation, get any needed dental work — extractions, fillings — done before your mask fitting. Dental work in a jaw that has already had radiation is much harder to do later. If your dentist and cancer team haven't spoken, ask them to.
If you have long hair
For scalp, brain or neck cancers, long hair may need to be trimmed or tied flat so the mask fits correctly against your head. The radiation team will advise. Wigs and hair extensions can't be worn during fitting or treatment.
Loose comfortable clothing
You lie on the treatment couch for each session. Wear soft, loose-fitting tops with a low neckline so the treatment area isn't covered. Bring a light layer — the treatment room is usually cool.
Remove jewellery, dentures + glasses
Before your mask fitting and each treatment session, take off earrings, chains, watches, dentures, and glasses. These can interfere with the mask fit or the beam. Some hospitals have lockers; others ask you to leave valuables at home.
Bring someone with you
Bring a family member at least for the mask fitting and the first few treatment sessions. The rooms are unfamiliar; a companion helps you take in what the team explains, and drives you home.
Tell the team if you feel claustrophobic
Some patients feel closed-in when the mask is first clipped on. Tell your team early — they can give you a mild calming medicine, and can speak to you through the intercom during the session. In rare cases the mask can be made with a bigger face opening.
Fitting day
A single appointment, usually with the planning CT
- 1
Getting into position
You lie on a couch in a specific position — head slightly tilted, arms at your sides, feet in a support. The team marks reference points on your skin with a pen. You'll be lying like this every day of treatment.
- 2
Warming the mask sheet
The mask starts as a flat mesh sheet. It's warmed in a water bath until it's soft and pliable — warm but not hot, similar to warm plasticine. It stays soft for about 3 to 4 minutes.
- 3
Moulding to your face + shoulders
Two team members drape the warm sheet over your face and shoulders, and gently press it down. It moulds to the exact shape of your face — you can feel it settling. Any pressure feels a bit odd for a moment. Openings are cut for your eyes and nostrils. The sheet cools and stiffens in place over 3 to 5 minutes.
- 4
Clipping the mask to the base
While the mask stiffens, it's clipped to the base of the treatment couch at 4 to 6 points. Those clips hold you still each day. Once cool, the team unclips it, checks the fit + comfort, and marks positioning lines on the mask itself.
- 5
A CT scan the same day
Right after the mask is finished, you have a CT scan while wearing it. The team uses this scan to design your treatment plan. Total time in the mask so far: about 15 to 20 minutes.
The 6 – 7 week course
Daily treatment + side-effect management
What each daily session looks like
Arrive 15 minutes before your slot. Change if needed. Lie on the couch. The team gets you into position, clips the mask on, and takes a quick scan to check the alignment. The radiation is then on for 2 to 5 minutes. Then the mask is unclipped and you leave. Total time in the room: usually 15 to 20 minutes.
The full course + your calendar
Head-and-neck courses usually run 30 to 35 sessions, one a day Monday to Friday, over 6 to 7 weeks. Weekends and public holidays are gaps. Build the routine into your family life — being consistent matters more than being perfect. Missing more than the occasional day risks giving the tumour time to grow back between sessions.
Side effects in weeks 2 to 4
For head-and-neck cancers, expect a gradually sore mouth and throat, dry mouth, changes in taste, and some skin redness where the beam enters. These are managed with special mouthwashes (avoid alcohol-based ones), pain medicine, saliva substitutes, and softer food. Your team will support you through the middle of the course — the last 2 weeks are often the toughest.
Looking after the skin
Keep the treatment area clean and dry. Wash with mild soap and lukewarm water; pat dry (don't rub). Avoid perfumes, deodorants, aftershaves in the treatment area. Only use the moisturiser your team recommends. Sunscreen matters — during treatment and for months afterwards — on the treated skin.
Eating + drinking matters
Eating hurts during treatment for head-and-neck patients — but eating and drinking is essential. Losing too much weight can force breaks in the treatment and make outcomes worse. Try small, frequent meals; high-calorie shakes; soft or blended food. If you're losing weight, ask for a dietician early. Some patients get a temporary feeding tube put in as a precaution — that's a helpful tool, not a failure.
Speak up during treatment
The team can hear you at all times through the intercom. If you feel unwell, dizzy, need to cough or sneeze or adjust something — wave (they see you on camera) or call out. They can stop the beam and come in within seconds. Being comfortable is being safe.
Worth knowing · Mask quality
A well-made mask is the difference between tolerable and grim by week 4
Not all thermoplastic masks are the same. The mesh geometry, mould-and-cool behaviour, ventilation opening and edge softness all affect two things — how reproducibly your position is held, and how comfortable the mask is by week 4 of treatment when your skin and mucosa are inflamed.
A mask that stays true from day 1 to day 30
The mask's whole job is holding you in the same position on session 1 and on session 30. A well-made mask keeps its shape day after day — so your position stays accurate to within a couple of millimetres, not a couple of centimetres.
A mask that stays comfortable by week 4
By week 4 or 5 of treatment, the sore mouth and skin reaction can make even a good mask feel uncomfortable. A well-made mask has enough ventilation around your nose, mouth and eyes, and a mesh that doesn't dig in at pressure points — that's what keeps it bearable through the toughest fortnight.
Questions to ask your care team
Eight questions worth writing down
- ❓How many sessions will I have, and over how many weeks?
- ❓Will my mask fitting and planning CT scan happen the same day, or on separate days?
- ❓What position will I be in — head straight, tilted, chin extended? Anything with my shoulders?
- ❓How do you check my position each day before the beam goes on?
- ❓What side effects should I expect for my specific treatment site?
- ❓Do I need any dental work done before starting, and by when?
- ❓Should I see a dietician or speech + swallowing therapist before starting?
- ❓Who do I call if I feel unwell between sessions? Is there a 24-hour number?