Your radiotherapy questions answered

We understand that when you, or a loved one, is going through treatment for a brain tumour there may be a million and one questions going through your mind.

We recently held a virtual Q&A session on radiotherapy in our online app, BRIAN, with expert medical professionals from Imperial College Healthcare NHS Trust.

Dr Matt Williams, Consultant Clinical Oncologist, led the session, with Debbie Thornberry and Shahlaa Alkalifa, Senior Therapy Radiographers.

There were lots of questions asked, which we’ve collated along with the team’s answers below.

About radiotherapy (RT)

How many weeks of radiotherapy do people generally have?

Matt: It varies by tumour type and patient factors. Generally, 3–6.5 weeks, but there are lots of variations.

How long does radiotherapy take?

Debbie: Daily treatment can last between 10–25 minutes depending on your personalised plan. Imaging is also taken on the first three days and then weekly, so these days can be a little longer, but never longer than 25 minutes from entering the room to leaving the room.

What does treatment feel like?

Debbie: When you’re undergoing radiotherapy, while you’re receiving the treatment you shouldn’t feel anything. The only thing you may find is that, as you can’t see clearly through your mask (shell), your other senses become more sensitive, so you may start to hear buzzing from the machine etc. and a sense of things moving around you (which they are). You may find that listening to music may help with this and most departments can play music for you in the room.

Can I breathe in my shell?

Shahlaa: The answer is yes you can. The shell has holes all over so you are able to see what the radiographers do and you can breathe freely.

Am I able to take diazepam to prevent anxiety attacks as I find the face mask very claustrophobic?

Debbie: Usually patients who suffer from claustrophobia during radiotherapy normally take lorazepam, but diazepam isn’t out of the question. However, please discuss this with your oncologist.

Is it always worth doing radiotherapy?

Matt: It really depends on the tumour type. For some tumours, chemotherapy is effective. However, for most brain tumours, radiotherapy is an important option (but there are more than 140 types of tumour, so it’s difficult to give a comprehensive answer).

How long after radiotherapy will you know if it has been successful?

Matt: It depends on the tumour. For some people, we can see a shrinkage at three months; for other people, having stable disease is a ’success’.

If your scar is still sore or swollen will radiotherapy make this worse?

Shahlaa: I don’t think RT makes the scar worse but we need to ensure it is healed before treatment starts.

Is radiosurgery just another type of radiotherapy? When would you choose to use radiosurgery?

Matt: Radiosurgery is still radiotherapy, but it is often very high-dose and very targeted. That is great (sometimes). If you have a tumour that is distinct from the brain, then stereotactic radiosurgery (SRS) can kill/damage all of the tumour. However, if the tumour infiltrates the brain, then we can’t use SRS very often, because we would also be killing normal brain cells. We tend to use SRS for metastatic disease and meningioma (sometimes). There is also a size limit for SRS.

Is chemoradiotherapy a specific type of treatment or just a term used whenever both chemotherapy and radiotherapy are applied?

Matt: The chemotherapy and radiotherapy used are still ’just’ chemo and radio. However, the protocol for using them together tends to be quite specific about doses and timings. For example, for treating glioblastoma, there are a couple of well-recognised protocols that have chemotherapy and radiotherapy together for three or six weeks, and then some more chemotherapy (by itself). The chemo drug is the same at both points (temozolomide) but the dose and the number of days it is taken for varies.

Can you have radiotherapy in the same place more than once, e.g. if the tumour grows again in the future?

Matt: This is a challenging topic. The role of re-irradiation is still debated. We do quite a lot of re-irradiation, and have lots of experience of it, but not all centres use it.

There is a need to be clear about the possible risks and benefits – balancing side-effects and risks. Those risks are very important, especially in the brain.

Meningiomas

Due to my meningioma I have gone blind in one eye. Will the radiotherapy give me my sight back?

Matt: While it is difficult to be certain (due to individual variation), most meningiomas don’t change very much in size after radiotherapy. Also, the damage to the nerve may not recover. So, as a general rule, I would be careful about expecting the radiotherapy to make your sight better (but individual patients may vary).

What is the next stage if it (radiotherapy) doesn’t work? And what are the percentage rates of success for a grade 2 meningioma?

Matt: Grade 2 meningiomas are very odd tumours; behaviour is very difficult to predict. Surgery and radiotherapy are probably the best way forward (although some patients may be able to go into the ROAM trial). For grade 2 meningiomas, around 30–50% will recur, and that number is reduced with radiotherapy (we think).

What is the ROAM trial?

Matt: A randomised clinical trial looking at the role of radiotherapy after surgery in patients with grade 2 meningioma. Link here: http://roam-trial.org.uk/

Are there any statistics about grade 2 meningioma recurrence after radiation therapy?

Matt: Unfortunately we don’t have very good data on this at the moment. One of the problems with meningioma is that our understanding of the disease has not been very good, and the term ’meningioma’ doesn’t capture the variation between patients. That is beginning to change: there are newer ways of looking at the tumour tissue, for example.

What is the difference between stereotactic and VMAT for a cavernous meningioma?

Matt: SRS and VMAT are both radiotherapy techniques. Both offer precision delivery and low doses to other bits of the brain. SRS is a little more focused than VMAT, but has a size limit, and takes longer to deliver.

Glioblastomas

Which sort of radiotherapy is used for glioblastoma?

Shahlaa: For glioblastoma, the radiotherapy could be from two weeks to six weeks depending on the patient and the tumour. The scan and the shell-making will be done prior to the treatment start. Glioblastomas are normally treated using the IMRT/VMAT technique so the planning needs to be accurate before the treatment starts.

For GBM what are the reasons for having radiotherapy on its own rather than with chemotherapy?

Matt: Two main reasons. For patients who are not that well, chemo-RT has more side-effects than RT alone, so RT alone might be a more achievable option. The second is that if we look at the MGMT status of the tumour: patients whose tumour is MGMT methylated get much more benefit from chemotherapy, whereas unmethylated tumours get very little chemo benefit.

Low grade gliomas

When needed, what type of radiation treatment is typically recommended for low grade oligodendrogliomas? Whole brain, gamma knife or proton? What are the costs and benefits of each?

Matt: For low grade gliomas (LGG), we should be using high-quality RT, but not Gamma Knife (or other SRS), and not whole brain. At present, good quality (IMRT/VMAT) photons are considered standard of care. Proton therapy might be better, but might not. Private protons are very expensive (£50–£100k). There is a plan for a trial to compare proton vs. photon RT in LGG.

What is the name of the proton vs. photon RT in low grade oligodendrogliomas?? Where is the trial and about when does it start? When I ask about costs and benefits of each RT above, I refer to health not money. Why might proton be better than photon, or reverse, for LGG?

Matt: It hasn’t yet been funded. But the idea is that proton RT may deliver less dose to the normal brain. However, entry dose is higher with protons and photons, and dosimetry is less well understood. So while protons might be better than photons, there is no data or evidence to show this. There are good reasons to think they might be, but some reasons why they might not be – and we have been wrong lots of times before in neuro-oncology, so I am careful about jumping to conclusions in this group of patients.

What is the quality difference between volumetric-modulated arc therapy (VMAT) and intensity-modulated radiation therapy (IMRT) for the treatment of LGG? If the tumour is diffuse, would it make a difference if you used photon or proton RT?

Matt: For diffuse gliomas, we still don’t know if photons or protons are better – the jury is still out.

Debbie: Both VMAT and IMRT are modulated types of RT (each beam is shaped specifically to the target). IMRT is static which means that the machine moves to specific positions and delivers treatment at these points, whereas VMAT is delivered in an arc (continually rotates around the patient and delivers treatment while changing shape as it goes to fit the target). In terms of quality, both are used equally for treatments, but in practice, which is used depends on patient-specific needs and tumour position.

Which hospitals in London do proton RT for LGG?

Matt: There are no proton hospitals in London, currently one in Manchester, and a few private centres elsewhere in the UK. The London proton centre should start treating next year, but will be for NHS-indicated proton indications – which at the moment does not include LGG patients.

Will the LGG trial be in London, Manchester or both? Other locations?

Matt: The trial will be run at multiple sites. If you are randomised to protons, you will have to go to Manchester/London. I would stress that this is not yet funded (and might not get funded), and definitely not open yet.

If you have any other questions about radiotherapy or brain tumour treatments and care, you can get in touch with our Information and Support line by emailing [email protected], calling 0808 800 0004 or through live chat by clicking the red button in the bottom corner of your screen.

Our next Q&A event

Our next Q&A event is on 24 November and is all about how the COVID-19 pandemic is affecting brain tumour treatment and care.