Introduction Optune is an FDA-approved therapy that uses Tumor Treating Fields (TTFields) to treat glioblastoma (GBM) by disrupting cancer cell division. Prescribing and monitoring Optune is not difficult, but requires a structured approach to ensure efficacy and patient adherence. Here we provide some simple clinical tips to help with that.

These tips are intended for experienced clinicians, who are used to treating patients with GBM. For that reason, we do not cover the general background to GBM, chemo-radiotherapy etc. It is also not a replacement for Novocure guidelines and training in the use of Optune.

1. Patient eligibility and initial assessment 

The EF-14 trial explored the impact of adding Optune to adjuvant Temozolomide in newly diagnosed patients with GBM. 

The decision to use Optune is an individual one; different patients feel differently about the use of Optune. We would strongly suggest that potential patients come and talk to existing patients at one of the Optune “Open” groups to hear patients talk about the reality of Optune.

Optune probably should not be used in patients with implanted devices (e.g. pacemakers, ICDs), although there is developing experience.

It is also important to think about the patient’s lifestyle and social situation; Optune places significant demands on the patient and carer. While many patients adapt to this well over time, having a supportive family and carer set-up is very helpful. 

Our final point is that patients should not start Optune thinking about “when” they will use it; instead, patients should aim to use it nearly continuously, with occasional breaks.

2. Prescribing Optune 

Optune is relatively easy to prescribe: it requires a signed prescription form, signed both by the prescribing physician and the patient. That form then goes to Novocure, who will arrange for a Device Support Specialist to set the patient up at home.

This process takes 2-3 weeks, so should ideally be started during chemo-radiotherapy. We normally aim to start Optune at about 2 weeks after chemo-radiotherapy.

3. Patient education and training

Educating patients helps them understand what Optune involves, and why we encourage increased weartime. We try and cover the following areas:

• How Optune works: Explain the mechanism of TTFields and how it affects cancer cells.
• Skin care: Advise on preventing and managing skin irritation caused by prolonged device wear.
• Lifestyle adaptation: How to use Optune as part of normal life

4. Monitoring and follow-up care 

For patients who are established on Optune, we normally recommend a clinical review once every 3 months; obviously more frequent reviews will happen during adjuvant chemotherapy. Our usual pattern is:

Early post-start consultation: 3-10 days after starting Optune. This will give the patient and carer a chance to have used Optune and done at least one electrode change, which makes this a good point to discuss issues. Ensure that patients and carers have details for the Optune Support Group and have been offered access to the Optune WhatsApp group.4 – 6 week consultation: (Normally to coincide with next chemotherapy visit): Review wear-time and skin condition; check that patients have been to Optune Support Group.

Ad-hoc Troubleshooting and support:

We know that skin side-effects can be resolved if treated early. Therefore, patients need to know that they should flag side-effects early, so that we can intervene early. We have skin-care guidelines for Optune patients, but the key elements are:

1. Identify problems early – do not wait until the skin becomes significantly damaged
2. Rotate electrode contact points   – so that irritated areas don’t get worse
3. Prevention is better than cure – focus on good skin care: soaking the electrodes off in the shower; meticulous shaving; moisturising the skin
4. Use a staged approach to skincare medication – Start with 1% hydrocortisone cream, and escalate if needed
5. Access specialist support when needed – We have access to dermatologists who have experience of supporting patients using Optune.

5. Combining Optune with other therapies

The EF-14 trial combined Optune with adjuvant TMZ, and until second progression of disease. It has therefore also been combined with a range of other therapies, including Lomustine, Carboplatin and Bevacizumab. In general terms, the side-effects of Optune are different to those of most chemotherapy agents, and therefore they can be combined relatively easily.

The TRIDENT trial added Optune at the time of radiotherapy; from our limited experience this was tolerated reasonably well, but is not yet standard of care.

For patients who have repeat surgery, we would normally suggest using Optune up until the point of surgery, as long as the skin is intact. However, post-operatively we would suggest waiting at least 2 weeks before re-starting Optune, and checking the wound carefully before restarting.