A trial looking at treating dry mouth after radiotherapy for head and neck cancer (The LEONIDAS-2 study)

In this phase 3 trial , 86 people put into groups (randomised ). A computer put everyone into 1 of 2 groups. Neither they nor their doctors chose which group they went into or knew which group they were in. The number of people in each group was 43. 

Device use
The team looked at the average number of times a day the people used their devices over 1 year. For those using the:

• device it was 2.5 times
• dummy device it was 2.1 times 

The average time of daily use for each group was:

• 12 minutes and 30 seconds for those using the device
• 10 minutes and 30 seconds for those using the dummy device

Dropout rate
Of the 43 people randomised to use the device, the team were unable to get the results of 11 for various reasons.

Of the 43 people randomised to use the dummy device, the team were unable to follow up 7. The reasons were:

• 3 because they were not able to come to the follow up appointments 
• 3 due to discomfort using the dummy device
• 1 due to damage to the jawbone (osteonecrosis )

Relief of dry mouth symptoms
After a year of using the devices the team looked at how many people in each group had a reduction in their dry mouth symptoms by 30% or more. They found that it was:

• 11 people in the group who used the device
• 7 in the group who used the dummy device

Although the numbers look different, the number of people taking part was small. So the difference between the groups was not big enough to know that it hadn’t happened by chance. 

They found that there was no significant difference between the 2 groups:

• when the people scored how dry their mouth was
• in the amount of saliva produced when not using the devices
• in their quality of life 

Side effects
People found that using the devices was acceptable.  

The team looked at events that happened while the people were using the devices that may have been caused by them. They reported 4, which were:

• temporary pain where the electrodes of the device came into contact with the tissue of the mouth
• damage to the mouth tissue from rubbing causing the jawbone to be exposed and minor damage to it
• ongoing swelling of the major glands that make saliva (the parotid glands) when using the device

One person had an x-ray of the tummy (abdomen) because the doctor thought they may have swallowed a small piece of the electrode from the device. 

Conclusion
The team concluded that the device did not:

• reduce the symptoms of a dry mouth
• increase the amount of saliva produced
• increase quality of life

For future trials they suggest looking at:

• using a newer device that is one-size-fits-all, is easy to fit and is not dependent on the person to operate it
• taking into account whether they had radiotherapy to one of the major glands that makes saliva (the parotid gland)

Sometimes trials show a treatment might not be useful. But these trials still add to our knowledge and understanding of how to treat the side effects of cancer treatment.

More detailed information
There is more information about this research in the reference below. 

Please note, the information we link to here is not in plain English. It has been written for healthcare professionals and researchers.

Salivary Electrostimulation in the Treatment of Radiation Therapy–Induced Xerostomia (LEONIDAS-2): A Multicenter, Randomized, Double-Masked, Sham-Controlled, Phase 3 Trial
V Mercadante and others
International Journal of Radiation Oncology, Biology, Physics, 2023. Volume 118, issue 1, pages 142 to 153.

Where this information comes from    
We have based this summary on the information in the article above. This has been reviewed by independent specialists (peer reviewed ) and published in a medical journal. We have not analysed the data ourselves. As far as we are aware, the link we list above is active.