Photobiomodulation for Chemotherapy-Induced Peripheral Neuropathy

Chemotherapy-induced peripheral neuropathy, or CIPN, is a common side effect of several chemotherapy treatments.

It usually starts in the fingers and toes and may cause:

• tingling
• numbness
• burning or electrical pain
• altered hot and cold sensation
• loss of balance
• difficulty with fine hand movements
• weakness in more severe cases

It is particularly common with chemotherapy drugs such as paclitaxel, docetaxel and oxaliplatin, although several other treatments can also damage peripheral nerves.

Once significant neuropathy has developed, recovery can be slow and sometimes incomplete.

For that reason, I prefer to think about supporting nerve health early rather than waiting until neuropathy becomes severe.

Photobiomodulation, usually shortened to PBM, uses specific wavelengths of red and near-infrared light to influence cellular signalling, mitochondrial function and tissue responses.

PBM has been studied for a range of biological effects including:

• mitochondrial energy production
• inflammation
• microcirculation
• tissue repair
• pain
• nerve recovery

There is now a growing body of clinical research looking specifically at photobiomodulation for chemotherapy-induced peripheral neuropathy.

Studies have investigated PBM both:

• during neurotoxic chemotherapy, in an attempt to reduce the development or severity of neuropathy
• in people who already have established CIPN

The evidence is promising, but PBM is not yet an established standard treatment for chemotherapy-induced peripheral neuropathy.

I use it as a supportive therapy alongside conventional oncology care, not instead of it.

Peripheral nerves are particularly vulnerable to mitochondrial dysfunction, inflammation, oxidative stress and impaired cellular repair.

Red and near-infrared light may influence several of these pathways.

The wavelengths used in PBM can penetrate tissue to different depths. Near-infrared wavelengths are particularly useful when the target includes structures beneath the skin, such as peripheral nerves.

This does not mean PBM can prevent every case of CIPN.

Whilst the evidence remains preliminary, I consider PBM a reasonable supportive option in selected patients.

PBM is only one part of my approach to chemotherapy-induced peripheral neuropathy.

In practice, I also look at the chemotherapy being used, the timing and severity of symptoms, nutritional status, metabolic factors, exercise and rehabilitation, and selected supportive strategies that may help reduce nerve injury or improve recovery.

The best approach depends on the individual patient, the chemotherapy regimen and whether we are trying to prevent neuropathy, limit progression, or treat established CIPN.

For home PBM I currently recommend the SOHL range of red and near-infrared light panels. 

The SOHL Compact and SOHL Lite use five wavelengths:

• 630 nm
• 660 nm
• 810 nm
• 830 nm
• 850 nm

This combination gives a mix of superficial red light and deeper-penetrating near-infrared light.

SOHL Compact

The SOHL Compact is my preferred option if chemotherapy-induced neuropathy is the main reason you are buying a PBM panel.

It is easy to move and position and is large enough to treat the hands and feet comfortably.

SOHL Lite

The SOHL Lite uses the same wavelength combination but has a larger treatment area.

It is the better option if you also want to use PBM over larger areas such as:

• calves
• thighs
• back
• shoulders
• larger joints
• muscle groups

For CIPN, I use the same treatment settings with either panel.

For CIPN I use a deliberately short treatment. Treat bare skin. Do not move substantially closer to the panel or increase the treatment time in an attempt to get a stronger effect.

How to treat the hands

Treat each hand separately.

• Palm: 45 seconds
• Back of hand: 45 seconds

Keep the hand centred in front of the panel.

How to treat the feet

Treat each foot separately.

• Sole: 45 seconds
• Top of foot: 45 seconds

Treat bare skin rather than through socks.

If neuropathy extends well into the forearms or lower legs, the treatment area can be adjusted rather than simply increasing the exposure time.

The SOHL protocol described here is an evidence-informed translation of the published PBM literature. The SOHL panels themselves have not been tested in a clinical trial for CIPN.

PBM has what is called a biphasic dose response.

In simple terms:

too little light may do very little → an appropriate dose may be helpful → substantially more light is not necessarily better.

This is sometimes called the Goldilocks effect.

Several of the key human CIPN studies have used PBM doses in the range of approximately 4–8 J/cm².  Based on SOHL’s measured output, the 45-second protocol is designed to keep exposure within the range used in key published CIPN studies.

For that reason, I deliberately keep the treatment short.  I do not recommend turning a 45-second neuropathy treatment into a 10- or 20-minute session simply because longer exposure sounds stronger.  With PBM, more is not necessarily better.

If you are receiving chemotherapy with a significant risk of peripheral neuropathy, I prefer to start PBM early in the course of treatment.

Use the panel:

• twice each week
• approximately 3–4 days apart
• throughout the period in which you are receiving neurotoxic chemotherapy

You do not need to avoid PBM on chemotherapy day.

The clinical studies do not establish a required exclusion period before or after chemotherapy.

For example:

Monday chemotherapy → PBM Monday and Thursday

or:

PBM Tuesday and Friday

If chemotherapy is given every two or three weeks, continue PBM twice weekly between cycles rather than treating only during chemotherapy week.

This protocol is directed at the hands and feet.

It is not intended as PBM treatment over the tumour itself.

Use the same protocol:

Twice weekly for three weeks initially, then reassess after six treatments.

We look for changes in:

• tingling
• numbness
• burning or neuropathic pain
• hot and cold sensitivity
• balance
• walking
• sleep disturbance
• fine hand function

If there is a meaningful improvement, treatment can be continued.

Please tell your oncology team if you develop new or worsening:

• numbness
• tingling
• burning pain
• weakness
• loss of balance
• difficulty walking
• difficulty using your fingers
• significant changes in temperature sensation

Worsening CIPN can sometimes mean the chemotherapy dose or schedule needs to be reviewed.

PBM should never be used to hide a complication that your oncology team needs to know about.

The evidence is still developing, but several human clinical studies have reported encouraging results.

The most relevant include:

Photobiomodulation can be useful, but I do not treat CIPN with light alone.

My broader approach looks at:

• the chemotherapy drug and cumulative exposure
• whether symptoms are just beginning or already established
• nutritional and metabolic factors that may affect nerve health
• exercise, balance and rehabilitation
• other supportive treatments that may be appropriate
• careful monitoring so that worsening neuropathy is recognised early

There is no single protocol that is right for everyone.

A patient developing tingling after the first few cycles of chemotherapy needs a different strategy from someone who completed treatment six months ago and still has numb feet, poor balance and neuropathic pain.

That is where an individual assessment becomes useful.

If you are starting chemotherapy associated with peripheral neuropathy, or already have CIPN, you are welcome to book a consultation with me so that we can build a broader prevention or treatment plan around your particular situation.

PBM can be an important part of that plan — but it is rarely the whole plan.