DOSIMETRY OF THE LASER TREATMENT

 

The dosimetry is for the laser that is the posology for the drug.

The energy dosage to deliver inside the tissue is depending of the depth, the area

and the duration of the pathological state of the injury.

 

Then it's the quality of the diagnostic which gives the quality and the success for the treatment

 

With the advent of high power therapeutic lasers, treatment times are reduced, and they permit to increase the insurance of a fast and successful action; because we can increase the energy dosage with reasonnable treatment times.

 

VERY IMPORTANT

 

In fact, the exact dosage to deliver is very difficult to know, and the expertise of the doctor makes

the difference...

BUT NOW, a Novelty

A clinical report brings to the practitioner a very nice and visible diagnostic, when using a high power laser; it's the skin color modification, which becomes rose purple during illumination, at the right dosis

It's the clinical sign that the right dosis had been given and then the result could be immediate, for example on pain.

 

 

 DOSAGE CALCULATIONS

 

The formula giving the amount of energy, according to power and time, is as follows:

Energy = Power x Time       or  1Joule = 1 Watt x 1 second

To understand the concept of energy, expressed in Joules, we can compare the laser to a garden hose

to fill a pool. When increasing the diameter and then the flow of the hose, the filling time for the pool is going short and short.

The flow is as the power of the laser, and the volume of the pool the energy.

 

When working on an area, we indicate the energy, not in Joules, but in Joules/cm2 by convention,

to  include the area size to be treated, in the equation.

 

The equation becomes

Energy/cm2 =  Power / cm2 x time     or     J/cm2 =  W x seconds / cm2

 

                 The following chart gives the treatment time to reach 1 Joule of energy dosage

NB : The energy dosage, in (J) for one point or in (J/cm2) for an area, is common for all the lasers.

 

Power in mW

Power in Watt

Time in seconds to reach 1J  for a point

Time in minutes  to reach 1J/cm2

for an 100cm2 area ( 10 x 10 cm2 )

10

0.01

100

10000 sec =  167 minutes

50

0.05

20

2000 sec = 33 minutes

100

0.1

10

1000 sec = 17 minutes

250

0.25

4

400 sec = 6 minutes 40 seconds

500

05

2

200 sec = 3 minutes 20 seconds

1000

1

1

100 sec = 1 minute 40 second

5000

5

0.2

                              20 seconds

 

Generally, protocols are given with energy dosages between 3 and 5 J/cm2, thus we multilpy

the times by 3 to 5, for the same area, and we divide by the ratio treated area/100cm2.

Then, to treat large areas, it's better and shorter to use a higher laser power.

The number of treatments varies from 1 to 10 depending on the pathology.

biophoton 35 rue leon blum 31140 Saint Alban France tel:  33 5 61 70 34 55   fax: 33 5 61 70 35 65   info@biophoton.fr