Use of Small Spot IPL For Treatment of Pigmented Lesion,
Multi-Fluence Comparison Study in Asian Skin

Kei Negishi, M.D., Kumiko Nagao, M.D., Shingo Wakamatsu, M.D.

Tokyo Women's University, Aoyama Institute of Women's Medicine, Tokyo, Japan

Background and Objectives:

  • Asian physicians treating pigmented lesions often use IPLs instead of Q-switched lasers to avoid post inflammatory hyperpigmentation, even if the efficacy of IPLs is lower.
  • Large spot-size, high-fluence IPL irradiation may cause epidermal burns in normal surrounding areas in darker skin types.
  • Fig 1. Masking paper to
    protect surrounding area
    To avoid adverse effects with IPLs, masking paper can be used to limit the treatment to specific lesions.
  • The AcuTip500TM provides high-fluence irradiation with pinpoint accuracy, eliminating the need for masking paper.
  • This study has two objectives:
    • Evaluate the efficacy of the AcuTip500TM on skin types III-V
    • Compare the results of mild and aggressive treatments with the AcuTip500TM
 

Materials and Methods:

  • Patients: 46 females with facial pigmented lesions (solar lentigines or freckles), skin types III to V.
  • Equipment: AcuTip500TM (CUTERA, Brisbane, CA), a 600-635nm wavelength, 6.35mm spot size IPL. The pulse width automatically lengthens with increasing fluence (ranging 2.0-16.0ms).
  • Treatments: Patients were randomly divided into two groups (A and B).
    • Group A = “Aggressive Treatment” – immediate obvious darkening of the lesion
    • Group B = “Mild Treatment” – very slight darkening of the lesion
  • Each patient received two treatments separated by approximately three weeks.
  • Fig 2. AcuTip500TM and treatment
    Photographs were recorded pretreatment and 4 weeks post-second treatment.
  • Evaluation: Percent improvement was determined using the following grading scale:
    • “a” = 75-100%, “b”=55-74%, “c”=25-54%, “d”=0-24%, “e”=worse
 

Results:

Tbl 1: Patients, lesions and parameters used in this study
  Group
A		 Group
B
number of cases 22 24
number of sites 67 65
age
mean age		 28~77
1.7 		31~81
51.9
skin type III
IV
V 		37
30
0 		26
33
5
lesion size (mm) ~10
~15
20 		48
15
4 		44
14
7
fluence (J/cm2)
mean fluence(J/cm2) / first Tx.
/ second Tx.		 9~17
12.6
13.0 		8~15
11.4
11.8
  • Group A:
    • 67 lesions on 22 patients
    • 35.82%=Grade “a” after two treatments
    • 74.63%=Grade “a” or “b” after two treatments
  • Group B:
    • 65 lesions on 24 patients
    • 26.15%=Grade “a” after two treatments
    • 76.92%=Grade “a” or “b” after two treatments
  • Grade “e” results only occurred in Group A (7.46%)
Tbl 2: Results after two treatments
Grade a b c d e
Group A post one Tx. 12 17.91% 29 43.28% 17 25.37% 6 8.96% 3 4.48%
67 lesions post two Tx. 24 35.82% 26 38.81% 8 11.94% 4 5.97% 5 7.46%
Group B post one Tx. 7 10.77% 33 50.77% 18 27.69% 7 10.77% 0 0.00%
65 lesions post two Tx. 17 26.15% 33 50.77% 9 13.85% 6 9.23% 0 0.00%
Fig 3. Group A, Grade “a”, Fluence 14J/cm2
pre                           post two Tx.   
Fig 4. Group A, Grade “a”, Fluence 9J/cm2
pre                       post two Tx.  
 
Fig 5. Group B, Grade “b” -> “a”, Fluence 12,13J/cm2
pre                   post one Tx.          post two Tx.    
Fig 6. Group A, Grade “e”, Fluence 15J/cm2
pre                8 wks post Tx.         
 
Fig 7. Time-course microscopy (50X): Group B, Grade “a”, Fluence 14,15J/cm2
pre                    day 1                day 7                 day 21          day 1 (second Tx.)       day 5        
 

Discussion:

  • Pinpoint radiation with controlled short wavelength IP provided high-level clearance in pigmented lesions.
  • Fig 8. Prolonged erythema
    pre 4            wks after (14J/cm2)   
    Prolonged erythema lasting over 4 weeks was only seen in Group A. This is caused by inflammation in the superficial dermis caused by increased heat from higher fluence treatments.
  • Increased inflammation from more aggressive treatments may lead to post-inflammatory hyperpigmentation in darker skin type patients.
  • To avoid treatment complications associated with skin type IV or V patients and/or patients with lentigines with melasma, we now perform two passes using mild settings.
 

Conclusions:

  • The AcuTip500TM treatments are safe and effective for use on skin types III-V.
  • Aggressive treatments have higher clearance rates after one treatment and a greater percentage of Grade “a” clearances after two treatments, but increase the risk of post-inflammatory hyperpigmentation.
  • Lower fluencies minimize the risk of adverse effects for darker skin types.
  • Adjusting treatment parameters to account for different skin types is important for safe and effective treatments.