Biomedical Engineering Reference
In-Depth Information
during ALA-PDT. With a typical treatment, we treat individual
lesions fi rst with subpurpuric doses of a PDL, followed by full-
face treatment by an IPL, and lastly illumination with a blue
and/or red light source. It should be noted that the IPL also
results in hair reduction, so judicious use should be exercised
in hair-bearing areas, such as the scalp and beard area.
the application stick. At least two coats of the solu-
tion are recommended, and the entire contents of the
Kerastick should be used. It is important to get close to
the eyes, otherwise it will be apparent that the perior-
bital skin was not treated.
6. Allow the Levulan to incubate for 60 minutes on the
skin. The patient should remain indoors during the
incubation period.
7. Remove the Levulan prior to any light treatment by
requesting the patient to wash his/her face with a
gentle soap and water.
8. Activate the Levulan with the appropriate light
source(s):
Patient Comfort and Photoprotection and Follow-Up
We do not routinely use topical or intralesional anesthesia prior
to ALA-PDT. With a 1-hour incubation time, our clinical expe-
rience is that the procedure is well tolerated by the overwhelm-
ing majority of patients. We use forced air cooling (Fig. 10.6)
and refrigerated conductive gel during the IPL portion of pho-
toactivation, and the forced air cooling during blue light and
red light exposure. For longer incubation periods, the use of
oral analgesics, topical lidocaine preparations, and ice packs in
conjunction with PDT may increase patient comfort (72).
Immediately following treatment, we apply an aloe vera-
based gel to the treated skin to calm erythema and irritation.
A sunblock (physical blocker) containing zinc oxide and tita-
nium dioxide is applied to the treated skin. To avoid phototox-
icity during daylight hours, our patients are scheduled for
treatment in the late afternoon, so they may depart the clinic
during twilight hours. Patients are given a protective visor if
the face was treated, and patients are asked to wear sunglasses
and protective clothing during their ride home.
We instruct patients to avoid sunlight and bright indoor
light sources for 36 hours following treatment. We request
patients return to clinic at 1 week and 2 months following
PDT for routine follow-up. We perform subsequent rounds of
ALA-PDT at 1-2 month intervals. We counsel patients to
anticipate two ALA-PDT sessions for the treatment of AKs,
while photorejuvenation, especially when sebaceous hyperpla-
sia is present, usually requires 3-4 sessions. These recommen-
dations are consistent with consensus guidelines from the
American Society of Photodynamic Therapy (37).
AKs: PDL is used to target individual lesions at sub-
purpuric settings, followed by treatment with blue
light and red LED simultaneously. The blue light
(Blu-U, DUSA Pharmaceuticals, Inc.) should be
positioned approximately 25-50 mm from the treat-
ment area (Fig. 10.14) and the red light source (Akti-
lite CL 128, Galderma, Fort Worth, Texas, USA)
should be positioned 50-80 mm from the skin.
●
Photorejuvenation +/− AKs: PDL is used to target
individual lesions at subpurpuric settings, including
AKs, sebaceous hyperplasia, solar lentigines, and tel-
angiectasias. IPL treatment follows using a double-
pulse and 560 nm cutoff fi lter for Fitzpatrick skin
types I-III and the 590 nm fi lter for skin types IV.
Fluence, pulse duration, and pulse delay settings are
determined according to skin type and type of pho-
todamage. Lastly, the patient is treated with the
Blu-U and the red LED (Aktilite) simultaneously in a
similar manner to the AK protocol.
●
1. Wash the patient's face again to remove any residual
Levulan on the skin's surface.
2. Apply soothing gel or lotion (we recommend an
aloe vera-based gel) to the treated area after the
illumination period.
3. Apply a physical sunblock containing zinc oxide and
titanium dioxide to the treated area. Instruct the
patient on strict photoprotection for the following
clinical technique
Summarized below is our treatment protocol for ALA-PDT
(18). This is supplied as an example, but is by no means the
only way to successfully perform PDT. This may be used as a
general guideline and practitioners must decide for themselves
the most effective and effi cient use of ALA-PDT in their offi ce.
aminolevulinic acid-photodynamic
therapy for actinic keratoses
and photorejuvenation
1. Cleanse the patient's skin with mild soap and
water (Cetaphil cleanser or Neutrogena Foaming
Facial Wash).
2. Perform microdermabrasion with the Vibraderm
over the treated area (Fig. 10.11).
3. Scrub the skin vigorously using a 4 × 4 inch acetone-
soaked gauze (Fig. 10.12).
4. Break the two glass ampules in the Levulan Kerastick
as per the package insert (38). Shake the stick for about
2 minutes.
5. Apply the ALA solution to the treatment area. This is
best accomplished by painting the Levulan on using
Figure 10.14
Simultaneously illumination with blue (Blu-U®) and red light
(Aktilite®).
