INTRODUCTION
Discrete  actinic  keratoses  (AKs)  may  be  treated  by
cryosurgery with liquid nitrogen, curettage with electrodessication,  topical  creams  (imiquimod,  5-fluorouracil,  diclofenac),  or  surgery;  however,  targeted  therapeutic
modalities are not as effective for widespread and subclinical
lesions. In 1999, photodynamic therapy (PDT) with topical aminolevulinic acid (ALA) was approved by the FDA for treatment
of AKs on the face and scalp.1-3  ALA PDT indiscriminately treats
an  entire  area  of  skin,  allowing  for  management  not  only  of
discrete lesions, but also subclinical ones.3-15  Here we report the
presentation of new skin cancers in patients with a history of
NMSC and AKs 1 year after treatment with ALA PDT.  
METHODS AND MATERIALS
Study Design and Patient Selection
This observational study with 1-year follow-up assessed the preventative effects of ALA PDT in patients with a history of skin cancer and the presence of AKs. Exclusion criteria included a history of
any  adverse  reaction  to  visible  light  exposure  (such  as  photoexacerbated seizures), personal or family history of porphyrias,
and  immunocompromised  patients,  such  as  those  with  organ
transplants. Once qualified for the study, patients were counseled
about ALA PDT risks and benefits and consent was obtained. All
patients were followed for 1 year after the initial treatment. 
ALA PDT Treatment Technique and Follow-up Care
Live  and  photographic  assessments  were  performed  before
treatment sessions to document AK and NMSC lesions. Prior
to treatment, the skin was gently cleansed with soap and water,
followed by an acetone scrub. Ampules of 20% 5-aminolevulinic acid (ALA, Levulan Kerastick, DUSA, Wilmington, MA) were
prepared  for  application  per  manufacturer  protocol  (ampules
were  crushed  then  shaken  continuously  for  3  minutes  prior
to application). Topical ALA was applied liberally to the entire 
                     
						





