Field cancerization treatment: Adjustments to an ALA red light photodynamic therapy protocol to improve pain tolerance. uri icon

abstract

  • BACKGROUND: Field cancerization (FC) is described as an area with multiple actinic keratosis (AK) in an actinic damaged skin that requires treatment. Photodynamic therapy (PDT) is a treatment option, however, long drug light intervals (DLI) and pain during the illumination remain a challenge OBJECTIVE: Pain and the efficacy of changes in DLI and illumination during PDT treatment for FC were evaluated METHODS: Thirty patients with widespread AK of upper limbs were selected. A 20% aminolevulinic acid (ALA) cream was applied on both forearms and hands after a light curettage. Three groups were evaluated: G1 (3h of DLI); G2 (1.5h of DLI); and, G3 (1.5h of DLI with two-minutes pauses every 10min during illumination). The limbs were treated with a LED prototype at 630nm (36J/cm2 of fluence in 40min of irradiation). The pain score during illumination was evaluated with a numeric scale (from 0 to 10) and pain was defined as low (0-3), moderate (4-6), and severe (7-10). The AK counting was clinically performed before and 30 days after PDT. Significance between groups was tested using ANOVA single factor. RESULTS: A mean reduction in AK number of 56% in G1, 55% in G2, and 66% in G3 were observed, with no statistical significance. The comparison pain among the groups showed best results for G3 (p<0,05). CONCLUSION: Using paused illumination and 1.5h of DLI was possible to improve tolerance maintaining the clearance in red light ALA - PDT treatment.

published proceedings

  • Photodiagnosis Photodyn Ther

author list (cited authors)

  • Salvio, A. G., Stringasci, M. D., Requena, M. B., de Oliveira, E. R., da Costa Medeiro, M. M., & Bagnato, V. S.

complete list of authors

  • Salvio, Ana Gabriela||Stringasci, Mirian D||Requena, Michelle B||de Oliveira, Elisangela Ramos||da Costa Medeiro, Maira Monique||Bagnato, Vanderlei Salvador

publication date

  • September 2021