title: Confocal microscopy insights into the treatment and cellular immune response of Basal cell carcinoma to photodynamic therapy.
abstract: BACKGROUND
  Photodynamic therapy (PDT) represents an optimal treatment for basal cell carcinoma (BCC). Reflectance confocal microscopy (RCM) is a noninvasive imaging tool that has been applied in skin oncology and for BCC diagnosis. Moreover, RCM is a useful tool to determine noninvasive treatment efficacy of nonmelanoma skin cancer.
  
  
  OBJECTIVE
  We aimed to investigate the role of RCM in assessing the efficacy of PDT in the treatment of BCC and to evaluate the skin changes following the PDT.
  
  
  METHODS
  Ten patients with 12 BCCs were treated with PDT. Dermoscopy and RCM imaging were performed at baseline as well as 7 days (T1), 30 days and 18 months after PDT. Cytological examination was taken at baseline and in case of BCC persistence.
  
  
  RESULTS
  At T1, RCM showed the presence of several dendritic-shaped cells within the epidermis, corresponding to activated Langerhans cells. After 1 month, RCM showed the persistence of 2 BCCs, which escaped the clinical and dermoscopic diagnosis. At the long-term follow-up, none of the tumors revealed signs of persistence or recurrence.
  
  
  CONCLUSIONS
  RCM is a valuable noninvasive tool for the diagnosis and treatment monitoring of BCC using PDT.
authors.affiliation: Dermatology and Skin Cancer Unit, Arcispedale Santa Maria Nuova, IRCCS, University of Modena and Reggio Emilia, Reggio Emilia, Italy. longo.caterina@gmail.com
authors.forename: Caterina
authors.initials: C
authors.lastname: Longo
authors.forename: Alice
authors.initials: A
authors.lastname: Casari
authors.forename: Patrizia
authors.initials: P
authors.lastname: Pepe
authors.forename: Elvira
authors.initials: E
authors.lastname: Moscarella
authors.forename: Iris
authors.initials: I
authors.lastname: Zalaudek
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Argenziano
authors.forename: Giovanni
authors.initials: G
authors.lastname: Pellacani
mesh_terms: D002280:Basal Cell Carcinoma / Q000188:drug therapy* / Q000276:immunology / Q000473:pathology; D046169:Dermoscopy; D005260:Female; D006801:Humans; D007111:Immunity, Cellular / Q000502:physiology; D008297:Male; D018613:Microscopy, Confocal / Q000379:methods; D008875:Middle Aged; D010778:Photochemotherapy / Q000379:methods*; D012878:Skin Neoplasms / Q000188:drug therapy* / Q000276:immunology / Q000473:pathology; D016896:Treatment Outcome