title: Cryosurgery in the treatment of basal cell carcinoma. Assessment of one and two freeze-thaw cycle schedules.
abstract: BACKGROUND
  It has become routine practice in many centers to use two successive freeze-thaw cycles in the treatment of the common types of basal cell carcinoma. Because of the potential morbidity caused by this, we have investigated the cure rate achieved with one freeze-thaw cycle compared with that achieved with two freeze-thaw cycles in the treatment of facial basal cell carcinomas of a uniform type and clinically in the best prognostic group. Superficial truncal basal cell carcinomas are reported to respond to less aggressive cryosurgery, and we have investigated the cure rate achieved with one freeze-thaw cycle.
  
  
  OBJECTIVE
  To compare the efficacy of one freeze-thaw cycle versus two freeze-thaw cycles in the treatment of facial basal cell carcinomas. Second, to investigate the efficacy of one freeze-thaw cycle in the treatment of superficial truncal basal cell carcinomas. This was investigated in a prospective randomized post-treatment follow-up study.
  
  
  METHODS
  Over the past 7 years, we have treated 84 facial basal cell carcinomas with either a single 30-second freeze-thaw cycle or a double 30-second freeze-thaw cycle. Patients were allocated randomly into one of the two treatment schedules, and the cure rates achieved were compared. Second, 29 superficial truncal basal cell carcinomas were treated with a single 30-second freeze-thaw cycle. Patients were followed up to assess response to therapy.
  
  
  RESULTS
  A 95.3% cure rate was achieved in the treatment of facial basal cell carcinomas with a double freeze-thaw cycle. This compared with a cure rate of only 79.4% when facial lesions were treated with a single freeze-thaw cycle. Treatment of superficial truncal basal cell carcinomas with a single freeze-thaw cycle achieved a cure rate of 95.5%.
  
  
  CONCLUSIONS
  We recommend that, in order to achieve high cure rates that are equivalent to many reports of formal excision or radiotherapy, facial basal cell carcinomas require a double freeze-thaw cycle with liquid nitrogen. One freeze-thaw cycle to truncal basal cell carcinomas achieves high cure rates, equal to that achieved with a double freeze-thaw cycle to facial basal cell carcinomas.
authors.affiliation: Department of Dermatology, Oxford Radcliffe Hospital, United Kingdom.
authors.forename: E
authors.initials: E
authors.lastname: Mallon
authors.forename: R
authors.initials: R
authors.lastname: Dawber
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002280:Basal Cell Carcinoma / Q000601:surgery*; D003452:Cryosurgery / Q000379:methods*; D005069:Evaluation Studies as Topic; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000453:epidemiology; D012074:Remission Induction; D012878:Skin Neoplasms / Q000601:surgery*