title: Learning curve of combined modality treatment in peritoneal surface disease.
abstract: BACKGROUND
  Cytoreductive surgery with intraperitoneal chemotherapy has emerged as a new standard approach for peritoneal surface disease. This study investigated the learning curve of this combined modality treatment at a single institute.
  
  
  METHODS
  Variables analysed over three consecutive treatment periods (1996-1998, 1999-2002 and 2003-2006) included number of abdominal regions affected, Simplified Peritoneal Cancer Index (SPCI) score, result of cytoreduction, morbidity, duration of hospital stay and survival.
  
  
  RESULTS
  A total of 323 procedures were performed between January 1996 and June 2006, 184 for peritoneal carcinomatosis of colorectal cancer origin and 139 for pseudomyxoma peritonei (PMP), including second procedures in 11 patients with PMP. The mean SPCI score decreased significantly over the study period (P < 0.001), but the number of regions affected did not. The rate of complete cytoreductions increased from 35.6 to 65.1 per cent (P = 0.012). The postoperative morbidity rate decreased from 71.2 to 34.1 per cent (P < 0.001). The median duration of hospital stay decreased from 24 to 17 days. The peak of the learning curve, graded by the percentage of complete cytoreductions, was reached after approximately 130 procedures.
  
  
  CONCLUSIONS
  The learning curve of combined modality treatment for peritoneal surface disease is long, and reflects patient selection and treatment expertise.
authors.affiliation: Department of Surgery, Netherlands Cancer Institute-Antoni van Leeuwenhoek Hospital, Amsterdam, The Netherlands.
authors.forename: R M
authors.initials: RM
authors.lastname: Smeenk
authors.forename: V J
authors.initials: VJ
authors.lastname: Verwaal
authors.forename: F A N
authors.initials: FA
authors.lastname: Zoetmulder
mesh_terms: D000328:Adult; D000368:Aged; D002983:Clinical Competence / Q000592:standards*; D015179:Colorectal Neoplasms / Q000188:drug therapy / Q000601:surgery*; D003131:Combined Modality Therapy; D005260:Female; D013502:General Surgery / Q000193:education* / Q000592:standards; D006801:Humans; D007858:Learning; D007902:Length of Stay; D008297:Male; D008875:Middle Aged; D010534:Peritoneal Neoplasms / Q000188:drug therapy / Q000601:surgery*; D011553:Pseudomyxoma Peritonei / Q000188:drug therapy / Q000601:surgery*; D016019:Survival Analysis