title: Retroperitoneal metastases in testicular cancer: role of CT measurements of residual masses in decision making for resection after chemotherapy.
abstract: OBJECTIVE
  To determine the relative importance of computed tomographic (CT) measurements for the prediction of histologic findings in residual masses in patients with nonseminomatous testicular cancer.
  
  
  METHODS
  Measurements of the maximum transverse size of retroperitoneal metastases before and after chemotherapy were available in 641 patients who underwent resection after chemotherapy while their levels of tumor markers were normal. Radiologic measurements of mass size and clinical characteristics (histologic findings in primary tumor and levels of alpha-fetoprotein, human chorionic gonadotropin, and lactate dehydrogenase before chemotherapy) were related to histologic findings in the residual mass with logistic regression analysis.
  
  
  RESULTS
  At resection, 302 patients had benign tissue, and 339 had residual tumor (mature teratomas or cancer). Tumor was more frequent in larger masses after chemotherapy but was unrelated to mass size before chemotherapy. Inclusion of the reduction in size significantly improved the logistic regression model, which included mass size after chemotherapy. This model was further improved with the addition of clinical characteristics. Areas under the receiver operating characteristic curves increased from 0.74 to 0.77 and 0.83 with these models.
  
  
  CONCLUSIONS
  A small retroperitoneal mass after chemotherapy is an important predictor of benign histologic findings in residual masses in patients with nonseminomatous testicular cancer. However, better predictions can be made when the reduction in size and clinical characteristics are considered as well. Decisions regarding resection should be based on the combination of these characteristics rather than on only mass size after chemotherapy.
authors.affiliation: Dept of Public Health, Center for Clinical Decision Sciences, Ee 2091, Erasmus University, 3000 DR Rotterdam, the Netherlands. steyerberg@mgz.fgg.eur.nl
authors.forename: E W
authors.initials: EW
authors.lastname: Steyerberg
authors.forename: H J
authors.initials: HJ
authors.lastname: Keizer
authors.forename: D T
authors.initials: DT
authors.lastname: Sleijfer
authors.forename: S D
authors.initials: SD
authors.lastname: Fossâ
authors.forename: D F
authors.initials: DF
authors.lastname: Bajorin
authors.forename: A
authors.initials: A
authors.lastname: Gerl
authors.forename: R
authors.initials: R
authors.lastname: de Wit
authors.forename: W J
authors.initials: WJ
authors.lastname: Kirkels
authors.forename: H S
authors.initials: HS
authors.lastname: Koops
authors.forename: J D
authors.initials: JD
authors.lastname: Habbema
mesh_terms: D019540:Area Under Curve; D014408:Biomarkers, Tumor / Q000032:analysis; D002277:Carcinoma / Q000188:drug therapy / Q000473:pathology / Q000556:secondary / Q000601:surgery; D006063:Chorionic Gonadotropin / Q000032:analysis; D003657:Decision Making; D005544:Forecasting; D006801:Humans; D007770:L-Lactate Dehydrogenase / Q000032:analysis; D016015:Logistic Models; D008207:Lymphatic Metastasis; D008297:Male; D018365:Neoplasm, Residual / Q000473:pathology; D016017:Odds Ratio; D010347:Patient Care Planning; D011446:Prospective Studies; D012372:ROC Curve; D012186:Retroperitoneal Neoplasms / Q000188:drug therapy / Q000473:pathology / Q000556:secondary* / Q000601:surgery; D013724:Teratoma / Q000188:drug therapy / Q000473:pathology / Q000556:secondary / Q000601:surgery; D013736:Testicular Neoplasms / Q000473:pathology*; D014057:Tomography, X-Ray Computed; D000509:alpha-Fetoproteins / Q000032:analysis
chemical_list: D014408:Biomarkers, Tumor; D006063:Chorionic Gonadotropin; D000509:alpha-Fetoproteins; D007770:L-Lactate Dehydrogenase