title: Computed tomography 21 days after chemotherapy, three-dimensional estimates of metastatic volume and the need for surgery in patients with germ cell cancer.
abstract: OBJECTIVE
  To assess whether the response visible on computed tomography (CT) 21 days after the first course of chemotherapy in patients with nonseminomatous germ cell tumour predicts the need for surgery and whether three-dimensional (3D) reconstruction adds to the diagnostic accuracy.
  
  
  METHODS
  CT scans from 52 patients treated with cisplatin-based chemotherapy were assessed for tumour shrinkage by measuring the changes of a one-dimensional (1D) measurement of the maximum transverse diameter, and comparing CT scans before, 21 days after the first course and at the end of chemotherapy (1D method). In a subset of patients, using a special formula, the 1D-derived 2D and 3D shrinkage (2Dder and 3Dder) were compared with four other computed or calculated methods (1D, 2D, 3Dcalc, 3Dcomp).
  
  
  RESULTS
  At day 21, in 32 of 52 patients (62%) there was < 50% tumour shrinkage using the 1D assessment; 21 of them (66%) needed surgery, compared with none of the 20 patients with > 50% tumour shrinkage by day 21 (chi2 = 22.83, P < 0.001). The 1D method showed significantly less shrinkage than all the other methods but when this was used to derive a 3D shrinkage, assuming the mass to be spherical (3Dder), it was not statistically different from that of 3Dcomp.
  
  
  CONCLUSIONS
  The assessment of the response from 1D CT scan estimates 21 days after initiating chemotherapy identifies a subgroup of patients who have a high probability of needing surgery. Although expected to be more accurate, the 3Dcomp estimate of tumour shrinkage was no better than the 3Dder estimate.
authors.affiliation: Departments of Medical Oncology, Radiology and Urology, and Computer Services Department, St. Bartholomew's and Royal London School of Medicine, London, UK.
authors.forename: H S
authors.initials: HS
authors.lastname: Bozcuk
authors.forename: R
authors.initials: R
authors.lastname: Ravi
authors.forename: B
authors.initials: B
authors.lastname: Turner
authors.forename: D
authors.initials: D
authors.lastname: Tsetis
authors.forename: J M
authors.initials: JM
authors.lastname: Thomas
authors.forename: O
authors.initials: O
authors.lastname: Chan
authors.forename: R
authors.initials: R
authors.lastname: Reznek
authors.forename: W F
authors.initials: WF
authors.lastname: Hendry
authors.forename: R T
authors.initials: RT
authors.lastname: Oliver
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D000970:Antineoplastic Agents / Q000627:therapeutic use; D002945:Cisplatin / Q000627:therapeutic use; D003131:Combined Modality Therapy; D006801:Humans; D008297:Male; D011182:Postoperative Care / Q000379:methods; D012189:Retrospective Studies; D018239:Seminoma / Q000000981:diagnostic imaging* / Q000188:drug therapy / Q000601:surgery; D012680:Sensitivity and Specificity; D013997:Time Factors; D014057:Tomography, X-Ray Computed / Q000379:methods; D016896:Treatment Outcome
chemical_list: D000970:Antineoplastic Agents; D002945:Cisplatin