COMPUTED TOMOGRAPHY Optimisation of volume-doubling time cutoff for fast-growing lung nodules in CT lung cancer screening reduces false-positive referrals Marjolein A. Heuvelmans & Matthijs Oudkerk & Geertruida H. de Bock & Harry J. de Koning & Xueqian Xie & Peter M. A. van Ooijen & Marcel J. W. Greuter & Pim A. de Jong & Harry J. M. Groen & Rozemarijn Vliegenthart Received: 2 October 2012 / Revised: 31 December 2012 / Accepted: 14 January 2013 / Published online: 19 March 2013 # European Society of Radiology 2013 Abstract Objective To retrospectively investigate whether optimisa- tion of volume-doubling time (VDT) cutoff for fast-growing nodules in lung cancer screening can reduce false-positive referrals. Methods Screening participants of the NELSON study underwent low-dose CT. For indeterminate nodules (volume 50–500 mm 3 ), follow-up CT was performed 3 months after baseline. A negative baseline screen resulted in a regular second-round examination 1 year later. Subjects referred to a pulmonologist because of a fast-growing (VDT <400 days) solid nodule in the baseline or regular second round were included in this study. Histology was the reference for diagnosis, or stability on subsequent CTs, confirming benig- nity. Mean follow-up of non-resected nodules was 4.4 years. Optimisation of the false-positive rate was evaluated at maintained sensitivity for lung cancer diagnosis with VDT <400 days as reference. Results Sixty-eight fast-growing nodules were included; 40 % were malignant. The optimal VDT cutoff for the 3- The institutions where the work was performed: University of Groningen/University Medical Center Groningen, Groningen, The Netherlands; University Medical Center Utrecht, Utrecht, The Netherlands; Kennemer Gasthuis, Haarlem, The Netherlands; University Hospital Gasthuisberg Leuven, Leuven, Belgium M. A. Heuvelmans : M. Oudkerk : X. Xie : P. M. A. van Ooijen : R. Vliegenthart Center for Medical Imaging-North East Netherlands, University of Groningen, University Medical Center Groningen, Hanzeplein 1, 9713 GZ Groningen, The Netherlands G. H. de Bock Department of Epidemiology, University of Groningen, University Medical Center Groningen, Hanzeplein 1, 9713 GZ Groningen, The Netherlands H. J. de Koning Department of Public Health, Erasmus Medical Center Rotterdam, PO Box 2040, 3000 CA Rotterdam, The Netherlands P. M. A. van Ooijen : M. J. W. Greuter : R. Vliegenthart (*) Department of Radiology, EB44, University of Groningen, University Medical Center Groningen, Hanzeplein 1, 9713 GZ Groningen, The Netherlands e-mail: r.vliegenthart@umcg.nl P. A. de Jong Department of Radiology, University Medical Center Utrecht, Heidelberglaan 100, 3584 CX Utrecht, The Netherlands H. J. M. Groen Department of Pulmonology, University of Groningen, University Medical Center Groningen, Hanzeplein 1, 9713 GZ Groningen, The Netherlands Eur Radiol (2013) 23:1836–1845 DOI 10.1007/s00330-013-2799-9