title: Low-dose computed tomography for lung cancer screening: comparison of performance between annual and biennial screen.
abstract: OBJECTIVE
  To compare the performance metrics of two different strategies of lung cancer screening by low-dose computed tomography (LDCT), namely, annual (LDCT1) or biennial (LDCT2) screen.
  
  
  METHODS
  Recall rate, detection rate, interval cancers, sensitivity, specificity, positive and negative predictive values (PPV and NPV, respectively) were compared between LDCT1 and LDCT2 arms of the MILD trial over the first seven (T0-T6; median follow-up 7.3 years) and four rounds (T0-T3; median follow-up 7.3 years), respectively.
  
  
  RESULTS
  1152 LDCT1 and 1151 LDCT2 participants underwent a total of 6893 and 4715 LDCT scans, respectively. The overall recall rate was higher in LDCT2 arm (6.97 %) than in LDCT1 arm (5.81 %) (p = 0.01), which was counterbalanced by the overall lower number of LDCT scans. No difference was observed for the overall detection rate (0.56 % in both arms). The two LDCT arms had similar specificity (99.2 % in both arms), sensitivity (73.5 %, in LDCT2 vs. 68.5 % in LDCT1, p = 0.62), PPV (42.4 %, in LDCT2, vs. 40.6 %, in LDCT1, p = 0.83) and NPV (99.8 %, in LDCT2 vs. 99.7 %, in LDCT1, p = 0.71).
  
  
  CONCLUSIONS
  Biennial screen may save about one third of LDCT scans with similar performance indicators as compared to annual screening.
  
  
  CONCLUSIONS
  • Biennial LDCT screening may be as efficient as the annual screening. • Annual and biennial LDCT screening have similar frequency of interval lung cancers. • Biennial screening may save about one third of LDCT scans.
authors: Radiology, Department of Surgical Sciences, University of Parma, Parma, Italy. nicolasve@tiscali.it.
authors: Nicola
authors: N
authors: Sverzellati
authors: Radiology, Department of Surgical Sciences, University of Parma, Parma, Italy.
authors: M
authors: M
authors: Silva
authors: Department of Radiology, Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy.
authors: G
authors: G
authors: Calareso
authors: Department of Statistics and Quantitative Methods, Division of Biostatistics, Epidemiology and Public Health, Laboratory of Healthcare Research and Pharmacoepidemiology, University of Milano-Bicocca, Milan, Italy.
authors: C
authors: C
authors: Galeone
authors: Department of Radiology, Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy.
authors: A
authors: A
authors: Marchianò
authors: Department of Surgery, Section of Thoracic Surgery, Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy.
authors: S
authors: S
authors: Sestini
authors: Tumor Genomics Unit, Department of Experimental Oncology and Molecular Medicine, Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy.
authors: G
authors: G
authors: Sozzi
authors: Department of Surgery, Section of Thoracic Surgery, Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy.
authors: U
authors: U
authors: Pastorino
mesh_terms: D000368:Aged; D055088:Early Detection of Cancer / Q000379:methods*; D005260:Female; D006801:Humans; D008168:Lung / Q000000981:diagnostic imaging*; D008175:Lung Neoplasms / Q000175:diagnosis*; D008297:Male; D008403:Mass Screening / Q000379:methods*; D008875:Middle Aged; D009367:Neoplasm Staging / Q000379:methods; D012372:ROC Curve; D011829:Radiation Dosage; D013997:Time Factors; D014057:Tomography, X-Ray Computed / Q000379:methods*
keywords: Biennial screening; Interval cancer; Low-dose computed tomography; Lung cancer screening; Strategy