Abstract
Purpose
Error and variation in reporting remains one of the weakest features of clinical imaging despite enormous technological advances in nuclear medicine and radiology. The aim of this study was to evaluate agreement amongst experienced readers in staging non-small-cell lung cancer (NSCLC) with PET-CT.
Methods
A series of 18F-FDG PET-CT scans from 100 consecutive patients were reviewed independently by three experienced readers, with two readers reviewing each scan series a second time. Individual mediastinal lymph node stations were assessed as benign/inflammatory, equivocal or malignant, and AJCC N and M stage were also assigned. Kappa (κ) was used to compare ratings from two categories and weighted kappa (κw) for three or more categories, and kappa values were interpreted according to the Landis-Koch benchmarks.
Results
Both intra- and interobserver agreement for N and M staging were high. For M staging there was almost perfect intra- and interobserver agreement (κ = 0.90–0.93). For N staging, agreement was either almost perfect or substantial (intraobserver κw = 0.79, 0.91; interobserver κw = 0.75–0.81). Importantly, there was almost perfect agreement for N0/1 vs N2/3 disease (κ = 0.80–0.97). Agreement for inferior and superior mediastinal nodes (stations 1, 2, 3, 7, 8, 9) was either almost perfect or substantial (κw = 0.71–0.88), but lower for hilar nodes (10; κw = 0.56–0.71). Interreporter variability was greatest for aortopulmonary nodes (5, 6; κw = 0.48–0.55).
Conclusion
Amongst experienced reporters in a single centre, there was a very high level of agreement for both mediastinal nodal stage and detection of distant metastases with PET-CT. This supports the use of PET-CT as a robust imaging modality for staging NSCLC.
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References
Robinson PJ. Radiology’s Achilles’ heel: error and variation in the interpretation of the Röntgen image. Br J Radiol 1997;70:1085–98.
Shim SS, Lee KS, Kim BT, Chung MJ, Lee EJ, Han J, et al. Non-small cell lung cancer: prospective comparison of integrated FDG PET/CT and CT alone for preoperative staging. Radiology 2005;236:1011–9.
Lardinois D, Weder W, Hany TF, Kamel EM, Korom S, Seifert B, et al. Staging of non-small-cell lung cancer with integrated positron-emission tomography and computed tomography. N Engl J Med 2003;348:2500–7.
van Tinteren H, Hoekstra OS, Smit EF, van den Bergh JH, Schreurs AJ, Stallaert RA, et al. Effectiveness of positron emission tomography in the preoperative assessment of patients with suspected non-small-cell lung cancer: the PLUS multicentre randomised trial. Lancet 2002;359:1388–93.
Mountain CF, Dresler CM. Regional lymph node classification for lung cancer staging. Chest 1997;111:1718–23.
Greene FL; American Joint Committee on Cancer. AJCC cancer staging manual. 6th ed. American Cancer Society. New York: Springer; 2002. xiv; p. 421.
Cohen J. A coefficient of agreement for nominal scales. Educ Psychol Meas 1960;20:37–46.
Cohen J. Weighted kappa: nominal scale agreement with provision for scaled disagreement or partial credit. Psychol Bull 1968;70:213–20.
Landis JR, Koch GG. The measurement of observer agreement for categorical data. Biometrics 1977;33:159–74.
Efron B, Tibshirani R. An introduction to the bootstrap. Monographs on statistics and applied probability; 57. New York: Chapman & Hall; 1993. p. 436. xvi.
Stata Corporation. Stata statistical software: release 9.2. College Station: Stata Corporation; 2007.
Smulders SA, Gundy CM, van Lingen A, Comans EF, Smeenk FW, Hoekstra OS. Observer variation of 2-deoxy-2-[F-18]fluoro-D-glucose-positron emission tomography in mediastinal staging of non-small cell lung cancer as a function of experience, and its potential clinical impact. Mol Imaging Biol 2007;9:318–22.
Marom EM, Munden RF, Truong MT, Gladish GW, Podoloff DA, Mawlawi O, et al. Interobserver and intraobserver variability of standardized uptake value measurements in non-small-cell lung cancer. J Thorac Imaging 2006;21:205–12.
Guyatt GH, Lefcoe M, Walter S, Cook D, Troyan S, Griffith L, et al. Interobserver variation in the computed tomographic evaluation of mediastinal lymph node size in patients with potentially resectable lung cancer. Canadian Lung Oncology Group. Chest 1995;107:116–9.
Cascade PN, Gross BH, Kazerooni EA, Quint LE, Francis IR, Strawderman M, et al. Variability in the detection of enlarged mediastinal lymph nodes in staging lung cancer: a comparison of contrast-enhanced and unenhanced CT. AJR Am J Roentgenol 1998;170:927–31.
Ciatto S, Ambrogetti D, Bonardi R, Catarzi S, Risso G, Rosseli Del Turco M, et al. Second reading of screening mammograms increases cancer detection and recall rates. Results in the Florence screening programme. J Med Screen 2005;12:103–6.
Okada M, Tsubota N, Yoshimura M, Miyamoto Y, Matsuoka H. Prognosis of completely resected pN2 non-small cell lung carcinomas: what is the significant node that affects survival? J Thorac Cardiovasc Surg 1999;118:270–5.
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Hofman, M.S., Smeeton, N.C., Rankin, S.C. et al. Observer variation in FDG PET-CT for staging of non-small-cell lung carcinoma. Eur J Nucl Med Mol Imaging 36, 194–199 (2009). https://doi.org/10.1007/s00259-008-0946-3
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DOI: https://doi.org/10.1007/s00259-008-0946-3