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Randomized Controlled Trial
. 2023 May 17;23(1):45.
doi: 10.1186/s40644-023-00567-6.

PET/CT reading for relapse in non-small cell lung cancer after chemoradiotherapy in the PET-Plan trial cohort

Alexander Brose  1   2 , Kerstin Michalski  3   4 , Juri Ruf  4 , Marco Tosch  5   6 , Susanne M Eschmann  7 , Mathias Schreckenberger  8 , Jochem König  9 , Ursula Nestle  10   11 , Matthias Miederer  12   8
Affiliations
Randomized Controlled Trial

PET/CT reading for relapse in non-small cell lung cancer after chemoradiotherapy in the PET-Plan trial cohort

Alexander Brose et al. Cancer Imaging. .

Abstract

Background: Current studies indicate that fluorine-18-fluorodeoxyglucose positron emission tomography/ computed tomography ([18F]FDG PET/CT) is the most accurate imaging modality for the detection of relapsed locally advanced non-small cell lung cancer (NSCLC) after curatively intended chemoradiotherapy. To this day, there is no objective and reproducible definition for the diagnosis of disease recurrence in PET/CT, the reading of which is relevantly influenced by post radiation inflammatory processes. The aim of this study was to evaluate and compare visual and threshold-based semi-automated evaluation criteria for the assessment of suspected tumor recurrence in a well-defined study population investigated during the randomized clinical PET-Plan trial.

Methods: This retrospective analysis comprises 114 PET/CT data sets of 82 patients from the PET-Plan multi-center study cohort who underwent [18F]FDG PET/CT imaging at different timepoints for relapse, as suspected by CT. Scans were first analyzed visually by four blinded readers using a binary scoring system for each possible localization and the associated reader certainty of the evaluation. Visual evaluations were conducted repeatedly without and with additional knowledge of the initial staging PET and radiotherapy delineation volumes. In a second step, uptake was measured quantitatively using maximum standardized uptake value (SUVmax), peak standardized uptake value corrected for lean body mass (SULpeak), and a liver threshold-based quantitative assessment model. Resulting sensitivity and specificity for relapse detection were compared to the findings in the visual assessment. The gold standard of recurrence was independently defined by prospective study routine including external reviewers using CT, PET, biopsies and clinical course of the disease.

Results: Overall interobserver agreement (IOA) of the visual assessment was moderate with a high difference between secure (ĸ = 0.66) and insecure (ĸ = 0.24) evaluations. Additional knowledge of the initial staging PET and radiotherapy delineation volumes improved the sensitivity (0.85 vs 0.92) but did not show significant impact on the specificity (0.86 vs 0.89). PET parameters SUVmax and SULpeak showed lower accuracy compared to the visual assessment, whereas threshold-based reading showed similar sensitivity (0.86) and higher specificity (0.97).

Conclusion: Visual assessment especially if associated with high reader certainty shows very high interobserver agreement and high accuracy that can be further increased by baseline PET/CT information. The implementation of a patient individual liver threshold value definition, similar to the threshold definition in PERCIST, offers a more standardized method matching the accuracy of experienced readers albeit not providing further improvement of accuracy.

Keywords: NSCLC; Oncology; PET/CT; Relapse criteria; Tumor recurrence.

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Conflict of interest statement

The authors have no relevant financial or non-financial interests to disclose that are relevant to the content of this article.

Figures

Fig. 1
Fig. 1
Inflammatory changes in fibrotic tissue after radiation. Axial fused PET/CT image (A), attenuation corrected PET image (B), CT image in lung window (C) and 3D VRT images of the whole body (D) showing fibrotic changes without locoregional tumor recurrence. PET shows diffuse FDG uptake (SUVmax 3.5, SULpeak 2.7) of the right upper lobe 5 years after radiation therapy
See this image and copyright information in PMC

References

    1. Siegel RL, Miller KD, Jemal A. Cancer statistics, 2019. CA Cancer J Clin. 2019;69(1):7–34. doi: 10.3322/caac.21551. - DOI - PubMed
    1. Sung H, Ferlay J, Siegel RL, Laversanne M, Soerjomataram I, Jemal A, Bray F. Global Cancer Statistics 2020: GLOBOCAN Estimates of Incidence and Mortality Worldwide for 36 Cancers in 185 Countries. CA Cancer J Clin. 2021;71(3):209–249. doi: 10.3322/caac.21660. - DOI - PubMed
    1. Duma N, Santana-Davila R, Molina JR. Non-Small Cell Lung Cancer: Epidemiology, Screening, Diagnosis, and Treatment. Mayo Clin Proc. 2019;94(8):1623–1640. doi: 10.1016/j.mayocp.2019.01.013. - DOI - PubMed
    1. van Tinteren H, Hoekstra OS, Smit EF, van den Bergh JH, Schreurs AJ, Stallaert RA, van Velthoven PC, Comans EF, Diepenhorst FW, Verboom P, 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(9315):1388–1393. doi: 10.1016/S0140-6736(02)08352-6. - DOI - PubMed
    1. MacManus MP, Hicks RJ, Matthews JP, Hogg A, McKenzie AF, Wirth A, Ware RE, Ball DL. High rate of detection of unsuspected distant metastases by pet in apparent stage III non-small-cell lung cancer: implications for radical radiation therapy. Int J Radiat Oncol Biol Phys. 2001;50(2):287–293. doi: 10.1016/S0360-3016(01)01477-8. - DOI - PubMed

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