Article Text
Abstract
Introduction Dynamic contrast-enhanced CT (DCE-CT) and positron emission tomography/CT (PET/CT) have a high reported accuracy for the diagnosis of malignancy in solitary pulmonary nodules (SPNs). The aim of this study was to compare the accuracy and cost-effectiveness of these.
Methods In this prospective multicentre trial, 380 participants with an SPN (8–30 mm) and no recent history of malignancy underwent DCE-CT and PET/CT. All patients underwent either biopsy with histological diagnosis or completed CT follow-up. Primary outcome measures were sensitivity, specificity and overall diagnostic accuracy for PET/CT and DCE-CT. Costs and cost-effectiveness were estimated from a healthcare provider perspective using a decision-model.
Results 312 participants (47% female, 68.1±9.0 years) completed the study, with 61% rate of malignancy at 2 years. The sensitivity, specificity, positive predictive value and negative predictive values for DCE-CT were 95.3% (95% CI 91.3 to 97.5), 29.8% (95% CI 22.3 to 38.4), 68.2% (95% CI 62.4% to 73.5%) and 80.0% (95% CI 66.2 to 89.1), respectively, and for PET/CT were 79.1% (95% CI 72.7 to 84.2), 81.8% (95% CI 74.0 to 87.7), 87.3% (95% CI 81.5 to 91.5) and 71.2% (95% CI 63.2 to 78.1). The area under the receiver operator characteristic curve (AUROC) for DCE-CT and PET/CT was 0.62 (95% CI 0.58 to 0.67) and 0.80 (95% CI 0.76 to 0.85), respectively (p<0.001). Combined results significantly increased diagnostic accuracy over PET/CT alone (AUROC=0.90 (95% CI 0.86 to 0.93), p<0.001). DCE-CT was preferred when the willingness to pay per incremental cost per correctly treated malignancy was below £9000. Above £15 500 a combined approach was preferred.
Conclusions PET/CT has a superior diagnostic accuracy to DCE-CT for the diagnosis of SPNs. Combining both techniques improves the diagnostic accuracy over either test alone and could be cost-effective.
Trial registration number NCT02013063
- lung cancer
- imaging/CT MRI etc
Data availability statement
Individual participant data will be made available, including data dictionaries, for approved data sharing requests. Individual participant data will be shared that underlie the results reported in this article, after deidentification and normalisation of information (text, tables, figures and appendices). The study protocol and statistical analysis plan will also be available. Anonymous data will be available for request from three months after publication of the article, to researchers who provide a completed data sharing request form that describes a methodologically sound proposal, for the purpose of the approved proposal and if appropriate, signed a Data Sharing Agreement. Data will be shared once all parties have signed relevant data sharing documentation, covering SCTU conditions for sharing and if required, an additional Data Sharing Agreement from Sponsor. Proposals should be directed to ctu@soton.ac.uk. Individual participant data will be made available, including data dictionaries, for approved data sharing requests. Individual participant data will be shared that underlie the results reported in this article, after de-identification and normalisation of information (text, tables, figures, and appendices). The study protocol and statistical analysis plan will also be available. Anonymous data will be available for request from three months after publication of the article, to researchers who provide a completed Data Sharing request form that describes a methodologically sound proposal, for the purpose of the approved proposal and if appropriate, signed a Data Sharing Agreement. Data will be shared once all parties have signed relevant data sharing documentation, covering SCTU conditions for sharing and if required, an additional Data Sharing Agreement from Sponsor. Proposals should be directed to ctu@soton.ac.uk.
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Data availability statement
Individual participant data will be made available, including data dictionaries, for approved data sharing requests. Individual participant data will be shared that underlie the results reported in this article, after deidentification and normalisation of information (text, tables, figures and appendices). The study protocol and statistical analysis plan will also be available. Anonymous data will be available for request from three months after publication of the article, to researchers who provide a completed data sharing request form that describes a methodologically sound proposal, for the purpose of the approved proposal and if appropriate, signed a Data Sharing Agreement. Data will be shared once all parties have signed relevant data sharing documentation, covering SCTU conditions for sharing and if required, an additional Data Sharing Agreement from Sponsor. Proposals should be directed to ctu@soton.ac.uk. Individual participant data will be made available, including data dictionaries, for approved data sharing requests. Individual participant data will be shared that underlie the results reported in this article, after de-identification and normalisation of information (text, tables, figures, and appendices). The study protocol and statistical analysis plan will also be available. Anonymous data will be available for request from three months after publication of the article, to researchers who provide a completed Data Sharing request form that describes a methodologically sound proposal, for the purpose of the approved proposal and if appropriate, signed a Data Sharing Agreement. Data will be shared once all parties have signed relevant data sharing documentation, covering SCTU conditions for sharing and if required, an additional Data Sharing Agreement from Sponsor. Proposals should be directed to ctu@soton.ac.uk.
Footnotes
Twitter @jweirmccall, @DrPhilCrosbie
Deceased PM, CM, AF, SG
Contributors FJG (Professor, Honorary Consultant Radiologist and Cochief Investigator) was involved in the design of the study, delivery of the study, interpretation of the results and writing of the report. SHarris (Associate Professor of Medical Statistics) was involved in the design of the study, delivery of the study, statistical analysis, interpretation of the results and writing of the report, and is the study guarantor. KAM (Honorary Professor, Radiology and Nuclear Medicine) was involved in the design of the study, delivery of the study and interpretation of the results. JW-M (University Lecturer, Radiology) was involved in the delivery of the study and interpretation of the results and writing of the report. NRQ (Consultant Cardiothoracic Radiologist) was involved in the design of the study, delivery of the study and interpretation of the results. RCR (Professor of Thoracic Oncology) was involved in the design of the study, delivery of the study and interpretation of the results. SD (Principal Lead Consultant in Imaging and Nuclear Medicine) was involved in the design of the study, delivery of the study and interpretation of the results. LP (Clinical Scientist) was involved in the design of the study and took responsibility for the PET accreditation and quality Assurance and chapter writing. DS (Medical Physicist) was involved in PET accreditation and quality Assurance aspects of SPUtNIk. AS (Clinical Scientist) was involved in the design of the study and took responsibility for the DCE-CT accreditation and Quality Assurance. RE (Clinical Scientist) was involved in the design of the study and took responsibility for the DCE-CT accreditation and Quality Assurance and chapter writing. JJ (Health Economist) was involved in the design of the study and took responsibility for the Health Economics model development and chapter writing. AClegg (Professor of Health Services Research) was involved in the design of the study, systematic review of cost effectiveness, health economics model development, delivery and chapter writing. VB (Research Associate, Health Economics) was involved in the systematic review of cost effectiveness, health economics model development and analysis of the model results, delivery and chapter writing. JH (Senior Lecturer, Evidence Synthesis) was involved in the Systematic review of cost effectiveness, delivery and chapter writing. ACook (Associate Director, Southampton Clinical Trials Unit) oversaw the study management and was involved in the interpretation of the results. DT (Health Economist) was involved in the Health Economics model development and analysis of model results, interpretation and chapter writing LV (Professor of Health Economics) was involved in the Health Economics model development and analysis of model results, interpretation and chapter writing. LB (Associate Professor in Early Diagnosis Research) developed and conducted the analysis for the IPCARD sub study and chapter writing. JM (Trials Manager) was involved in the design of the study, and was responsible for study management. KC (Senior Trials Manager) was responsible for study management. LL (Senior Trials Manager) was involved in the design of the study, oversaw the study management and was involved in the interpretation of the results. KE (Data Coordinator) was responsible for data management. PM (Patient Representative) was the patient representative on the Trial Management Group. CM (Patient Representative) was the patient representative on the Trial Management Group. CP (Consultant Radiologist) was involved in the design of the study and was responsible for recruiting participants. AB (Consultant Thoracic oncology and tuberculosis) was involved in the design of the study and was responsible for recruiting participants. SHan (Consultant in Nuclear Medicine) was responsible for recruiting participants. F-WP (Consultant Radiologist) was involved in the design of the study and was responsible for recruiting participants. AMG (Director, Institute of Nuclear Medicine) was involved in the design of the study and was responsible for recruiting participants. LK (Consultant Radiologist) was involved in the design of the study and was responsible for recruiting participants. AF (Professor in Respiratory Medicine) was involved in the design of the study and was responsible for recruiting participants. MEJC (Consultant in Respiratory Medicine) was involved in the design of the study and was responsible for recruiting participants. PAC (Clinical Senior Lecturer and Honorary Consultant in Respiratory Medicine) was involved in the design of the study and was responsible for recruiting participants. FVG (Professor of Radiology) was involved in the design of the study and was responsible for recruiting participants. KK (Radiology Consultant) was involved in the design of the study and was responsible for recruiting participants. OK (Consultant Respiratory Physician) was involved in the design of the study and was responsible for recruiting participants. SG (Consultant Clinical Epidemiologist and Cochief Investigator) was involved in the design of the study, delivery of the study and interpretation of the results. All authors reviewed the final report.
Funding The trial is funded by the NIHR HTA Programme (grant no: 09/22/117) and is being run by Southampton Clinical Trials Unit who are part funded by CRUK. AClegg, VB and JH are partfunded by the National Institute for Health Research Applied Research Collaboration North West Coast (NIHR ARC NWC). FJG is an NIHR Senior Investigator. RCR is part funded by the Cambridge Biomedical Research Centre, Cancer Research UK Cambridge Centre and the Cancer Research Network: Eastern. NRQ is part funded by the Cambridge Biomedical Research Centre. This research was supported by the NIHR Cambridge Biomedical Research Centre (BRC-1215-20014), the NIHR Manchester Biomedical Research Centre, and the NIHR UCL/H Biomedical Research Centre. The views expressed are those of the author(s) and not necessarily those of the NIHR or the Department of Health and Social Care.
Competing interests None declared.
Provenance and peer review Not commissioned; externally peer reviewed.
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