Accuracy of individual variables in the monitoring of long-term change in pulmonary sarcoidosis as judged by serial high-resolution CT scan data.
BACKGROUND
In pulmonary sarcoidosis, the optimal means of quantifying change is uncertain. The comparative usefulness of simple lung function trends and chest radiography remains unclear. We aimed to explore and contrast the disease-monitoring strategies of serial pulmonary function tests (PFTs) and chest radiography compared against morphologic change on high-resolution CT (HRCT) scan.


METHODS
Seventy-three patients with sarcoidosis were identified who had two HRCT scans with concurrent chest radiography and PFTs. Chest radiography and HRCT scans were assessed by two radiologists for change in disease extent. Concordance between the scoring systems, as well as agreement between PFT trends (% change from baseline in FEV, FVC, and diffusing capacity of the lung for carbon monoxide [Dlco]), chest radiography, and chest HRCT scan change, were examined using the weighted κ coefficient of variation (Kw).


RESULTS
There was fair agreement between change in extent of disease on chest radiograph and significant PFT trends (Kw = 0.35, P &lt; .001) and moderate agreement between change in extent of disease on serial HRCT scan and significant PFT trends (Kw = 0.64, P &lt; .0001). The integration of Dlco trends did not improve concordance between change on HRCT scan and PFT change. Change in gas transfer coefficient (ie, Dlco/alveolar volume) displayed no overall linkage with change in disease extent on chest radiograph (Kw = 0.07, P = .27) and only poor agreement with change in disease extent on HRCT scan (Kw = 0.17, P = .07).


CONCLUSIONS
Significant PFT trends correlate better with morphologic change as defined by serial HRCT scan than extent of disease on radiograph. Isolated change in gas transfer coefficient is more frequently discordant with change in disease extent on chest radiograph and HRCT scan and may suggest a pulmonary vascular component.
Department of Respiratory Medicine, Royal Brisbane and Women's Hospital, Brisbane, QLD, Australia; Interstitial Lung Disease Unit, Royal Brompton Hospital and National Heart and Lung Institute London, England; Department of Medicine, University of Melbourne, Melbourne, VIC, Australia.
Christopher J
CJ
Zappala
The Department of Radiology, King's College Hospital, London, England.
Sujal R
SR
Desai
the Department of Radiology, Hammersmith Hospital, London, England.
Susan J
SJ
Copley
Interstitial Lung Disease Unit, Royal Brompton Hospital and National Heart and Lung Institute London, England; Department of Lung Physiology, Royal Brompton Hospital and National Heart and Lung Institute London, England.
Paolo
P
Spagnolo
Interstitial Lung Disease Unit, Royal Brompton Hospital and National Heart and Lung Institute London, England; Department of Lung Physiology, Royal Brompton Hospital and National Heart and Lung Institute London, England.
Dushendree
D
Sen
Interstitial Lung Disease Unit, Royal Brompton Hospital and National Heart and Lung Institute London, England.
Salma M
SM
Alam
Interstitial Lung Disease Unit, Royal Brompton Hospital and National Heart and Lung Institute London, England.
Roland M
RM
du Bois
Department of Imaging, Royal Brompton Hospital and National Heart and Lung Institute London, England.
David M
DM
Hansell
Interstitial Lung Disease Unit, Royal Brompton Hospital and National Heart and Lung Institute London, England. Electronic address: athol.wells@rbht.nhs.uk.
Athol U
AU
Wells
D000328:Adult; D001944:Breath Tests; D002248:Carbon Monoxide; D018450:Disease Progression; D005260:Female; D005541:Forced Expiratory Volume; D006801:Humans; D008168:Lung / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D012129:Respiratory Function Tests; D017565:Sarcoidosis, Pulmonary / Q000000981:diagnostic imaging* / Q000503:physiopathology; D014057:Tomography, X-Ray Computed; D014797:Vital Capacity; D014965:X-Rays
D002248:Carbon Monoxide