Difficulties Diagnosing Idiopathic Pulmonary Fibrosis

Transcription

1 1. er Encuentro Entre Neumólogos y Radiólogos, Madrid, Spain, 2016, October 14th Difficulties Diagnosing Idiopathic Pulmonary Fibrosis Simon Walsh King s College Hospital Foundation Trust London, United Kingdom

2 Outline HRCT pattern revision Fibrotic lung disease Radiologic diagnosis of UIP/IPF Radiologic challenges

3 Making a HRCT diagnosis in fibrotic lung disease: key questions. Is it a fibrotic lung disease? If so, is it classical UIP? If no, what are the alternatives?

4 Making a HRCT diagnosis in fibrotic lung disease: key questions. Is it a fibrotic lung disease?

5 Revision: HRCT patterns of fibrosis (++++ = complete certainty) Honeycombing +++(+) Traction bronchiectasis ++(+) Volume loss +

6 Revision: HRCT patterns of fibrosis (++++ = complete certainty) Honeycombing +++(+)

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8 How easy is honeycombing to identify?

9 43 Observers 27 Expert chest radiologists 80 single images Kw = <0.4 = poor, = satisfactory, = good,>0.8 = excellent Watadani et al, Radiology, 2013:266:936

10 Some inconsistency.. Weighted kappa s for honeycombing Lynch et al, AJRCCM, 2005:172:488 Kappa = Sundaram et al, AJR, 2008:191:1032 Kappa = Goldin et al, Chest, 2009:136:1333 Kappa = 0.39 <0.4 = poor, = satisfactory, = good, >0.8 = excellent

11 Some inconsistency.. Weighted kappa s for honeycombing Lynch et al, AJRCCM, 2005:172:488 Kappa = patients with biopsy proven IPF Expert thoracic radiologists <0.4 = poor, = satisfactory, = good, >0.8 = excellent

12 Identification of honeycombing on HRCT - cardinal sign of UIP False positive identification Severe traction bronchiolectasis Centrilobular/paraseptal emphysema e.g. superimposed on NSIP Oedema/infection superimposed on emphysema Other cystic conditions e.g. Langerhans CH

13 Paraseptal Emphysema Honeycombing

14 Paraseptal Emphysema Honeycombing

15 Paraseptal Emphysema Honeycombing

16 Lung biopsy: Fibrotic NSIP and centrilobular emphysema

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18 Revision: HRCT patterns of fibrosis (++++ = complete certainty) Traction bronchiectasis ++(+)

19 Traction Bronchiectasis

20 Traction Bronchiectasis Non-tapering airway surrounded by abnormal lung parenchyma

21 Identification of traction bronchiectasis on HRCT False positive identification Within honeycombing Dilated bronchi within OP / DAD Conspicuous, but not dilated, bronchi within GGO False negative Within honeycombing (advanced) Severity of traction reduced if coexistent emphysema

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23 How easy is traction bronchiectasis to identify?

24 Observer agreement for traction bronchiectasis in various FLD Fibrotic IIPs (UIP and NSIP) Edey 2011 Eur Radiol Rheumatoid Arthritis-related FLD Kim 2010 Eur Respir J Chronic hypersensitivity pneumonitis Walsh SLF 2012 Eur Radiol All comers connective tissue disease FLD Walsh SLF 2014 Thorax Kappas for traction bronchiectasis =

25 Traction bronchiectasis - identification by CALIPER software: differentiation from honeycombing unreliable

26 Revision: HRCT patterns of fibrosis (++++ = complete certainty) Volume loss +

27 Volume loss can be difficult to appreciate.

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29 Honeycombing Traction bronchiectasis Volume loss

30 Making a HRCT diagnosis in fibrotic lung disease: key questions. If so, is it classical UIP?

31 3 diagnosis categories UIP pattern ( definite, classic ) Possible UIP pattern Inconsistent with a UIP pattern Raghu et al. AJRCCM 2011;183:788

32 Subpleural, basal honeycombing = classic UIP

33 Characteristic/Definite UIP pattern on CT Supportive CT features (unofficial) Propeller blade cranio-caudal distribution Nodular ossifications within fibrosis Asymmetric distribution of fibrosis Component of pleuroparenchymal fibroelastosis (PPFE)

34 Supportive/ancillary features of UIP on CT: Propeller blade distribution* Subpleural disease anterior in upper lobes Subpleural disease posterior in lower lobes

35 Supportive/ancillary features of UIP on CT: R to L asymmetry of fibrosis [anecdotal]

36 Nodular ossification (white spots) in fibrosis 29% prevalence (c.f. 8% in other FLD) [in press]

37 Supportive/ancillary features of UIP on CT: Pleuroparenchymal Fibroelastosis (PPFE) + UIP PPFE associated with lower zone UIP in 32% of patients [unpublished data]

38 Accuracy of a CT diagnosis of UIP/IPF Study Correctness of confident first choice CT diagnosis - definite UIP JR Mathieson et al, Radiology, 1989;171:111 KS Lee et al, Radiology 1994;191:669 S Swenson et al, Radiology, 1997;205:229 GW Hunninghake, AJRCCM, 2001;164:193 95% 100% 100% 96%

39 Accuracy of a CT diagnosis of UIP/IPF Study Correctness of confident first choice CT diagnosis - definite UIP % of cases of UIP without a confident CT diagnosis - atypical UIP JR Mathieson et al, Radiology, 1989;171:111 KS Lee et al, Radiology 1994;191:669 S Swenson et al, Radiology, 1997;205:229 GW Hunninghake, AJRCCM, 2001;164:193 95% 38% 100% 39% 100% 33% 96% 52%

40 Definite UIP 32.9% Probable UIP or possible UIP 61.9% Possible UIP 4.9% Richeldi et al, NEJM, 2011;370:2071

41 What do these atypical cases look like?

42 Spectrum of atypical radiologic appearances of biopsy proven UIP Most common radiologic diagnoses in 34 patients with biopsy proven UIP whose CT does not meet radiologic criteria for definite UIP (i.e. basal, subpleural honeycombing): NSIP 18 CHP 4 Sarcoidosis 3 OP 1 Other 8 Sverzellati et al. Radiology 2009;254:987

43 Recap: Radiologic presentation of UIP/IPF 30-40% Definite UIP Radiologic presentation: Basal, subpleural, honeycombing 60-70% Not definite UIP Radiologic presentation: Fibrotic NSIP (most common)* CHP (rare) Fibrotic Sarcoidosis (very rare) 95+% accurate for histopathologic UIP *Not entirely clear what fibrotic NSIP is on HRCT

44 Recap: Radiologic presentation of UIP/IPF 30-40% Definite UIP Radiologic presentation: Basal, subpleural, honeycombing 60-70% Not definite UIP Radiologic presentation: Fibrotic NSIP (most common)* CHP (rare) Fibrotic Sarcoidosis (very rare) 95+% accurate for histopathologic UIP *Not entirely clear what fibrotic NSIP is on HRCT

45 Some pitfalls: IMPORTANT: confidence accuracy Fiducia precisione

46 RADIOLOGIST IPF MDT DIAGNOSIS Chronic hypersensitivity pneumonitis IPF Fibrotic NSIP IPF Sarcoidosis (very rare)

47 HRCT diagnosis fibrotic lung disease If no, what are the alternatives?

48 Fell et al. AJRCCM, 2010;181:

49 Column 3 as a checklist to differentiate UIP from others fibrosing lung diseases Not basal Bronchocentric Mosaicism (lobules) Nodules GGO > reticular Cysts Consolidation Chronic hypersensitivity pneumonitis

50 UIP NSIP OP LIP HP DIP/ RB-ILD pre 2002 ATS/ERS IIP classification

51 OP UIP HP NSIP LIP DIP/ RB-ILD Silva et al, Radiology 2008;246:288

52 OP UIP NSIP LIP HP DIP/ RB-ILD 2016

53 HRCT pointers to chronic hypersensitivity pneumonitis: Lobules of decreased attenuation in spared (nonfibrotic) lung Occasional septal thickening may be a bit more obvious than in other fibrotic IIPs x3 distributions of fibrosis: UZ, LZ or random - sometimes vague/subtle bronchocentricity if UZ Coexistent subacute changes - indistinct relatively low attenuation centrilobular nodules (rare)

54 Lobules of decreased attenuation in spared lung

55 Chronic HP UIP

56 Septal thickening in chronic hypersensitivity pneumonitis

57 Unusual distribution of fibrosis, particularly vague bronchocentricity when upper lobe predominant: n.b. Bronchocentricity, when present, is much more subtle than the bronchocentric fibrosis in sarcoidosis

58 Coexisting chronic and subacute features of HP (relatively rare)

59 BAL lymphocytosis 27% MDT diagnosis of Chronic HP UIP on lung biopsy MDT diagnosis of IPF

60 Column 3 as a checklist to differentiate UIP from others fibrosing lung diseases Not basal Bronchocentric Mosaicism (lobules) Nodules GGO > reticular Cysts Consolidation

61 DMH SLFW AD NS

62 Inconsistent All could pass for possible UIP Inconsistent Inconsistent

63 Biopsy == UIP

64 IPF Scleroderma IPF Smoking related ILD (RBILD/DIP)

65 Let s get back to IPF

66 Radiologic diagnosis: The IPF challenge Misdiagnosis of IPF Clarify status of possible UIP Detection of early disease

67 ATS/ERS/JRS/ALAT guidelines: Radiologic misdiagnosis is a problem Clinicians perspective: majority of clinicians found a HRCT diagnosis of IPF to be reliable in less than a third of practicing radiologists.. AU Wells - straw poll, Berlin IPF AIR meeting, November 2011

68 ESTI (European Society of Thoracic Imaging) BSTI (British Society of Thoracic Imaging) STR (Society of Thoracic Radiology) KSTR (Korean Society of Thoracic Radiology)

69 Observer agreement: 112 thoracic radiologists from 5 continents Kw = 0 47 ± 0.05 <0.4 = poor, = satisfactory, = good, >0.8 = excellent Walsh et al, Thorax 2016;71:45-51

70 Observer agreement: > 25 years experience (n=22) Kw = 0 37 ± 0.11 <0.4 = poor, = satisfactory, = good, >0.8 = excellent Walsh et al, Thorax 2016;71:45-51

71 Example

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79 112 thoracic radiologists ESTI, STR, BSTI, KSTR Honeycombing % UIP 33.9% Possible UIP 56.5% Walsh et al, Thorax 2016;71:45-51

80 112 thoracic radiologists ESTI, STR, BSTI, KSTR

81 112 thoracic radiologists ESTI, STR, BSTI, KSTR Deciding between the presence of traction bronchiectasis OR honeycombing can be the difference between definite UIP and possible UIP

82 Radiologist s Challenge 2: Clarify possible UIP status Significant proportion of IPF patients have HRCT appearances that meet possible UIP criteria Many unable or unwilling to undergo lung biopsy Guideline-based IPF diagnosis not possible

83 Radiologist s Challenge 2: Clarify possible UIP status Are there specific CT features that predict histopathologic UIP? Fell et al. AJRCCM, 2010;181:

84 Clinical predictors of IPF The importance of age IPF or fibrotic NSIP? Fell et al. AJRCCM, 2010;181:

85 Clinical predictors of IPF The importance of age In idiopathic fibrotic lung disease, increasing age increases likelihood of a diagnosis of UIP/IPF >70 years PPV 95% >75 years PPV 100% Fell et al. AJRCCM, 2010;181:

86 Age >= 60 Reticular abnormality > 1/3 total lung Probability of IPF >80% Specificity for IPF 96% 16% of biopsies avoided Salisbury et al. Respir Med 2016 Sep;118:88-9

87 Gruden et al 2013 Raghu et al 2014 Chung et al 2015

88 Coarse heterogeneous fibrosis without honeycombing highly predictive of histologic UIP and a UIP-like disease course Gruden et al, AJR 2013;200:458

89 Counter argument: How important is this distinction? Inpulsis HRCT entry criteria == Possible UIP (with traction bronchiectasis) Richeldi et al, NEJM, 2014;370:

90 Definite UIP 32.9% Probable UIP or possible UIP 61.9% Possible UIP 4.9% i.e. honeycombing present in only 1/3 patients, in practice may be 20-45% Richeldi et al, NEJM, 2011;370:2071

91 Best use of HRCT? Working diagnosis of IPF * Less dependent on absence/presence of specific HRCT patterns HRCT truth data when histopathology unavailable (e.g. note importance of age*) Take CT appearance as starting point Dynamic diagnostic process Integrate other important non-radiological information, in particular DISEASE BEHAVIOUR *Athol Wells, personal communication *CD Fell et al, AJRCCM 2010;181:832

92 An evaluation of interobserver agreement and accuracy for solo clinicians diagnoses in the setting of diffuse lung disease 60 cases of DPLD Provide a differential diagnosis 673 clinician's signed up (21/9/2016) 11,737 patient evaluations (21/9/2016)

93 wkappa s for probability of an IPF diagnosis Overall (n=125) = 0.55 Expert panel (n=14) = 0.68 No MDT available (n=25) = 0.49 Dedicated ILD MDT (n=65) =

94 Inter-MDT agreement for diagnostic likelihood of a diagnosis of IPF Kw = 0.71 <0.4 = poor, = satisfactory, = good, >0.8 = excellent Walsh SLF et al. Lancet RM, 2016;4:557-65

95 Conclusion Radiologic diagnosis of UIP/IPF Working diagnosis of IPF * approach HRCT as a starting point Challenges in 2016 for the radiologist Agreement issues for key observations Possible and inconsistent with UIP categories