The Outcome of the Follow-Up of Consolidations on Chest Radiographs in a Maltese Population, Presenting from the Community, Aged 50 or over – a Retrospective Study.

Authors

    Julian Delicata, Sophie Degiorgio, Simon Gatt, Luke Sultana, Adrian Mizzi, Christopher Zammit

Abstract

Background: The British Thoracic Society (BTS) guidelines for community-acquired pneumonia (CAP) suggest a repeat chest radiograph 6 weeks after treatment for patients over the age of 50 to screen for lung malignancy. The benefit of thispractice is not well determined.

Method: We conducted a retrospective study involving patients from the community over 50 years old with consolidations on chest radiography. These patients presented in Mater Dei Hospital, Gozo General Hospital and Maltese Health Centres during the months of January 2013-2017 and August 2013-2016.

The occurrence of follow-up imaging and subsequent diagnosis of lung malignancy was documented. All chest radiographs were reviewed by a radiologist.

Results: 402 patients met our inclusion criteria. Follow-up imaging was done in 214 patients (53.2%) within 12 weeks. There was no statistical significance in the follow-up rates when matched for the presenting month, whether radiologists recommended repeat imaging, whether patients were admitted to hospital, and for the patients’ age and gender.

The diagnostic yield of lung malignancy was 1.74% (7 patients) within 12 weeks with all malignancies being at an advanced stage at diagnosis (lowest stage being IIIA) when detected. All seven patients had a smoking history. 

Conclusion: 53.2% of community-acquired pneumonia patients over the age of 50 had follow-up imaging within 12 weeks. No clinical variables explaining this low rate could be identified.

This practice results in a low diagnostic yield. Moreover, the diagnosis of lung malignancy is achieved at an advanced stage, making it a poor screening tool. 

Scheduling repeat imaging in patients diagnosed with community acquired pneumonias (CAPs) with a consolidation on radiographs is routine practice for many a physician. Lung malignancies can have similar radiological features to that of a consolidation, while an airspace shadow caused by an infection can easily mask an underlying neoplasm. It is on this trail of thought that repeat imaging is routinely done within the first 2 to 3 months. The 2009 British Thoracic Society (BTS) guidelines1 on Community Acquired Pneumonias mention that repeat chest radiography should be performed 6 weeks after the initial chest X-ray in patients over the age of 50 or those with a smoking history. Similarly, the 2005 American College of Chest Physicians guidelines2 suggest follow-up radiography after approximately 8 weeks. On the other hand, the 2007 Infectious Disease Society of America and the American Thoracic Society consensus guidelines3 do not mention any follow-up chest radiography in the management of CAPs. More detailed guidelines on follow-up imaging are conspicuous by their absence. Consequently, physicians are left with their clinical judgment and patchy guidelines when they need to decide who the patients meriting future chest imaging are. To address this void in the management of community acquired pneumonias, we have embarked on this retrospective study where our aims were twofold. Firstly, are patients over the age of 50 diagnosed with a community acquired pneumonia really being followed-up, as suggested by the BTS guidelines, and if not, why? Secondly, is this practice really feasible and efficient? Using this strategy, what is the diagnostic yield of lung malignancy and is the diagnosis being achieved early enough? Methodology In this retrospective study, we considered patients 50 years old or over who presented to Mater Dei Hospital, Gozo General Hospital and Maltese Health Centres with radiological findings of a pneumonia. The age 50 was chosen since the The 2009 British Thoracic Society (BTS) guidelines1 on Community Acquired Pneumonias actually consider patients over the age of 50 to be at high risk for lung malignancy when recommending repeat chest imaging. Patients were recruited by searching for the keywords “consolidation”, “pneumonia” and “opacification” in the radiologist reports for all the radiographs done in the months of January during the years 2013, 2014, 2015, 2016 and 2017 and the months of August in the years 2013, 2014, 2015 and 2016. These reports were obtained using the local Picture Archiving and Communication System (PACS) software used in all Maltese state hospitals and health centres. The patients whose reports had one or more of these keywords were then sieved through according to the inclusion and exclusion criteria as mentioned in Tables 1 and 2.

Table 1:Inclusion criteria for patients to be eligible to form part of the study cohort
Inclusion Criteria
Patients whose chest radiographs’ reports contained the search words “consolidation”, “opacification” and/or “pneumonia”
Age: 50 years or over
Consolidation must be seen on chest radiograph
Patients presenting in the months of January 2013-2017
Patients presenting in the months of August 2013-2016
Chest X-rays performed in Mater Dei Hospital, Gozo General Hospital and Maltese Health Centres
Table 2:Exclusion criteria preventing patients from being eligible for the study cohort
Exclusion Criteria
Patients under the age of 50
Patients who had chest imaging other than chest radiographs done in the first week after the initial chest X-ray
Patients deceased within 12 weeks of initial chest radiographs
Hospital Acquired Pneumonias, i.e. patients who had been admitted in hospital at any stage during the three weeks prior to presentation
Chest radiographs that were never formally reported
Lesion described on chest x-ray was already identified in previous imaging
Patients with pleural effusions that required drainage
Lung transplant patients
Patients with active pulmonary tuberculosis
Patients who did not have a fixed address in Malta (thus potentially making follow-up less likely)
Chest X-rays done over 24 hours after admission if no CXR was performed on admission
Presenting CXRs where the reporting radiologist recommended cross-sectional imaging and/or bronchoscopy and/or PET scans due to a high index of suspicion for a lung malignancy
The consolidation must have been present only on chest radiographs. Thus, patients who had other modalities of chest imaging for up to one week after the presenting chest radiograph were excluded. Since this study focuses specifically on community acquired pneumonias, patients who were admitted for any reason in hospital during the three weeks prior to the chest radiograph were excluded. Patients with active malignancy were also excluded. A radiologist higher specialist trainee reviewed all the chest radiographs which were reported to have a consolidation. This helped ensure that only chest radiographs with clear signs of consolidations were included in this study. The final number of patients who satisfied all the aforementioned was 402 (n). The patients’ demographics were documented along with the mortality and whether or not follow-up imaging was done or not. The initial chest radiograph reports were analysed to see whether the reporting radiologist had recommended follow-up imaging and consequently whether this affected the rate of follow-up or not. Other variables that may have affected rate of follow-up such as whether the patient was admitted and whether the consolidations were unilateral or bilateral were also documented. All follow-up imaging done from one week until 12 weeks after the initial chest radiograph was scrutinized. The data collected was analysed using Statistical Package for Social Sciences (SPSS) software. Where relevant, the histology, if available, and stage of the lung malignancy were noted. The 8th edition TNM classification4 was used to assess staging. Results As mentioned previously, a total of 402 patients met our inclusion criteria. 207 were male (51.5%) and the age ranged from 50 till 99 years. The mean age was 74.18 years (S.D. ±11.8 years) with the median being 76 years. Follow-up imaging was performed in 214 patients within 12 weeks after the initial chest radiograph. This implies that 214 patients had chest imaging done between 1 week and 12 weeks after initial presentation (as documented in Table 3). Chest radiographs done on admitted patients who were in hospital for at least 24 hours were excluded.
Table 3:Overview of the data gathered from all 402 patients with radiological signs of a lung consolidation and presenting with a community-acquired pneumonia from the months of January and August 2013-2016 and the month of January 2017.
Number of Patients (n) 402
Number of Males 207
Patients over 80 years old 143
Patients 50-80 years olds 259
Patients requiring admission 316
Follow-up imaging done (within 12 weeks) 214
% Follow-up done imaging within 12 weeks 53.2%
Follow-up Recommended by Radiologist 130
Follow-up done after Radiologist Recommendation (within 12 weeks) 76
% 12 week follow-up rate after Radiologist Recommendation 58.5%
12 week follow-up in patients over 80 years old 73
% 12-week follow up in  patients over 80 years old 51.0%
12 week follow-up in patients 50-80 years old 141
% 12-week follow up in patients 50-80 years old 54.4%
Number of males with a follow-up chest imaging within 12 weeks 110
%12-week follow up in males 53.1%
Number of females with a follow-up chest imaging within 12 weeks 104
%12-week follow up in females 53.3%
Lung malignancy cases diagnosed on follow-up of non-resolving lesions 7
% diagnostic yield on follow-up (i.e. number of patients diagnosed with lung malignancy compared to total number - n) 1.74%
% of followed-up patients diagnosed with lung malignancy 3.27%
Chest imaging done within 12 months 320
% of cases having chest imaging done within 12 months 79.6%
Lung malignancy cases diagnosed within 12 months 8
% potential diagnostic yield (as identified by looking at all imaging done within 12 months) 1.99%
316 patients of the cohort of 402 patients (78.6%) required hospital admission after the initial chest radiograph. Repeat imaging after treatment of the pneumonia was suggested by a radiologist in 130 chest radiographs, i.e. in 32.3% of the CAP population. Refer to Tables 3 and 4 for an overview of the data collected.
Table 4:Comparing community-acquired pneumonias’ follow-up in the months of August 2013-2016 with the months of January 2013-2017
  Januaries 2013-2017 Augusts 2013-2016
Number of Patients (n) 270 132
Number of Males 133 74
Patients over 80 years old 96 47
Patients 50-80 years olds 174 85
Follow-up imaging done (within 12 weeks) 147 67
% Follow-up done imaging within 12 weeks 54.4% 50.8%
Patients requiring admission 215 101
Follow-up done in admitted patients (within 12 weeks) 114 53
% 12 week follow-up rate in admitted patients 53.0% 52.5%
Follow-up Recommended by Radiologist 98 32
Follow-up done after Radiologist Recommendation (within 12 weeks) 59 17
% 12 week follow-up rate after Radiologist Recommendation 60.2% 53.1%
12 week follow-up in patients over 80 years old 46 27
% 12-week follow up in  patients over 80 years old 47.9% 57.4%
12 week follow-up in patients 50-80 years old 101 40
% 12-week follow up in patients 50-80 years old 58.0% 47.1%
Number of males with a follow-up chest imaging within 12 weeks 72 38
%12-week follow up in males 54.1% 51.4%
Number of females with a follow-up chest imaging within 12 weeks 75 29
%12-week follow up in females 54.7% 50.0%
Lung malignancy cases diagnosed on follow-up of non-resolving lesions 4 3
% diagnostic yield on follow-up (i.e. number of patients diagnosed with lung malignancy compared to total number - n) 1.48% 2.27%
% of followed-up patients diagnosed with lung malignancy 2.72% 4.48%
Chest imaging done within 12 months 217 103
% of cases having chest imaging done within 12 months 80.4% 78.0%
Lung malignancy cases diagnosed within 12 months 5 3
% potential diagnostic yield (as identified by looking at all imaging done within 12 months) 1.85% 2.27%
Different follow-up rates within 12 weeks were compared according to gender, the month of presentation and whether follow-up was recommended by radiologist or not (Figure 1), if the consolidations was bilateral and whether the patient required admission by using a chi square statistical test for each variable. {*figure 1*} Taking a p-value of

Figure

Test image

Author Biographies

  • Julian Delicata, MD

    Department of Medicine,
    Mater Dei Hospital,
    Malta

  • Sophie Degiorgio, MD, Mater Dei Hospital, Malta

    Department of Medicine,
    Mater Dei Hospital,
    Malta

  • Simon Gatt, MD

    Department of Radiology,
    Mater Dei Hospital,
    Malta

  • Luke Sultana, MD, Mater Dei Hospital, Malta

    Department of Medicine,
    Mater Dei Hospital,
    Malta

  • Adrian Mizzi, MD

    Department of Radiology,
    Mater Dei Hospital,
    Malta

  • Christopher Zammit, MD

    <p>Department of Respiratory Medicine,<br/>Mater Dei Hospital,<br/>Malta</p>

Additional Files

Published

2019-12-09

Issue

Vol. 3 No. 3 (2019)

Section

Original Articles

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