Dual time PET-CT for mediastinal nodal staging in patients diagnosed with non-small cell lung cancer in an area with high prevalence of infectious granulomatous disease (LACOG-0114).

e20083 Background: The role of dual-time-point PET/CT acquisition for mediastinal node staging in non-small cell lung cancer (NSCLC) is still controversial. Interpretation of PET/CT results is challenging in areas with high prevalence of infectious granulomatous diseases, whereas the use of dual-time PET/CT could reduce the false-positive results. This study aims to evaluate the performance of dual-time PET-CT for mediastinal node staging in patients with NSCLC in an area with high prevalence of infectious granulomatous diseases (i.e. 99 cases of tuberculosis per 100.000 habitants). Methods: Patients diagnosed with clinical stages I-III NSCLC performed dual-time-point PET/CT (images acquired in hour 1 and 2) followed by mediastinal lymph node biopsy. Different cut-offs for SUV were evaluated to test accuracy in each time-point. Results: One hundred patients were enrolled, of which 85 had mediastinal node biopsy after PET-CT. Median age was 65 years (range 47-80), 49 (58%) were male, 80 (94%) were current or former smokers, and 1 (1.2%) had history of tuberculosis. Dual-time-point acquisition results were similar to those in single-time-point (Table 1). The highest sensitivity (87%) and NPV (90%) was achieved when a cut-off SUV > 0 was used. Conclusions: Dual-time point PET/CT did not improve accuracy of PET/CT-based LN staging in NSCLC in an area with high prevalence of infectious granulomatous diseases. [Table: see text]

Download Full-text

Real-world data evaluating the value of PET-CT for mediastinal staging in patients diagnosed with non-small cell lung cancer in an area with high prevalence of granulomatous diseases: The LACOG-0114 study.

Journal of Clinical Oncology ◽

10.1200/jco.2017.35.15_suppl.e20065 ◽

2017 ◽

Vol 35 (15_suppl) ◽

pp. e20065-e20065

Author(s):

Carlos Cezar Fritscher ◽

Mara Lise Zanini ◽

Eduardo Herz Berdichevski ◽

Eduardo Vilas ◽

Bruno Hochhegger ◽

...

Keyword(s):

Lung Cancer ◽

Small Cell Lung Cancer ◽

Small Cell ◽

Small Cell Lung ◽

Mediastinal Staging ◽

Pet Ct ◽

High Prevalence ◽

Histopathological Evaluation ◽

Mediastinal Involvement ◽

Granulomatous Diseases

e20065 Background: Evaluation of the mediastinum is critical for therapeutic decision in patients with operable non-small cell lung cancer. This analysis aims to evaluate specificity and positive predictive value (PPV) of PET-CT in mediastinal staging of patients diagnosed with NSCLC in South Brazil, an area with high prevalence of infectious granulomatous disease, such as tuberculosis (estimated incidence of 45 cases/100.000 and only 63.7% of cure rate) (http://www.saude.rs.gov.br/upload/1459169540_RELATÓRIO%20TUBERCULOSE%202016.pdf). Methods: Patients with stages I-III NSCLC underwent 18FDG PET-CT before invasive mediastinal staging. Different SUV cut-offs were evaluated, but for the purpose of this analysis were considered positive all PET-CTs showing any mediastinal uptake > 5 SUV. This abstract shows the specificity and the PPV associated with PET-CT when this high-uptake cut-of is considered. Results: From Aug/2014 to Aug/2016, 100 patients were enrolled, all treated at the Brazilian Public Health System, of which 85 were submitted to mediastinoscopy after PET-CT. Median age was 65 years (range 47-80). At baseline, 49 (58%) patients were male and 68 (80%) white. Current or former smokers accounted for 94% (80/85) of the sample. The prevalence of mediastinal involvement was 27% (23/85) confirmed by histopathological evaluation. PET-CT showed specificity of 79% (95% CI 67%–88%) and PPV of 54% (95% CI 40%–67%) when a SUV > 5 was used as cut-off for positivity (see table). Conclusions: These findings consolidate the clinical impression that a positive PET-CT does not confirm the diagnosis of mediastinal involvement in NSCLC patients treated in areas with high prevalence of infectious granulomatous diseases. In this scenario, all positive findings should be confirmed with histopathological evaluation to assure the diagnosis. Clinical trial information: NCT02664792. [Table: see text]

Download Full-text