A Randomised Study Evaluating Diagnostics of Pleural Effusion Among Patients Suspect of Cancer.

Local Anesthetic Thoracoscopy Versus Ultrasound Guided Pleural Biopsies and Repeat Thoracocentesis in Pleural Effusion After Inconclusive Initial Thoracentesis: a Randomized Study

Pleural fluid can be caused by cancer. Patients with repeated presentation of pleural fluid where initial diagnostic tests have been inconclusive are the focus of this trial. In this clinical trial patients are randomized into two groups and the efficacy of local anesthetic thoracoscopy (LAT) is compared to an ultrasound guided biopsy of the outer lining of the lung. The aim is not only the diagnostic yield in diagnosing cancer, but also the procedures ability to diagnose specific cancer mutations and immune system markings.

Methods and objectives:

Patients with reoccuring one-sided pleural fluid, with a marked clinical risk of cancer based on findings in medical work-up, radiological scans, biochemistry and medical history and who are undiagnosed upon initial pleural fluid analysis are the target patients of the trial. Patients are randomized into two groups to have undertaken either pleural biopsy at the optimal site for a repeat thoracentesis or LAT. Thus diagnostic yield for both fluid analysis and biopsy analysis will be compared to tissue samples taken with LAT.

We hypothesize that LAT is superior both to pleural biopsy and repeat thoracentesis in providing diagnostic clarification and providing sufficient basis for treatment without further procedures resulting in less time consumption, cost and discomfort for the patient.

Inclusion Criteria:

• Age 18 years or older patients with single previous thoracentesis of a unilateral pleural exudate according to Lights criteria without malignant cells.
• Lights Criteria:

Pleural fluid protein/serum protein ratio greater than 0.5 pleural fluid LDH/serum LDH ratio greater than 0.6 Pleural fluid LDH greater than two-thirds the upper limits of the Laboratorys normal Serum LDH

• Contrast enhanced CT of the Chest and abdomen performed
• Clinical suspicion of cancer such as, but not limited to, weight loss, malaise, anemia
• Pet-CT results or former cancer diagnosis Informed consent

Exclusion Criteria:

• bilateral pleural effusions
• known cause of pleural effusion
• likely non-malignant course of a unilateral pleura effusion such as (but not restricted to) pneumonia, trauma, pleuritis, heart failure
• any contraindication to the study procedures