The Efficacy of Combining Endoscopic Modalities for the Diagnosis of Solitary Pulmonary Lesions

Background:

Despite recent years' improvement regarding the treatment of lung cancer, it remains the leading cause of cancer deaths in Denmark. This is partly due to many patients being diagnosed in an advanced stage limiting the possibilities of curative treatment. Much attention has therefore been aimed at developing tools for early identification of patients with possible lung cancer . Screening or easy access to CT of the chest may help to identify patients with possible early stage lung cancer. Performing biopsies of small lung lesions in a safe manner without inexpedient complications, however, is an ongoing diagnostic challenge especially for the increasing elderly patient population and patients with decreased lung function. If patients are to benefit from an improved identification of possible early stage lung cancer, it is necessary to also further improve the methods for obtaining biopsies in this patient population in order to decrease the morbidity during the diagnostic work-up and to prepare the patients for treatment in a secure manner.

Current methods for performing biopsies of small lung lesions are transthoracic, endoscopic or surgical. When compared to surgery, the endoscopic methods have the advantages of being easily accessible, cheap, safe with a very low risk of complications, and have limited patient discomfort following the procedure. The major drawback is the diagnostic yield still being significantly lower than surgery.

In recent years, two methods have been developed which seem to improve the diagnostic yield of bronchoscopy for diagnosing peripheral lung lesions. The rationale behind both techniques is to improve identification of the lung lesions prior to performing the biopsies and thereby improving the chance of obtaining representative tissue samples. One method involves the use of a radial ultrasound probe inserted in the working channel of the bronchoscope, which enables the proceduralist to perform radial endobronchial ultrasound (rEBUS) to more accurately identify the lung lesions before sampling them. The other method involves the use of electromagnetic navigation bronchoscopy (ENB) to guide the operator to the lung lesion. One small randomised clinical trial has indicated that the diagnostic yield can be further improved by a multimodal approach, which combines both rEBUS and ENB in the same procedure. The drawbacks of such a combination are however increased costs and procedure time, thus limiting the number of procedures which can be performed within a given time frame.

This PhD thesis aims to determine whether a combination of rEBUS and ENB is superior to ENB alone in patients with suspected lung cancer due to a peripheral lung lesion as well as an estimate of the hospital costs of the entire diagnostic work up for lung cancer when combining ENB and rEBUS as compared to ENB alone.