When a patient is diagnosed with cancer it's critical for their health care providers to know exactly what stage of disease there is, how extensive the spread is and precisely where it's located in the body. Staging is the process of determining all of this, so that the best treatments can be given. Normally staging is done surgically, but newer techniques of imaging are also useful.
In a study done at the Academic Research Center in Amsterdam, endosonography, an imaging technique for staging lung cancer, was compared with tradition surgical staging using the mediastinoscopy process where incisions are made in the neck and the chest. In a surprising finding, the results showed that the imaging was far better at detecting mediastinal nodal metastases than the surgery. Imaging found the metastases in 94% of cases, whereas the surgery only found it in 79% of cases. Despite the significant differences, survival rates were almost exactly equal, with no increased survival in the imaging group. Both groups had a survival rate of 35%. While there seems to be no explanation for the difference, the team said that the imaging is a preferable procedure, even without an increased survival benefit because it's less invasive and carries less risk.