<qa>  What is the name of the test that is open to patients whose tumour is shown to expressThe study is open to patients whose tumour is shown to express the 806 antigen by a special test. Further tests are required to determine eligibility for the study. These tests determine general health and include: physical examination; blood samples for routine tests; routine tests to determine the extent of tumour prior to starting treatment with 111 In-ch806 eg. X-ray, CT scan, etc. 