<qa>  How long will blood samples be taken before the treatment infusion?Blood samples will be taken just before the treatment infusion and then weekly for 9 weeks and again at 12 weeks. There will be weekly physical examinations until 9 weeks after the treatment infusion and again at 12 weeks. Total study duration is 13 weeks from the trace labelled infusion of 131I-hu A33, that is 12 weeks from the treatment infusion of 131I-hu A33. Patients will only receive one treatment infusion of 131I hu-A33 antibody. 