Zevalin Post-marketing Surveillance for Adequateness of Image Interpretation Criteria in Japan

This study is a regulatory post-marketing surveillance of Zevalin (ibritumomab tiuxetan) in Japan. In-111 Zevalin is, at first, injected to patient for gamma scan imaging to assess biodistribution of the Zevalin. When the imaging shows no altered distribution, Y-90 Zevalin is injected to the patient for the actual treatment. The objective of this study is to assess appropriateness and necessity of revision of the standardized criteria for image interpretation of In-111 Zevalin by comparing assessment by the investigator and the members of the committee for image interpretation of In-111 Zevalin. A total 40 patients will be recruited.