J Nucl Med. 2007; 48 (Supplement 2):428P
Instrumentation & Data Analysis: Instrumentation
Instrumentation Posters |
Development of imaging system for 90Y malignant lymphoma treatment using an imaging plate
Shigeki Ito1,
Kouichi Adachi1,
Takuya Saze2,
Shizuhiko Deji3,
Masahiro Hirirota4,
Kazuyuki Mori5 and
Kunihide Nishizawa1
1 Nagoya University, Nagoya, Japan; ;
2 Radioisotope Research Center, Tokunima University, Tokushima, Japan; ;
3 Advanced Telecommunications Research Institute International, Kyoto, Japan; ;
4 National Institute of Radiological Sciences, Chiba, Japan; ;
5 ING Co. Ltd., Tokyo, Japan
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Objectives: 90Y-Iritumomab tiuxetan as a radioimmunotherapeutic agent is used for the treatment of patients with relapsed or refracyory low-grade, follicular, or CD20+ tranceformed non-Hodgkin’s lymphoma (NHL). However, there is no device for imaging 90Y lymph nodes because 90Y emits only ß-particles. A two-dimensional nuclear imaging system using an imaging plate (IP) and an image analyzer (IP system) were devised in our previous study. If the IP system can be applied to the 90Y imaging, 90Y treatment effect will be easily confirmed without 111In imaging. The purposes of this study are to demonstrate the feasibility of 90Y lymph nodes imaging using the IP system and to determine the system performance of the IP system to 90Y. Methods: System spatial resolution of the IP systems to 90Y was determined by referring to the National Electrical Manufacturers Association standard. A 1 mm thick polyethylene resin capillary tube with a 0.9 mm inner diameter and 80 mm in length loaded with 90YCl solution of 3.7 MBq was used as a line source. The sensitivity was represented by using lower detection limits. The lower detection limits of the IP system was calculated with the count-activity conversion coefficients. The coefficients were determined by using a 90Y point source and acrylic plates. A 3mm diameter charcoal filter loaded with 90YCl solution of 170kBq (70µl) was used as a point source. Acrylic plates’ thicknesses were 1, 3, 4, 5, 6, 8, 9, 12 mm. Results: Images of 90Y ß-particles after passing through the 12 mm acrylic plate were displayed by using the IP system, though the maximum range of ß-particles emitted from 90Y was 12 mm. The full width at half maximum (FWHM) of the IP system without scatterer was 2.5±0.7 mm, and that with scatterer was 4.9±0.5 mm. The lower detection limit of the IP system was 28 Bq at 12 mm from the body surface. Conclusions: An IP system is applicable for obtaining 90Y images in lymph nodes distributed from the body surface to 12 mm in depth. The system spatial resolution and the lower detection limit were 2.5 mm and 28 Bq, respectively.
