TY - JOUR T1 - Visualization and dose estimation of 90Y-ibritumomab-tiukisetan accumulation in lymphoma patients using TOF PET/CT JF - Journal of Nuclear Medicine JO - J Nucl Med SP - 1987 LP - 1987 VL - 52 IS - supplement 1 AU - Shingo Baba AU - Koichiro Abe AU - Hirofumi Sawamoto AU - Yoshitaka Tanabe AU - Yasuhiro Maruoka AU - Masayuki Sasaki AU - Hiroshi Honda Y1 - 2011/05/01 UR - http://jnm.snmjournals.org/content/52/supplement_1/1987.abstract N2 - 1987 Objectives 90Y-labelled compounds used in targeted radiotherapy are usually imaged with SPECT by recording the bremsstahlung X-rays of the β decay. The continuous shape of the X-ray spectrum induced the presence of a significant fraction of scatter rays in the acquisition energy window, reducing the accuracy of biodistribution and of dosimetry assessment. The aim of this study was to assess the feasibility of PET/CT using instead the low branch of e- e+ pair production in the 90Y decay. Methods Biodistribution of 90Y tracer in the tumor was estimated using preceding 111In SPECT data of 8 patients and determined the rage of radioactivity for phantom study. Linearity of the 90Y signal was evaluated by phantom experiment using two PET/CT scanners (BGO system and LSO system) with various acquisition parameters including Time of Flight (TOF). In clinical study, 48hours after administration of 90Y labeled antibody to three patients, distribution of the activity was measured by 40 minute acquisition using clinical PET/CT scanner. Results Average uptake of 90Y in the tumor estimated by 111In SPECT was 127.2±77MBq/ml(40~250). Best linear relationship was obtained with LSO with TOF system. Linearity was maintained at the range of 70 to 2500 (KBq/ml) with this system. Radioactivity smaller than 200 KBq was unmeasurable by BGO system. Image quality of LSO-TOF system was superior to that of LSO without TOF system. Lesions with estimated radioactivity larger than 740kBq/ml can be visible by both PET systems. Tumor uptake was observed in all three patients with LSO-TOF system correspondent to the lesions determined by 111In SPECT and 18F-FDG PET. Conclusions LSO-TOF system was superior to BGO system for the purpose of visualizing 90Y signal with PET. Although noisy image, results of this study support the implementation of 90Y PET for the dose estimation of radio-immunotheraphy using 90Y -ibritumomab-tiukisetan ER -