Decreased 18F-FDG Uptake 1 Day After Initiation of Chemotherapy for Malignant Lymphomas

Journal of Nuclear Medicine

Hideo Uchida¹  Shinichi Ito¹  Osami Daimaru¹  Kazuhiko Yoshiya¹  Satoshi Ito¹  Takeshi Nagata¹  Tomohiko Yamane¹ 

关键词: hematology;    oncology;    PET;    ¹⁸F-FDG;    malignant lymphoma;    chemotherapy;   

DOI  :  

学科分类：医学（综合）

来源: Society of Nuclear Medicine

【 摘 要 】

Several recent reports have described the judgment of chemotherapeutic effects on malignant lymphomas by use of 18F-FDG PET as early as a few courses after the initiation of chemotherapy. However, the optimal timing of 18F-FDG PET has yet to be clarified. Earlier 18F-FDG PET, such as day 1 after chemotherapy, may be affected by inflammation or chemotoxicity in addition to chemotherapeutic effects, but the ways in which uptake is changed are as yet unclear. We therefore examined changes in 18F-FDG PET results on day 1 after the initiation of chemotherapy for malignant lymphoma. Methods: Twelve patients with non-Hodgkin’s lymphoma were enrolled in this study. 18F-FDG PET was performed before therapy to determine baseline results and then was repeated at day 1 and day 20 after the initiation of chemotherapy (just before the initiation of the second course of chemotherapy) and at the end of chemotherapy. We selected 1–9 regions of interest (ROIs) from each patient and calculated the corrected standardized uptake value (SUVcor) by subtracting the SUV of surrounding normal tissue for a semiquantitative analysis. From the ROIs in each patient, the representative SUVcor with the highest SUVcor at baseline was selected, and the mean representative SUVcors for all 12 patients at baseline, day 1, day 20, and the end of chemotherapy were evaluated. Changes in the representative SUVcor were compared by use of paired t tests (2-tailed P values of <0.05 were considered statistically significant). Results: All representative SUVcors for each patient were lower on day 1 than at baseline, and the mean ± SD representative SUVcor for all patients was significantly decreased from 10.7 ± 7.9 at baseline to 5.8 ± 5.8 at day 1 (P = 0.0002; paired t test). On day 20, the mean ± SD SUVcor was 0.7 ± 1.0, showing a further decrease from the value at day 1 (P = 0.01). Although the mean ± SD SUVcor tended to decrease again to 0.4 ± 0.7 by the end of chemotherapy compared with the value at day 20, no significant difference was identified (P = 0.37). Conclusion: 18F-FDG uptake decreased as early as day 1 after the initiation of chemotherapy, indicating that 18F-FDG PET for initial diagnosis or staging must be performed before the onset of chemotherapy, as scan results might already be severely compromised after the first day.

【 授权许可】

Unknown