High Reproducibility of Tumor Hypoxia Evaluated by 18F-Fluoromisonidazole PET for Head and Neck Cancer

Journal of Nuclear Medicine

Yoichi M. Ito¹  Koichi Yasuda¹  Yuji Kuge¹  Tohru Shiga¹  Nagara Tamaki¹  Keiichi Magota¹  Katsuhiko Kasai¹  Hiroki Shirato¹  Shozo Okamoto¹ 

关键词: tumor hypoxia;    ¹⁸F-FMISO;    reproducibility;    head and neck cancer;   

DOI  :  10.2967/jnumed.112.109330

学科分类：医学（综合）

来源: Society of Nuclear Medicine

【 摘 要 】

Tumor hypoxia is well known to be radiation resistant. 18F-fluoromisonidazole (18F-FMISO) PET has been used for noninvasive evaluation of hypoxia. Quantitative evaluation of 18F-FMISO uptake is thus expected to play an important role in the planning of dose escalation radiotherapy. However, the reproducibility of 18F-FMISO uptake has remained unclarified. We therefore investigated the reproducibility of tumor hypoxia by using quantitative analysis of 18F-FMISO uptake. Methods: Eleven patients with untreated head and neck cancer underwent 2 18F-FMISO PET/CT scans (18F-FMISO1 and 18F-FMISO2) with a 48-h interval prospectively. All images were acquired at 4 h after 18F-FMISO injection for 10 min. The maximum standardized uptake (SUVmax), tumor-to-blood ratio (TBR), and tumor-to-muscle ratio (TMR) of 18F-FMISO uptake were statistically compared between the 2 18F-FMISO scans by use of intraclass correlation coefficients (ICCs). The hypoxic volume was calculated as the area with a TBR of greater than or equal to 1.5 or the area with a TMR of greater than or equal to 1.25 to assess differences in hypoxic volume between the 2 18F-FMISO scans. The distances from the maximum uptake locations of the 18F-FMISO1 images to those of the 18F-FMISO2 images were measured to evaluate the locations of 18F-FMISO uptake. Results: The SUVmax (mean ± SD) for 18F-FMISO1 and 18F-FMISO2 was 3.16 ± 1.29 and 3.02 ± 1.12, respectively, with the difference between the 2 scans being 7.0% ± 4.6%. The TBRs for 18F-FMISO1 and 18F-FMISO2 were 2.98 ± 0.83 and 2.97 ± 0.64, respectively, with a difference of 9.9% ± 3.3%. The TMRs for 18F-FMISO1 and 18F-FMISO2 were 2.25 ± 0.71 and 2.19 ± 0.67, respectively, with a difference of 7.1% ± 5.3%. The ICCs for SUVmax, TBR, and TMR were 0.959, 0.913, and 0.965, respectively. The difference in hypoxic volume based on TBR was 1.8 ± 1.8 mL, and the difference in hypoxic volume based on TMR was 0.9 ± 1.3 mL, with ICCs of 0.986 and 0.996, respectively. The maximum uptake locations of the 18F-FMISO1 images were different from those of the 18F-FMISO2 images and were within the full width at half maximum of the PET/CT scanner, except in 1 case. Conclusion: The values for 18F-FMISO PET uptake and hypoxic volume in head and neck tumors between the 2 18F-FMISO scans were highly reproducible. Such high reproducibility of tumor hypoxia is promising for accurate radiation planning.

【 授权许可】

Unknown