Local relapse of nasopharyngeal cancer and Voxel-based analysis of FMISO uptake using PET with semiconductor detectors

• Nishikawa, Yukiko

• Yasuda, Koichi

• Okamoto, Shozo

• Ito, Yoichi M.

• Onimaru, Rikiya

• Shiga, Tohru

• Tsuchiya, Kazuhiko

• Watanabe, Shiro

• Takeuchi, Wataru

• Kuge, Yuji

• Peng, Hao

• Tamaki, Nagara

• Shirato, Hiroki

Abstract

Background: Hypoxic cancer cells are thought to be radioresistant and could impact local recurrence after radiotherapy (RT). One of the major hypoxic imaging modalities is [18F]fluoromisonidazole positron emission tomography (FMISO-PET). High FMISO uptake before RT could indicate radioresistant sites and might be associated with future local recurrence. The predictive value of FMISO-PET for intra-tumoral recurrence regions was evaluated using high-resolution semiconductor detectors in patients with nasopharyngeal carcinoma after intensity-modulated radiotherapy (IMRT). Methods: Nine patients with local recurrence and 12 patients without local recurrence for more than 3 years were included in this study. These patients received homogeneous and standard doses of radiation to the primary tumor irrespective of FMISO uptake. The FMISO-PET image before RT was examined via a voxel-based analysis, which focused on the relationship between the degree of FMISO uptake and recurrence region. Results: In the pretreatment FMISO-PET images, the tumor-to-muscle ratio (TMR) of FMISO in the voxels of the tumor recurrence region was significantly higher than that of the non-recurrence region (p < 0.0001). In the recurrent patient group, a TMR value of 1.37 (95% CI: 1.36-1.39) corresponded to a recurrence rate of 30%, the odds ratio was 5.18 (4.87-5.51), and the area under the curve (AUC) of the receiver operating characteristic curve was 0.613. In all 21 patients, a TMR value of 2.42 (2.36-2.49) corresponded to an estimated recurrence rate of 30%, and the AUC was only 0.591. Conclusions: The uptake of FMISO in the recurrent region was significantly higher than that in the non-recurrent region. However, the predictive value of FMISO-PET before IMRT is not sufficient for up-front dose escalation for the intra-tumoral high-uptake region of FMISO. Because of the higher mean TMR of the recurrence region, a new hypoxic imaging method is needed to improve the sensitivity and specificity for hypoxia.

Journal

• Radiation oncology

  Radiation oncology 12 148-, 2017-09-06

  BioMed Central

Keywords

• [18F]fluoromisonidazole
• Positron emission tomography
• Hypoxia
• Intensity-modulated radiotherapy
• Nasopharyngeal carcinoma

Details

• CRID: 1050001202677838464
• NII Article ID: 120006360098
• DOI: 10.1186/s13014-017-0886-9
• HANDLE: 2115/67571
• ISSN: 1748717X
• Web Site: http://link.springer.com/content/pdf/10.1186/s13014-017-0886-9.pdf
• Text Lang: en
• Article Type: journal article
• Data Source:
  • IRDB
  • Crossref
  • CiNii Articles
  • KAKEN