High Spatial Resolution Digital Positron Emission Tomography Images With Dedicated Source-to-background Algorithm for Radiotherapy Planning

Takahiro Watakabe; Ryo Toya; Tetsuo Saito; Tomohiko Matsuyama; Shinya Shiraishi; Yudai Kai; Yoshinobu Shimohigashi; Natsuo Oya

doi:10.21873/anticanres.14227

High Spatial Resolution Digital Positron Emission Tomography Images With Dedicated Source-to-background Algorithm for Radiotherapy Planning

Anticancer Res. 2020 May;40(5):2567-2572. doi: 10.21873/anticanres.14227.

Authors

Takahiro Watakabe¹, Ryo Toya², Tetsuo Saito¹, Tomohiko Matsuyama¹, Shinya Shiraishi³, Yudai Kai^{4

5}, Yoshinobu Shimohigashi⁴, Natsuo Oya¹

Affiliations

¹ Department of Radiation Oncology, Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan.
² Department of Radiation Oncology, Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan ryo108@kumamoto-u.ac.jp.
³ Department of Diagnostic Radiology, Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan.
⁴ Department of Radiological Technology, Kumamoto University Hospital, Kumamoto, Japan.
⁵ Department of Health Sciences, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.

PMID: 32366401
DOI: 10.21873/anticanres.14227

Abstract

Background/aim: To evaluate the utility of high spatial resolution digital positron emission tomography images with the source-to-background ratio (SBR) algorithm for gross tumour volume (GTV) delineation.

Materials and methods: The bowl and spheres (10-37 mm) were filled with fluoro-2-deoxy-D-glucose to achieve 4-16 times background radioactivity. The images were reconstructed using three isotropic voxel sizes. The SBR and percentage threshold (TH) to SUV_max were calculated. The plots between SBR and TH were fitted using a regression equation. The contoured volumes (CVs) of the spheres were calculated by applying TH.

Results: TH was 38.6+75.0/SBR for 4 mm voxel size; 39.6+37.0/SBR for 2 mm; and 38.8+35.2/SBR for 1 mm. The mean relative errors between CV and true volume for 4, 2, and 1 mm voxel sizes were 15%, 7%, and 7%, respectively.

Conclusion: The present technique is useful for GTV delineation with reduced contouring error.

Keywords: Positron emission tomography; auto-delineation; digital positron emission tomography; gross tumour volume; radiotherapy planning.

MeSH terms

Algorithms*
Humans
Image Processing, Computer-Assisted*
Imaging, Three-Dimensional*
Neoplasms / diagnostic imaging
Neoplasms / pathology
Positron Emission Tomography Computed Tomography
Positron-Emission Tomography* / methods
Radiotherapy Planning, Computer-Assisted* / methods