ORIGINAL ARTICLE   

The Quarterly Journal of Nuclear Medicine and Molecular Imaging 2022 June;66(2):171-8

DOI: 10.23736/S1824-4785.19.03183-2

Copyright © 2019 EDIZIONI MINERVA MEDICA

lingua: Inglese

Respiratory gated multistatic PET reconstructions to delineate radiotherapy target volume in patients with mobile lung tumors

Sebastien HAPDEY ^{1, 2} ✉, Bernard DUBRAY ^{2, 3}, Mathieu CHASTAN ¹, Sebastien THUREAU ^{2, 3}, Pierrick GOUEL ¹, Agathe EDET-SANSON ^{1, 2}, Stéphanie BECKER ^{1, 2}, Pierre VERA ^{1, 2}, Anne-Charlotte BOUYEURE-PETIT ¹

¹ Department of Nuclear Medicine, Henri Becquerel Cancer Center, Rouen, France; ² QuantIF-LITIS EA4108, University of Rouen, Rouen, France; ³ Department of Radiotherapy, Henri Becquerel Cancer Center, Rouen, France

BACKGROUND: PET-CT with ¹⁸F-FDG or other radiopharmaceuticals is a recommended tool to help the delineation of lung cancers candidate to radiotherapy. The motion artifacts caused by respiratory movements are reduced by 4D acquisitions. We introduced an extended reconstruction algorithm (multiple reconstruct register and average [multi-RRA]) which requires much shorter acquisition times than standard 4D PET-CT. Our aim was to evaluate the interest on multi-RRA images as an alternative of 3D and 4D PET-CT for the delineation of lung lesion.
METHODS: PET acquisitions synchronized to the respiratory signal were obtained in 18 patients with mobile lung tumors. We compared the tumor volumes delineated on Multi-RRA images to 3D and 4D PET-CT, considering the 4D CT as a reference. The tumor volumes were delineated and compared with topologic similarity indexes (Dice, Jaccard and overlap).
RESULTS: Twenty tumors were delineated. The volumes delineated with multi-RRA and 4D PET were not significantly different (mean difference of 0.2±0.7 mL). Comparison by pairs (Tukey-Kramer test) showed that 3D-PET volumes were significantly smaller than 4D-PET and multi-RRA volumes (P<0.001). Topologic similarity indexes with 4D-PET were slightly statistically higher with multi-RRA than with 3D-PET (Dice and Jaccard) or 4D-CT (Dice, Jaccard and Overlap).
CONCLUSIONS: The tumor volumes delineated on multi-RRA are similar to the volumes obtained with 4D PET, with shorter acquisition time.

KEY WORDS: 18F-FDG; Positron emission tomography; Computed tomography; Lung cancer; Respiratory gating; Radiotherapy