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. 2025 Dec 8.
doi: 10.1186/s13550-025-01341-4. Online ahead of print.

Hypo-segmentation of 18F-BPA PET-based boron distribution: a pragmatic approach for efficient BNCT treatment planning

Yi-Chiao Teng  1   2 , Jiang Chen  2   3 , Wan-Bing Zhong  2 , Qin Lin  1 , Yuan-Hao Liu  4   5   6   7
Affiliations

Hypo-segmentation of 18F-BPA PET-based boron distribution: a pragmatic approach for efficient BNCT treatment planning

Yi-Chiao Teng et al. EJNMMI Res. .

Abstract

Background: Precise modeling of boron distribution is essential for boron neutron capture therapy (BNCT) dose calculation. While full-three-dimensional (f3D) voxel modeling of ¹⁸F-BPA PET data offers high spatial resolution, its clinical value is limited by intrinsic image resolution-especially PET-and by registration errors in multi-modality image fusion. These factors constrain the reliability of voxel-level dose interpretation and increase computational burden. We propose a hypo-segmentation (hS) method that groups target tissue-to-blood ratio (TBR) values into 0.5-unit intervals to approximate boron distribution. This study retrospectively evaluated four malignant brain tumor cases, comparing dosimetric metrics derived from hS and f3D approaches. Key dose-volume parameters (Dmean, D80, V14 Gy-Eq), spatial agreement (gamma pass rate), and dose-volume curve similarity (dynamic time warping, DTW) were assessed. Dose consistency in normal brain tissue was also evaluated using D0.1 cc, Dmean, and V13 Gy-Eq.

Results: The hS method showed strong agreement with f3D results: within 2% for tumor Dmean, 3% for D80, and 5% for V14 Gy-Eq. Gamma pass rates exceeded 90% in three of four cases. In brain tissue, dose deviations between hS and f3D remained within 2%, demonstrating reliability even in low-uptake, spatially uniform regions. A single small, heterogeneous tumor showed larger discrepancy (D95 deviation = 14.3%, gamma pass rate = 82%), which was mitigated by refining segmentation (h = 0.25).

Conclusions: The hS method offers a clinically practical and computationally efficient alternative to full voxel-wise modeling. It preserves dosimetric fidelity in both tumor and normal brain regions, while aligning with the intrinsic resolution of PET and multimodal imaging. This approach supports accurate yet streamlined BNCT dose planning, particularly in clinical settings where ultra-high spatial granularity provides limited added value.

Trial registration number (trn): ChiCTR2200066473, registered on December 16, 2022.

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Conflict of interest statement

Declarations. Ethics approval and consent to participate: The IIT was conducted in compliance with the Declaration of Helsinki and Good Clinical Practice guidelines, approved by the Medical Ethics Committee of Xiamen Humanity Hospital (Approval Number: HAXM-MEC-20220901-005-02) and the Institutional Review Board of the National Key Research and Development Program (Grant Number: 3502720201031). It was registered with the China Clinical Trial Registration Center (Registration Number: ChiCTR2200066473) [35] as well as with the National Medical Research Registration and Recordation Information System of the National Healthcare Security Administration. Informed consent was obtained from all participants. Consent for publication: All patients provided written informed consent for the use of anonymized imaging and clinical data for research and publication purposes. Competing interests: The authors declare that they have no competing interests.

References

    1. Barth RF, Gupta N, Kawabata S. Evaluation of sodium borocaptate (BSH) and Boronophenylalanine (BPA) as boron delivery agents for neutron capture therapy (NCT) of cancer: an update and a guide for the future clinical evaluation of new boron delivery agents for NCT. Cancer Commun. 2024;44(8):893–909.
    1. Hirose K, et al. Boron neutron capture therapy using cyclotron-based epithermal neutron source and Borofalan (10B) for recurrent or locally advanced head and neck cancer (JHN002): an open-label phase II trial. Radiother Oncol. 2021;155:182–7.
    1. Sato M, et al. Safety of boron neutron capture therapy with Borofalan (10B) and its efficacy on recurrent head and neck cancer: real-world outcomes from nationwide post-marketing surveillance. Cancers. 2024;16(5):869.
    1. Lan TL, et al. Advances in boron neutron capture therapy (BNCT) for recurrent intracranial meningioma. Int J Mol Sci. 2023;24(5):4978. https://doi.org/10.3390/ijms24054978.
    1. Fukuda H. Boron neutron capture therapy (BNCT) for cutaneous malignant melanoma using (10)B-p-boronophenylalanine (BPA) with special reference to the radiobiological basis and clinical results. Cells. 2021;10(11):2881. https://doi.org/10.3390/cells10112881.

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