Physica medica : PM : an international journal devoted to the applications of physics to medicine and biology : official journal of the Italian Association of Biomedical Physics (AIFB) · 2026
Optimization of a β probe for 18F radio-guided surgery.
СтатьяНазвание и аннотация: Перевод в очереди
Обработка статьи · этапы, ошибки и управление
Загрузка состояния…
Ошибки и ограничения
История · было → стало
Состояние обновляется каждые 5 секунд, пока блок открыт. Процент показывается только там, где известен объём работы. Пауза останавливает продолжение этапа; текущий запрос к источнику может завершиться.
Mirabelli R, Morganti S, Faccini R, Arsini L, Mancini-Terracciano C, Nicolanti F, Collamati F
Аннотация
BACKGROUND: Radio-Guided surgery (RGS) assists surgeons in achieving complete tumor resection through the intraoperative detection of radiation emitted by tumor-targeting radiopharmaceuticals. In recent years, direct detection of β-radiation from β-emitting radiopharmaceuticals has been investigated to overcome certain limitations of conventional γ-based RGS. In this context, a particle detector based on a lightweight scintillator (p-terphenyl) has been developed, demonstrating high β-particles efficiency and remarkable transparency to photons, motivating further optimization for applications with [18F]FDG.
METHODS: Detectors with p-terphenyl thicknesses of 3 mm, 1 mm, 0.6 mm, and 0.4 mm were tested using a liquid [18F]FDG source. Measurements were performed in two experimental configurations: signal, where both positrons and annihilation photons reach the detector, and far background, dominated by isotropic annihilation photons. Signal discrimination capability was quantified using the figure of merit R=Signal/Background, and pulse amplitude spectra were analyzed to investigate threshold effects.
RESULTS: Reducing the scintillator thickness resulted in a strong suppression of γ-induced background while preserving β-detection efficiency. Among the tested configurations, the 0.6 mm scintillator provided the best compromise, yielding an almost twofold improvement in signal-to-background discrimination with respect to the 3 mm reference detector. Spectral analysis confirmed that the previously adopted hardware threshold remains optimal for signal discrimination.
CONCLUSIONS: A p-terphenyl scintillator thickness of 0.6 mm offers the best trade-off between β sensitivity and γ rejection for β-guided surgery applications with [18F]FDG. This study completes the experimental optimization of the β-probe for low-energy positron emitters and provides a solid basis for future in-vivo validation.
METHODS: Detectors with p-terphenyl thicknesses of 3 mm, 1 mm, 0.6 mm, and 0.4 mm were tested using a liquid [18F]FDG source. Measurements were performed in two experimental configurations: signal, where both positrons and annihilation photons reach the detector, and far background, dominated by isotropic annihilation photons. Signal discrimination capability was quantified using the figure of merit R=Signal/Background, and pulse amplitude spectra were analyzed to investigate threshold effects.
RESULTS: Reducing the scintillator thickness resulted in a strong suppression of γ-induced background while preserving β-detection efficiency. Among the tested configurations, the 0.6 mm scintillator provided the best compromise, yielding an almost twofold improvement in signal-to-background discrimination with respect to the 3 mm reference detector. Spectral analysis confirmed that the previously adopted hardware threshold remains optimal for signal discrimination.
CONCLUSIONS: A p-terphenyl scintillator thickness of 0.6 mm offers the best trade-off between β sensitivity and γ rejection for β-guided surgery applications with [18F]FDG. This study completes the experimental optimization of the β-probe for low-energy positron emitters and provides a solid basis for future in-vivo validation.