Evidence map›Paper›PMID 39354330›Full record

ArticleAnnals of nuclear medicine2025

A Monte Carlo study comparing dead-time losses of a gamma camera between tungsten functional paper and lead sheet for dosimetry in targeted radionuclide therapy with Lu-177.

Kohei Nakanishi, Naotoshi Fujita, Haruna Iwanaga, Yuki Asano, Shinji Abe, Ryuichi Nishii, Katsuhiko Kato

Abstract readComparative Study
In one paragraph

Article in Annals of nuclear medicine, 2025. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

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0citing papers in PubMed
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1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

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Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

0 citing papers in PubMed.

No citing paper in PubMed yet.

4 · The record

Corrections and comments

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5 · Who and what money

Authors and funding

7 authors.

Kohei NakanishiFunctional Medical Imaging, Biomedical Imaging Sciences, Division of Advanced Information Health Sciences, Department of Integrated Health Sciences, Nagoya University Graduate School of Medicine, 1-1-20 Daiko-Minami, Higashi-Ku, Nagoya, Aichi, Japan. nakanishi.kouhei.c2@f.mail.nagoya-u.ac.jp.ORCID http://orcid.org/0000-0003-3135-1017
Naotoshi FujitaDepartment of Radiological Technology, Nagoya University Hospital, 65 Tsurumai-Cho, Showa-Ku, Nagoya, Aichi, Japan.
Haruna IwanagaDepartment of Radiological Technology, Nagoya University Hospital, 65 Tsurumai-Cho, Showa-Ku, Nagoya, Aichi, Japan.
Yuki AsanoDepartment of Radiological Technology, Nagoya University Hospital, 65 Tsurumai-Cho, Showa-Ku, Nagoya, Aichi, Japan.
Shinji AbeDepartment of Radiological Technology, Nagoya University Hospital, 65 Tsurumai-Cho, Showa-Ku, Nagoya, Aichi, Japan.
Ryuichi NishiiMedical Imaging Engineering, Division of AdvancedInformation Health Sciences, Department of Integrated Health Sciences, Biomedical Imaging Sciences, Nagoya University Graduate School of Medicine, 1-1-20 Daiko-Minami, Higashi-Ku, Nagoya, Aichi, Japan.
Katsuhiko KatoFunctional Medical Imaging, Biomedical Imaging Sciences, Division of Advanced Information Health Sciences, Department of Integrated Health Sciences, Nagoya University Graduate School of Medicine, 1-1-20 Daiko-Minami, Higashi-Ku, Nagoya, Aichi, Japan.

Funding

JSPS Grant-in-Aid for Young Scientists 23K14863
6 · The paper itself

Abstract

objectiveDead-time loss is reported to be non-negligible for some patients with a high tumor burden in Lu-177 radionuclide therapy, even if the administered activity is 7.4 GBq. Hence, we proposed a simple method to shorten the apparent dead time and reduce dead-time loss using a thin lead sheet in previous work. The collimator surface of the gamma camera was covered with a lead sheet in our proposed method. While allowing the detection of 208-keV gamma photons of Lu-177 that penetrate the sheet, photons with energies lower than 208 keV, which cause dead-time loss, were shielded. In this study, we evaluated the usefulness of tungsten functional paper (TFP) for the proposed method using Monte Carlo simulation.

methodsThe count rates in imaging of Lu-177 administered to patients were simulated with the International Commission on Radiological Protection (ICRP) 110 phantom using the GATE Monte Carlo simulation toolkit. The simulated gamma cameras with a 0.5-mm lead sheet, 1.2-mm TFP, or no filter were positioned closely on the anterior and posterior sides of the phantom. The apparent dead times and dead-time losses at 24 h after administration were calculated for an energy window of 208 keV ± 10%. Moreover, the dead-time losses at 24-120 h were analytically assessed using activity excretion data of Lu-177-DOTATATE.

resultsThe dead-time loss without a filter was 5% even 120 h after administration in patients with a high tumor burden and slow excretion, while those with a lead sheet and TFP were 0.22 and 0.58 times less than those with no filter, respectively. The count rates with the TFP were 1.3 times higher than those with the lead sheet, and the TFP could maintain primary count rates at 91-94% of those without a filter.

conclusionsAlthough the apparent dead time and dead-time loss with the lead sheet were shorter and less than those with TFP, those with TFP were superior to those without a filter. The advantage of TFP over the lead sheet is that the decrease in primary count rates was less.

Indexed as

Gamma CamerasLeadLutetiumMonte Carlo MethodRadioisotopesRadiometryTungstenHumansPhantoms, ImagingTime FactorsLeadLutetiumLutetium-177RadioisotopesTungstenDead timeGamma cameraLu-177Monte Carlo simulationQuantification

Identifiers

PMID39354330
PMCPMC11799075

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Registered trials

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.