Organ-specific SPECT activity calibration using 3D printed phantoms for molecular radiotherapy dosimetry

被引：28

作者：

Robinson, Andrew P. ^{[1
]}

Tipping, Jill ^{[2
]}

Cullen, David M. ^{[1
]}

Hamilton, David ^{[2
]}

Brown, Richard ^{[1
]}

Flynn, Alex ^{[1
]}

Oldfield, Christopher ^{[1
]}

Page, Emma ^{[1
,2
]}

Price, Emlyn ^{[1
]}

Smith, Andrew ^{[1
]}

Snee, Richard ^{[1
]}

机构：

[1] Univ Manchester, Schuster Lab, Sch Phys & Astron, Manchester M13 9PL, Lancs, England

[2] Christie NHS Fdn Trust, CMPE, Wilmslow Rd, Manchester M20 4BX, Lancs, England

来源：

EJNMMI PHYSICS | 2016年 / 3卷 / 01期

基金：

英国科学技术设施理事会;

关键词：

Activity quantification; SPECT; Molecular radiotherapy; 3D printing; Absorbed dose; ABSORBED FRACTIONS; ELECTRONS; ACCURACY; SPHERES;

D O I：

10.1186/s40658-016-0148-1

中图分类号：

R8 [特种医学]; R445 [影像诊断学];

学科分类号：

1002 ; 100207 ; 1009 ;

摘要：

Background: Patient-specific absorbed dose calculations for molecular radiotherapy require accurate activity quantification. This is commonly derived from Single-Photon Emission Computed Tomography (SPECT) imaging using a calibration factor relating detected counts to known activity in a phantom insert. Methods: A series of phantom inserts, based on the mathematical models underlying many clinical dosimetry calculations, have been produced using 3D printing techniques. SPECT/CT data for the phantom inserts has been used to calculate new organ-specific calibration factors for Tc-99m and Lu-177. The measured calibration factors are compared to predicted values from calculations using a Gaussian kernel. Results: Measured SPECT calibration factors for 3D printed organs display a clear dependence on organ shape for Tc-99m and Lu-177. The observed variation in calibration factor is reproduced using Gaussian kernel-based calculation over two orders of magnitude change in insert volume for Tc-99m and Lu-177. These new organ-specific calibration factors show a 24, 11 and 8 % reduction in absorbed dose for the liver, spleen and kidneys, respectively. Conclusions: Non-spherical calibration factors from 3D printed phantom inserts can significantly improve the accuracy of whole organ activity quantification for molecular radiotherapy, providing a crucial step towards individualised activity quantification and patient-specific dosimetry. 3D printed inserts are found to provide a cost effective and efficient way for clinical centres to access more realistic phantom data.

引用

页码：1 / 11

页数：11