Artery-Specific SPECT/CT Partition Model Dosimetry:
Image-Guided Personalized Predictive Dosimetry for State-of-the-Art Yttrium-90 Radioembolization
Authors
Yung Hsiang KAO (1), Andrew EH TAN (1), Mark C BURGMANS (2), Farah G IRANI (2),
Li Ser KHOO (2), Richard HG LO (2), Kiang Hiong TAY (2), Bien Soo TAN (2),
Pierce KH CHOW (3, 4), David CE NG (1), Anthony SW GOH (1)
(1) Department of Nuclear Medicine and PET, Singapore General Hospital
(2) Department of Diagnostic Radiology, Singapore General Hospital
(3) Department of General Surgery, Singapore General Hospital
(4) Office of Clinical Sciences, Duke-NUS Graduate Medical School, Singapore
References
Kao et al. Image-guided personalized predictive dosimetry by artery-specific SPECT/CT partition modeling for safe and effective 90Y radioembolization. J Nucl Med 2012; 53:1–10
Overview
The aim of personalized predictive dosimetry is to guide radionuclide therapy in achieving the maximum tumor radiation absorbed dose (Gy) while minimizing collateral radiation injury to normal tissue, and the avoidance of futile therapy. As a form of arterial territory-specific point-source brachytherapy, yttrium-90 radioembolization (also known as yttrium-90 selective internal radiation therapy, Y-90 SIRT) is always effective when delivered at the right location, in the right dose (Gy), with the right intent. Yttrium-90 radioembolization failure is invariably due to failure of one or a combination of these three factors.
To date, radionuclide internal dosimetry for yttium-90 radioembolization using resin microspheres (SIR-Spheres®, Sirtex Medical Limited, Australia) has yet to embrace newer imaging modalities such as catheter-directed CT hepatic angiography (CTHA) and single photon emission computed tomography with integrated low-dose CT (SPECT/CT).
The ‘artery-specific SPECT/CT partition model’ is a dosimetric technique developed by Singapore General Hospital. It integrates catheter-directed CTHA, technetium-99m macroaggregated albumin (Tc-99m MAA) SPECT/CT and MIRD macrodosimetry (‘partition model’) into a single unified technique of personalized predictive dosimetry for state-of-the-art yttrium-90 radioembolization. Catheter-directed CTHA accurately delineates the margins of planning target volumes, superior to digital subtraction angiography. Tc-99m MAA SPECT/CT tomographically evaluates Tc-99m MAA hepatic biodistribution, superior to planar scintigraphy. The partition model is a validated and scientifically sound method of MIRD macrodosimetry for yttrium-90 resin microspheres, superior to the body surface area method.
Our results show that personalized predictive dosimetry by artery-specific SPECT/CT partition modeling can achieve high clinical success rates for safe and effective yttrium-90 radioembolization of inoperable hepatocellular carcinoma. Advanced clinical applications include sub-lesional dosimetry, radioembolization segmentectomy/lobectomy, and radioembolization of hypovascular liver tumors and extra-hepatic solid tumors.
More information:
(Note: Version 12.01.12 incorporates personalized predictive Tc-99m MAA SPECT/CT tumor, liver and lung dosimetry, patient- and scan-specific lung CT morphometry, tri- and bi-compartmental MIRD macrodosimetry, and supersedes earlier versions using planar lung dosimetry.)