EANM dosimetry committee series on standard operational procedures : a unified methodology for ^99mTc-MAA pre- and ⁹⁰Y peri-therapy dosimetry in liver radioembolization with ⁹⁰Y microspheres

Summary, in English

The aim of this standard operational procedure is to standardize the methodology employed for the evaluation of pre- and post-treatment absorbed dose calculations in ⁹⁰Y microsphere liver radioembolization. Basic assumptions include the permanent trapping of microspheres, the local energy deposition method for voxel dosimetry, and the patient–relative calibration method for activity quantification.The identity of ^99mTc albumin macro-aggregates (MAA) and ⁹⁰Y microsphere biodistribution is also assumed. The large observed discrepancies in some patients between ^99mTc-MAA predictions and actual ⁹⁰Y microsphere distributions for lesions is discussed. Absorbed dose predictions to whole non-tumoural liver are considered more reliable and the basic predictors of toxicity. Treatment planning based on mean absorbed dose delivered to the whole non-tumoural liver is advised, except in super-selective treatments. Given the potential mismatch between MAA simulation and actual therapy, absorbed doses should be calculated both pre- and post-therapy. Distinct evaluation between target tumours and non-tumoural tissue, including lungs in cases of lung shunt, are vital for proper optimization of therapy. Dosimetry should be performed first according to a mean absorbed dose approach, with an optional, but important, voxel level evaluation. Fully corrected ^99mTc-MAA Single Photon Emission Computed Tomography (SPECT)/computed tomography (CT) and ⁹⁰Y TOF PET/CT are regarded as optimal acquisition methodologies, but, for institutes where SPECT/CT is not available, non-attenuation corrected ^99mTc-MAA SPECT may be used. This offers better planning quality than non dosimetric methods such as Body Surface Area (BSA) or mono-compartmental dosimetry. Quantitative ⁹⁰Y bremsstrahlung SPECT can be used if dedicated correction methods are available. The proposed methodology is feasible with standard camera software and a spreadsheet. Available commercial or free software can help facilitate the process and improve calculation time.

• Författare: Carlo Chiesa; Katarina Sjogreen-Gleisner; Stephan Walrand; Lidia Strigari; Glenn Flux; Jonathan Gear; Caroline Stokke; Pablo Minguez Gabina; Peter Bernhardt; Mark Konijnenberg
• Avdelning/ar: Medicinsk strålningsfysik, Lund; Nuclear Medicine Physics
• Publiceringsår: 2021-12
• Språk: Engelska
• Publikation/Tidskrift/Serie: EJNMMI Physics
• Volym: 8
• Issue: 1
• Länkar: http://dx.doi.org/10.1186/s40658-021-00394-3
• Dokumenttyp: Artikel i tidskrift
• Förlag: Springer
• Ämne: Radiology, Nuclear Medicine and Medical Imaging; Cancer and Oncology; Other Physics Topics
• Nyckelord: Y microspheres; Y PET; Tc-MAA; Liver dosimetry; Lung shunt; Prospective/retrospective dosimetry; Radioembolization dosimetry; Tumour dosimetry
• Status: Published
• Forskningsgrupp: Nuclear Medicine Physics
• ISBN/ISSN/Övrigt: ISSN: 2197-7364