Minicursos

Medicina Nuclear/Nuclear Medicine

Quantification and Standardisation in PET/CT

Terez Sera - University of Szeged, Hungria

Departamento de Medicina Nuclear da Universidade de Szeged

Auditora da IAEA

 

Short Summary:

Quantification of FDG PET/CT studies is often based on so-called standardised uptake values (SUV) which is the FDG concentration observed by PET usually normalised by net injected activity per patient weight. SUVs or other metabolic parameters, such as metabolic volume and total lesion glycolysis, and their change can be used for e.g. metabolic tumour response assessment. These FDG uptake parameters are simplified metrics for tracer uptake and consequently associated by various sources of bias and uncertainties. Factor influencing SUV results can be described as technical, imaging physics related or biological uncertainties. In this lecture various factors affecting PET/CT SUV quantification, imaging procedure guidelines and the need for PET/CT system accreditation will be discussed.

 

Educational Objectives:

  • To understand the requirements for FDG PET to be used as quantitative imaging biomarker
  • To learn the uncertainties affecting PET quantification and response assessment
  • To learn how these uncertainties can be mitigated
  • To understand the need for imaging procedure and PET/CT system performance harmonization
  • To understand the rationale and implementation of the EARL PET/CT accreditation program

 

Summary:

Quantification of FDG PET/CT studies is often based on so-called standardised uptake values (SUV) which is the FDG concentration observed by PET usually normalised by net injected activity per patient weight. SUVs or other metabolic parameters, such as metabolic volume and total lesion glycolysis, and their change can be used for metabolic tumour response assessment.  These FDG uptake parameters are simplified metrics for tracer uptake and consequently associated by various sources of bias and uncertainties [1]. Factor influencing SUV results can be described as technical, imaging physics related or biological uncertainties [1]. Within multicentre studies it is required to obtain SUV that can be exchanged or pooled. The latter implies that the effects of the above mentioned factors on SUV should be mitigated and/or harmonized as much as possible [2,3]. Harmonization of PET/CT examination in multicentre studies aims at making SUV reads as exchangeable (comparable) as possible by harmonizing imaging procedures, image quality and quantitation and harmonizing data analysis methods and interpretation. The main challenge of harmonisation efforts arises from differences in both PET/CT imaging procedures and in technology across multiple sites. To this end the European Association of Nuclear Medicine published FDG PET/CT imaging guidelines [2,3] and started a multicentre calibration/accreditation program to harmonise quantitative imaging system performance[4]. Moreover, continuous monitoring of the FDG PET/CT data quality is warranted [5]. In this lecture various factors affecting PET/CT quantification by SUV, imaging procedure guidelines and the need for PET/CT system accreditation will be discussed.

 

Key Words:

PET/CT, quantification, standardisation, harmonisation, response assessment, guideline, EARL.

 

References:

Boellaard R. Standards for PET image acquisition and quantitative data analysis. JNM 2009

Boellaard R, O'Doherty MJ, Weber WA, Mottaghy FM, Lonsdale MN, Stroobants SG, Oyen WJ, Kotzerke J, Hoekstra OS, Pruim J, Marsden PK, Tatsch K, Hoekstra CJ, Visser EP, Arends B, Verzijlbergen FJ, Zijlstra JM, Comans EF, Lammertsma AA, Paans AM, Willemsen AT, Beyer T, Bockisch A, Schaefer-Prokop C, Delbeke D, Baum RP, Chiti A, Krause BJ. FDG PET and PET/CT: EANM procedure guidelines for tumour PET imaging: version 1.0. Eur J Nucl Med Mol Imaging. 2010

Boellaard R, Delgado-Bolton R, Oyen WJ, Giammarile F, Tatsch K, Eschner W, Verzijlbergen FJ, Barrington SF, Pike LC, Weber WA, Stroobants S, Delbeke D, Donohoe KJ, Holbrook S, Graham MM, Testanera G, Hoekstra OS, Zijlstra J, Visser E, Hoekstra CJ, Pruim J, Willemsen A, Arends B, Kotzerke J, Bockisch A, Beyer T, Chiti A, Krause BJ; European Association of Nuclear Medicine (EANM). FDG PET/CT: EANM procedure guidelines for tumour imaging: version 2.0. Eur J Nucl Med Mol Imaging 2015

http://earl.eanm.org/cms/website.php?id=/en/projects/fdg_pet_ct_accreditation.htm

Hristova I, Boellaard R, Vogel W, Mottaghy F, Marreaud S, Collette S, Schöffski P, Sanfilippo R, Dewji R, van der Graaf W, Oyen WJ. Retrospective quality control review of FDG scans in the imaging sub-study of PALETTE EORTC 62072/VEG110727: a randomized, double-blind, placebo-controlled phase III trial. Eur J Nucl Med Mol Imaging. 2015