Evaluation of a cumulative SUV-volume histogram method for parameterizing heterogeneous intratumoural FDG uptake in non-small cell lung cancer PET studies

• Published in: European journal of nuclear medicine and molecular imaging 2011-09, Vol.38 (9), p.1636-1647
• Main Authors: van Velden, Floris H. P., Cheebsumon, Patsuree, Yaqub, Maqsood, Smit, Egbert F., Hoekstra, Otto S., Lammertsma, Adriaan A., Boellaard, Ronald
• Format: Article
• Language: English
• Subjects: Aged; Biological Transport; Cancer; Carcinoma, Non-Small-Cell Lung - diagnostic imaging; Carcinoma, Non-Small-Cell Lung - metabolism; Carcinoma, Non-Small-Cell Lung - pathology; Cardiology; Female; Fluorodeoxyglucose F18 - metabolism; Humans; Image Processing, Computer-Assisted - methods; Imaging; Lung Neoplasms - diagnostic imaging; Lung Neoplasms - metabolism; Lung Neoplasms - pathology; Male; Medicine; Medicine & Public Health; Middle Aged; Nuclear Medicine; Oncology; Original; Original Article; Orthopedics; Positron-Emission Tomography - methods; Radiology; Tomography; Tumor Burden
• ISSN: 1619-7070; 1619-7089
• DOI: 10.1007/s00259-011-1845-6

Purpose Standardized uptake values (SUV) are commonly used for quantification of whole-body [ 18 F]fluoro-2-deoxy- D -glucose (FDG) positron emission tomography (PET) studies. Changes in SUV following therapy, however, only provide a proper measure of response in case of homogeneous FDG uptake in the tumour. The purpose of this study was therefore to implement and characterize a method that enables quantification of heterogeneity in tumour FDG uptake. Methods Cumulative SUV-volume histograms (CSH), describing % of total tumour volume above % threshold of maximum SUV (SUV max ), were calculated. The area under a CSH curve (AUC) is a quantitative index of tumour uptake heterogeneity, with lower AUC corresponding to higher degrees of heterogeneity. Simulations of homogeneous and heterogeneous responses were performed to assess the value of AUC-CSH for measuring uptake and/or response heterogeneity. In addition, partial volume correction and image denoising was applied prior to calculating AUC-CSH. Finally, the method was applied to a number of human FDG scans. Results Partial volume correction and noise reduction improved CSH curves. Both simulations and clinical examples showed that AUC-CSH values corresponded with level of tumour heterogeneity and/or heterogeneity in response. In contrast, this correspondence was not seen with SUV max alone. The results indicate that the main advantage of AUC-CSH above other measures, such as 1/COV (coefficient of variation), is the possibility to measure or normalize AUC-CSH in different ways. Conclusion AUC-CSH might be used as a quantitative index of heterogeneity in tracer uptake. In response monitoring studies it can be used to address heterogeneity in response.