RT Journal Article
SR Electronic
T1 Assessment of reproducibility in quantitative FDG PET and CT measurements of tumor response to therapy
JF Journal of Nuclear Medicine
JO J Nucl Med
FD Society of Nuclear Medicine
SP 1624
OP 1624
VO 50
IS supplement 2
A1 Jacene, H
A1 Leboulleux, Sophie
A1 Baba, Shingo
A1 Chatzifotiadit, Daniel
A1 Horton, Karen
A1 Kamel, Ihab
A1 Teytelbaum, Oleg
A1 Macura, Katarzyna
A1 Kowalski, Jeanne
A1 Wahl, Richard
YR 2009
UL http://jnm.snmjournals.org/content/50/supplement_2/1624.abstract
AB 1624 Objectives To directly compare inter-observer reproducibility of 1) SUV and CT size measurements in malignant tumors pre- and post-therapy and 2) percent change in these parameters in response to therapy in the same patients. Methods 52 tumors (25 pts) were evaluated by FDG PET/CT pre- and post-therapy. Maximum single-pixel SUVbw (SUV) and CT size measurements were determined for each tumor independently pre- and post-therapy by 8 readers (4 PET, 4 CT) each using routine non-automated clinical methods. Percent changes in SUV and CT size between pre- and post-therapy scans were calculated. Inter-observer reproducibility is described by the intraclass correlation coefficient (ICC), with ICC >0.6 considered significantly reproducible. Results ICC for SUV was 0.93 (95% CI 0.90-0.96) pre-therapy and 0.91 (95% CI 0.86-0.94) post-therapy. For the longest CT dimension, ICC was 0.72 (95% CI 0.61-0.82) pre-therapy and 0.85 (95% CI 0.77-0.91) post-therapy. For the two-dimensional CT size, ICC was 0.61 (95% CI 0.48-0.74) pre-therapy and 0.45 (95% CI 0.30-0.61) post-therapy. ICC for percent change in SUV was 0.94 (95% CI 0.90-0.96), for the longest CT dimension 0.70 (95% CI 0.57-0.81) and the two-dimensional size 0.33 (95% CI 0.18-0.50). Conclusions Inter-observer reproducibility of single-pixel SUVbw max is high for both untreated and treated tumors and better than inter-observer reproducibility of CT size measurements. Changes in tumor SUV were more highly reproducible measures of tumor response than changes on anatomic imaging, the current standard for assessing tumor response to therapy in the same patient.