. Author manuscript; available in PMC: 2013 Feb 1.

Published in final edited form as: Acad Radiol. 2011 Nov 21;19(2):184–190. doi: 10.1016/j.acra.2011.10.008

Table 1.

Selected sample size calculations for randomized trial to detect a true effect of 20% difference in average percent FDG uptake change between two treatments (80% power, Type I error rate (α) = 0.05).

		Sample Size
Trial Scenario	σ ^*	1^st tertile SUV_baseline≤3 50% sens.^†	2^nd tertile 3≤SUV_baseline≤5.2 70% sens.^†	3^rd tertile SUV_baseline≤5.2 90% sens.^†	kinetic modeling 100% sens.^†
Single site	10%	32	17	10	8
Multi-center (good calibration)	20%	126	65	39	32
Multi-center (poor calibration)	40%	503	257	156	126

Standard deviation of percent FDG uptake change, with larger values attributable to greater measurement error

^†

Sensitivity to a true effect size of 20 percentage point difference FDG uptake change