Observer variability in RECIST-based tumour burden measurements: a meta-analysis

Abstract

BackgroundResponse Evaluation Criteria in Solid Tumours (RECIST)-based tumour burden measurements involve observer variability, the extent of which ought to be determined. MethodsA literature search identified studies on observer variability during manual measurements of tumour burdens via computed tomography according to the RECIST guideline. The 95% limit of agreement (LOA) values of relative measurement difference (RMD) were pooled using a random-effects model. ResultsTwelve studies were included. Pooled 95% LOAs of RMD in measuring unidimensional longest diameters of single lesions ranged from −22.1% (95% confidence interval [CI], −30.3% to −14.0%) to 25.4% (95% CI, 17.2% to 33.5%) between observers and −17.8% (95% CI, −23.6% to −11.9%) to 16.1% (95% CI, 10.1% to 21.8%) for a single observer. Pooled 95% LOAs of RMD in measuring the sum of multiple lesions ranged from −19.2% (95% CI, −23.7% to −14.9%) to 19.5% (95% CI, 15.2% to 23.9%) between observers, and −9.8% (95% CI, −19.0% to −0.3%) to 13.1% (95% CI, 3.6% to 22.6%) for a single observer. Pooled 95% LOA of RMD in calculating the interval change of tumour burden with a single lesion ranged from −31.3% (95% CI, −46.0% to −16.5%) to 30.3% (95% CI, 15.3% to 44.8%) between observers. Studies on calculating the interval change of tumour burden for a single observer or with multiple lesions were lacking. ConclusionInterobserver RMD in measuring single tumour burden and calculating its interval change may exceed the 20% cut-off for progression. Variability decreased when tumour burden was measured by a single observer or assessed by the sum of multiple lesions.