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In RECIST1.1, the following calculations are used in determination of the target response: sum of the diameters of target tumors (target sum), percentage change from baseline in the target sum, and percentage change from nadir in the target sum (smallest target sum at any assessment). These are referred to as summary values in the examples below. These summary values are not typically collected/calculated in investigator CRFs but they are usually provided by independent assessors. Summary values not in the collected data may be derived in the analysis datasets (i.e., ADaM).
A RECIST 1.1 recommends a standardized value of 5 mm is used in the calculation of sum of diameters when a target tumor is “too small to measure". The is too small to measure. Note that this imputation should only be done when the lesion diameter is too small to measure. When a numerical value is given for the lesion diameter, then that value will be used even if the diameter is less than 5 mm. The original or collected value "TOO SMALL TO MEASURE" should be represented in the TRORRES variable and the standardized value should be represented in the TRSTRESC and TRSTRESN variables. For absent non-lymph node target tumors, 0 mm is used in the calculation of the target sum. The longest perpendicular measurements of lymph node target tumors which are pathological (> 10 mm) or non-pathological pathological (<= 10 mm) are included in the target sum.
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