As previously noted, when lesions can be evaluated by both clinical examination and imaging, imaging evaluation s hould be under taken since it is more objective and may also be reviewed at the end of the study. 1.4.2.4 Ultrasound Ultrasound is notuseful in assessment of lesion size and s hould not be used as a method of measurement. If new lesions are identified by ul trasound in the course of the study, confirmation by CT or MRI is advised. 1.4.2.5 Endoscopy, Laparoscopy The utilization of these techniques for objective tumor evaluation is not advised. 2 BASELINE DOCUMENTATION OF ‘TARGET’ AND ‘NON-TARGET’ LESIONS 2.1 Target Lesions When more than 1 measurable lesion is present at baseline, all lesions up to a maximum of 5 lesions total (and a maximum of 2 lesions per organ) that are representative of all involved organs should be identified as target lesions and will be recorded and measured at baseline. Target lesions should be selected on the basis of their size (lesions with the longest diameter), should be representative of all involved organs, and should lend themselves to reproducible repeated measurements . A sum of the diameters for all target lesions will be calculated and reported as the baseline sum diameters . For non-nodal lesions, the longest axis should be included in the baseline sum diameters. If lymph nodes are to be included in the sum, then as noted below, only the short axis is added into the baseline sum diameters. The baseline sum diameters will be used as reference to further characterize any objective tumor regression in the measurable dimension of the disease. 2.1.1 Lymph Nodes Lymph nodes merit special mention since they are normal anatomical structures that may be visible by imaging even if not involved by tumor. Pathological nodes that are defined as measurable, and may be identified as target lesions, must meet the criterion of a short axis of ≥≥15 mm by CT scan . Only the short axis of these nodes will contribute to the baseline sum diameters. Nodes that have a short axis < 10 mm are considered nonpathological and s hould not be recorded or followed. Revised Protocol No.: 04 Date: 31-May-2019 183 Approved 5.0 v Approved 1.0 v Clinical Protocol CA021002 BMS-986226 anti-ICOS 2.2 Non-target Lesions All other lesions (or sites of disease) including pathological lymph nodes s hould be identified as non-target lesions and should also be recorded at baseline. Measurements are not required and these lesions should be followed as ‘present’ , ‘absent’ , or in rare cases ‘unequivocal progression’ .