Mieke Bus

4 57 Table 1: Patient characteristics. N Gender Age (Yr) Location Treatment 1 M 56 renal pelvis nephroureterectomy 2* M 63 proximal, mid, and distal ureter nephroureterectomy 3 M 53 renal pelvis nephroureterectomy 4* M 60 renal pelvis, proximal, mid, and distal ureter nephroureterectomy 5 M 67 proximal ureter nephroureterectomy 6* F 76 renal pelvis and proximal ureter nephroureterectomy 7 F 48 distal ureter nephroureterectomy 8 F 78 renal pelvis nephroureterectomy In-vivo measurements were performed during URS. *Cases are highlighted in the text. Seven of eight patients had visible papillary tumors on URS, in the eight patient random biopsies confirmed CIS. For seven of eight patients OCT staging of the visible tumors was in accordance with histology. In the eighth patient, assessment of tumor invasiveness was hampered by thickness of exophytic tumorbulk exceeding OCT imaging depth (Table 2). Table 2: Histopathological tumor characteristics (stage and grade), corresponding OCT staging, and OCT attenuation coefficients. N Tumor stage OCT stage Tumor Grade µ oct 1 pT3 invasive 3 2.9 ± 0.4 mm -1 2* pTa non invasive 2 2.3 ± 0.3 mm -1 3 pTa non invasive 2 1.9 ± 0.3 mm -1 4* pTIS non invasive 3 NA 5 pT3 invasive 3 3.7 ± 0.3 mm -1 6* pT3 invasive 3 3.8 ± 0.8 mm -1 7 pT1 invasive 2 2.4 ± 0.6 mm -1 8 pTa inconclusive 2 2.3 ± 0.5 mm -1 pT1 is considered invasive. *Cases are highlighted in the text. In patients with invasive tumors, clear interruption of the basement membrane was seen. In the two patients with non-invasive tumors, the basement membrane was seen as a thin dark line below the tumor growth. In one patient, a flat broadened urothelial layer with low reflectivity was seen without interruption of the basement membrane; histology showed multifocal CIS. Figure 3 demonstrates exemplary individual depth profiles of grade 2 (blue) and grade 3 (red) lesions. For all individual OCT measurements, the median (interquartile range) µ oct was 1.97 mm -1 (1.57-2.30) in grade 2 lesions and 3.53 mm -1 (2.74-3.94) (p-value <0.001) in grade 3 lesions.