Mieke Bus

76 Chapter 5 Figure 3: Biopsy and OCT results for grading and staging, compared to the histology of the resected specimen in 24 patients who had in-vivo OCT measurement and biopsy of the lesion during URS. In two patients no biopsies were taken during URS. Results are compared to final pathology after radical nephroureterectomy or partial ureter resection. A: Staging results in OCT matched in 83% with final histology and staging results in biopsies matched in 49% with histology. B: Grading results in OCT matched in 88% with histology. Grading results in biopsies matched in 79% with histology. Biopsy Staging For tumour staging, nine patients (38%) had non-diagnostic biopsy results and in three patients (13%) biopsy showed non-invasive UTUC but had invasive UTUC on final pathologic examination on the nephroureterectomy specimen (Figure 3A). Statistical testing resulted in a sensitivity of 29% with a confidence interval of 4-71%, specificity of 100% (63-100%), PPV of 100% (16-100%) and NPV of 62% (32-86%) (Table 3) . OCT analysis OCT Grading For all individual OCT measurements, median (IQR) µ oct is 2.1 (1.7-2.3 mm -1 ) in low-grade lesions and 3.0 (2.9-3.7 mm -1 ) in high-grade lesions (p-value <0.006) (figure 4A). No reliable µ oct could be obtained from normal appearing urothelium or CIS due to the small thickness of the urothelial layer resulting in one non-diagnostic scan for grading.