The Association between Reconstructed Bladder Wall Dose and Chronic Urinary Toxicity Following Prostate Radiotherapy

patients. Histopathological analysis was used to confirm clinical treatment response. Results/Benefits/Challenges: Clinical responders showed a significant increase (p<0.05) in QUS parameters after four weeks of treatments, relative to the baseline: MBF (+7.90 dBr 1.39 [SE]) and 0-MHz intercept (+8.55 dBr 1.84). Spectral slope was however invariant. At similar time intervals, clinical responders also demonstrated significant percent changes to DOSI markers, such as total hemoglobin (HbT, -32.84% 4.07%), water fraction (%Water, -53.97% 3.29%) and scatter power (SP, -45.25% 1.42%). The sensitivity (Sn) and specificity (Sp) for QUS demonstrated that the MBF and 0-MHz intercept were good predictors of response at week 4 (MBF; Sn1⁄492.9%, Sp1⁄4100%, p<0.05), and this also corresponded with HbT (Sn1⁄492.9%, Sp1⁄487.5%, p<0.05) at the same time interval. In addition, QUS and DOSI parameters demonstrated an increase in the Sn/Sp as early as after 1 week of treatment (0-MHz intercept + %Water), (Sn1⁄492.9%, Sp1⁄4100.0%). Conclusion/Impact/Outcomes: QUS and DOSI demonstrated potential, as coincident markers for treatment response and may potentially facilitate response-guided therapies.