Poster, Podium & Video Sessions
Presentation Authors: Amir H. Lebastchi*, Christopher M. Russel, Kenny H. Cha, Lubomir Hadjiyski, Haeng-Ping Chan, Rich Cohan, Elaine Caoili, Ajjai Alva, Alon Z. Weizer, Ann Arbor, MI
Introduction: Neoadjuvant chemotherapy (NAC) for bladder cancer is underutilized in partdue to concern for disease progression during chemotherapy. In an effort to quantify lesion response during NAC, we describe the utilization of a computerized system for segmenting bladder lesions on contrast enhanced pelvic CT scans. The accuracy of this modality is then demonstrated through a comparison of the computerized estimation of lesion volume change and pT0 status with an experienced radiologists assessment and RECIST criteria.
Methods: Pre and posttreatment CT scans were reviewed in 82 patients receiving NAC for bladder cancer prior to cystectomy. Patient information and disease outcomes at the time of cystectomy were abstracted. Estimations of the response to treatment were obtained through either (1) the computerized volume analysis system utilizing 3D CT segmentation of bladder lesions, or (2) using RECIST criteria as characterized by one of two independent board certified radiologists. Receiver operating characteristic (ROC) curves were generated to identify sensitivity and specificity of detecting pT0 (complete response) at the time of cystectomy and an area under the curve (AUC) was calculated.
Results: There were 67 men and 15 women with a mean age of 64 years (64.0± 10.6, age range 37 to 84 years of age). All patients had clinical stage T2- T4, N0 tumors, and received 3 to 6 cycles of a platinum based chemotherapy. A total of 27% of patients had pT0 disease at time of cystectomy. The AUC for correct prediction of pT0 at the time of cystectomy was 0.77 ±0.05 for the computer assisted technique compared to 0.75 ±0.05 and 0.70 ±0.06 when two separate radiologists predicted pT0 disease using RECIST criteria (Figure 1).
Conclusions: The utilization of a computerized segmentation system for the assessment of change in tumor volume and subsequent pT0 disease following cystectomy is equivalent to that performed by experienced radiologists. Furthermore, the accurate assessment of timely treatment response during NAC may have important implications in determining duration of chemotherapy and in the utilization of bladder preservation protocols.
Source Of Funding: None
University of Michigan
Amir H. Lebastchi graduated from the University of Hamburg in Germany. He then started his surgical training at Yale University prior to moving to Ann Arbor in Michigan. He is currently a PGY-4 Urology Resident at the University of Michigan. After completion of his Urology training in Michigan he is planning a fellowship in Urological Oncology.