Scintigraphic load of bone disease evaluated by DASciS software as a survival predictor in mCRPC patients candidates to 223RaCl treatment
Objective. Aim of our study was to assess the load of bone disease at starting and during Ra-223 treatment as an overall survival (OS) predictor in mCRPC patients. Bone Scan Index (BSI) is defined as the percentage total amount of bone metastasis on whole-body scintigraphic images. We present a specific software (DASciS) developed by an engineering team of “Sapienza” University of Rome for BSI calculation.
Methods. 127 mCRPC patients bone scan images were processed with DASciS software, and BSI was tested as OS predictor.
Results. 546 bone scans were analyzed revealing that the basal percentage of disease is a predictor of OS (0-3% = 28 months of median survival (MoMS), 3%-5% = 11 MoMS, >5% = 5 MoMS). BSI was analyzed as a single parameter for OS, determining an 88% AUC. Moreover, the addition of the BSI to the 3-PS (3-variable prognostic score) determines a dramatic improvement of the AUC (91%), appears to be the best OS predictor.
Conclusions. This study suggests that OS is inversely correlated with the load of bone disease in mCRPC Ra-223-treated subjects. DASciS software appears a promising tool in identifying mCRPC patients that more likely take advantage from Ra-223 treatment. BSI is proposed as a predictive variable for OS and included to a multidimensional clinical evaluation permits to approach the patients’ enrollment in a rational way, allowing to enhance the treatment effectiveness together with cost optimization.