8:40 AM Abstract No. 64 - Selective internal Yttrium-90 radioembolization therapy (90-Y SIRT) in patients with unresectable metastatic melanoma (MM) to liver, refractory to systemic therapy: analysis of imaging findings, survival and factors associated with prolonged survival

Abstract

Purpose To investigate the correlation of imaging findings with survivals in patients (pts) with unresectable metastatic melanoma (MM) to liver, refractory to systemic therapy , treated with selective internal yttrium-90 radioembolization therapy (90-Y SIRT). Materials and Methods Consecutive pts with unresectable MM to liver, who failed with systemic therapy, treated with resin-based 90Y SIRT in last 9 years, and who had cross sectional imaging (PET in 75% and chest abdomen pelvis CT or MR in 25% of pts) before 90-Y SIRT were evaluated retrospectively. Imaging findings were correlated with progression free survival (PFS) and overall survival (OS). RECIST 1.1 criteria were used for liver disease. The OS times were calculated from diagnosis of primary melanoma (OS-dx), from first 90Y SIRT (OS–90-Y) and from MM to liver (OS-MM). Absence of progression of MM to liver was considered as PFS. Kaplan Meir method tested with log rank test and Cox proportional hazard model were used for survival analysis. Results 24 pts (mean age 48.8 years, SD 14.5) with MM to liver underwent 42 90-Y SIRTs. The median OS-dx, OS-MM and OS-90Y were 121.4, 27.9 and 13.4 months(m) respectively. The median PFS was 10.1 m. PFS in partially responded (n=3), stable disease (n=15) and progressive disease (n=6) according RECIST 1.1 criteria were 19.6, 10.3 and 1.3 m respectively (p=0.001). Before 90-Y SIRT, the pts had Child-Pugh class A (n=21), B (n=2) and C (n=1) with corresponding median OS-90Y of 15, 2.6 and 0.9 m (p=0.02) respectively. More than 8 MM lesions to liver were present in 29.2% pts and had median OS–90-Y of 5.5 m vs 17.7 m in pts with Conclusion RECIST 1.1 responses, less than 8 MM to liver lesions and absence of extrahepatic MM disease before 90Y SIRT were found predictor of prolonged survival.