Is it possible to extract HCV RNA from blood samples of HCV patients using an FTA card only without any commercial kit like QIAGEN RNA mini kit?

According to the majority of literature, is this process necessary to use the commercial kit again after elution of RNA/DNA with an FTA card? (Because of RNA purification?)

We tried HCV RNA PCR with FTA card using various washing method and elute solution. But, the result of beta actin is good, whereas HCV RNA did not perform well in PCR.

I am curious whether this result came out because the amount of RNA was relatively different between beta actin and HCV.